Diversity Analysis Of Culturable Microorganisms And Their Macrogenes In Rock Scallop Viscera And Intestine

In this paper,the bacteria in the visceral mass and digestive tract of Canadian rock scallop and the first generation of congener rock scallop from artificial breeding in China were isolated and cultured by the traditional method,The 16SrRNA gene of the isolated bacteria was examined and taxonomic status was identified.Total DNA was extracted from the above samples,using IonS5^TMXL high throughput sequencing platform to analyze bacterial community diversity.The results showed that 83 strains of culturable strains were obtained by the traditional method,and 31 strains of representative strains were sequenced and compared,they were Psychrobacter,Planococcus,Vibrio,Pseudomonas,Pseudoalteromonas,Bacillus,Kocuria and Paracoccus.The high throughput sequencing results showed that the effective sequence community structure of the 4 samples could be divided into 9 phyla,they were Proteobacteria,Deinococcus-Thermus,Bacteroidetes,Firmicutes,Cyanobacteria,Tenericutes,Actinobacteria,Planctomycetes,Vercomicrobia.The dominant taxa in the intestinal samples of Canadian rock scallops were Proteobacteria,accounting for 80%,and the subdominant taxa were Bacteroidetes,accounting for 15%.The dominant taxa in the visceral mass samples of Canadian rock scallops were Proteobacteria,accounting for 52%,and the subdominant taxa were Bacteroidetes,accounting for18%.Among the intestinal samples of the subgeneration rock scallops bred in domestic,the dominant phylum was Proteobacteria,accounting for 61%,while the subdominant phylum was Bacteroides,accounting for 26%.Among the visceral mass samples of the first generation rock scallops,the dominant phylum was Proteobacteria,accounting for 73%,and the subdominant phylum was Bacterioids,accounting for17%.The intestinal and visceral microorganisms of rock scallops were rich in diversity,but there were some differences between Canadian rock scallop and subgeneration rock scallops bred in domestic.The results of extracellular enzyme activities of two selected strains showed that the highest activity of protease was 0.32U/mL,the highest activity of amylase was0.44U/mL,the highest activity of lipase was 0.03U/mL,the highest activity of protease was 0.55U/mL,the highest activity of amylase was 0.43U/mL,and the highest activity of lipase was 0.10U/mL in crude enzyme solution of strain YN-1-1-1.Prime enzyme.The changes of crude enzyme activity of the two strains were basically the same with time,and both of them had the trend of increasing first and then decreasing.However,the enzyme activities of different strains varied greatly in the same period.According to the results of extracellular enzyme activity,the two strains of bacteria can promote food digestion in scallop.Feeding the strain as a bait additive has potential application significance for improving the survival rate and growth rate of scallop seedlings in the process of culture.