Showing papers in "Biocatalysis and agricultural biotechnology in 2021"

Biodiversity of pesticides degrading microbial communities and their environmental impact

Abstract: A number of hazardous pesticides (pure substances or mixtures of chemicals) are being used by the farmers in agricultural fields to control undesired microbes during production, harvesting and storage of food stuff. These potent chemicals are jeopardizing not only the crop fertility and productivity but affecting human health, directly or indirectly. As far as in the interest of people, such hazardous chemicals are gaining access to get inside the food chain indirectly leading to adversely affecting individual's health with passage of time. The microbial resources in consortia or alone are able to degrade them upto considerable extent and converting them less hazardous. The field workers especially the farmers, whose health status is most compromised due chronic exposure of such hazardous chemicals leading to various chronic diseases like diabetes, hypertension etc. which farmers may not aware of until they have been tested for it. There are different groups of microbes including the members of phylum Actinobacteria, Ascomycota, Bacteroidetes, Basidiomycota, Chlorophyta, Cyanobacteria, Firmicutes and Proteobacteria were found to be best sources for degradation of diverse groups of pesticide (Carbamate, Organochlorine, Organophosphate and Pyrethroids). Among different groups of microbes, Arthrobacter, Aspergillus, Bacillus, Burkholderia, Chlamydomonas, Methylobacterium, Nocardioides, Nostoc, Phanerochaete, Pseudomonas, Sphingobacterium, Sphingomonas and Trichoderma were isolated and characterised for the degradation of different pesticides. The role of microbes, in the remediation and degradation of chemical pesticides are elaborated into this compilation with the recent insights.

Therapeutic potential of medicinal plants against COVID-19: The role of antiviral medicinal metabolites

Abstract: There are numerous trials underway to find treatment for the COVID-19 through testing vaccines as well as existing drugs. Apart from the many synthetic chemical compounds, plant-based compounds could provide an array of \suitable candidates for testing against the virus. Studies have confirmed the role of many plants against respiratory viruses when employed either as crude extracts or their active ingredients in pure form. The purpose of this review article is to highlight the importance of phytomedicine against COVID-19. The main aim is to review the mechanistic aspects of most important phytochemical compounds that have showed potential against coronaviruses. Glycyrrhizin from the roots of Glycyrrhiza glabra has shown promising potential against the previously epidemic coronavirus, SARS-CoV. Other important plants such as Artemisia annua, Isatis indigotica, Lindera aggregate, Pelargonium sidoides, and Glychirrhiza spp. have been employed against SARS-CoV. Active ingredients (e.g. emodin, reserpine, aescin, myricetin, scutellarin, apigenin, luteolin, and betulonic acid) have shown promising results against the coronaviruses. Phytochemicals have demonstrated activity against the coronaviruses through mechanisms such as viral entry inhibition, inhibition of replication enzymes and virus release blockage. However, compared to synthetic drugs, phytomedicine are mechanistically less understood and should be properly evaluated before application. Nonetheless, phytochemicals reduce the tedious job of drug discovery and provide a less time-consuming alternative for drug testing. Therefore, along with other drugs currently tested against COVID-19, plant-based drugs should be included for speedy development of COVID-19 treatment.

Protective role of zinc oxide nanoparticles based hydrogel against wilt disease of pepper plant

Abstract: In the current study, eco-friendly superabsorbent hydrogel based on zinc oxide nanoparticles (ZnO-NPs) and watermelon peel waste (WPW) was utilized to protect the plant against Fusarium wilt. The designed hydrogel was characterized using IR and XRD, SEM and TGA. Results revealed that, the designed hydrogel exhibited promising antifungal activity towards phytopathogen F. oxysporum in-vitro. The characterization illustrated that the size of ZnO-NPs in range 10–20 nm. Likewise, the hydrogel is highly significantly reduced the wilt disease symptoms incidence caused by F. oxysporum of pepper plant. Additionally, pepper plants treated with hydrogel show variability in number, relative mobility and density of polypeptide polyphenol oxidase in the leaf healthy and infected with F. oxysporum under different levels of irrigation. In conclusion, the designed superabsorbent hydrogel based on ZnO-NPs and WPW has the ability to control of Fusarium wilt disease as well as to decrease the irrigation water for pepper plant to one-third.

Salicylic acid: An efficient elicitor of secondary metabolite production in plants

Abstract: Thousands of structurally and chemically diverse phytochemicals called secondary metabolites are ubiquitously found in the plant kingdom. They are not essential for plant growth and development, yet they act as herbivore repellents and pollinator attractants. This fundamental role is facilitated via modulating the colour and fragrance of the plant/parts. However, they are economically important for humans in pharmaceuticals, nutraceuticals, food additives, and agrochemicals. Therefore, different ways and means have been explored to enhance their production and accumulation in the plants. Salicylic acid (SA) is one of the most important plant phenolics that affects seed germination, stomatal movements, pigment accumulation, photosynthesis, ethylene biosynthesis, heat production, enzyme activities, abscission reversal, nutrient uptake, flower induction, membrane functions, legume nodulation, metabolic activities and overall growth and development of the plants. Due to its hormone-like activity, SA has also been employed to different plant species, both in vivo and in vitro, to explore its role in the secondary metabolite synthesis and accumulation. These studies clearly demonstrate that SA can efficiently recuperate the biosynthesis of secondary metabolites in plants. Moreover, plant tissue culture technique per se elicits the secondary metabolites production. Supplementation of SA to the culture medium or short term exposure of the cultures to SA additively boosts the biosynthesis and accumulation of secondary metabolites. All this information is consolidated and presented here in detail to add a new dimension to the role of SA in plants as well as to explore a potent strategy to enhance the production and accumulation of secondary metabolites in plants.

