Polycyclic Hydrocarbons Vol. 1. Pp. xxvi + 487. 126S. (With a chapter on carcinogenesis by Regina Schoental.) Vol. 2. Pp. lvii + 487. 140s. By E. Clar. (London and New York: Academic Press; Berlin: Springer-Verlag, 1964.)

Polycyclic Aromatic Hydrocarbons

A chimeric gene was constructed consisting of the promoter of the nopaline synthase gene of Agrobacterium and the structural gene of the aminoglycoside phosphotransferase of Tn5. This chimeric gene was recombined into the T-DNA of Agrobacterium. When this strain was used in a cocultivation experiment, transformed calli could be selected out of a pool of non-transformed calli when kanamycin was added into the growing medium

Chimeric genes as dominant selectable markers in plant cells

Nanotechnology is a promising field of interdisciplinary research. It opens up a wide array of opportunities in various fields like medicine, pharmaceuticals, electronics and agriculture. The potential uses and benefits of nanotechnology are enormous. The current global population is nearly 7 */billion with 50% living in Asia. A large proportion of those living in developing countries face daily food shortages as a result of environmental impacts or political instability, while in the developed world there is surplus of food. For developing countries, the drive is to develop drought and pest resistant crops, which also maximize yield. The potential of nanotechnology to revolutionise the health care, textile, materials, information and communication technology, and energy sectors has been well publicized. The application of nanotechnology to agriculture and food industries is also getting attention nowadays. Investments in agriculture and food nanotechnologies carry increasing weight because their potential benefits range from improved food quality and safety to reduced agricultural inputs and improved processing and nutrition. While most investment is made primarily in developed countries, research advancements provide glimpses of potential applications in agricultural, food, and water safety that could have significant impacts on rural populations in developing countries. This review is concentrated on modern strategies used for the management of water, pesticides, limitations in the use of chemical pesticides and potential of nano-materials in sustainable agriculture management as modern approaches of nanotechnology. 
 
   
 
 Key words: Agriculture, nanotechnology, nanofertilizer, nanoencapsulation, nanoherbicides.

Nanotechnology in sustainable agriculture: Present concerns and future aspects

Nanotechnology in agriculture: Current status, challenges and future opportunities

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained tremendous attention attributed to their unique properties. Notably, evidence has shown that zinc is an important nutrient in living organisms. As such, both prokaryotes and eukaryotes including bacteria, fungi and yeast are exploited for the synthesis of ZnO NPs by using microbial cells or enzyme, protein and other biomolecules compounds in either an intracellular or extracellular route. ZnO NPs exhibit antimicrobial properties, however, the properties of nanoparticles (NPs) are depended upon on their size and shape, which make them specific for various applications. Nevertheless, the desired size and shape of NPs can be obtained through the optimization process of microbes mediated synthesis by manipulating their reaction conditions. It should be noted that ZnO NPs are synthesized by various chemical and physical methods. Nonetheless, these methods are expensive and not environmentally friendly. On that account, the microbes mediated synthesis of ZnO NPs have rapidly evolved recently where the microbes are cleaner, eco-friendly, non-toxic and biocompatible as the alternatives to chemical and physical practices. Moreover, zinc in the form of NPs is more effective than their bulk counterparts and thus, they have been explored for many potential applications including in animals industry. Notably, with the advent of multi-drug resistant strains, ZnO NPs have emerged as the potential antimicrobial agents. This is mainly due to their superior properties in combating a broad spectrum of pathogens. Moreover, zinc is known as an essential trace element for most of the biological function in the animal’s body. As such, the applications of ZnO NPs have been reported to significantly enhance the health and production of the farm animals. Thus, this paper reviews the biological synthesis of ZnO NPs by the microbes, the mechanisms of the biological synthesis, parameters for the optimization process and their potential application as an antimicrobial agent and feed supplement in the animal industry as well as their toxicological hazards on animals.

/pdf/microbial-synthesis-of-zinc-oxide-nanoparticles-and-their-58qajgqkov.pdf

Microbial synthesis of zinc oxide nanoparticles and their potential application as an antimicrobial agent and a feed supplement in animal industry: a review

Potential Role of Beneficial Microbes for Sustainable Treatment of Sewage Sludge and Wastewater

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.

https://www.mdpi.com/2223-7747/10/6/1216/pdf

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress.

