Anu Kalia

Effect of pesticide application on soil microorganisms

Modern agriculture largely relies on the extensive application of agrochemicals, including inorganic fertilizers and pesticides. Indiscriminate, long-term and over-application of pesticides have severe effects on soil ecology that may lead to alterations in or the erosion of beneficial or plant probiotic soil microflora. Weathered soils lose their ability to sustain enhanced production of crops/grains on the same land. However, burgeoning concern about environmental pollution and the sustainable use of cropping land have emphasized inculcation of awareness and the wider application of tools, techniques and products that do not pollute the environment at all or have only meager ecological concerns. This review covers the types of, concerns about and current issues regarding the extensive application of agrochemicals, in particular pesticides, on a variety of microorganisms integrated in successive food chains in the soil food web.

Sodium alginate and gum acacia hydrogels of ZnO nanoparticles show wound healing effect on fibroblast cells

An ideal biomaterial for wound dressing applications should possess antibacterial and anti-inflammatory properties without any toxicity to the host cells while providing the maximum healing activity. Zinc oxide nanoparticles (ZnONPs) possess antimicrobial activity and enhance wound healing, but the questions regarding their safety arise before application to the biological systems. We synthesized ZnONPs-loaded-sodium alginate-gum acacia hydrogels (SAGA-ZnONPs) by cross linking hydroxyl groups of the polymers sodium alginate and gum acacia with the aldehyde group of gluteradehyde. Here, we report the wound healing properties of sodium alginate/gum acacia/ZnONPs, circumventing the toxicity of ZnONPs simultaneously. We demonstrated the concentration-dependent zones of inhibition in treated cultures of Pseudomonas aerigunosa and Bacillus cereus and biocompatability on peripheral blood mononuclear/fibroblast cells. SAGA-ZnONPs hydrogels showed a healing effect at a low concentration of ZnONPs using sheep fibroblast cells. Our findings suggest that high concentrations of ZnONPs were toxic to cells but SAGA-ZnONPs hydrogels significantly reduced the toxicity and preserved the beneficial antibacterial and healing effect.

Proteomics: A Paradigm Shift

ABSTRACT Proteome—the protein complement of a genome—has become the protein renaissance and a key research tool in the post-genomic era. The basic technology involves the routine usage of gel electrophoresis and spectrometry procedures for deciphering the primary protein sequence/structure as well as knowing certain unique post-translational modifications that a particular protein has undergone to perform a specific function in the cell. However, the recent advancements in protein analysis have ushered this science to provide deeper, bigger and more valuable perspectives regarding performance of subtle protein-protein interactions. Applications of this branch of molecular biology are as vast as the subject is and include clinical diagnostics, pharmaceutical and biotechnological industries. The 21st century hails the use of products, procedures and advancements of this science as finer touches required for the grooming of fast-paced technology.

Novel Trends to Revolutionize Preservation and Packaging of Fruits/Fruit Products: Microbiological and Nanotechnological Perspectives

Fruit preservation and packaging have been practiced since ages to maintain the constant supply of seasonal fruits over lengthened periods round the year. However, health and safety issues have attracted attention in recent decades. The safety and quality assurance of packaged fruits/fruit products are vital concerns in present day world-wide–integrated food supply chains. The growing demand of minimally or unprocessed packaged fruits has further aggravated the safety concerns which fuelled in extensive research with objectives to develop novel techniques of food processing, preservation, and packaging as well as for rapid, accurate, and early detection of contaminant products/microbes. Nevertheless, fruits and fruit-based products have yet to observe a panoramic introduction. Tropics and subtropics are the stellar producers of a variety of fruits; majority if not all is perishable and prone to postharvest decay. This evoked the opportunity to critically review the global scenario of emerging and novel techniques for fruit preservation and packaging, hence providing insight for their future implementation. This review would survey key nanotechnology innovations applied in preservation, packaging, safety, and storage of fruits and fruit-based products. The challenges and pros and cons of wider application of these innovative techniques, their commercial potential, and consumer acceptability have also been discussed.

ZnO nanoparticles induced exopolysaccharide production by B. subtilis strain JCT1 for arid soil applications

ZnO nanoparticle induced exopolysaccharide (EPS) production from Bacillus subtilis strain JCT1 (NCBI GenBank Accession No. JN194187) is a novel approach for arid soil applications. In the series of investigations, environmentally benign protocol was followed for the synthesis of ZnO nanoparticles using extracellular enzymes obtained from Aspergillus fumigatus TFR8. Putative characterization techniques were employed for confirmation of size, shape, surface structure, crystalline nature and elemental proportion of ZnO nanoparticles. Results established an average size of ZnO nanoparticles to be 2.9 nm at least at one dimension and oblate spherical in structure. The qualitative composition of the nanoparticles exhibited 97.5% Zn element atom percentage. Biosynthesized ZnO nanoparticles enhanced exopolysaccharide production by 596.1% as compared to control and further EPS amelioration led to enhanced soil aggregation (up to 82%), moisture retention (10.7-14.2%) and soil organic carbon. Soil aggregation stability was further confirmed by Fourier transform infra-red spectroscopy. A possible ZnO nanoparticle mediated biological mechanism for enhancing exopolysaccharide production has been discussed.