Biodiversity, and biotechnological contribution of beneficial soil microbiomes for nutrient cycling, plant growth improvement and nutrient uptake

Abstract: Soil, the skin of the Earth is one of the fundamental natural resource and important component that contributes to the ecosystem. Soil performs a wide range of ecosystem services like food production, climate and water regulation, provision of energy and inhabiting various life forms. This fundamental natural resource of ecosystem is a home of diverse ranges of microbes (beneficial and pathogenic) known as soil microbiome, which are grouped into three domains i.e. archaea, bacteria, eukarya (fungi, algae and nematodes) of life. Diversity of soil microbiome varies with environment and their existence. They exist in bulk soil as well as root influenced soil. Soil microbes also show their existence in the different extreme environments. The microbial genera such as Achromobacter, Arthrobacter, Azospirillum, Azotobacter, Bacillus, Burkholderia, Exiguobacterium, Flavobacterium, Herbaspirillum, Methylobacterium, Paenibacillus, Pseudomonas, Rhizobium, Serratia and Staphylococcus have been reported as predominant in all the different conditions of soil. All the different groups of microbes present in the soil naturally plays a several significant roles like nutrients cycling, recycling of ground water, maintenance of soil fertility, decomposition of organic matter and formation of fossil fuels. As their role in environment these microbes may have several applications and can be used as in agriculture as plant protector and plant growth enhancer. Soil microbes can also be used in the environment for pollutants remediation and decomposition purposes. Present review deals with the biodiversity of beneficial soil microbiomes and their potential biotechnological contribution for nutrient cycling, plant growth improvement and nutrient uptake.

Current strategies and prospects in algae for remediation and biofuels: An overview

Abstract: Phycoremediation is an environmentally sustainable method that utilizes macro and microalgae to remediate polluted land and water. Phycoremediation consists of two elements: the microbial niche around the algae and the second by the algae itself, which absorb and degrade the toxic pollutants into less or non-toxic components. The advanced gene cloning technology on algae could improve gene efficiency and produce the active xenobiotic degrading enzyme. As a result, remedial rates have improved, allowing large areas of contaminated sites to be addressed in the process of large-scale application. Many organizations worldwide are already focusing on this bioremediation element, special attention on algae to replace the costly physical or chemical remediation methods. Thus, this review reported the Scenedesmus sp. algae used in the polluted tannery site, and the maximum removal was observed in Pb: 75–98% and Zn: 65–98%. Scenedesmus obliquus illustrated the significant Fe3+ (100%) removal applied in the polluted soil. Moreover, since nuclear and chloroplast transformations are important in commercial applications, C. reinhardtii remains the most effective transgenic algae applied for pollutant deduction. It was discovered that Chlorella, Chlamydomonas, and Scenedesmus sp. had the highest pollutant removal efficacy in medicine polluted sites. Furthermore, Kirchneriella sp. and Enteromorpha clathrate were observed to have the largest algal oil yield than other algal species.

Kombucha beverage from non-conventional edible plant infusion and green tea: Characterization, toxicity, antioxidant activities and antimicrobial properties

Abstract: Kombucha is a beverage based on a sugared medium fermented by a symbiotic culture of bacteria and yeast. The aim of this study was to produce unfermented and kombucha beverages with Malvaviscus arboreus and Camellia sinensis as substrates, and assess their physico-chemical characteristics, in vivo toxicities, antioxidant activities and antimicrobial properties. The beverages were prepared from infusions (0.5%, w/v), with sucrose (5.0%, w/v), kombucha culture (2.5%, w/v), and 1.0% (v/v) of the previously fermented beverage, and incubated at 24 ± 2 °C for 14 days. The results showed that both produced kombuchas are within the physico-chemical and microbiological parameters recommended by the Food and Drug Administration. None of the tested samples showed toxicity from the in vivo model of Galleria mellonella larvae. A significant increase of 145% w/v was observed on the total phenolic content of the Malvaviscus arboreus kombucha when compared to its infusion. Green tea and green tea kombucha showed antifungal activity against the pathogenic fungus Paracoccidioides brasiliensis. Green tea was also the only beverage to present antimicrobial activity against all fungi cultures evaluated and against Staphylococcus aureus and Listeria monocytogenes. Thus, it is possible that the type of substrate used in the kombucha production interferes with its bioactive properties. This report shows the potential use of non-conventional edible plant, such as Malvaviscus arboreus, as substrate for kombucha fermentation and for the first time the use of Galleria mellonella larvae as in vivo model of toxicity in the analysis of kombucha.