Monitoring of the polycyclic aromatic hydrocarbons content in chernozem soils under longterm industrial pollution

Rapid urbanization is one of the key factors that leads to defragmentation and the shrinking of agricultural land. It further leads to the generation of an ample amount of municipal waste. Several technologies have emerged in the past for its utilization, and in this regard, composting is one of the conventional approaches gaining popularity in modern agriculture. To overcome the possible criticality of intense urbanization, the concept of urban agriculture is taking shape. Municipal solid waste compost (MSWC) has been popularly explored for the soil amendments and nutritional requirements of crops. With this, the assessment of soil pollution (due to the heavy metals presently found in MSWC) is a required step for its safe application in agriculture. The present study aims at assessing the utilization of MSWC (in different ratios) to amend the soil and its impact on the growth and yield of brinjal (Solanum melongena), tomato (Solanum lycopersicum), and okra (Abelmoschus esculentus). The study also explored the uptake of heavy metals by plants and their risk to human consumption. The findings suggested that MSWC amendments upgraded the physio-chemical properties of soil, including organic matter (OM) and micronutrients, and increased the heavy metal concentrations in soil. Heavy metal analysis underlined the presence of several heavy metals both in soil and crops. Total metal concentration in soil increased with increased MSWC dosage. Concerning metal uptake by crop plants, 25% of MSWC was found to impart metal concentrations within permissible values in edible parts of crops. On the contrary, 50%, 75%, and 100% compost showed higher metal concentrations in the crops. A Health Risk Index (HRI) of less than 1 was found to be associated with soil amended with 25% MSWC. Our study implies that MSWC significantly improved the growth and yield of crops, and it can be considered an alternative to chemical fertilizer but only in a safer ratio (≤25%). However, further studies are required, especially on field conditions to validate the findings regarding metal accumulation.

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Assessment of Heavy Metal Distribution and Health Risk of Vegetable Crops Grown on Soils Amended with Municipal Solid Waste Compost for Sustainable Urban Agriculture

It is necessary to apply modern approaches to prevent the spread/toxic effects of pollution caused by a changing climate; especially metal pollutants to the soil. Thus, the present investigation was aimed to examine chemical speciation of soil samples collected from the River floodplain and its effects on native plant species; Phragmites australis. Synchrotron radiation (SR) tools for Zn speciation in soil and scanning electron microscopy for anatomical changes in plants were applied. Speciation of Zn was a dominant pollutant in Technosols. Two local surroundings were observed for Zn corresponding to its coordination by O and by S, close to ZnS. Whereas, the mixed local surrounding was noted with Zn–S and Zn–O bonds. The analysis of X-ray absorption fine structure results revealed that Technosols contained 70 and 30% of Zn–S and Zn–O bonds, respectively. SR results could be summarized that the main contribution in Technosols was from the authigenic minerals of metals with S: würtzite (hexagonal ZnS), sphalerite (cubic ZnS), bornite (Cu5FeS4), and covellite (CuS). The investigation on growth and modifications in the ultrastructure of P. australis roots and stems showed changes in cellular tissues such as in epidermis and mesoderm, and in subcellular organelles: mitochondria, chloroplast, cell membrane, etc. It is established that the soil contamination with exceeded limits slows down the ontogenetic developments of P. australis. Our findings could provide insight into the physiochemical characteristics of polluted soil as well as information on the toxic effects of pollutants on plants based on non-destructive approaches.

Vishnu D. Rajput

Papers

Potential Role of Beneficial Microbes for Sustainable Treatment of Sewage Sludge and Wastewater

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress.

Monitoring of the polycyclic aromatic hydrocarbons content in chernozem soils under longterm industrial pollution

Assessment of Heavy Metal Distribution and Health Risk of Vegetable Crops Grown on Soils Amended with Municipal Solid Waste Compost for Sustainable Urban Agriculture

Determination of zinc speciation in soil using synchrotron radiation and its effects on cellular organelles of Phragmites australis