| 【Objective】The study is aimed at isolating and identifying Bacillus which can produce digestive enzyme
metabolites from marine organisms and environment, and providing probiotics for the development of its microecologics.
【Method】Samples were collected from the coastal waters of Leizhou Peninsula, and the isolated strains were obtained
by high temperature treatment, enrichment culture, isolation and cultivation method. The isolated strains were identified
by their colony morphology, cell structure, staining characteristics, biochemical test and 16S rRNA gene sequencing. The
determination of protease, amylase and lipase activity in the metabolites of the isolated strains was detected by Folin phenol
colorimetry, starch iodine colorimetry and olive oil emulsification method, respectively.【Result】Forty three suspected
Bacillus strains are identified from 22 samples. Eight strains of them with the strongest comprehensive activities of three
digestive enzymes are screened out, and identified through biochemical test and 16S rRNA gene sequencing as three
strains of Bacillus cereus ,three strains of Bacillus siamensis, one strain of Bacillus tequilensis, and one strain of Bacillus
xylanilyticus. Among them, Bacillus xylolylysine BC1 produces the highest lipase activity（52.13 U/mL）, Bacillus cereus
BC3 produces the highest protease activity（4.78 U/mL）and Bacillus Siamese BC6 produces the highest amylase activity （2.35 U/mL）.【Conclusion】Marine Bacillus producing digestive enzyme metabolites are screened out successfully. |
