Benchmarking of different microbes for their biosurfactants antifungal action against plant pathogens

The biotic stress caused by phytopathogens (bacteria, fungus, yeast and insect pests) is a primary factor in yield loss of plants. Biocontrol agents and their active compounds are used to manage such plant pathogens. Here, in our study, we screened four bacterial isolates identified as Bacillus cereus, B. anthracis, B. velezensis and Serratia marcescens after morphological, biochemical and molecular characterization (16s rDNA sequencing) for production of biosurfactant by foam forming activity, oil spreading tests and emulsification activity. Highest foam stability (75 min) and maximum emulsification activity E24% (75%) was observed by B. velezensis strain. Among all the four isolates, Bacillus velezensis strain produced maximum biosurfactant (0.349±0.004 g/50 mL). Biosurfactant of all the four bacterial isolates were checked for fungal inhibiton on PDA plate(s). Bacillus velezensis showed comparatively the highest percent inhibition 58.82, 88.15, 78.45,72.68, 83.96, 75.47, 68.07 and 88.44% against Colletotrichum falcatum, Fusarium oxysporum f sp. ciceri, Helminthosporium maydis, F. oxysporum f. sp. lycopersici, Aspergillus niger, Mucor sp., Helminthosporium oryzae and Rhizoctonia solani, respectively. Bacillus velezensis biosurfactant among all the four bacterial isolates was found to be most effective against the tested phytopathogens

A Combined Use of Rhizobacteria and Moringa Leaf Extract Mitigates the Adverse Effects of Drought Stress in Wheat (Triticum aestivum L.)

Less nutrient availability and drought stress are some serious concerns of agriculture. Both biotic and abiotic stress factors have the potential to limit crop productivity. However, several organic extracts obtained from moringa leaves may induce immunity in plants under nutritional and drought stress for increasing their survival. Additionally, some rhizobacterial strains have the ability to enhance root growth for better nutrient and water uptake in stress conditions. To cover the knowledge gap on the interactive effects of beneficial rhizobacteria and moringa leaf extracts (MLEs), this study was conducted. The aim of this experimental study was to investigate the effectiveness of sole and combined use of rhizobacteria and MLEs against nutritional and drought stress in wheat. Nitrogen-fixing bacteria Pseudomonas aeruginosa (Pa) (10(8) CFU ml(-1)) was inoculated to wheat plants with and without foliar-applied MLEs at two different concentrations (MLE 1 = 1:15 v/v and MLE 2 = 1:30 v/v) twice at 25 and 35 days after seed sowing (50 ml per plant) after the establishment of drought stress. Results revealed that Pa + MLE 2 significantly increased fresh weight (FW), dry weight (DW), lengths of roots and shoot and photosynthetic contents of wheat. A significant enhancement in total soluble sugars, total soluble proteins, calcium, potassium, phosphate, and nitrate contents validated the efficacious effect of Pa + MLE 2 over control-treated plants. Significant decrease in sodium, proline, glycine betaine, electrolyte leakage, malondialdehyde, hydrogen peroxide, superoxide dismutase (SOD), and peroxide (POD) concentrations in wheat cultivated under drought stress conditions also represents the imperative role of Pa + MLE 2 over control. In conclusion, Pa + MLE 2 can alleviate nutritional stress and drought effects in wheat. More research in this field is required to proclaim Pa + MLE 2 as the most effective amendment against drought stress in distinct agroecological zones, different soil types, and contrasting wheat cultivars worldwide.Peer reviewe

Lipopeptides as the Antifungal and Antibacterial Agents: Applications in Food Safety and Therapeutics

