Showing papers in "Chemical and Biological Technologies in Agriculture in 2017"

Multiple benefits of legumes for agriculture sustainability: an overview

Abstract: Food security, lowering the risk of climate change and meeting the increasing demand for energy will increasingly be critical challenges in the years to come. Producing sustainably is therefore becoming central in agriculture and food systems. Legume crops could play an important role in this context by delivering multiple services in line with sustainability principles. In addition to serving as fundamental, worldwide source of high-quality food and feed, legumes contribute to reduce the emission of greenhouse gases, as they release 5–7 times less GHG per unit area compared with other crops; allow the sequestration of carbon in soils with values estimated from 7.21 g kg−1 DM, 23.6 versus 21.8 g C kg−1 year; and induce a saving of fossil energy inputs in the system thanks to N fertilizer reduction, corresponding to 277 kg ha−1 of CO2 per year. Legumes could also be competitive crops and, due to their environmental and socioeconomic benefits, could be introduced in modern cropping systems to increase crop diversity and reduce use of external inputs. They also perform well in conservation systems, intercropping systems, which are very important in developing countries as well as in low-input and low-yield farming systems. Legumes fix the atmospheric nitrogen, release in the soil high-quality organic matter and facilitate soil nutrients’ circulation and water retention. Based on these multiple functions, legume crops have high potential for conservation agriculture, being functional either as growing crop or as crop residue.

The role of biostimulants and bioeffectors as alleviators of abiotic stress in crop plants

Abstract: The use of bioeffectors, formally known as plant biostimulants, has become common practice in agriculture and provides a number of benefits in stimulating growth and protecting against stress. A biostimulant is loosely defined as an organic material and/or microorganism that is applied to enhance nutrient uptake, stimulate growth, enhance stress tolerance or crop quality. This review is intended to provide a broad overview of known effects of biostimulants and their ability to improve tolerance to abiotic stresses. Inoculation or application of extracts from algae or other plants have beneficial effects on growth and stress adaptation. Algal extracts, protein hydrolysates, humic and fulvic acids, and other compounded mixtures have properties beyond basic nutrition, often enhancing growth and stress tolerance. Non-pathogenic bacteria capable of colonizing roots and the rhizosphere also have a number of positive effects. These effects include higher yield, enhanced nutrient uptake and utilization, increased photosynthetic activity, and resistance to both biotic and abiotic stresses. While most biostimulants have numerous and diverse effects on plant growth, this review focuses on the bioprotective effects against abiotic stress. Agricultural biostimulants may contribute to make agriculture more sustainable and resilient and offer an alternative to synthetic protectants which have increasingly falling out of favour with consumers. An extensive review of the literature shows a clear role for a diverse number of biostimulants that have protective effects against abiotic stress but also reveals the urgent need to address the underlying mechanisms responsible for these effects.

Plant growth promoting bacteria and humic substances: crop promotion and mechanisms of action

Abstract: High-external input agriculture is one of the most disruptive human activities, which have been justified by the current economic paradigm due to high productivity and the need to feed a growing population. However, we are dangerously close to the edge of the planet resources and both hunger and food insecurity has increased. Limiting the use of non-renewable chemical fertilizers and pesticides, changing water management, enhancing diversity and considering the often-neglected social dimension of agriculture are the bases to other chemical and biological technologies to agriculture. Biological inputs can stimulate the substitution of chemical inputs without questioning the current fundaments or can be adopted as a turning point to intensify the harsh processes of transition to more environmental friendly agriculture. The debate is open and our contribution is to develop the scientific basis for biological inputs that, unlike soluble fertilizers and pesticides, depend on a number of factors for its success in promoting crop yield. In this review, we showed the results obtained with the combined use of diazotrophic endophytic bacteria and humic substances in diverse crops (sugarcane, maize, tomato, common beans and pineapple), presenting the main morphological and physiological changes induced by biological technology. A snapshot of the state of the art of the use of plant growth promoting bacteria together with humic substances was provided, showing their potential especially when plants are subjected to moderate to severe abiotic stress. The number of studies reporting the combined use of plant growth promoting bacteria and humic substances is surprisingly low. There is an open avenue for research and encouraging debate is the goal. To overcome the conventional agriculture, maintaining productivity levels is more than scientific challenge, is a humanitarian duty. The biological inputs can help in this purpose.

NMR-based metabolomics in wine quality control and authentication

Abstract: A comprehensive summary of research work related to applications of NMR spectroscopy in combination with multivariate statistical analysis techniques for the analysis, quality control, and authentication of wine is presented. NMR spectroscopy is used to obtain the non-volatile metabolic profile and/or phenolic profile of wines, with the help of 2D NMR spectroscopy. Metabolomics is then used as an analytical tool to investigate the variability of the metabolic profile of wines due to a series of different factors involved during wine production, including terroir, pedoclimatic conditions, vintage, vineyard practices, wine-making, barrel maturation, and aging. The discriminating power of the NMR-obtained wine metabolome is utilized as a wholistic analytical approach in efforts to authenticate wine with respect to important economic attributes, such as cultivar, vintage, and geographical origin.

