title: Isolation and characterization of bacteria from the gut of Bombyx mori that degrade cellulose, xylan, pectin and starch and their impact on digestion.
abstract: Bombyx mori L. (Lepidoptera: Bombycidae) have been domesticated and widely used for silk production. It feeds on mulberry leaves. Mulberry leaves are mainly composed of pectin, xylan, cellulose and starch. Some of the digestive enzymes that degrade these carbohydrates might be produced by gut bacteria. Eleven isolates were obtained from the digestive tract of B. mori, including the Gram positive Bacillus circulans and Gram negative Proteus vulgaris, Klebsiella pneumoniae, Escherichia coli, Citrobacter freundii, Serratia liquefaciens, Enterobacter sp., Pseudomonas fluorescens, P. aeruginosa, Aeromonas sp., and Erwinia sp.. Three of these isolates, P. vulgaris, K. pneumoniae, C. freundii, were cellulolytic and xylanolytic, P. fluorescens and Erwinia sp., were pectinolytic and K. pneumoniae degraded starch. Aeromonas sp. was able to utilize the CMcellulose and xylan. S. liquefaciens was able to utilize three polysaccharides including CMcellulose, xylan and pectin. B. circulans was able to utilize all four polysaccharides with different efficacy. The gut of B. mori has an alkaline pH and all of the isolated bacterial strains were found to grow and degrade polysaccharides at alkaline pH. The number of cellulolytic bacteria increases with each instar.
authors.affiliation: Research Centre for Biological Sciences, Naesam Trust, Ellis Nagar, Madurai, 625016, India. alwinprem@gmail.com
authors.forename: A Alwin Prem
authors.initials: AA
authors.lastname: Anand
authors.forename: S John
authors.initials: SJ
authors.lastname: Vennison
authors.forename: S Gowri
authors.initials: SG
authors.lastname: Sankar
authors.forename: D Immanual Gilwax
authors.initials: DI
authors.lastname: Prabhu
authors.forename: P Thirumalai
authors.initials: PT
authors.lastname: Vasan
authors.forename: T
authors.initials: T
authors.lastname: Raghuraman
authors.forename: C Jerome
authors.initials: CJ
authors.lastname: Geoffrey
authors.forename: S Ezhil
authors.initials: SE
authors.lastname: Vendan
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D012831:Bombyx / Q000382:microbiology*; D002482:Cellulose / Q000378:metabolism; D004032:Diet; D004063:Digestion; D004798:Enzymes / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000382:microbiology; D010368:Pectins / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D013559:Symbiosis; D014815:Vitamins / Q000378:metabolism; D014990:Xylans / Q000378:metabolism
chemical_list: D004798:Enzymes; D011134:Polysaccharides; D014815:Vitamins; D014990:Xylans; D010368:Pectins; D002482:Cellulose; D013213:Starch