Identification and partial purification of thuricin 4AJ1 produced by Bacillus thuringiensis

• Published in: Archives of microbiology 2020-05, Vol.202 (4), p.755-763
• Main Authors: Su, Xiaoyu, Li, Lifen, Pan, Jieru, Fan, Xiao, Ma, Shenglong, Guo, Yachong, Idris, Aisha Lawan, Zhang, Lingling, Pan, Xiaohong, Gelbič, Ivan, Huang, Tianpei, Guan, Xiong
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial activity; Antibiotics; Bacillus cereus - drug effects; Bacillus thuringiensis; Bacillus thuringiensis - chemistry; Bacillus thuringiensis - metabolism; Bacteriocins; Bacteriocins - chemistry; Bacteriocins - isolation & purification; Bacteriocins - pharmacology; Biochemistry; Biomedical and Life Sciences; Biotechnology; Catalase; Cell Biology; Chymotrypsin; Ecology; Electrophoresis, Polyacrylamide Gel; Endopeptidase K; Food Microbiology; Gel electrophoresis; Life Sciences; Lipase; Microbial Ecology; Microbiology; Molecular Weight; Original Paper; Proteinase; Sodium lauryl sulfate; Stationary phase; Websites; α-Amylase
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s00203-019-01782-1

Thuricin 4AJ1, produced by Bacillus thuringiensis strain 4AJ1, showed inhibition activity against Bacillus cereus 0938 and ATCC 10987. It began to appear in the stationary phase and reached its maximum activity level of 209.958 U at 18 h against B. cereus 0938 and 285.689 U at 24 h against B. cereus ATCC 10987. Tricine–SDS-PAGE results showed that the partly purified thuricin 4AJ1 was about 6.5 kDa. The molecular weights of the known B. thuringiensis bacteriocins and the ones obtained by the two mainstream websites for predicting bacteriocins were inconsistent with the size of the thuricin 4AJ1, indicating that the bacteriocin obtained in this study may have a novel structure. Based on the biochemical properties, the thuricin 4AJ1 activities increased after treatment with proteinase K and lipase II, and were not affected by a-amylase, catalase, α-chymotrypsin VII and α-chymotrypsin II. It was heat tolerant, being active up to 90º C. In the pH 3–10 range, it maintained most of its activity. Finally, the sensitivity of the strain 4AJ1 to commonly used antibiotics was tested. In view of its stability and antibacterial activity, thuricin 4AJ1 may be applied as a food biopreservative. Graphic abstract