A Bottom-Up Approach To Develop a Synthetic Microbial Community Model: Application for Efficient Reduced-Salt Broad Bean Paste Fermentation

Abstract

Humans have used high salinity for the production of bean-based fermented foods over thousands of years. Although high salinity can inhibit the growth of harmful microbes and select functional microbiota in an open environment, it also affects fermentation efficiency of bean-based fermented foods and has a negative impact on people’s health. Therefore, it is imperative to develop novel defined starter cultures for reduced-salt fermentation in a sterile environment. Here, we explored the microbial assembly and function in the fermentation of traditional Chinese broad bean paste with 12% salinity. The results revealed that the salinity and microbial interactions together drove the dynamic of community and pointed out that five dominant genera (Staphylococcus, Bacillus, Weissella, Aspergillus, and Zygosaccharomyces) may play different key roles in different fermentation stages. Then, core species were isolated from broad bean paste, and their salinity tolerance, interactions, and metabolic characteristics were evaluated. The results provided an opportunity to validate in situ predictions through in vitro dissection of microbial assembly and function. Last, we reconstructed the synthetic microbial community with five strains (Aspergillus oryzae, Bacillus subtilis, Staphylococcus gallinarum, Weissella confusa, and Zygosaccharomyces rouxii) under different salinities and realized efficient fermentation of broad bean paste for 6 weeks in a sterile environment with 6% salinity. In general, this work provided a bottom-up approach for the development of a simplified microbial community model with desired functions to improve the fermentation efficiency of bean-based fermented foods by deconstructing and reconstructing the microbial structure and function. IMPORTANCE Humans have mastered high-salinity fermentation techniques for bean-based fermented product preparation over thousands of years. High salinity was used to select the functional microbiota and conducted food fermentation production with unique flavor. Although a high-salinity environment is beneficial for suppressing harmful microbes in the open fermentation environment, the fermentation efficiency of functional microbes is partially inhibited. Therefore, application of defined starter cultures for reduced-salt fermentation in a sterile environment is an alternative approach to improve the fermentation efficiency of bean-based fermented foods and guide the transformation of traditional industry. However, the assembly and function of self-organized microbiota in an open fermentation environment are still unclear. This study provides a comprehensive understanding of microbial function and the mechanism of community succession in a high-salinity environment during the fermentation of broad bean paste so as to reconstruct the microbial community and realize efficient fermentation of broad bean paste in a sterile environment.

The ultra-structural, metabolomic and metagenomic characterisation of the sudanese smokeless tobacco ‘Toombak’

“…Atopostipes suicloacalis, Atopococcus tabaci, Oceanobacillus chironomi, Staphylococcus gallinarum, Enteractinococcus lamae, Facklamia tabacinasalis as well as Alloiococcus genera also predominantly defined the final composition of Toombak. Furthermore, Staphylococcus cohnii was found to be highly abundant amongst Toombak samples analysed by Smyth et al [ 85 ], while Staphylococcus gallinarum was the most abundant species in our samples; known to be highly salt tolerant [ 86 ].…”

Environmental Filtering by pH and Salinity Jointly Drives Prokaryotic Community Assembly in Coastal Wetland Sediments

“…This is reasonable because coastal sediment microorganisms generally adapt to the saline environments, thus promoting the microbial α-diversity and activity (Morrissey et al, 2014). Low salinity sediments may provide appropriate mineral elements for microbial growth and promote their biodiversity (Jia et al, 2020). Furthermore, the increased relative abundances of keystone OTUs could contribute to the α-diversity of bacterial and archaeal communities.…”

Composition, source, and influencing factors of white spots formation in soybean paste

“…After that, the concentrations of tyrosine and phenylalanine were slightly decreased until the end of fermentation. In our previous researches, we found that during soybean paste fermentation, A. oryzae 3.042 dominated the early and middle fermentation process, while Bacillus , Staphylococcus , Weissella , and Zygosaccharomyces genera were found to be responsible for the late fermentation (Jia et al., 2020). Therefore, the top 12 bacteria strains ( L. acidipiscis , P. acidilacticis , T. halophilus , E. faecium , S. piscifermentans , S. carnosus X1, W. confusa , S. piscifermentans , P. lolii , P. pentosaceus , S. carnosus X2, and W. paramesenteroides ) and one fungi strain ( A. oryzae 3.042) were selected and their effect on tyrosine accumulation was tested.…”

“…As shown in Figure 4, the tyrosine concentration increased in the first 60 hr and significantly decreased afterward. In soybean paste fermentation, A. oryzae 3.042 was the dominant microbe in the first 20 days and it gradually disappeared in the following fermentation period (Jia et al., 2020). Since the other important microbes in soybean paste fermentation had few effect on tyrosine accumulation, we proposed that the majority of tyrosine in soybean paste were produced by the degradation of proteins through the proteolytic enzymes secreted by A. oryzae 3.042 (Zhou et al., 2019).…”