Potential of three microbial bio-effectors to promote maize growth and nutrient acquisition from alternative phosphorous fertilizers in contrasting soils

Abstract: Agricultural production is challenged by the limitation of non-renewable resources. Alternative fertilizers are promoted but they often have a lower availability of key macronutrients, especially phosphorus (P). Biological inoculants, the so-called bio-effectors (BEs), may be combined with these fertilizers to improve the nutrient use efficiency. The goal of this study was to assess the potential of three BEs in combination with alternative fertilizers (e.g., composted manure, biogas digestate, green compost) to promote plant growth and nutrient uptake in soils typical for various European regions. Pot experiments were conducted in Czech Republic, Denmark, Germany, Italy, and Switzerland where the same variety of maize was grown in local soils deficient in P in combination with alternative fertilizers and the same set of BEs (Trichoderma, Pseudomonas, and Bacillus strains). Common guidelines for pot experiment implementation and performance were developed to allow data comparison, and soils were analyzed by the same laboratory. Efficiency of BEs to improve maize growth and nutrient uptake differed strongly according to soil properties and fertilizer combined. Promising results were mostly obtained with BEs in combination with organic fertilizers such as composted animal manures, fresh digestate of organic wastes, and sewage sludge. In only one experiment, the nutrient use efficiency of mineral recycling fertilizers was improved by BE inoculation. These BE effects are to a large extent due to improved root growth and P mobilization via accelerated mineralization.

Portable NMR in food analysis

Abstract: Low-field 1H NMR relaxometry is an important tool used to investigate on the most abundant components of intact foodstuffs based on relaxation parameters and amplitude of the NMR signals. In particular, information on water compartments, diffusion and movement can be obtained by detecting proton signals prevalently ascribable to H2O contained in foodstuffs. The main advantage of this technique is that it does not require any pretreatment of the sample and once developed, standard protocols based on rapid measurements can be easily transferred to quality control applications. An actual breakthrough for the low-field NMR application to food science has certainly been the development of unilateral NMR sensors. These devices present an attractive option for non-invasive assessment of compositional and microstructure of food materials. They are portable and allow easy sample access, which makes them attractive for quality control in industrial environments and directly on sealed packaged foods. A price to pay is the inhomogeneity of the magnetic field, which compromises the sensitivity of these devices. However, recent developments in unilateral magnets design offer larger sensitive volume, higher sensitivity and shorter dead times. In this brief review, we highlight the different uses of unilateral NMR devices in food analysis.

Characterizing phosphorus forms in cropland soils with solution 31P-NMR: past studies and future research needs

Abstract: Understanding the forms and dynamics of soil phosphorus (P) is essential to maintain agricultural productivity while minimizing environmental risks. Since it was first used on soil extracts in 1980, 31P-nuclear magnetic resonance spectroscopy (P-NMR) has emerged as the leading technique to characterize extractable soil organic P forms. However, it is still underutilized in agriculture; of the more than 200 soil P-NMR papers published to date, only 44 have been conducted in non-pasture soils used for the production of annual or perennial crops, and only nine of those have linked identified P forms to agronomic parameters such as yield. This paper reviews these prior studies, suggesting gaps in research with respect to cropping systems and geographical regions. In particular, there have been few recent P-NMR studies that have fully identified P forms in African soils, and few studies of permanent crops such as orchards and vineyards. There is a need to link future P-NMR studies of cropping systems to agronomic parameters, and combine P-NMR with other techniques to fully capture P dynamics in cropping systems.

Plant growth promotion using microbial IAA producers in conjunction with azolla: a novel approach

Abstract: Studies were conducted to find efficient Indole acetic acid producing strains and assessing the effectiveness of combined dose of azolla (dried) and IAA producers on plant growth. Out of ten isolates, only two isolates, viz, F1 and G2 were found to be potent IAA producers and were used for further experiments. It was found that the isolate F1 and G2 produced maximum amount of IAA at 0.9% tryptophan and incubation for 72 h at room temperature. The optimum pH for IAA production for isolates F1 and G2 was found to be at pH 9. The isolates were also assessed for the presence of other plant growth promoting activity, such as hydrogen cyanide production, oxalate solubilization, phosphate solubilization and zinc solubilization. Effect of IAA producers on seed germination was done by pot experiments carried out into sets. Isolates F1 and G2 were found efficient for plant growth promotion in desired aspects. Effect of combined dose of azolla and IAA producers on seed germination was assessed by pot experiments. For this, dried powder of azolla was added during sowing of culture treated seeds. No further culture supply was given to the seeds. Azolla has high protein content. Slow protein releasing property of azolla can be useful to provide constant supply of the precursor (tryptophan) for IAA synthesis by isolate. In addition to the plant exudates, azolla may also give constant supply of tryptophan. From all the assessed samples, the isolates FI and G2 showed efficient growth of plants in all aspects. G2 was found to be more potent than F1. So as to assess the compatibility of isolate in natural conditions, field studies were done. Four plots designed having individual size 9 × 5 m, were used. It was found that plots 3 (only culture) and 4 (culture with azolla) showed better plant growth as compared to others. On the basis of IAA producing ability of G2, pot experiments and field studies, it was concluded that isolate G2 can be used alone or in conjunction with azolla as a biofertilizer to get better plant growth.

