Identification of Enterococcus sp. from midgut of silkworm based on biochemical and 16S rDNA sequencing analysis

Abstract

Enterococcus sp. was isolated from the midgut of silkworm against the germination of Nosema bombycis spores. Identification was based on the biochemical characteristics, 16S rDNA sequences analysis and species-specific probes of Enterococcus spp. The isolated strains fermented sorbitol and arabinose but did not ferment raffinose. Enterococcus sp. was clustered together with Enterococcus mundtii ATCC 43188 and 100% sequence homology was found by 16S rDNA sequences BLAST analysis and constructing the phylogenetic tree. Comparison of the sequences of the 16S rDNA species-specific probes of Enterococcus spp. with the 16S rDNA sequence of isolate revealed similar segment to the species-specific probe of E. mundtii. So, we can make conclusion the 16S rDNA segment of Enterococcus sp. can hybridise with species-specific probe of E. mundtii. Enterococcus mundtii was detected for the first time in the intestine of silkworm.