Artificial neural network hybridized with a genetic algorithm for optimization of lipase production from Penicillium roqueforti ATCC 10110 in solid-state fermentation

Abstract: In the present work, an artificial neural network hybridized with a genetic algorithm (ANN-GA) has been applied to optimize Penicillium roqueforti ATCC 10110 lipase production in solid-state fermentation (SSF). For such a purpose, a feed-forward ANN with polynomial configuration 3-49-1 (i.e. 3 neurons in the input layer, 49 neurons in the hidden layer and 1 neuron in the output layer) was used to computationally model the experiment and a GA was used to optimize lipase production through the ANN model. The input variables optimized by the ANN-GA were fermentation time (1 day), incubation temperature (31.2 °C) and percentage moisture content (78%). Validation was performed by considering the optimal and central point conditions, thus obtaining a lipase activity value of 48.00 U g−1, which is three times greater than by using other methodologies. Furthermore, the ANN model was obtained using 28 essays (small dataset) with interpolation and generalization capability based on a significant and precise data choice and justified by mean square error and determination coefficient values. A total of 5.0 × 107 artificial tests were simulated from the small dataset of 28 experiments.

In vitro study of the effect of xylooligosaccharides obtained from banana pseudostem xylan by enzymatic hydrolysis on probiotic bacteria

Abstract: Xylooligosaccharides (XOS) are xylose oligomers, recognized for their prebiotic effect, with the ability to impact health by influencing the gut microbiota. This study aimed to produce XOS by xylan enzymatic hydrolysis and evaluate the prebiotic effect. Endoxylanase was produced by Aspergillus versicolor and purified, and the xylan from banana pseudostem was alkali extracted. XOS production was performed through enzymatic hydrolysis by varying the parameters of xylanase load, substrate mass load, and reaction time. Lactobacillus plantarum and Lactobacillus fermentum were grown using XOS as a carbon source. Using an enzymatic load of 30 IU. g−1, it was possible to obtain a good amount of XOS and good yield, around 11 g.L−1, and 61%, respectively. Regarding the substrate concentration, the increase of concentration also increased XOS production, however, decreased the yield. There was not significant XOS production until 16 h and production was similar after 24 h. XOS with a higher degree of polymerization were mainly produced. Both probiotic bacteria were able to grow on XOS containing medium. Up to 48 h, the growth was similar, of 1010 CFU/mL, with glucose and XOS as the carbon source. The growth with XOS increased after 48 h, while the growth with glucose remained stationary. This study demonstrates that XOS from banana pseudostem xylan presents prebiotic properties by increasing probiotic bacteria growth.

Enhancement of growth and yield, leaching reduction in Triticum aestivum using biogenic synthesized zinc oxide nanofertilizer

Abstract: Agriculture sector have seen a huge spike in research related to application of nanomaterials for increasing production of crop in last two decades. Zinc is one such micronutrient which is widely explored for use in agriculture as nanofertilizer or for other novel applications. Despite being the widely researched nutrient, almost negligible studies have been carried out studying the impact of leaching of zinc in soil after crop harvesting. In our present work we tried to explore the potential of zinc as nanofertilizer in wheat via studying its impact on biochemical, physiological, morphological and yield related parameters of wheat along-with leaching of zinc in soil. Wheat plants were grown to harvesting stage and were treated with three different concentrations of nano zinc oxide (40, 80, 120 ppm), zinc nitrate along-with a control setup having no external zinc supplement. Nano-zinc oxide at the concentration of 80 ppm showed the best results and causes maximum increase in plant height, seeds per spike, 100 seed weight, yield, and biomass accumulation compared to the control and zinc nitrate treatment. In case of 80 ppm nano zinc oxide spray, yield obtained was 19.94g which was significantly much higher than chemical zinc (6.96g) and control (4.38g). Nano zinc oxide application also caused better absorption of zinc and least amount of zinc was left in the soil when compared to control and zinc nitrate treatment. These results indicate that nano zinc oxide can be applied to wheat plants for enhanced yield, quality and at the same time being less harmful for environment.

Actinomycetes – The microbial machinery for the organic-cycling, plant growth, and sustainable soil health

Abstract: Soil actinomycetes are known as very versatile micro-machinery having tremendous potential to produce enzymes like cellulases, chitinases, proteases, and other agro-biochemicals, which are very instrumental in soil reclamation and sustainable soil health. The metabolic aspects of actinomycetes offer enormous possibilities for industrial and commercial applications in the food, textile, fermentation, and paper industry. They have long been known for their degrading function of complex biomass, cellulose, lignocelluloses, xylene, pectin, and other complex polysaccharides present in soils. They have been studied as saprophytes, which makes them very suitable for their decomposing actions of complex polysaccharides like lignin and cellulose materials for the production of soil organic matter and composting. They maintain biotic equilibrium by antagonistic activities against pathogens present in the soil. The present review is a repertoire of information available actinomycetes which play a significant role in the soil as plant growth-promoting rhizobacteria (PGPR) as well as the commercial biofertilizers.

