Antagonistic Mechanisms of Bacillus methylotrophicus and Bacillus subtilis: Exploring Cell Wall-Degrading Enzymes and Siderophore Production for Foliar Blight Management in Wheat | Chapter 8 | Research Perspectives of Microbiology and Biotechnology Vol. 9

Bipolaris sorokiniana and Alternaria triticina are major cereal pathogens causing spot blotch and leaf blight disease in wheat, with yield losses of up to 85%. These play a central role in wheat foliar blight pathogens of wheat so effective management is essential for sustainable production. Bacillus methylotrophicus (P10) and Bacillus subtilis (UP11) are effective biocontrol agents against foliar blight pathogens Alternaria triticina and Bipolaris sorokiniana.  Dual culture assays showed significant growth inhibition, with P10 and UP11 reducing pathogen growth by 77.56% and 67.83% for A. triticina and 73.97% and 62.16% for B. sorokiniana. These strains produce cell wall-degrading enzymes (chitinase, protease, β-1,3-glucanase) and siderophores, peaking at 96 hours in co-cultures with pathogens. Antibiosis and direct inhibition are the primary mechanisms by which these strains suppress the mycelial growth of Bipolaris sorokiniana and Alternaria triticina, emphasizing their role as sustainable biocontrol agents in managing wheat diseases. Their potential as biological control agents underscores the need for further investigation as bioactive ingredients in biopesticide formulations.

 

Author (s) Details

 

Neha Saini
Department of Microbiology, G.B. Pant University of Agriculture and Technology, Pantnagar-263145, Uttarakhand, India.

 

Vindhya Bundela
Department of Microbiology, G.B. Pant University of Agriculture and Technology, Pantnagar-263145, Uttarakhand, India.

 

Ajay Veer Singh
Department of Microbiology, G.B. Pant University of Agriculture and Technology, Pantnagar-263145, Uttarakhand, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/rpmab/v9/4076

Genes chi of Native Bacillus thuringiensis Strains from Maranhão Active against Aedes aegypti Larvae | Chapter 6 | Innovations in Biological Science Vol. 7

 Bacillus thuringiensis is visualized as a multifaceted microbial factory for the production of several biomolecules. The Cry and Cyt proteins are used in commercial products sold worldwide as the most important bioinsecticides. However, there is increasing interest in lesser-known metabolites synthesized by B. thuringiensis, including Chi (chitinases) proteins. Several studies have observed that Chi proteins increase the insecticidal activity of Cry proteins, as these proteins degrade the peritrophic membrane, which is mainly composed of a chitin structure and proteins like those of Aedes aegypti larvae, allowing greater access of Cry proteins to their respective receptors on midgut cells. This research carried out a survey of strains of B. thuringiensis that amplified to the chi gene in combination with the cry and cyt genes and were pathogenic to Ae. aegypti larvae. The genomic DNA of 322 B. thuringiensis from different regions of the Maranhão, isolated from soil and water samples, were screened by PCR with primer pairs specific for the endogenous chitinase gene and 28 B. thuringiensis isolates were amplified, 14 of which were isolated from soil (published data) and 14 from water. Seven isolates killed 100% of the larvae within 24 hours and ten amplified for all the dipteran-specific cry and cyt genes. Ten isolates may be potential candidates to expand the alternative means in which these bacteria can be produced industrially as a biopesticide for the control of Ae. aegypti due to its high pathogenicity rate and great variability of the cry and cyt genes. However, more studies are needed for specific biotechnological applications and to potentially help in vector control, including determining the levels of chitinase synthesis in qualitative and quantitative assays to select B. thuringiensis isolates with a high level of protein production that could be a useful component of B. thuringiensis based biopesticides.

 

Author (s) Details

 Dr. Maria Cleoneide da Silva
Entomopathogenic Bacteria and Molecular Markers Laboratory, Maranhão State University (UEMA), Campus Caxias, Caxias, MA, Brazil.

 Jeverson Renato Moraes Brito
Entomopathogenic Bacteria and Molecular Markers Laboratory, Maranhão State University (UEMA), Campus Caxias, Caxias, MA, Brazil.

 Emanuelle Cristine Pereira de Sousa
Entomopathogenic Bacteria and Molecular Markers Laboratory, Maranhão State University (UEMA), Campus Caxias, Caxias, MA, Brazil.

 Dalton Kaynnan de Prado Costa
Complex Genetics and Molecular Biology Laboratory, Maranhão State University (UEMA), Campus Caxias, Caxias, MA, Brazil.

 Alessandra Maria Silva Vidigal
Complex Genetics and Molecular Biology Laboratory, Maranhão State University (UEMA), Campus Caxias, Caxias, MA, Brazil.

 

Please see the link :- https://doi.org/10.9734/bpi/ibs/v7/1061