Screening and characterization of LAB-produced bacteriocin-like substances from the intestine of grey mullet (Mugil cephalus L.) as potential biocontrol agents in aquaculture.
OBJECTIVE
To isolate and characterize bacteriocin-like inhibitory substance (BLIS)-producing lactic acid bacteria from the intestine of grey mullet.


RESULTS
Inhibitory activity against at least one or more indicator strains was observed in one Enterococcus thailandicus, one Enterococcus faecium and two Lactococcus garvieae strains. Enterococcus faecium B3-8 and Ent. thailandicus B3-22 showed the greatest inhibitory activities against Listeria monocytogenes ATCC 19111 and were therefore further characterized. The results suggested that the inhibitory substances from the two strains showed similar characteristics with respect to sensitivity to heat and proteolytic enzymes. BLIS from Ent. thailandicus B3-22 was characterized by a broader inhibitory spectrum than that from Ent. faecium B3-8. SDS-PAGE revealed that the molecular size of partially purified BLISs from Ent. faecium B3-8 and Ent. thailandicus B3-22 was c. 5 and 3 kDa, respectively. The molecular mass of purified bacteriocin from Ent. thailandicus B3-22 was further determined to be 6319 Da by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The results indicated that BLIS from Ent. thailandicus B3-22 can effectively inhibit the growth of all tested L. garvieae strains.


CONCLUSIONS
The findings obtained in this study suggest the potential use of Ent. thailandicus B3-22 as a biocontrol agent against pathogenic L. garvieae in the aquaculture.


CONCLUSIONS
This is the first report describing the characteristics of BLIS from Ent. thailandicus that showed potential for use as a biocontrol agent in the aquaculture.
Department of Biotechnology, Ming Chuan University, Gui-Shan, Taiwan.
Y-H
YH
Lin
Y-S
YS
Chen
H-C
HC
Wu
S-F
SF
Pan
B
B
Yu
C-M
CM
Chiang
C-M
CM
Chiu
F
F
Yanagida
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017756:Aquaculture; D001430:Bacteriocins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D061046:Biological Control Agents; D016983:Enterococcus / Q000302:isolation & purification / Q000378:metabolism*; D016984:Enterococcus faecium / Q000302:isolation & purification / Q000378:metabolism*; D006358:Hot Temperature; D007422:Intestines / Q000382:microbiology; D008089:Listeria monocytogenes / Q000187:drug effects; D008970:Molecular Weight; D023701:Smegmamorpha / Q000382:microbiology*
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D061046:Biological Control Agents