The biostimulant manufactured using diazotrophic endophytic bacteria and humates is effective to increase sugarcane yield

Abstract: The use of biostimulants in agriculture has demonstrated great potential but more consistent field results are required for wider farm acceptance We evaluated different delivering methods for the biostimulant produced with plant growth-promoting bacteria mixed with humic acid-like substances isolated from vermicompost in the commercial sugarcane crop yield during 3 consecutive years Foliar spray had a better performance than furrow application and the best result was obtained when the biostimulant was applied at 60 days after emergence, thus enhancing 37% of the stem yield when compared to control In the first and second ratoons, the productivity increases 5 and 24%, respectively The first ratoon was marked by severe drought stress that hit all the southeastern of Brazil Moreover, the assay using strip plot design with a large parcel area confirms the promotion of sugarcane yields by biostimulant during two consecutive ratoons increasing 19 and 18% that represent 11 and 13 tons ha−1 more than the control The use of biostimulant did not change soluble solid content and polarizable sugars in the sugarcane juice obtained from both experiments The biostimulant formulated with endophytic diazotrophic bacteria and humic acids represents a low-cost technology that increases the sugarcane yield with economic use of fertilizers to enhance crop yield

Mixed rhizobia and Herbaspirillum seropedicae inoculations with humic acid-like substances improve water-stress recovery in common beans

Abstract: Common beans are a staple food in many developing countries. However, changes in global precipitation patterns, particularly short droughts during the rainy season, have affected crop production because nodulation is greatly affected by water shortages. Plant growth-promoting bacteria, together with humic substances, can alleviate the negative effects of soil stresses, including drought. This work aimed to evaluate the effects of co-inoculations of rhizobia and Herbaspirillum seropedicae in the presence of humic acid-like substances isolated from vermicompost on the recovery of common beans after a controlled water stress. Two independent experiments were conducted in a greenhouse using Phaseolus vulgaris cv. Grafite and cv. Bonus, which originated in Brazil and Mozambique, respectively. The soil humidity was maintained at field capacity in pots, and the water suppression was induced at the pre-flowering stage. After 12 days, the water was restored, and the beans were evaluated. In the first experiment with ‘Grafite’ beans, the relative water content of the foliar disks was significantly higher in the co-inoculated treatment, as were the numbers and masses of nodules. The phenylalanine ammonia lyase activity was induced by drought, and its activity was higher in co-inoculated plant leaves. In the second experiment, the rate of net photosynthesis and stomatal conductance were also evaluated. The recuperation of common beans after water stress was improved by co-inoculation with rhizobia and H. seropedicae in the presence of humic acid-like substances.

Panel test and chemical analyses of commercial olive oils: a comparative study

Abstract: The quality grade of an olive oil is defined according to the results of analytical and organoleptic examinations.The increasing attention towards both olive oil quality and quality verification methods prompted us to undertake a “critical” analysis of analytical and sensory data supplied by an International Certificated Body (ICB), relative to commercial olive oils produced in Mediterranean areas and purchased in Italy and in USA. ICB data included chemical analyses namely free acidity, peroxide index, spectrophotometric UV evaluation, fatty acid ethyl esters and stigmadiens content and organoleptic evaluations carried out by nine official International Olive Council labs according to EEC Regulation 2568/91. The results of the chemical analyses, except the fatty acid ethyl ester content, obtained from the nine labs were consistent giving rise to the same quality grade. In nearly all samples, the fatty acid ethyl ester content was close to the threshold established for extra virgin olive oils indicating a non-excellent quality of the olive oils. Organoleptic evaluations, commonly called panel test, given by the nine labs were not consistent. The EEC Regulation 2568/91 does not give any indication on the way to report the uncertainty of the results, and in the case of extra virgin olive oils with a borderline value, the way to report the fatty acid ethyl ester content, with or without the uncertainty, can create confusion in defining the olive oil quality grade. Panel test seemed to work well only in the case of extremely good olive oils, whereas, in commercial extra virgin olive oils with borderline value of fatty acid ethyl ester content, a different sensory sensibility seems to be in the different IOC labs.

HRMAS NMR spectroscopy applications in agriculture

Abstract: The relatively recent and advanced high-resolution magic angle spinning (HRMAS) NMR technique enables the direct application of NMR spectroscopy to semi-solid and gel-like samples. It combines the advantages of both solid- and liquid-state NMR by allowing to concomitantly measure intact and non-manipulated samples. Based on both 1D and 2D homo- and heteronuclear NMR spectra, HRMAS evaluates the composition of fresh semi-solid samples with a similar resolution as that of classical liquid-state NMR techniques. The enhanced spectral quality still obtained for semi-solid samples is mainly due to the MAS system, whose rapid spinning and sample orientation minimize the anisotropic processes that prevent the acquisition of meaningful NMR spectra for non-liquid materials. Moreover, HRMAS allows us to use edited pulse sequences which, especially in the case of biological tissues or agrofood products, may provide a simultaneous information on polar and non-polar components without the need of preliminary sample extraction. Additionally, this technique may differentiate molecular species according to their degree of mobility in hydrated matrices. The evident versatile potential of the HRMAS NMR makes this technique particularly useful for life science molecular studies. Despite the focus of HRMAS has been greatly devoted on clinical biomedicine, materials chemistry, and metabolomics, there are already enough studies that show useful applications on agricultural issues. This report reviews the latest representative studies that employ HRMAS NMR on systems related to agricultural chemistry, requiring the characterization and dynamics of soil components, plant tissues, agrofood products, and in vivo organisms.

