Abstract
Bacteriocinogenic Lactobacillus fermentum BZ532 with novel bacteriocin LF-BZ532 was originally isolated from Chinese cereal fermented drink, showing an antimicrobial characteristic during fermentation. This study aimed to explore the in situ antimicrobial activities of L. fermentum BZ532 and co-culturing investigation against key food pathogens, i.e., Staphylococcus aureus and Escherichia coli K-12, was conducted during fresh bozai production. The growth of spoilage bacteria was suppressed and bacterial count was reduced to a significantly low level during 48 h of co-cultures. In situ production of antimicrobial compounds expressed positive activity against S. aureus and E. coli K-12, but negative acitivity against Salmonella sp. D104. The total viable count of bozai BZ-Lf (bozai fermented with BZ532 strain) had a comparatively lower viable count than bozai BZ-C (bozai as an experimental control without BZ532) during storage of 7 days. Titratable acidity of bozai treatments (BZ-C, BZ-Lf) was increased, while pH declined accordingly during storage of 7 days. The organoleptic quality of bozai BZ-C had low sensorial scores as compared with BZ-Lf during storage. In comparison with naturally fermented bozai (BZ-C), L. fermentum BZ532 (BZ-Lf) could significantly reduce the microbial spoilage and extend the shelf-life based on microbiological examination. Conclusively, L. fermentum BZ532 can be used as a bio-protective culture for improving the safety of bozai.
Highlights
Microbes compete for the nutrients and limited space existing in natural ecological niches
This study aimed to investigate the effect of bacteriocinogenic Lactobacillus fermentum BZ532 strain (L. fermentum BZ532) on freshly prepared bozai, with regards to co-culturing of BZ532 strain against food spoilage microorganisms, i.e., E. coli, S. aureus, in situ bacteriocin production evaluation by agar well diffusion assay against key food pathogens, and physicochemical and sensory evaluation with and without bacteriocinogenic L. fermentum BZ532
A bozai drink was developed by inoculation of L. fermentum BZ532 and compared with a control group of bozai with natural starter (Sourdough) inoculation
Summary
Microbes compete for the nutrients and limited space existing in natural ecological niches. They have developed numerous approaches to survive; production of antimicrobial compounds like bacteriocins is one of them. Bacteriocins are antimicrobial peptides/proteins synthesized ribosomally broadly dispersed in nature [1]. This peptide biodiversity is supported by numerous differences in its characterization and structures. The application of purified or semi-purified bacteriocins or bacteriocinogenic lactic acid bacteria (LAB) as protective cultures is one technological alternative to traditional preservation strategies (i.e., chemical additives). Bacteriocins are considered the most appropriate substitutes to synthetic preservatives due to their non-toxic nature to eukaryotic cells [1]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