Overview on toxicity of nanoparticles, it's mechanism, models used in toxicity studies and disposal methods – A review

Abstract: The usage of nanoparticles in the recent years have gained a huge importance in various fields due to their unique properties such as electrical, optical, magnetic abilities that contribute to the growth of science and technology. Therefore, it has become vital to understand the impact of nanoparticles on the human health and environment as they are expected to impose a negative threat in the environment due to its exploitation and improper disposal. As a result, nanotoxicology has been emerged as new realm of toxicology that mainly deals with understanding of the interaction between the nanoparticles with the environment. Due to the increased exposure of nanoparticles to the environment, a better assessment of nanotoxicity is required along with imposing methods for a more efficient use of nanoparticles and with proper disposal methods to help reduce the adverse effects. Therefore, this review paper provides a detailed understanding of the mechanism that is responsible for nanoparticles toxicity and its interaction with the environment along with the factors that contribute to its toxic effects with specific information of metal nanoparticles such as gold, silver, superparamagnetic iron oxide, platinum and zinc nanoparticles. It also provides a detailed explanation on adverse effects on human cell lines and clinical data derived from studies conducted on various in-vitro and in-vivo models utilized to assess the toxic impacts of the nano-sized particles.

Characterization, antibacterial and photocatalytic evaluation of green synthesized copper oxide nanoparticles

Abstract: Nanoparticles are extensively studied for their greater physical and biological properties. In the present study, copper oxide nanoparticles were produced by green synthesis route using Cardiospermum halicacabum extract as reducing and capping agent. The synthesized nanoparticles were characterized using UV–visible spectroscopy, FTIR, XRD, Particle size analyzer, FE-SEM with EDS and HR-TEM. Well diffusion assay and bacterial cell viability assay was performed against clinical pathogens to determine the antibacterial activity of green synthesized copper oxide nanoparticles (GCuO NPs) and photocatalytic activity was determined against the organic dye (methylene blue). Morphological analysis of GCuO NPs revealed that the synthesized nanoparticles were spherical with narrow size distribution, and exhibit monoclinic structure as confirmed by XRD. GCuO NPs displayed strong antibacterial activity against Gram-positive organisms such as Bacillus subtilis, Staphylococcus aureus, and Methicillin Resistant Staphylococcus aureus. Furthermore, GCuO NPs degraded ~93% of methylene blue dye. These results clearly demonstrated that GCuO NPs have potent antibacterial and photocatalytic activities suggesting their potential applications as antibacterial agent and photocatalysts.

Improved salinity tolerance of Medicago sativa and soil enzyme activities by PGPR

Abstract: Abiotic stresses such as salinity are common adverse conditions that significantly affect agricultural productivity worldwide. This study aimed to select halotolerant plant-growth-promoting rhizobacteria (PGPR) capable to promote plant growth and to improve soil functioning under salinity stress conditions. Thirty-two bacterial isolates were studied for their PGP traits and NaCl resistance. Four selected potential PGPR were identified by using 16S rDNA sequencing and tested for their PGP traits in the presence of 2–6% NaCl. Their effect on growth, chlorophyll content, oxidative stress and root arbuscular mycorrhizal (AM) colonization of Medicago sativa, was studied under salt stress in pots experiment. The bacteria were also tested for their effect on soil enzyme activities. Overall results showed that the isolates displayed various PGP properties and variable levels of NaCl resistance. The four selected potential PGPR strains were identified as Pseudomonas putida, Alcaligenes sp., Klebsiella sp., and Pseudomonas cedrina. The bacteria retained most of the PGP traits in the presence of the tested concentrations of NaCl. The inoculation of M. sativa plants by the four strains allowed overcoming the negative effects of stress due to NaCl and increased plant growth, roots AM colonization and the leaves chlorophyll content, compared to the non-inoculated control. It also lowered the levels of the indicators of oxidative damage, malondialdehyde, hydrogen peroxide, and proline. Besides, the strains had a positive effect on soil phosphatase, β-galactosidase, and arylamidase activities. This study showed that the selected isolates have an interesting potential to be used as bio-inoculants for plants growing under salt stress.

Bioactive and pH-sensitive films based on carboxymethyl cellulose and blackberry (Morus nigra L.) anthocyanin-rich extract: A perspective coating material to improve the shelf life of cherry tomato (Solanum lycopersicum L. var. cerasiforme)

Abstract: This study aimed to produce an innovative antioxidant and pH-sensitive film packaging based on carboxymethyl cellulose (CMC) and incorporating different amounts of blackberry (Morus nigra L.) anthocyanin rich-extract. The films were characterized and applied as a coating in the postharvest conservation of cherry tomato (Solanum lycopersicum L. var. cerasiforme) to demonstrate the effectiveness for food conservation. The results obtained demonstrated that the films presented considerable good physicochemical parameters, especially a low water solubility (below 15%) and high UV-blocking property (transmittance below 0.8%). The films presented high content of phenolic compounds and anthocyanins, increasing according to the addition of blackberry extract in the film formulation. Moreover, the controlled release of the active compounds indicated a constant profile between 2 and 240 h, which suggests a promising behavior for food conservation. Based on the presence of anthocyanins, the films changed the color according to the pH exposed, and then, can be classified as pH-sensitive packaging. The CMC films demonstrated positive behavior in the postharvest conservation of cherry tomato for 15 days of storage, maintaining constant fruit weight and firmness. In the sensorial attributes, the concentration of anthocyanin-rich extract used for the film formulation significantly affected visual acceptance. Beyond, the highest concentrations of extract negatively affected the purchase intention of cherry tomatoes. In conclusion, the biodegradable CMC films can release bioactive-antioxidant compounds and increase the shelf life of cherry tomatoes, and therefore, may be considered as a new alternative to packaging in food systems.