An antioxidant activity of the whole body of Holothuria scabra

Abstract: Holothuria scabra is the potential source of terpene with high antioxidant capacity and one of the most valuable species in the trade. The results indicated that antioxidant activity of crude methanol extracts and three pure compounds, Friedelin, 3-Hydroxybenzaldehyde and 4-Hydroxybenzaldehyde, from sea cucumber was determined using DPPH, Folin–Cioccalteau reagent. The results indicated the total phenolic contents at 30.52.28 ± 0.21 GAE/g dry weight equivalent and the effective concentration (EC50) value were found to be 33.77 ± 0.24, 14.63 ± 0.01, 14.62 ± 0.01 and 14.78 ± 0.11 mg/ml whole body of Holothuria scabra, Friedelin, 3-Hydroxybenzaldehyde and 4-Hydroxybenzaldehyde, respectively. In conclusion, the methanol extract and pure compounds of whole body parts of sea cucumber showed the highest antioxidant activity with EC50 value of 33.77 ± 0.24, 14.63 ± 0.01, 14.62 ± 0.01 and 14.68 ± 0.11 mg/ml. It also showed the highest total phenolic content at 30.52 ± 0.21 GAE/g dry weight.

Fractionation and availability of phosphorus in acid soils of Hagereselam, Southern Ethiopia under different rates of lime

Abstract: Phosphorus (P) availability is commonly assumed to limit productivity in many tropical soils, yet there is relatively little information on the phosphorus chemical forms, distribution, and transformations that P undergoes in Ethiopian soils. We used a sequential fractionation scheme to assess phosphorus fractions of acid soils of Southern Ethiopia. The study area called Hagereselam is characterized by high soil acidity, and the availability of P in the study area is relatively low. As crop production in Ethiopia is dominated by low external input practices, native P remains the main contributor to plant P nutrition in many locations. Although the total P concentration is 829.7 mg kg−1, the organic P content was relatively low (58 mg kg−1) and constituted on average less than 7% of the total P. The ratio of organic carbon to organic P was generally greater than 240, suggesting the potential for immobilization of P. The Al + Fe-associated P was the dominant inorganic P pool. The majority of the P occurred in recalcitrant form (568.3 mg kg−1). Readily available, exchangeable phosphate, as extracted by anion-exchange resin membranes, was present in very low concentrations (3.3 mg kg−1); moreover, labile P accounted for less than 2% (9.9 mg kg−1) of the total soil P. Lime was used as a reclamation material for acid soils, and the application of lime significantly affected the different P fractions and was involved in the transformation of P fraction. Organic P forms were significantly lower for higher levels of lime application, suggesting that lime amendment enhanced organic P decomposition. Moreover, application of lime increased Ca-P and decreased Al + Fe–P for acid soils.

Effect of arbuscular mycorrhizal fungi and water stress on ultrastructural change of glandular hairs and essential oil compositions in Ocimum gratissimum

Abstract: The objective of this work is to study the influence of arbuscal mycorrhizal fungi (Glomus intraradices) and water stress on the ultrastructural change of basil glandular hair and also on the essential oil synthesis, especially on the isomerization of the two main compounds methyl chavicol and trans-anethole. The results of this study show that mycorrhization increases the yield of essential oils, with a maximum recorded in mycorrhizal stressed plants (0.33%) and a minimum among non-mycorrhizal unstressed plants (0.22%). Oxygenated monoterpenes represent the main family of essential oils. Furthermore, the chemical composition of these essential oils changed under the condition in which the plant is. However, the main compound methyl chavicol was found to be at maximum concentration (93%) in mycorrhizal stressed plants and minimum in non-mycorrhizal stressed plants (84%). Contrariwise, its isomer trans-anethole reached the maximum (8%) among non-mycorrhizal non-stressed plants and minimum (2%) in non-mycorrhizal stressed plants. Ocimum gratissimum L. leaves showed the presence of two types of peltate glands: the first one with 4 secreting cells and the second with 8 secreting cells. The diameter of these glands changed with the hydric state of plants; in the absence of mycorrhization, stress causes a decrease in the extracellular cavity diameter of glandular trichomes and their deflation which would cause a concentration of essential oil in the glands.

Chemical and rheological characterization of arabinoxylan isolates from rye bran

Abstract: Rye arabinoxylans (AXs) might be used as baking improvers for gluten-free (GF) bread. However, their extraction process still needs to be improved. The aim of this study was to simplify AX extraction of rye bran by varying temperature and pH and evaluate its chemical and rheological properties for application in GF bread. The results demonstrated that higher amounts of AX and impurities were extracted with the increasing pH and temperature. AX yield reached values up to 3.3 g AX/100 g bran. Highest ferulic acid (FA) content (117.27 ± 1.46 mg/100 g) was achieved at the mildest extraction conditions (30 °C and 0.17 M NaOH). A/X ratio of isolates ranged between 0.53 and 0.57 and the gluten content between 81.30 and 216.78 ppm. Rheological measurements revealed typical pseudoplastic behavior of isolates. AX extracted at 30 °C and 0.17 M NaOH showed a slightly higher initial viscosity in comparison with the other isolates but was still inferior to carboxylmethylcellulose (CMC) and hydroxypropyl methylcellulose (HPMC).

