Genetic diversity of bacteria inhabiting the gut of isopods (Isopoda, Crustacea)

Abstract

Rod-like bacteria attached to cuticular spines in the hindgut of the terrestrial isopod Porcelio scaber were observed by scanning electron microscopy. The attached bacteria could represent the autochthonous microbial flora, which has not been reported yet. Because the observed bacteria can not be cultured, molecular approach to identification was applied. Total DNA was isolated from well rinsed hindguts of five healthy and mature isopods and subsequently bacterial 16S rDNA genes were amplified. The amplified genes were incorporated into plasmid vector and transformed into E.coli competent cells. Plazmid DNAs from 37 transformants were subjected to restriction analysis with Dde I and Taq I endonucleases. An RFLP phenogram was constructed using the UPGMA method. 16S rRNA genes can be clustered into at least three distinctive groups which could indicate that several bacterial species are attached to the cuticular spines in the hindgut of P. scaber.