ABSTRACT
26 heterotrophic bacteria strains were isolated from grown abalone digestion guts and their fanning waters in Jiansheng Abalone Farm in Shangwei, Guangdong province. Analyses of extra-cellular pathogenic factors were performed and API 20 E strips were employed to identify all the isolates. Results indicated that isolates from digestion guts displayed greater ability of producing protease , amylase, gelatinase and/or hemolysis than those from farming waters, while their ability of producing lipase and phospholipase were lower than the later. Regardless of their source of origins, there were some isolates which had great abilities of producing extra-cellular products and most of them were Sphingomonas paucimobilis. Therefore, Sphingomonas paucimobilis should be considered as an opportunistic pathogen in the abalone fanning environments, while the digestion guts and fanning waters should be both regarded as the sources of harboring potential pathogens. In addition, apart from predominant strains, the roles of extra-cellular products of the bacteria community as a whole should be taken into consideration when dealing with fish diseases.