MALDI-TOF mass spectroscopy of yeasts and filamentous fungi for research and diagnostics in the agricultural value chain

Abstract: Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS; MALDI biotyping) has become a standard tool for the accurate, rapid, and economical identification of pathogens in the clinical diagnostics laboratory. The method is continuously being improved, and new applications for distinguishing strains, identifying metabolites or functional characteristics (e.g., antibiotic resistance), and detecting microbes directly in patient samples have been developed. Adopting these methods in other disciplines than clinical diagnostics, for example, in agriculture, food safety and quality testing, or ecology, will open up new opportunities for diagnostics and research. This review focuses on MALDI-TOF MS approaches for the identification of yeasts and filamentous fungi. In contrast to bacterial diagnostics, MALDI biotyping of fungi is more challenging and less established. We thus start by discussing the role of MALDI-TOF MS as a tool for species identification; in particular with respect to DNA-based identification methods. The review then highlights the value of custom-made reference spectra for MALDI biotyping and points out recent advancements of MALDI-TOF MS, mainly from the field of clinical diagnostics that may be adopted and used for fungal diagnostic challenges. The overview ends with a summary of MALDI-TOF MS studies of yeasts and filamentous fungi of agricultural relevance.

Xylella fastidiosa and olive quick decline syndrome (CoDiRO) in Salento (southern Italy): a chemometric 1H NMR-based preliminary study on Ogliarola salentina and Cellina di Nardò cultivars

Abstract: Xylella fastidiosa is a Gram-negative bacterium which lives in the xylem of plants, causing its occlusion and other alterations inducing eventually the death of the infected plants. In Salento, the sub-peninsula in the south-eastern of Apulia Region (southern Italy), the infection of X. fastidiosa has been associated with the widespread presence of CoDiRO (complex of parasitic agents that constitute the so-called “olive quick decline syndrome”) and currently represents a serious local emergence. The need to adopt specific agronomic measures to contrast the further disease spread has been recently raised. The extensive NMR-based metabolomic approach to study the metabolic effects of CoDiRO on local olive cultivars such as Ogliarola salentina and Cellina di Nardo was used. In this study, the effects of a CE approved fertilizer containing zinc, copper, and citric acid, known as DENTAMET®, on CoDiRO-exhibiting olive trees infected by X. fastidiosa were studied by 1H NMR spectroscopy. The changes in the metabolomic profiles of aqueous extracts obtained from leaves of the two olive cultivars are reported. Upon the DENTAMET® treatments, different and opposite polyphenolic and sugars patterns in the two cultivars, which showed a different incidence and severity of disease before the treatments, were detected. Differences in the sugars and polyphenols content of treated versus untreated trees could potentially contribute to the syndrome monitoring and might be related to the X. fastidiosa presence.

Water-extractable organic matter and its fluorescence fractions in response to minimum tillage and organic farming in a Cambisol

Abstract: Minimum tillage (MT) and organic farming (OF) are increasingly conducted in agricultural managements from the interest of optimizing soil conditions and developing sustainable agriculture. Our understanding of their effects on water-extractable organic matter (WEOM) is still insufficient. To study the effects of MT and OF on WEOM, we analyzed soil materials sampled at two depths (0–8-cm-upper soil and 12–25-cm-deeper soil) from long-term field experiments using different farming and tillage methods. The content, composition, and quality of WEOM were examined. The results showed organic farming significantly decreased water-extractable organic carbon and nitrogen, but had positive effect on WEOM humic-like components revealed by parallel factor analysis with excitation–emission matrix, soil organic carbon (SOC), total nitrogen (TN), as well as SOC/TN. In addition, organic farming increased the aromaticity and condensation of WEOM as indicated by specific UV absorption and humification index. MT had no effect on WEOM both quantitatively and qualitatively but significantly decreased SOC and TN of the whole investigated soil profile. The depth effect was significant with strong stratification of WEOM, WEOM components as well as SOC and total N in upper soil. Moreover, the WEOM spectroscopic quality showed sharp differences between the upper and deeper soils. The results indicated that in the combined presence both tillage management and farming management, farming management imposed more influence on WEOM than tillage, and organic farming may facilitate the transformation of WEOM and lead to formation of WEOM with high stability. MT significantly changed the distribution of SOC and WEOM in soil, profile but did not increase the contents of SOC and WEOM in the site of the present study. However, the presence of larger pool of WEOM in MT + OF treatment at upper soil is likely to fuel possibly greater microbial activity and more rapid nutrient cycling in soil which can be favorable practice with potential in improving soil conditions in view of developing a sustainable ecosystem in the studied site

Comparative study of hermetic and non-hermetic storage on quality of cowpea in Ghana

