关键词: 珍珠龙胆石斑鱼, 枯草芽孢杆菌, 16S rDNA序列, 产酶能力, Epinephelus fuscoguttatus♀ × Epinephelus lanceolatus♂, Bacillus subtilis, 16S rDNA sequences, ectoenzyme-producing ability

Abstract: Four suspected Bacillus strains were isolated from the intestine of healthy hybrid grouper, which were named as B1, B2, B3 and B4 and studied on the bacterial morphology, biochemistry characteristic, 16S rDNA sequences and ectoenzyme-producing analysis. The results showed that four strains were consistent with Bacillus on biochemistry characteristic. Meanwhile, the 16S rDNA sequences of four strains were clustered at similarity levels (≥99%) with Bacillus. Finally, the results showed that four strains were all Bacillus. With the founded of ectoenzyme-producing experiment, four strains all had ectoenzyme-producing ability, such as cellulase, amylase and protease. And B3 strain had higher zymogenicities of cellulase, protease, and amylase than B1, B2 or B4. So this experiment finally selected B3 as a strain with potential probiotic.