@article {56, title = {Isolation, Characterization, and Optimization of Protease-Producing Bacterium Bacillus thuringiensis from Paddy Field Soil}, journal = {Pharmacognosy Research}, volume = {13}, year = {2021}, month = {May 2021}, pages = {89-95}, type = {Original Article}, chapter = {89}, abstract = {

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\ Bacillus.\ Results:\ 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{\textdegree}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.

}, keywords = {16S ribosomal RNA, Bacillus thuringiensis, Biochemical identification, Isolation, Optimization, Paddy soil}, doi = {10.4103/pr.pr_83_20}, author = {Poojitha B Sridhara and Chandan Dharmashekara and Chandrashekar Srinivasa and Chandan Shivamallu and Shiva Prasad Kollur and SM Gopinath and Asad Syed and Sharanagouda S Patil and Ashwini Prasad and DE Salamun} }