Synthesis of nanosilica from agricultural wastes and its multifaceted applications: A review

Abstract: Agricultural wastes management is one of the biggest burdens in the 21st century. To reduce pollution from agricultural waste, different types of research have been conducted to convert agricultural wastes into value-added products. In recent decades, agricultural wastes are utilized as source material for nanoparticle synthesis. Nanoparticles with large surface area, small size, biocompatibility, and adjustable functionalization are now booming in different areas of science and technology. Among different types of nanoparticles, the silica nanoparticles (SiNPs) were favored to synthesize from agro-wastes as the major agricultural crop residues are silica enriched, especially the cereal crops. Moreover, the bound silica in the agricultural wastes is conventionally extracted by thermal, chemical, and biological treatment. Owing to the structural flexibility, tuneable pore size, and less toxicity made the SiNPs are more attractive to use in various fields than other metallic nanoparticles. SiNPs are now extensively used in biomedical, agricultural, and environmental remediation purposes. This review paper is an assemblage of different approaches aimed to synthesize nanosilica from agro-wastes along with its potential application areas.

In vitro screening of phytochemicals, antioxidant, antimicrobial, and cytotoxic activity of Echinops setifer extract

Abstract: Medicinal plants expose a specific capacity in drug discovery due to their therapeutic capability that can cover the uncertainties and deficiency of modern medication by in vitro documents. This study was conducted to assess the functional groups, total phenolic and total flavonoid compounds, the antioxidant, antimicrobial, and cytotoxic activity of Echinops setifer extract. Hence, functional groups in the ethanolic extract of Echinops setifer were analyzed by FT-IR analysis. The total phenolic compounds (TPC), flavonoid compounds (TFC), and the antioxidant activity of Echinops setifer were determined. The antiproliferative activity of the extract was elucidated against HT-29 cell lines through the intensification in concentrations. More ever, the antimicrobial potential of the extract in the lowest concentration developed the inhibition zone against all the studied bacteria except Pseudomonas aeruginosa and Salmonella typhi, in both DDA and WDA methods. Listeria innocua by DDA method and Staphylococcus aureus through WDA method illustrated the highest inhibition zone in the maximum extract concentration. The MIC and MBC of ethanolic extract of E. setifer for Staphylococcus aureus, Listeria innocua, Bacillus cereus, P. aeruginosa, Escherichia coli, and S. typhi were reported. Compelling, this research exposed that Echinops setifer extract had a great potential to fight free radical chain reaction, cytotoxic and antimicrobial activity leading to a high value in the application for usage in therapeutic purposes.

Variability of oil content and its physicochemical traits from the main almond [Prunus dulcis Mill. DA Webb] cultivars grown under contrasting environments in north-eastern Morocco

Abstract: To produce nut virgin oils at a large scale, mechanical extractions have become widely accepted to obtain nut oils of higher quality without chemical residues. Little is known about kernel oil from the commercially grown almond cultivars in Morocco obtained by press extraction. This work was set up to evaluate effects of different environments on almond oil content (OC) and related quality traits, namely polyphenols (PP), saturated (SFA), monounsaturated (MUFA), polyunsaturated fatty acids (PUFA), and oleic/linoleic (O/L) ratio. To this end, the main cultivars were compared across various sites belonging to northern (typical Mediterranean climate) and the eastern Morocco (hot Mediterranean climate) over three growing seasons (2016–2018). Virgin oil achieved via mechanical press showed high quality as demonstrated by lower records of routinely measured parameters (acid value, peroxide value, and UV absorption coefficients K232 and K270) on one hand and higher records of PP and O/L on the other hand. Cultivars of longer fruit development period (FDP) such as ‘Marcona’ displayed higher OC, while ‘Tuono’ and ‘Fournat de Brezenaud’ (shorter FDP) presented the best record of PP. 2016 (the driest season) had the best scores of OC and PP. Eastern Morocco (relatively hot and dry) showed higher OC, PP, PUFA, but lower MUFA and, therefore, lower O/L. In conclusion, drier environments could enhance OC and foster the accumulation of more PP, PUFA but lower MUFA with a decreased oil stability.

“Phytochemical and antimicrobial investigation of Methanolic Extract/Fraction of Ocimum basilicum L.”

