Properties of Bac W42, a bacteriocin produced by Bacillus subtilis W42 isolated from Cheonggukjang.
Ten Bacillus strains with antimicrobial activities were isolated from Cheonggukjang produced at different parts in Korea. They all inhibited Listeria monocytogenes ATCC 19111 and nine inhibited Bacillus cereus ATCC 14579. Four isolates (W42, H27, SKE 12, and K21) showing strong inhibiting activities were identified as B. subtilis. B. subtilis W42 was the most inhibiting strain. The antimicrobial activity of culture supernatant from B. subtilis W42 was destroyed completely by proteinase K treatment, indicating that a bacteriocin was the responsible agent. The bacteriocin, Bac W42, was most stable at pH 7 and stable between pH 3-6 and 8-9. Bac W42 was stable up to 80°C. BHI (brain heart infusion) and TSB (tryptic soy broth) were the best media for the activity (320 AU/ml) followed by LB (160 AU/ml). Bac W42 was partially purified by column chromatographies. The specific activity was increased from 1,151.2 AU/ml to 9,043.5 AU/ml and the final yield was 26.3%. Bac W42 was 5.4 kDa in size as determined by SDS-PAGE. Bac W42 showed bactericidal activity against L. monocytogenes ATCC 19111.
Division of Applied Life Science (BK21), Graduate School, Gyeongsang National University, Jinju 660-701, Korea.
Salum
S
Kindoli
Hwang A
HA
Lee
Jeong Hwan
JH
Kim
D001412:Bacillus subtilis / Q000302:isolation & purification / Q000378:metabolism*; D001430:Bacteriocins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019286:Endopeptidase K / Q000378:metabolism; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007723:Korea; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development; D008969:Molecular Sequence Data; D008970:Molecular Weight; D055550:Protein Stability; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013696:Temperature
D001430:Bacteriocins; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D019286:Endopeptidase K