九孔鲍肠道及其养殖水体中异养细菌产酶能力的分析

2002年5月从汕尾健生鲍鱼场养殖水体和成鲍肠道中分离筛选到26株异养细菌,其中11株来自成鲍肠道,15株来自养殖水体。对它们产胞外酶的能力进行了比较分析。结果表明肠道异养细菌中有72.7%能分泌蛋白酶、淀粉酶或明胶酶,9.1%分泌脂肪酶,45.5%分泌卵磷脂酶;水体异养细菌中则有46.7%能分泌蛋白酶或脂肪酶,66.7%分泌卵磷脂酶、淀粉酶或明胶酶。比较发现,肠道中脂肪酶或卵磷脂酶生产菌的比例小于水体异养细菌的比例;而蛋白酶、淀粉酶或明胶酶生产菌的比例却高于水体中异养细菌的比例。另外,水体异养细菌分泌多种胞外酶的能力强于肠道异养细菌。由此揭示现有鲍鱼肠道菌群结构的不完善,进而为通过添加有益菌而提高鲍鱼饲料利用率提供了可能。     

Characterization of Bacterial Community Associated with Four Organs of the Yesso Scallop (Patinopecten yessoensis) by High-Throughput Sequencing

We used Illumina high-throughput sequencing of PCR-amplified V3-V4 16 S rRNA gene regions to characterize bacterial communities associated with the adductor muscles, gills, gonads and intestines of the Yesso scallop(Patinopecten yessoensis) from waters around Zhangzidao, Dalian, China. Overall, 421,276 optimized reads were classified as 25 described bacterial phyla and 308 genera. Firmicutes, Proteobacteria, Tenericutes, Bacteroidetes, Chlamydiae and Spirochaetae accounted for > 97% of the total reads in the four organs. The bacterial 16 S rDNA sequences assigned to Firmicutes and Proteobacteria were abundant in the adductor muscles, gills and gonads; while reads from Tenericutes were dominant in the intestines, followed by those from Firmicutes, Chlamydiae, Proteobacteria and Bacteroidetes. At the genus level, the dominant genera in the adductor muscles, gills and gonads appeared to be Bacillus, Enterococcus and Lactococcus, whereas Mycoplasma was dominant in the intestines. The relative abundances of Bacillus, Enterococcus, Lactococcus, Alkaliphilus, Raoultella, Paenibacillus and Oceanobacillus were significantly lower in the intestine than in the other three organs. Cluster analysis and principal coordinates analysis of the operational taxonomy units profile revealed significant differences in the bacterial community structure between the intestine and the other three organs. Taken together, these results suggest that scallops have intestine-specific bacterial communities and the adductor muscles, gills and gonads harbor similar communities. The difference in the bacterial community between organs may relate to unique habitats, surroundings, diet and their respective physiological functions.