TRACING OF BIOSURFACTANT SYNTHESIZING GENES IN BACILLUS SP., BY IN VITRO AND IN SILICO TECHNIQUES USING SRFA GENE AS MARKER

Biosurfactant production enhances the establishment of bacteria in its environment. It was confirmed among the food borne pathogens of Bacillus cereus, B. licheniformis and B. subtilis isolated from spoiled dairy products. Molecular weights of the purified DNA from these isolates were determined as > 4000 Kb. Restriction digestion of extracted genomic DNA by EcoRI and HindIII and amplification by genus specific 16S rRNA derived primer confirmed the homology among all. Production of biosurfactant by these bacteria was confirmed by drops collapse test, reduction in surface tension of culture media and emulsification properties.  Purified biosurfactants from these isolates were characterized as surfactin, lichenysin and plipastatin from B. subtilis, B. licheniformis and ­­B. cereus respectively. BLAST analysis of surfactin synthesizing gene srfA from B. subtilis showed 80% similarity with surfactant coding gene of lichenysin in B. licheniformis, 76% similarity with an unknown non-ribosomal peptidyl protein and 73% with bacitracin synthetase in B. cereus. So, the unknown plipastatin coding genes in B. cereus predicted as a non-ribosomal in origin and have antimicrobial properties

A Recent Update on the Impact of Nano-Selenium on Plant Growth, Metabolism, and Stress Tolerance

Selenium (Se) is a microelement that plays an important nutrient role by influencing various physiological and biochemical traits in plants. It has been shown to stimulate plant metabolism, enhancing secondary metabolites and lowering abiotic and biotic stress in plants. Globally, the enormous applications of nanotechnology in the food and agricultural sectors have vastly expanded. Nanoselenium is more active than bulk materials, and various routes of synthesis of Se nanoparticles (Se-NPs) have been reported in which green synthesis using plants is more attractive due to a reduction in ecological issues and an increase in biological activities. The Se-NP-based biofortification is more significant because it increases plant stress tolerance and positively impacts their metabolism. Se-NPs can enhance plant resistance to various oxidative stresses, promote growth, enhance soil nutrient status, enhance plant antioxidant levels, and participate in the transpiration process. Additionally, they use a readily available, biodegradable reducing agent and are ecologically friendly. This review concentrates on notable information on the different modes of Se-NPs’ synthesis and characterization, their applications in plant growth, yield, and stress tolerance, and their influence on the metabolic process