Abstract: Cowpea (Vigna unguiculata) serves as a major food and income generation crop for millions of people in sub-Saharan Africa and Central America. However, post-harvest losses associated with this crop still remain a critical issue of concern in most developing countries. This study was therefore carried out to investigate the effect of hermetic and non-hermetic storage on cowpea in plastic containers in the tropics. The cowpeas were stored in hermetic and non-hermetic containers over a period of 12 weeks. The parameters evaluated were the moisture content, insect infestation, usable proportion, and 1000 grain mass in both hermetic and non-hermetic systems. The moisture content in the hermetic containers increased slightly from 11.7 to 11.9% compared to a sharp increase from 11.7 to 17.2% in the non-hermetic plastic containers. From the fourth week to the twelfth week, the number of live insects drastically reduced to zero in the hermetic system. In the case of the non-hermetic containers, the population of live insects/100 g of grains increased from 5 on week 0–71 on the twelfth week. Also, the mass of 1000 grains reduced from 156.50 g on week 0–145.21 g in the non-hermetically stored grains, while the hermetically stored grains recorded a decrease to 148.95 g. Finally, the usable proportion of grains in the hermetic system declined from 98.55 to 94.80% after 12 weeks of storage as compared to the drop to 85.69% seen in the non-hermetic system. Based on our findings, it was further concluded that hermetic storage could offer a better way of storing cowpea as compared to the non-hermetic system.

Composition and structure of natural organic matter through advanced nuclear magnetic resonance techniques

Abstract: Natural organic matter (NOM) plays important roles in biological, chemical, and physical processes within the terrestrial and aquatic ecosystem. Despite its importance, a clear and exhaustive knowledge on NOM chemistry still lacks. Aiming to prove that advanced solid-state 13C nuclear magnetic resonance (NMR) techniques may contribute to fill such a gap, in this paper we reported relevant examples of its applicability to NOM components, such as biomass, deposition material, sediments, and kerogen samples. It is found that nonhydrolyzable organic carbons (NHC), chars, and polymethylene carbons are important in the investigated samples. The structure of each of the NHC fractions is similar to that of kerogens, highlighting the importance of selective preservation of NOM to the kerogen origin in the investigated aquatic ecosystems. Moreover, during the artificial maturation experiments of kerogen, the chemical and structural characteristics such as protonated aromatic, nonprotonated carbons, and aromatic cluster size play important roles in the origin and variation of nanoporosity during kerogen maturation.

Evaluation of antioxidant activity and total phenol content of Gracilaria bursa-pastoris harvested in Nador lagoon for an enhanced economic valorization

Abstract: The Gracilaria bursa-pastoris is an abundant alga that is responsible for the eutrophication in Nador lagoon in Morocco. Therefore, the lagoon is a deposit of bioresources whose economic value can be enhanced. Antioxidative properties of seaweed extracts have been studied in several geographic regions, but only a few studies have been performed on tropical seaweed species, and no research has been done to determine antioxidant activity and valorization of the indigenous algae in Nador lagoon in Morocco. The present study evaluated the antioxidant potential of methanolic and aqueous extracts from Gracilaria bursa-pastoris by measuring the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total content of phenolic, flavonoids and flavonols content in each extract. This study showed that this macroalgae contained a high total phenolic content (142.26 and 79.43 mg GAE g−1 extract) for ethanolic and aqueous extracts, respectively. All extracts exhibited a DPPH radical scavenging activity, and the methanolic extracts demonstrated a great antioxidant potential with very low value of EC50 (0.085 mg/mL), significantly equivalent to EC50 (0,028 mg/mL) of commercial antioxidant ascorbic acid. These results suggest that the macroalgae have a great antioxidant potential which could be considered for future applications in medicine, food production or cosmetic industry in Morocco. This work showed that the ethanolic extract was rich in phenolic compounds. This extract exhibited the highest antioxidant activity which may be explained by the presence of a large quantity of phenolic compounds. The Gracilaria bursa-pastoris can be utilized as a source of natural antioxidant compounds.

Encapsulation of a free-solvent extract of lycopene in alginate-Ca(II) beads containing sugars and biopolymers

Abstract: The purpose of the present study was to enhance the stability toward isomerization and control the release of an encapsulated free-solvent extract of lycopene, obtained from a nonconventional natural source, by means of alginate beads containing sugar (trehalose) and biopolymers (chitosan, low methoxyl pectin, and arabic gum). Lycopene was extracted from freeze-dried pulp of pink grapefruit obtaining a free solvent extract. Lycopene encapsulation was conducted by a double procedure consisting of emulsification and ionotropic gelation in alginate-Ca(II) beads, modified by the addition of sugar and biopolymers. The influence of beads’ composition was studied on lycopene stability and release, as well as molecular mobility and diffusion in the beads. The addition of a second excipient (besides alginate) in the formulation should be carefully conducted, since stability during alginate-Ca(II) bead generation could be even compromised, leading to high lycopene losses. Beads containing trehalose and chitosan were the ones that best preserved the lycopene content and minimized isomerization changes. This could be related to the reduced molecular mobility and lower diffusion coefficient of this system. Lycopene release was severely affected by the composition of the beads, allowing to modulate its release depending on a desired application. Then, a good strategy to obtain high lycopene formulations ready to use or for their incorporation in a subsequent technological process (such as freeze-drying or extrusion) was reported in the present study.

