High prevalence of Bacillus subtilis-infecting bacteriophages in soybean-based fermented foods and its detrimental effects on the process and quality of Cheonggukjang.

Food Microbiol

Department of Food Science and Technology, College of Agriculture and Life Sciences, Chonbuk National University, Jeonju, Jeollabuk-do 561-756, South Korea. Electronic address:

Published: December 2018

While the detrimental effect of bacteriophages on lactic acid bacterial fermentation is well documented, the importance of Bacillus subtilis phages in soybean-based fermented foods is not. In this study, we show for the first time that 100% of Korean soybean-based fermented foods (Doenjang, Gochujang, and Cheonggukjang) and 70% of raw materials (Meju and rice straw) were contaminated with B. subtilis-infecting phages (as high as 3.7 × 10 PFU g). Among 15 isolated B. subtilis-infecting phages, BSP18 was selected for further studies due to its specificity to and relatively broad host infectivity (34%) against B. subtilis. This Myoviridae family phage, BSP18 could infect all of the tested wild-type and commercially-used strains for soybean-based fermented food preparation. Furthermore, artificial contamination of as low as 10 PFU g of BSP18 significantly inhibited B. subtilis growth during Cheonggukjang fermentation. Moreover, phage-treated samples contained considerably more degraded γ-PGA which could negatively affect the functional property of Cheonggukjang. We also present the data, strongly suggesting BSP18-encoded, not bacterial, γ-PGA hydrolase was responsible for γ-PGA degradation. In conclusion, B. subtilis phages are widespread in Korean soybean-based fermented foods and it should be of great concern as phages may hamper the bacterial growth during fermentation and yield poor quality products.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fm.2018.05.007DOI Listing

Publication Analysis

Top Keywords

soybean-based fermented
20
fermented foods
16
subtilis phages
8
korean soybean-based
8
subtilis-infecting phages
8
soybean-based
5
fermented
5
phages
5
high prevalence
4
prevalence bacillus
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!