Abstract: The crude solvent extracts of medicinal plants may be exploited as medicines for the betterment of human health. The isolation, purification and characterization of active phytochemical components and their mechanism of action is of predominant grandness. Keeping in view the importance of Ocimum basilicum, the present study was designed to document the phytochemical and antimicrobial activity of methanolic extract of O. basilicum stem. For this purpose dried powdered stem was extracted by successive solvent extraction using petroleum ether (for non-polar Fractions), chloroform (for constituents of intermediate polarities) and methanol (for polar constituents). Six major fractions Ob-1 to Ob-6 were separated from the methanolic extract of O. basilicum stem by column chromatography and purified by thin layer chromatography. All biological active and purified fractions were analyzed by Ultra Violet (UV) and Fourier Transform Infrared (FTIR) spectroscopy. These extracts were initially subjected to screening of antimicrobial activities. The results of the initial screening indicated that methanolic extract was more active than other solvent extracts. Antimicrobial potential of six major fractions Ob-1 to Ob-6 was determined against three species of gram-positive (Clostridium defficile, Bacillus subtilis and Staphylococcus aureus) bacteria, three species of gram-negative (Escherichia coli, Salmonella typhi and Klebsiella pneumoniae) bacteria and three species of fungi (Aspergillus flavus, Aspergillus niger and Candida albicans). All the six isolated fractions displayed well-marked antimicrobial potential against nine microbes. Ob-4, Ob-5 and Ob-6 appeared to be most potent than other fractions, but lesser than the standard antibiotics.

A novel sodium alginate active films functionalized with purple onion peel extract (Allium cepa)

Abstract: The purple onion peel extracts (POPE) have a high content of phenolic compounds and can be used as a promising strategy in the development of active packaging. Biodegradable sodium alginate films have good characteristics of gel formation, flexibility, transparency, brightness, and low oil permeability. The incorporation of bioactive compounds from plant residues can be a low-cost technique to functionalize alginate-based materials. The aim of this work was to evaluate the effects of POPE incorporation on the physical, mechanical, barriers, antioxidants, and antimicrobial properties of alginate-based films. Filmogenic solutions were prepared with a concentration of 0, 10, 20, and 30% of POPE and glycerol was used as plasticizer. The addition of POPE in the sodium alginate matrix promoted the development of opaque red films, with a content of phenolic compounds 43 times greater than the film without extract. As expected, the incorporation of POPE increased the antioxidant activity and the thickness of the alginate-based films. In addition, the incorporation of phenolic compounds promoted better interaction between the polymeric networks, reducing the water solubility of the alginate films. The results indicated that the sodium alginate films incorporated with several concentration of POPE have been shown to be an interesting material for the production of active packaging, being possible to apply them in foods with high water activity or susceptible to lipid oxidation, to preserve and extend the shelf life of these products.

Bacteriocin: A new strategic antibiofilm agent in food industries

Abstract: Contamination of food products with microorganisms from various sources is a serious concern as it not only affects the food quality also leads to spoilage and therefore may cause several illnesses. Chemical preservatives may not be considered as a potential way as it has many disadvantages. The use of bio-preservatives can replace it. Bacteriocins are recently drawing attraction to be used in food products because of several benefits. These are antibiotics that can act against pathogenic microorganisms. It is absolutely safe to use them and can be easily digested in the human body. Bacteriocins are of three types and each one has a specific mechanism of action against biofilms. Biofilms are found in the extracellular matrix of different colonizing species and in the food industry they can be formed easily in different conditions. In specific conditions, bacteriocins cannot function against microorganisms and to enhance their functions hurdle technology is found highly suitable. It has been observed that the use of hurdle technology can promote the activity of bacteriocins to a greater extent. The incorporation of bacteriocins into packaging films can protect the food product from spoilage. There are several ways to insert bacteriocin into packaging material. This method is a great option to enhance the shelf life of food products by reducing the number of spoilage organisms. Further study is required to understand its mechanism of action more vividly which may help to use them as a bio preservative in the food industry in a broader spectrum.

Recent advances in itaconic acid production from microbial cell factories

Abstract: Itaconic acid is an unsaturated organic acid with two carboxyls and one methylene group. The presence of these functional groups, along with a conjugated double bond, makes itaconic acid a versatile molecule with a vast number of applications. Itaconic acid can be produced through chemical as well as biological routes. Aspergillus terreus is the most prevalent microbial cell factory for the biological production of itaconic acid, reaching titers of >100 g/L. However, it suffers from low yield and volumetric productivities leading to high manufacturing costs. The wider applications of itaconic acid can be enabled with a low-cost production process, which can be achieved with cheaper feedstocks and robust cell factories accumulating itaconic acid efficiently. The current review summarizes the recent advances in the biological production of itaconic acid with a focus on the metabolic engineering of prokaryotic and eukaryotic systems for the overproduction of itaconic acid. It comprehensively describes various microbial cell factories with an insight into the pathway leading to itaconic acid production in natural producers like A. terreus and U. maydis. It also discusses the metabolic engineering approaches to improve strain performance in terms of high itaconic acid productivity, less by-product generation, and the ability to utilize unconventional cheap substrates. Moreover, the alternative strategies for the development of non-native producers through genome engineering and the hurdles related to itaconic acid production have been elaborated.