Red rot resistant transgenic sugarcane developed through expression of β-1,3-glucanase gene

Sugarcane (Saccharum spp.) is a commercially important crop, vulnerable to fungal disease red rot caused by Colletotrichum falcatum Went. The pathogen attacks sucrose accumulating parenchyma cells of cane stalk leading to severe losses in cane yield and sugar recovery. We report development of red rot resistant transgenic sugarcane through expression of β-1,3-glucanase gene from Trichoderma spp. The transgene integration and its expression were confirmed by quantitative reverse transcription-PCR in first clonal generation raised from T0 plants revealing up to 4.4-fold higher expression, in comparison to non-transgenic sugarcane. Bioassay of transgenic plants with two virulent C. falcatum pathotypes, Cf 08 and Cf 09 causing red rot disease demonstrated that some plants were resistant to Cf 08 and moderately resistant to Cf 09. The electron micrographs of sucrose storing stalk parenchyma cells from these plants displayed characteristic sucrose-filled cells inhibiting Cf 08 hyphae and lysis of Cf 09 hyphae; in contrast, the cells of susceptible plants were sucrose depleted and prone to both the pathotypes. The transgene expression was up-regulated (up to 2.0-fold in leaves and 5.0-fold in roots) after infection, as compared to before infection in resistant plants. The transgene was successfully transmitted to second clonal generation raised from resistant transgenic plants. β-1,3-glucanase protein structural model revealed that active sites Glutamate 628 and Aspartate 569 of the catalytic domain acted as proton donor and nucleophile having role in cleaving β-1,3-glycosidic bonds and pathogen hyphal lysis.

Piriformospora indica: Perspectives and Retrospectives

Mycorrhizal fungi are relevant members of the rhizosphere mutualistic microsymbiont populations that provide a direct physical link between soil and plant roots to increase soil nutrient exploitation and transfer of minerals to the root due to symbiotic association with higher plants. These include several types such as external mantle or sheath forming ectomycorrhiza, ectendomycorrhiza, and the very popular endomycorrhiza or arbuscular mycorrhizal fungi (AMF). Piriformospora indica is an endophytic fungus that exhibits AM fungus-like properties and potentials. This chapter reviews the past and present status of P. indica, its taxonomical hierarchy, molecular characteristics, and diverse applications as biotization, biocontrol, plant probiotic, and plant growth-promoting agent.

Assessing the Benefits of Azotobacter Bacterization in Sugarcane: A Field Appraisal

Biofertilizers have long been assessed as powerful technology to obtain sustainable enhanced crop production. The present investigation revealed the positive effects of inoculation of Azotobacter biofertilizer on growth and yield parameters in sugarcane var. CoJ 83 under field conditions. Application of Azotobacter biofertilizer at both the nitrogen levels (N75% Rec and N100% Rec levels) resulted in significant increase in the cane yield over the respective controls. Maximum increase in cane yield was recorded by Azotobacter inoculation at recommended dose of nitrogen. Inoculation with Azotobacter at N75% Rec level of N fertilizer resulted in cane yield that was observed to be statistically at par with N100% Rec level. The application of this biofertilizer would not only be beneficial keeping in view the phenomenon of enhanced productivity using environmentally benign technology, but also would be useful to obtain better yield with improvement of the soil microbial ecology/soil food web.

Antimicrobial Activity of Potato Starch-Based Active Biodegradable Nanocomposite Films

Food-borne pathogens such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) create a lot of problems worldwide and are a major concern of food producers and consumers. To protect the food from spoilage due to these bacteria, antimicrobial packaging is one of the most promising active packaging systems. Environmental concerns associated with plastic waste emphasized the development of packaging films from natural polymers such as starch. Therefore, in the present study, potato starch-based biodegradable and antimicrobial nanocomposite films were prepared with constant concentration of zinc oxide nanoparticles using casting method. Films were prepared using three antimicrobial agents, cinnamon oil, clove oil, and potassium sorbate and were tested against four microbes, S. aureus, E. coli, Salmonella typhi (S. typhi), and Campylobacter jejuni (C. jejuni). The films prepared with clove oil were most effective against S. aureus (22–100% inhibition), those prepared with cinnamon oil were effective against C. jejuni (19–22% inhibition) and growth of E. coli was inhibited (33–40% inhibition) to maximum extent by potassium sorbate incorporated films. However, for complete inhibition of C. jejuni and E. coli, higher concentrations of cinnamon oil and potassium sorbate are required. Increasing concentration of antimicrobial agents decreased the tensile strength of the films. Tensile strength decreased up to 13% in cinnamon oil films, 23% in clove oil films and up to 34% in potassium sorbate incorporated films. Based on the results, it can be concluded that cinnamon oil is a better antimicrobial agent due to its least effect on tensile strength and also due to its antibacterial effect against the three bacteria.

Bio-inoculants enhance growth, nutrient uptake, and buddability of citrus plants under protected nursery conditions

ABSTRACT Bio-inoculants have been used for enhancing plant growth in horticultural crops even in nutrient-limited soils. The present research evaluated the effect of inoculation of two growing media with six biofertilizer consortia on the growth and buddability of ‘Rough lemon’ rootstock subsequently budded with ‘Kinnow’ mandarin variety. Soil + FYM + Cocopeat (SFC) with Azospirillum (Azo) + AM fungi consortium improved seed germination, seedling growth, chlorophyll, P, K, root growth, root epidermis, and cortical region thickness; xylem and phloem diameter in rough lemon; budding success and growth in Kinnow mandarin saplings. It also increased OC, P, and K levels in growing media. AM spore count and AM root colonization showed a positive correlation with budding success, root P and soil P content. SFC fortified with Azo + AM fungi resulted in better growth and buddability of rough lemon seedlings along with better growth of Kinnow mandarin saplings.