Studies on the polysaccharide-producing bacteria, shewanella putref aciens isolated from marine sponge, theonella sp.

Abstract

Marine sponge, Theonella sp. is found in great quantity from Malaysian’s ocean. Theonella sp. are one of marine sponges that produces a significant bioactive compounds. They are stated to be potential drug lead producers having exceptional structures that are unavailable from terrestrial region. Marine bacteria associated with sponges are significance as new promising source of large amount of biologically active compounds. The aims of this study were to identify polysaccharide-producing bacteria isolated from Theonella sp., to screen selected bacterial polysaccharides for antibacterial and toxicity and to determine composition of selected bacterial polysaccharide, Shewanella putrefaciens. Subsequent to this, bacterial sampling of Theonella sp. from Bidong Island in Terengganu was conducted. A total of seven types of bacteria were identified as Shewanella putrefaciens, Brevundimonas diminuta, Alcaligenes faecalis, Burkholderia cepacia, Fusobacterium varium, Capnocytophaga sp. and Vibrio damsela. S. putrefaciens, Capnocytophaga sp., B. diminuta and B. cepacia were determined as polysaccharide-producing bacteria. Disc diffusion test and brine shrimp lethality test have shown that only S. putrefaciens crude polysaccharide gave antibacterial activity and also toxic towards brine shrimp, Artemia salina. Composition analysis determined S. putrefaciens crude and acidic polysaccharides were hetero polysaccharide consisted of glucose, trehalose and mannose, respectively. Only crude polysaccharide contained trace elements of sulphur and uronic acid with molecular weight of 250.5 kDA. The presence of suphur and uronic acid in S. putrefaciens crude polysaccharide have been significantly ascertained to be sulfated polysaccharide. The presence of trace elements associated with polysaccharide gave positive result and potential value towards medicinal and pharmaceutical purposes.