Robust Domination of Lactobacillus sakei in Microbiota During Traditional Japanese Sake Starter Yamahai-Moto Fermentation and the Accompanying Changes in Metabolites

Abstract

The successful production of sake (Japanese rice wine) is brought about by drastic changes in microbial flora and chemical components during fermentation. In the traditional manufacturing process of sake starter (yamahai-moto), spontaneous growth of lactic acid bacteria suppresses inappropriate microorganisms and prepares the optimum environment for the alcohol fermentative yeast. In this study, we analyzed the changes in bacterial flora and chemical components of yamahai-moto. High-throughput next-generation sequencing (NGS) of the 16S ribosomal RNA gene V4 region revealed that various kinds of bacteria, including nitrate-reducing bacteria, existed in the early fermentation stage; however, Lactobacillus sakei then increased drastically to become dominant in the middle stage. Interestingly, this result was different from that obtained in the previous year at the same manufacturer; the early-stage major bacterium was Lactobacillus acidipiscis. Lactic acid, glucose, isomaltose, and total free amino acids increased throughout the fermentation process, which was attributable to the metabolism of L. sakei and the koji mold. It is noteworthy that significant ornithine accumulation and arginine consumption were observed from the middle to late stages. Thirty-eight percent of the L. sakei isolates from yamahai-moto exhibited significant ornithine production, indicating that the arginine deiminase pathway of L. sakei was working to survive the extremely low pH environment of the moto after the middle stage. This is the first report that includes concurrent analyses of the NGS-based bacterial flora and chemical components of yamahai-moto, providing further knowledge to help understand and improve the process of sake brewing.

Major Metabolites and Microbial Community of Fermented Black Glutinous Rice Wine With Different Starters

“…As an alternative approach, the continuous development of high-throughput sequencing (HTS) technology now enables more in-depth and precise evaluations of complex microflora with a reasonably low cost and in a relatively short period (Delgado et al, 2014;Lee et al, 2016) and has thus been widely applied for comprehensive analyses of microorganisms in various fermented foods, such as Shaoxing rice wine (Nie et al, 2015), Fagopyrum tataricum (buckwheat) wine (Ren et al, 2019), and Sake (Atsushi et al, 2018). High-throughput sequencing-based analysis of bacterial 16S rRNA genes and fungal ITS genes showed correlations between the final rice wine quality and the microbial composition of the starter.…”

Co-fermentation Involving Saccharomyces cerevisiae and Lactobacillus Species Tolerant to Brewing-Related Stress Factors for Controlled and Rapid Production of Sour Beer

“…Lactobacilli are frequently associated with food and beverages produced through mixed fermentations where both bacteria and yeast are involved. Examples of such products include wine (Mtshali et al, 2012;Wang et al, 2018), kefir (Guzel-Seydim et al, 2011), sake (Tsuji et al, 2018), sour dough bread (Minervini et al, 2014;Ripari et al, 2016), and beer (Vriesekoop et al, 2012).…”

Sake Brewing and Bacteria Inhabiting Sake Breweries

“…Although all (or most) microorganisms die due to the high ethanol concentration, their DNA is present in the final sake product. Thus, the DNA sequences in sake can be analyzed to determine and compare the microbial flora contained in sake (Bokulich et al, 2014;Koyanagi et al, 2016;Terasaki et al, 2017;Tsuji et al, 2018).…”

“…Specific bacteria appear to affect specific chemical components during the production of the fermentation starter moto. For example, the ornithine composition increases and the arginine composition decreases during the production process of the fermentation starter yamahai-moto (also known as kimoto; traditional fermentation starter), and ornithine-producing Latilactobacillus sakei has been isolated from yamahai-moto (Tsuji et al, 2018). The bacteriocins produced by Lactococcus lactis inhibit the growth of sake-spoiling bacteria (Taniguchi et al, 2010).…”