Statistical analyses of the effect of rhamnolipid biosurfactant addition on the enzymatic removal of Bisphenol A from wastewater

Abstract: Bisphenol A (BPA), a major phenolic pollutant, is hazardous, toxic, and mutagenic. Although there are some chemical and physical processes to treat wastewater polluted with BPA, most of these methods are either costly or detrimental to the environment (i.e., generate serious secondary pollution). Unlike chemical and physical treatment methods, enzymatic treatment is environmentally friendly, more selective towards the targeted phenolic pollutant(s) and uses sustainably produced materials (i.e., enzymes). In this work, a clean process based on enzyme (i.e., laccase) and biosurfactant (i.e., rhamnolipid) is developed in order to study the removal of BPA from wastewater. Several statistical analyses of the effect of rhamnolipid (RL) addition on the enzymatic removal of BPA under different process conditions have been performed. The results revealed a positive correlation between RL addition and BPA removal irrespective of the initial BPA concentration, reaction time, reaction temperature, pH of the reaction medium, and wastewater salinity. The statistical analyses also revealed that the two-way interactions between RL addition and reaction time and between RL addition and the initial BPA concentration are significant. However, the two-way interactions between RL addition and the reaction temperature, RL addition and the pH of the reaction medium, and RL addition and the wastewater salinity are insignificant, unlike the significant effects of the individual factors.

Green synthesis of silver nanoparticles, characterization, and use for sustainable preservation of historical parchment against microbial biodegradation

Abstract: Green chemistry is considered a suitable approach for the sustainable preparation of nanoparticles (NPs) attributable to it is safe and clean technique. In the present work, tea tree leaves extract were used for preparing silver nanoparticles (Ag-NPs). Ecofriendly fashioned Ag-NPs was evaluated by transmission electron microscopy (TEM), X-ray diffraction pattern (XRD), ultraviolet–visible (Uv–Vis) spectroscopy, and dynamic light scattering (DLS). The obtained results confirmed the capability of tea tree leaves extract to produce spherical Ag-NPs with an average size of 40 nm at wavelength 468 nm. Furthermore, the XRD analysis affirmed the crystallographic structure of the synthesized Ag-NPs. DLS displayed that the particle size of Ag-NPs with an average diameter of about 40 nm. This study aimed to examine the influence of green synthesis Ag-NPs disinfection process on the reduction of the number of microorganisms: Aspergillus fumigatus EGY-N1, Byssochlamys spectabilis EGY-N2, Cladosporium xanthochromaticum N3-EGYand Streptomyces albidoflavus SP11 previously isolated from historical parchment manuscript. Correspondingly, the chemical, mechanical, and morphological characteristic changes of disinfected parchment arising through disinfection and after the accelerated aging process were assessed. The obtained data revealed that Ag-NPs are microbiostatic against tested microbes at a concentration of 0.005%. The microbicidal effect was achieved at a concentration of 0.025%. Moreover, the established sensitivity of microorganisms was in the following order (Streptomyces albidoflavus > Cladosporium xanthochromaticum > Byssochlamys spectabilis > Aspergillus fumigatus). Finally, chemical as well as mechanical characteristics of disinfected parchment did not significantly influence during the accelerated thermal aging at 80 °C for three weeks. Thus, Ag-NPs could be a good candidate for sustainable maintenance of historical parchment against microbial biodegradation.

Preparation of chitosan-based antimicrobial active food packaging film incorporated with Plectranthus amboinicus essential oil

Abstract: The steep increase in global food packaging waste has caused various environmental concerns and demands a reliable alternative. To meet the demand, bioactive and biodegradable films can be used as packaging material and the incorporation of natural food additives can also further increase the shelf life of the food. The essential oil extracted from plants and spices have a broad spectrum of antimicrobial activity and antioxidant activity which can be used as an additive in food packaging material to reduce the deterioration of food by common food borne pathogens. In this report, we have extracted essential oil from Plectranthus amboinicus and incorporated it into chitosan films. This biodegradable film incorporated with Plectranthus amboinicus essential oil showed improved functional properties of the films such as tensile strength, opacity, and water vapor barrier. The essential oil also exhibited promising antimicrobial activity against food pathogens. Hence, essential oil incorporated biodegradable films can be used for food packaging to extend its shelf life.

Phytochemical components, antioxidant and anticancer activity of 18 major medicinal plants in Albaha region, Saudi Arabia

Abstract: Medicinal plants have a great role in influencing health all over the world. There are few studies for the phytochemical investigations in medicinal plants were conducted in Saudi Arabia especially in Albaha region in south-western Saudi Arabia. Therefore this study focused on the detection of the phytochemical composition of the most dominant eighteen natural medicinal plant varieties found in Albaha region. Aqueous extracts of the dried aerial parts of these plants were prepared. The phytochemical composition of these extracts was investigated. Also, the antioxidants and anti-cancer activity of these plants' extracts were evaluated. The results revealed that phenols, flavonoids saponins and glycosides cyanides were the most abundant phytochemical components in the investigated plants. Dodonaea viscosa, Solanum incanum, Olea europaea subsp. cuspidata and Aerva javanica were the highest plants in their phytochemical components and their antioxidant capacity. Their antioxidant capacity recorded 38, 32, 22 and 14% increase more than that of the standard (Ascorbic acid) respectively. Also, these plants showed an interesting anticancer effect compared to the other studied plants. Their IC50 against studied cancer cell lines was lower than 20 μg/ml. This low IC50 is an evidence to be a promising anticancer agent for crude extracts. Thus the present study highlighted the importance of these detected plant varieties as a source of anticancer agents. More intensive studies are needed to verify the most effective chemical components in these investigated plants.

