Isolation and molecular identification of entomopathogens microorganisms infecting mulberry silkworm, Bombyx mori L. in Egypt

Abstract

Sericulture, silkworm rearing, is an economically important agro-industry, particularly in developing countries. However, silkworm production is frequently hampered by various diseases caused by entomopathogens, leading to significant economic losses. Accurate and rapid identification of these pathogens are crucial for effective disease management strategies. Current study delves into the application of various molecular techniques, including PCR-based methods, sequencing, and phylogenetic tree using MEGA 11 program, to identify bacteria and fungi isolated from infected mulberry silkworm larvae. Results showed that two fungi and one bacterium species were isolated, identified and submitted to GenBank to have an accession number. Sequence alignments of the fungal isolates SHK-F1 and SHK-F2 showed identities 100 % with isolate Aspergillus flavus AJ38 and Penicillium oxalicum, respectively. However, the 16S rDNA gene amplicon obtained from bacterial isolate strain (SKH-B1) showed identity 99 %to the partial sequence of the gene in Bacillus velezensis. This is the first record of Penicillium oxalicum and Bacillus velezensis as entomompathogenic form B. mori L.