Opportunities to improve the seasonal dynamics of water use in lentil (Lens culinaris Medik.) to enhance yield increase in water‑limited environments

Abstract: Lentil (Lens culinaris Medikus) is one of the most important annual food legumes that plays an important role in the food and nutritional security of millions in the world. Lentil is mainly grown under rainfed environments, where drought is one of the most challenging abiotic stresses that negatively impacts lentil production in the arid and semi-arid areas. Therefore, development of drought-adapted cultivars is one of the major objectives of national and international lentil breeding programs. The goal of this review is to provide a report on the current status of traits of lentil that might result in yield increases in water-limited environments and identify opportunities for research on other traits. Lately, traits that are either related to developmental plasticity and/or altered rooting and shoot characteristics have received considerable attention in the efforts to increase lentil yield in water-limited environments. However, two traits that have recently been proven to be especially useful in other legumes are still missing in lentil drought research: early partial stomatal closure under soil drying, and limited-transpiration under high atmospheric vapor pressure deficit. This review provides suggestions for further exploitation of these two soil–water-conservation traits in lentil.

Densely rooted rhizosphere hotspots induced around subsurface NH 4 + -fertilizer depots: a home for soil PGPMs?

Abstract: Populations of plant growth-promoting microorganisms (PGPMs) inoculated in natural soil typically decline over time due unfavourable biotic and/or abiotic factor(s). Improving subsurface root density may enhance PGPM establishment due to high concentrations of organic nutrients released as root exudates. Placing subsurface root-attracting NH4 +-fertilizer depots may form such zones of dense localized rooting (“rhizosphere hotspots”) that can enhance PGPM survival. Nevertheless, required soil conditions that favour formation of rhizosphere hotspots are unknown. This study aimed to investigate: (1) background soil N min effect on NH4 +-depot-zone root growth; (2) PGPM tolerance to high NH4 + concentrations (± nitrification inhibitor, DMPP); (3) ability to solubilize sparingly soluble inorganic phosphates; (4) and establishment in a subsurface NH4 +-depot. We conducted a greenhouse rhizobox experiment using spring wheat (Triticum aestivum L.) to investigate the effect of background N min (0, 5, 20 and 60 mg N kg−1) on root growth around a 1 g NH4 +–N depot. The tolerance of selected PGPMs to 0, 2, 10, 50, 250, 1250 mM NH4–N and 0, 0.1, 1 and 3 M NH4–N ± DMPP was investigated via in vitro culture tests. Promising candidates were further tested for solubilization of tri-calcium phosphate (Ca–P), rock phosphate (RP) or sewage sludge ash (SA). One PGPM was inoculated in a 15N-labelled (NH4)2SO4 + DMPP depot in rhizobox-grown maize (Zea mays L.) and root colonization was measured. N min 5–20 mg N kg−1 improved depot-zone root growth, whereas 60 mg N kg−1 reduced it. Tested PGPMs were tolerant to up to 1250 mM NH4–N. Pseudomonas sp. DSMZ 13134 and B. amyloliquefaciens FZB42 (not Trichoderma harzianum T-22) solubilized Ca–P and RP via acidification, whereas SA was not solubilized despite marked acidification. Placed 15N-labelled (NH4)2SO4 + DMPP depot led to increased localized rooting, rhizosphere acidification, shoot 15N signal, N and P concentrations and contents than homogenously applied Ca(NO3)2. Inoculation of Pseudomonas sp. DSMZ 13134 tended to increase shoot N and P concentrations, and shoot N content relative to the control. Higher colonization of Pseudomonas sp. DSMZ 13134 was measured in soil around the NH4 +-depot than in corresponding soil zone in treatments with NO3 −. These results show the first promising effects of combining fertilizer placement and application of P-solubilizing PGPMs on plant growth.

In situ polymerization of soil organic matter by oxidative biomimetic catalysis

Abstract: Agricultural practices that enhance organic matter content in soil can play a central role in sequestering soil organic carbon (SOC) and reducing greenhouse gases emissions. We used a water-soluble iron-porphyrin to catalyze directly in situ oxidative polymerization of soil organic matter in the presence of H2O2 oxidant, with the aim to enhance OC stabilization, and, consequently, reduce CO2 emissions from soil. The occurred SOC stabilization was assessed by monitoring soil aggregate stability, OC distribution in water-soluble aggregates, soil respiration, and extraction yields of humic and fulvic acids. Soil treatment with H2O2 and iron-porphyrin increased the physical stability of water-stable soil aggregates and the total OC content in small aggregates, thereby suggesting that the catalyzed oxidative polymerization increased OC in soil and induced a soil physical improvement. The significant reduction of CO2 respired by the catalyst- and H2O2-treated soil indicated an enhanced resistance of polymerized SOC to microbial mineralization. The catalyzed oxidative polymerization of SOC also significantly decreased the extraction yields of humic and fulvic acids from soil. The oxidative catalytic technology described here may become an efficient agricultural practice for OC sequestration in soils and contribute to mitigate global changes.