Mycofabrication of gold nanoparticles: Optimization, characterization, stabilization and evaluation of its antimicrobial potential on selected human pathogens

Abstract: In this study, aqueous fungus extract from edible mushroom Agaricus bisporus was prepared and utilized as reducing and stabilizing agents towards a green synthesis of gold nanoparticles (Au NPs). The biophysical characterization of Au NPs was done by UV–Vis absorption spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and High Resolution Transmission Electron Microscopy (TEM). The mycosynthesized Au NPs were primarily confirmed by the color change from yellow to dark violet in 72 h of reaction due to the reduction of Au3+ ions to Au0. A sharp peak at 540 nm in the UV–Visible spectrum proved the synthesis of Au NPs. The different parameters viz., the concentration of gold chloride, ratio of gold chloride concentrations with a volume of a mushroom extract, pH, temperature, reaction mode, and the reaction time were optimized for the mycosynthesis of Au NPs. The stability of Au NPs was well proved in the in-vitro stability test under various conditions viz., 10 % NaCl; 0.2 M Cysteine; different pH; sterilized conditions (121 °C at 15 lbs for 20 min) and unsterilized. The mycosynthesized Au NPs have significantly inhibited the growth of clinically important pathogenic Gram-positive bacteria (Streptococcus pyogenes & Staphylococcus aureus); Gram-negative bacteria (Klebsiella pnemoniae & Shigella flexneri) and pathogenic fungi (Candida albicans & Aspergillus fumigatus). This study suggests that the mycosynthesized Au NPs could be used as novel drug against various human pathogens and also a promising candidate for many biomedical applications.

Effects of vernonia amygdalina fractionate on glutathione reductase and glutathione-S-transferase on alloxan induced diabetes wistar rat

Abstract: s This research was conducted to examine the effect of vernonia amygdalina on Glutathione reductase and Glutathione-S-transferase in alloxan induced diabetic wistar rats. Sixty-six (66) adult male wistar rats weighing between 100 and 250 g were used for the study. The animals were induced by intraperitoneal injection of 60 mg of alloxan. The animals were divided into 11 groups of six (6) rats in phase 1 and phase 2 (normal control, crude extract, Metformin, glycoside, saponin and alkaloid) respectively. After 28days treatment, the rats were sacrificed using a gaseous anesthetic agent (chloroform), blood samples were collected from inferior Vena Cava for biochemical analysis and pancreas harvested for histopathological examination. The final fasting blood glucose level of the experimental animals showed no significant difference when compared to that of the control rats (at p

Xylooligosaccharides: prebiotic potential from agro-industrial residue, production strategies and prospects

Abstract: The use of agro-industrial residue in new processes has encouraged the development of biotechnological strategies to obtain biomolecules. Lignocellulosic materials are rich in xylan and can be used as an alternative and inexpensive source for xylooligosaccharide (XOS) production, contributing to the sustainable generation of products with high added-value. This article provides an overview of recent methodological strategies for XOS production, their health benefits as prebiotics, purification, and technological properties for industrial application. Classified as non-digestible, XOS are prebiotics and can be used as functional foods, promoting health benefits. The main advantages of XOS include the selective stimulation of beneficial microorganisms, the suppression of pathogenic bacteria and reduction of toxic compounds from the metabolism. XOS are produced from a wide diversity of lignocellulosic materials by chemical, physical and enzymatic methods, or by a combination of them. Physicochemical methods can generate undesirable by-products, and/or a large amount of monosaccharides, and result in a more difficult purification, while enzymatic hydrolysis allows milder process conditions because the reactions are specific and less pollutant residues are generated. Technological and nutritional approaches for XOS production which allow their use in different food and pharmaceutical products, and which stimulate the dissemination of researches in other technological areas, have also been discussed.

Antioxidant and antimicrobial activity displayed by a fungal endophyte Alternaria alternata isolated from Picrorhiza kurroa from Garhwal Himalayas, India

Abstract: Picrorhiza kurroa (Kutki) is a medicinal plant of Himalayan region which was exploited for its fungal endophytic association. Endophytic fungi isolated from plants have plant growth promoting attributes and biocontrol activity. We have isolated endophytic fungi to investigate the bioactive compounds which was used for the biocontrol of bacteria of clinical importance. The morphological analysis as well as the molecular characterization using 18s rRNA and phylogenetic analysis, identified the fungus as Alternaria alternata. Investigation using GC-MS of methanolic and ethyl acetate extracts of fungal biomass, led to identification of many bioactive compounds. These chemicals have various medicinal purposes such as antimicrobial activity and antioxidant potential. Our results suggest that these compounds may have clinical importance. The extract from A. alternata was capable of inhibiting B. subtilis and S. aureus. This is the first study conducted about role of secondary metabolites produced by Alternaria alternata isolated from the Picrorhiza kurroa, possessing antibacterial properties and the bioactive compounds may have potential medicinal relevance.