Mugihito Oshiro

Sourdough, a traditional fermented dough, is made via natural fermentation by lactic acid bacteria (LAB). Its pH changes from near neutral to acid during the subculture process. However, the product quality of subcultured sourdough depends on the unpredictable succession of LAB communities, the influential factors of which are still unclear. To elucidate one end of the LAB community succession mechanism, we evaluated the effect of pH by designing four subculture experiments using a model medium

The spontaneous microbiota of wheat sourdough, often comprising one yeast species and several lactic acid bacteria (LAB) species, evolves over repeated fermentation cycles, which bakers call backslopping. The final product quality largely depends on the microbiota functions, but these fluctuate sometimes during the initial months of fermentation cycles due to microbiota evolution in which three phases of LAB relay occur. In this study, the understanding of yeast-LAB interactions in the start of

Traditionally, multispecies consisting of lactic acid bacteria and yeasts collaboratively engage sourdough fermentation, which determines the quality of the resulting baked goods. Nonetheless, the successive transfer of these microbial communities can result in undesirable community dynamics that prevent the formation of high-quality sourdough bread. Thus, a mechanistic understanding of the community dynamics is fundamental to engineer sourdough complex fermentation. This study describes the pop

Lactic acid bacteria (LAB) shape diverse communities in fermented foods. Developing comprehensive quantification methods for community structure will revolutionize our understanding of food LAB microbiome. For this purpose, 16S rRNA gene amplicon-based quantification, using spiked exogenous bacterial cells as an internal standard, shows potential for comprehensiveness and accuracy. We validated cell spike-in amplicon sequencing for quantifying LAB communities in food. Low efficiency of LAB DNA e

Here, we report the complete genome sequence of <i>Levilactobacillus acidifarinae</i> type strain JCM 15949 (DSM 19394), which was isolated from a Belgian artisanal wheat sourdough. The genome consisted of a circular chromosome (2,915,962 bp, 51.71% GC content) and a circular plasmid (30,910 bp, 39.78% GC content).

バイオディーゼル燃料 (BDF) ヘブタノールを添加することで, 流動点が下がり, 燃焼効率が向上する。アセトン・ブタノール (ABE) 発酵を用いたバイオブタノール生産は, 基礎から応用まで幅広く研究されている。これまで, 種々のABE生産菌が分離され, 標準株ではその代謝経路が明らかとなっている。サゴデンプン廃液などの生物系廃棄物の利用はコスト面で優位であり, これらを原料としたABE発酵が行われた。また, 抽出剤として植物油脂のBDFを用いた抽出発酵が試みられ, 効率的なブタノール生産と高性能なブタノール添加BDF生産が実現された。さらに, 種々の培養法を用いて, 高速高効率的なブタノール生産システムが開発された。その他, 遺伝子工学的手法を用いた高ブタノール生産菌の分子育種や, バイオインフォマティクスを利用した代謝解析も行われている。