A lot of crops are destroyed by the phytopathogens such as fungi, bacteria, and yeast leading to economic losses to the farmers. Members of the Bacillus genus are considered as the factories for the production of biologically active molecules that are potential inhibitors of growth of phytopathogens. Plant diseases constitute an emerging threat to global food security. Many of the currently available antimicrobial agents for agriculture are highly toxic and nonbiodegradable and thus cause extended environmental pollution. Moreover, an increasing number of phytopathogens have developed resistance to antimicrobial agents. The lipopeptides have been tried as potent versatile weapons to deal with a variety of phytopathogens. All the three families of Bacillus lipopeptides, namely, Surfactins, Iturins and Fengycins, have been explored for their antagonistic activities towards a wide range of phytopathogens including bacteria, fungi, and oomycetes. Iturin and Fengycin have antifungal activities, while Surfactin has broad range of potent antibacterial activities and this has also been used as larvicidal agent. Interestingly, lipopeptides being the molecules of biological origin are environmentally acceptable

Benchmarking of different microbes for their biosurfactants antifungal action against plant pathogens

931-938The biotic stress caused by phytopathogens (bacteria, fungus, yeast and insect pests) is a primary factor in yield loss of plants. Biocontrol agents and their active compounds are used to manage such plant pathogens. Here, in our study, we screened four bacterial isolates identified as Bacillus cereus, B. anthracis, B. velezensis and Serratia marcescens after morphological, biochemical and molecular characterization (16s rDNA sequencing) for production of biosurfactant by foam forming activity, oil spreading tests and emulsification activity. Highest foam stability (75 min) and maximum emulsification activity E24% (75%) was observed by B. velezensis strain. Among all the four isolates, Bacillus velezensis strain produced maximum biosurfactant (0.349±0.004 g/50 mL). Biosurfactant of all the four bacterial isolates were checked for fungal inhibiton on PDA plate(s). Bacillus velezensis showed comparatively the highest percent inhibition 58.82, 88.15, 78.45,72.68, 83.96, 75.47, 68.07 and 88.44% against Colletotrichum falcatum, Fusarium oxysporum f sp. ciceri, Helminthosporium maydis, F. oxysporum f. sp. lycopersici, Aspergillus niger, Mucor sp., Helminthosporium oryzae and Rhizoctonia solani, respectively. Bacillus velezensis biosurfactant among all the four bacterial isolates was found to be most effective against the tested phytopathogens

Ribonucleases and their Applications

Ribonuclease (RNase) is a type of nuclease that catalyzes degradation of RNA into smaller components. RNase can be classified into two broader categories namely endoribonucleases and exoribonucleases on the basis of their site of action. RNases play key roles in the maturation of all RNA molecules; endoribonucleases cleave the RNA molecules from the interior at 5′ end while exoribonucleases degrade RNA molecules in a 3′–5′ direction. With the advent of new frontiers in biotechnology, the applications of ribonucleases besides molecular biology have expended into many other fields like medicinal, clinical, and analytical chemistry. RNase A that belongs to pancreatic ribonucleases super family plays an important key role in structural, biochemical and evolutionary studies. Discovery of eukaryotic orthologues of the bacterial double stranded (ds) RNA-specific ribonuclease III (RNase III) suggests a central role for these enzymes in the regulation of ds-RNA and eukaryotic RNA metabolism. The more recent studies have shown that the mammalian and some fungal RNases are also bestowed with antiproliferative, antiangiogenic and/ or antitumor/ anticancer activities. Some of the members of RNase A superfamily such as RNase 6 and RNase 7 appears to be evolutionary conserved peptides with potent antimicrobial activities for upkeep of sterility in the urinary tract

Fabrication and functionalization of magnesium nanoparticle for lipase immobilization in n-propyl gallate synthesis

An extracellular lipase partially purified from Bacillus thermoamylovorans BHK67 was effectively immobilized onto modified magnetic MgFe2O4 nanoparticles (NPs). NPs were prepared by the sol-gel auto-combustion method and characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Ultra-Violet–Visible Spectroscopy (UV–vis) and atomic force microscopy (AFM). Protein loading reached a saturated amount of about 0.20 mg lipase per milligram of MgFe2O4 NPs with 78.9% binding efficiency. The NPs-bound lipase also showed stability following exposure to n-propanol and iso-propanol or FeCl2 and MgCl2 metal ions at (1 mM) at 55 °C. NPs-bound lipase also retained 50% of its original hydrolytic activity even after 8th cycle, as well as after 12 h of incubation at 55 °C. NPs-bound lipase in an esterification reaction of n-propanol and gallic acid (25 mM) performed for 12 h at 55 °C produced n-propyl gallate with a conversion rate of 82%. Synthesized n-propyl gallate possessed strong antioxidant activity, which was confirmed by DPPH assay, and in addition has anticancerous activity which was tested on a human L132 cell line

