Isolation, Characterization, and Optimization of Protease‑Producing Bacterium Bacillus thuringiensis from Paddy Field Soil

Poojitha B Sridhara; Chandan Dharmashekara; Chandrashekar Srinivasa; Chandan Shivamallu; Shiva Prasad Kollur; SM Gopinath; Asad Syed; Sharanagouda S Patil; Ashwini Prasad; DE Salamun

Isolation, Characterization, and Optimization of Protease‑Producing Bacterium Bacillus thuringiensis from Paddy Field Soil

Articles

Abstract

Pharmacognosy Research,2021,13,2,89-95.

DOI:10.4103/pr.pr_83_20

Published:May 2021

Type:Original Article

Authors:

Author(s) affiliations:

Poojitha B Sridhara¹, Chandan Dharmashekara², Chandrashekar Srinivasa¹, Chandan Shivamallu², Shiva Prasad Kollur³, SM Gopinath¹, Asad Syed⁴, Sharanagouda S Patil⁵, Ashwini Prasad⁶, DE Salamun⁷

¹Department of Biotechnology, Davangere University, Davangere, Karnataka, INDIA

²Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, Karnataka, INDIA

³Department of Sciences, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru, Karnataka, INDIA

⁴Department of Botany, College of Science, King Saud University, Riyadh, SAUDI ARABIA

⁵ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, Yelahanka, Bengaluru, Karnataka, INDIA

⁶Department of Microbiology, Faculty of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, INDIA

⁷Department of Biotechnology, School of Sciences Block 1, Jain (Deemed-to-be University), Bengaluru, Karnataka, INDIA

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°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.