Microbial quality of goat carcasses in Lilongwe, Malawi

Abstract: A study to evaluate the microbial quality of goat carcasses at Chinsapo-2 and Chigwirizano slaughter slabs in Lilongwe District, Malawi, was conducted in June 2014. A total of 154 swab samples were collected from 34 carcasses for identification of the isolates and bacterial total viable counts (TVCs). Cotton swab samples were also collected from clothes, knives and hands of butchers and water used in the slaughter process. The study found that predominant bacterial isolates at Chinsapo-2 were E. coli (29%), followed by Bacillus spp. (18%), Proteus spp. (15%) and Klebsiella spp. (13%). On the other hand, bacterial isolates from Chigwirizano were E. coli (38%), followed by Bacillus spp. (23%), Proteus spp. (13%) and Klebsiella spp. (5%). The mean bacterial TVC before treatment (washing hands, clean knives with hot water and provision of working gear) for Chinsapo-2 were 6.74 ± 0.38, 6.38 ± 0.38 and 8.26 ± 0.38, while Chigwirizano had 9.48 ± 0.50, 9.48 ± 0.50 and 8.24 ± 0.50 log10 CFU/cm2. After treatment, Chinsapo-2 recorded 8.03 ± 0.38, 7.67 ± 0.38 and 7.30 ± 0.38 log10 CFU/cm2 on hands, knives and clothes while Chigwirizano had 7.12 ± 0.50, 8.84 ± 0.50 and 8.73 ± 0.50 log10 CFU/cm2, respectively. Washing hands with tap water before slaughter significantly (P 4.3 log CFU/cm2. Therefore, further studies should be conducted to reduce the bacterial contamination.

Effect of the exogenous application of abscisic acid (ABA) at fruit set and at veraison on cell ripeness of olives Olea europaea L. and the extractability of phenolic compounds in virgin olive oil

Abstract: The effect of the exogenous application of abscisic acid (ABA) at the fruit set and veraison on the cell maturity of the olive Olea europaea L. and on the extractability of phenolic compounds (PC) in the virgin oil olive was studied. The ABA was sprayed on olive trees of the Moroccan Picholine variety at a concentration of 10−3 mg/l, some olive trees are treated at fruit set stage and other olive trees are treated at veraison stage. The effects of these treatments were evaluated by fruit yield and determination of the date of veraison and ripening period of the olives. The extractability of olive oil and diffusion of PC in the latter as well as the weakening of the parietal structures are also estimated. The application of ABA at fruit set causes a decrease in the production of fruit about 50% and precocity of ripening estimated 45 days. At this stage, comparing with the control in the same period, there was a significant accumulation of fat in olives, an increase in oil extractability and a significant improvement in the diffusion of PC in oils. The treatment of the olives by the ABA at veraison has no effect on yield. However, we observe physiological and biochemical changes to be identical during the treatment by ABA at veraison but smaller than that at fruit set.

Pyritic metals sequestration on mine dumps treated with oyster mushroom ( Pleurotus ostreatus, Jacq.et Fr.)

Abstract: Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released into the environment in an uncontrolled manner, causing widespread contamination of the ecosystem. Bioremediation is an innovative and promising technology available for removal and recovery of heavy metals from polluted environments. Field experiments based on a Latin Square Design were employed in this study in order to determine the effectiveness of oyster mushroom (P. ostreatus) as a bioremediation agent for the sequestration of pyritic heavy metals from mine dumps. Compared with the background values of heavy metals in virgin forest soil, concentrations of Mn2+; Cr2+; Pb2+; Fe3+; and Cd2+ were substantially enriched in the study sites. The propagation of oyster mushroom in wheat straw substrate and heavy metal-polluted pyritic mine waste, reduced considerably the concentrations of mobile heavy metals in the waste by 1.2 mg kg−1 (98%); 2.0 mg kg−1 (79%); 13.1 mg kg−1 (93%); 7.7 mg kg−1 (78%); and 6.5 mg kg−1 (88%) for Mn2+; Cr2+; Pb2+; Fe3+; and Cd2+, respectively. Results have shown that the greatest threat to the ecology in the mine dump sites is currently posed by Cd2+; Fe3+; and Pb2+, while the least ecological threat comes from the concentrations of Mn2+. The mean levels of reductions in heavy metal concentrations in pyritic mine waste after mycoremedial interventions observed in the current study clearly indicate that, in bio-sorption, P. ostreatus is more efficient in sequestering Mn2+; Fe3+; and Cd2+, in that order. The oyster mushroom is less efficient in the bio-sorption of Cr2+ and Fe3+ from heavy metal polluted mine waste.

Water-mediated NOE: a promising tool for interrogating interfacial clay–xenobiotic interactions

Abstract: The sorption of anthropogenic compounds on clay minerals is a complex molecular process with important implications for the fate of agrochemicals and organic pollutants in the environment. The present study illustrates the use of a water-mediated NOE approach to study clay binding interactions. This method exploits the interfacial water layer on clay surfaces as a hydrogen reservoir for magnetization transfer. The interactions of four different xenobiotics with clay suspension were investigated through this method to demonstrate its capability to screen for the clay–xenobiotic molecular affinity. Further, based on the NOE build-up rates, epitope map of clay–xenobiotic interactions can be generated, explaining the orientation and mechanism of the interactions. The water-mediated NOE approach has the potential to reveal key insights into the role that interfacial water plays in the binding process, providing a better understanding of the partitioning of anthropogenic compounds from bulk water into aqueous clay suspensions.