Production and Profitability of Hybrid Rice Is Influenced by Different Nutrient Management Practices

The government of Nepal has recommended blanket fertilizer application for rice cultivation, which results in lower nutrient use efficiency (NUE) particularly under rainfed conditions. With the aim of finding an appropriate nutrient management practices concerning rice production and profitability, a field experiment was conducted during rainy season of 2017 and 2018 at Kavrepalanchowk and Dang district of Nepal. Altogether, five treatments comprising various nutrient management practices viz. Nutrient Expert Model (NE), use of Leaf Color Chart (LCC), Government Recommended Fertilizer Dose (GON), Farm Yard Manure (FYM), and Farmers’ Field Practice (FFP), were laid out in RCBD with four replications in farmers’ fields. The analysis of variance showed significant difference between treatments for test weight and grain yield in Kavrepalanchowk whereas all traits except number of effective tillers were significant in Dang. The significantly higher grain yield and harvest index were obtained in NE, followed by LCC; and the overall straw yield was highest in LCC, followed by NE in both the locations. Also, yield gap analysis suggested the NE had 44.44% and 23.97% increase in yield as compared to FPP in Kavrepalanchowk and Dang, respectively. The combined analysis with Best Linear Unbiased Estimator revealed the interaction of nutrient management and location significantly effects the straw yield and harvest index across both the locations. The estimated mean straw yield and harvest index were 10.93 t/ha and 34.98%, respectively. Both correlation study and biplot of principal component analysis signaled grain yield had positive correlation with all other traits. Furthermore, the net revenue was maximum for NE, followed by LCC in both the locations. The benefit: cost ratio was highest for NE which was 1.55 in Kavrepalanchowk and 2.61 in Dang. On the basis of these findings, NE and LCC can be effectively used as nutrient management practice by the farmers to obtain maximum production and profitability in Rice

Production and Profitability of Hybrid Rice Is Influenced by Different Nutrient Management Practices

The government of Nepal has recommended blanket fertilizer application for rice cultivation, which results in lower nutrient use efficiency (NUE) particularly under rainfed conditions. With the aim of finding an appropriate nutrient management practices concerning rice production and profitability, a field experiment was conducted during rainy season of 2017 and 2018 at Kavrepalanchowk and Dang district of Nepal. Altogether, five treatments comprising various nutrient management practices viz. Nutrient Expert Model (NE), use of Leaf Color Chart (LCC), Government Recommended Fertilizer Dose (GON), Farm Yard Manure (FYM), and Farmers’ Field Practice (FFP), were laid out in RCBD with four replications in farmers’ fields. The analysis of variance showed significant difference between treatments for test weight and grain yield in Kavrepalanchowk whereas all traits except number of effective tillers were significant in Dang. The significantly higher grain yield and harvest index were obtained in NE, followed by LCC; and the overall straw yield was highest in LCC, followed by NE in both the locations. Also, yield gap analysis suggested the NE had 44.44% and 23.97% increase in yield as compared to FPP in Kavrepalanchowk and Dang, respectively. The combined analysis with Best Linear Unbiased Estimator revealed the interaction of nutrient management and location significantly effects the straw yield and harvest index across both the locations. The estimated mean straw yield and harvest index were 10.93 t/ha and 34.98%, respectively. Both correlation study and biplot of principal component analysis signaled grain yield had positive correlation with all other traits. Furthermore, the net revenue was maximum for NE, followed by LCC in both the locations. The benefit: cost ratio was highest for NE which was 1.55 in Kavrepalanchowk and 2.61 in Dang. On the basis of these findings, NE and LCC can be effectively used as nutrient management practice by the farmers to obtain maximum production and profitability in Rice