03344nas a2200313 4500008004100000245012900041210007100170260001300241300001000254490000700264520234400271653002202615653002702637653003102664653001402695653001702709653001502726100002602741700002702767700002902794700002402823700002602847700001702873700001502890700002702905700002002932700001602952856006202968 2021 eng d00aIsolation, Characterization, and Optimization of Protease‑Producing Bacterium Bacillus thuringiensis from Paddy Field Soil0 aIsolation Characterization and Optimization of Protease‑Producin cMay 2021 a89-950 v133 a

Background: The ubiquitous proteases that are commonly found in all living organisms play an important role in cell growth and cell differentiation. The bacterium Bacillus thuringiensis (Bt) produces delta-endotoxins that exhibit toxic properties against various insecticides and has demonstrated its potency and safety as a biopesticide agent for decades. The Bt protein includes vegetative, insecticidal, and crystal proteins that exhibit highly toxicants against immature insects (larvae). Objectives: The aim of this research was to use Bt as an alternative to chemical insecticides, and the source of Bt genes aids in the development of a resistant transgenic plant that improves not only productivity but also shift life. Materials and Methods: In the present study, bacterium Bt was isolated from various paddy files around the Hunsur region, Karnataka. The isolated bacteria show a potent protease activity on skim agar plates. Morphology, colony assay, and biochemical characterization were performed for the characteristic properties of bacteria. Further, 16S ribosomal RNA partial sequencing was carried out to identify the specific species of BacillusResults: Among nine samples from different paddy soils, three Bacillus isolates SAL-P1, SAL-P2, and SAL-P3 are the major dominant colonies which were streaked onto the fresh skim milk agar plates, out of which SAL-Pl shows an abundant growth and production of an enzyme at pH 7.0, 37°C, and 48 h, respectively. The study also shows the optimum condition of temperature, carbon, nitrogen source, pH for growth, as well as for biomass production. Conclusion: The results of this study confirm the significance of continuous exploration of new Bt strains from different ecological regions that could be more useful for Bt-based bioformulations and the generation of transgenic plants. Furthermore, the growth and biomass production of Btg (isolated from paddy soil) and Bti (reference strain) were found to be identical.

10a16S ribosomal RNA10aBacillus thuringiensis10aBiochemical identification10aIsolation10aOptimization10aPaddy soil1 aSridhara, Poojitha, B1 aDharmashekara, Chandan1 aSrinivasa, Chandrashekar1 aShivamallu, Chandan1 aKollur, Shiva, Prasad1 aGopinath, SM1 aSyed, Asad1 aPatil, Sharanagouda, S1 aPrasad, Ashwini1 aSalamun, DE uhttps://www.phcogres.com/article/2021/13/2/104103prpr8320