Molecular Characterization and Nematicidal Activity of Indigenous Bacillus thuringiensis isolate T210

Author: Berryish Metha C., Rajadurai G., Raghu R., Jayakanthan M., Kokiladevi E., Murugan M., and Balasubramani V.

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Abstract

Bacillus thuringiensis (Bt), renowned for its insecticidal properties, has emerged as a promising solution in pest management, addressing concerns over environmental impact, regulatory restrictions, and insect resistance to synthetic insecticides. This study focuses on the indigenous Bt isolate T210, which exhibits nematicidal activity against the model nematode Caenorhabditis elegans. The investigation begins with a comprehensive characterization of native Bt isolate T210, including colony morphology, protein profiling and toxicity analysis. T210 exhibited creamy white colour colonies with an irregular shape, fried egg-like surface pattern, flat elevation, and undulated margins. Microscopic examination reveals presence of bipyramidal, cuboidal, and spherical-shaped crystals in T210. Protein profiling through SDS-PAGE analysis highlights diverse protein bands with molecular weights around 135 kDa, 115 kDa, 50 kDa, 46 kDa, and 42 kDa. These findings suggest the presence of various toxic proteins in the Bt isolate T210, potentially contributing to its nematicidal activity. PCR screening for major insecticidal genes, including various cry and vip genes, yields negative results, indicating the absence of insecticidal genes screened in T210. This suggests the presence of novel genes with unique properties. The nematicidal activity of T210 is evaluated through in vitro bioassays, revealing 100 % larval mortality in C. elegans at 500 μg/ml of crude protein. Probit analysis of crude protein from T210, against C. elegans revealed the LC50 value of 323.79 μg/ml.

Keywords

Bt isolate, Caenorhabditis elegans, Molecular characterization, Nematode, T210

Conclusion

The presence of diversified proteins and their corresponding genes in T210 opens the door to further research into their potential for protecting agricultural crops against crop pests. In vitro bioassay study confirmed the toxicity potential of the Bt isolate T210 against nematodes, however discovering the new nematicidal toxic genes present in T210 is a compelling avenue for future exploration. Comprehensive analyses, such as whole genome sequencing and toxic protein expression, could provide invaluable insights into the protection of crops and, ultimately, benefit agriculture on a large scale.

References

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How to cite this article

Berryish Metha C., Rajadurai G., Raghu R., Jayakanthan M., Kokiladevi E., Murugan M., and Balasubramani V. (2023). Molecular Characterization and Nematicidal Activity of Indigenous Bacillus thuringiensis isolate T210. Biological Forum – An International Journal, 15(9): 274-281.