title: Monitoring of the microbiota profile in nukadoko, a naturally fermented rice bran bed for pickling vegetables.
abstract: Nukadoko is a fermented rice bran mash traditionally used for pickling vegetables in Japan. To date, the production of both homemade and commercial nukadoko depends on natural fermentation without using starter cultures. Here, we monitored chemical and microbiological changes in the initial batch fermentation of nukadoko. Nukadoko samples were prepared by spontaneous fermentation of four different brands of rice bran, and microbiome dynamics were analyzed for 2 months. In the first week, non-Lactobacillales lactic acid bacteria (LAB) species, which differed among the samples, grew proportionally to pH decrease and lactate increase. Thereafter, Lactobacillus plantarum started growing and consumed residual sugars, causing further lactate increase in nukadoko. Finally, microbial communities in all tested nukadoko samples were dominated by L. plantarum. Taken together, our results suggest that the mixture of the fast-growing LAB species and slow-growing L. plantarum may be used as a suitable starter culture to promote the initial fermentation of nukadoko.
authors.affiliation: Research Institute of Pickles Function, Tokai Pickling, Co. Ltd., 78-1 Mukaigo, Mukokusama, Toyohashi, Aichi 441-8142, Japan. Electronic address: ono-hir@kyuchan.co.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.affiliation: Research Institute of Pickles Function, Tokai Pickling, Co. Ltd., 78-1 Mukaigo, Mukokusama, Toyohashi, Aichi 441-8142, Japan. Electronic address: nishio-sho@kyuchan.co.jp.
authors.forename: Shoko
authors.initials: S
authors.lastname: Nishio
authors.affiliation: Research Institute of Pickles Function, Tokai Pickling, Co. Ltd., 78-1 Mukaigo, Mukokusama, Toyohashi, Aichi 441-8142, Japan. Electronic address: tsurii-jun@kyuchan.co.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Tsurii
authors.affiliation: Research Institute of Pickles Function, Tokai Pickling, Co. Ltd., 78-1 Mukaigo, Mukokusama, Toyohashi, Aichi 441-8142, Japan. Electronic address: kawamoto@kyuchan.co.jp.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Kawamoto
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. Electronic address: sonomoto@agr.kyushu-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sonomoto
authors.affiliation: Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. Electronic address: nakayama@agr.kyushu-u.ac.jp.
authors.forename: Jiro
authors.initials: J
authors.lastname: Nakayama
mesh_terms: D019149:Bioreactors; D005285:Fermentation; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007564:Japan; D019344:Lactic Acid / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D064307:Microbiota / Q000235:genetics; D012275:Oryza / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014675:Vegetables / Q000378:metabolism*
chemical_list: D019344:Lactic Acid
keywords: 16S rRNA; Fermented rice bran; Lactic acid fermentation; Lactobacillales; Lactobacillus plantarum; Microbiota; Nukadoko; Pyrotag sequencing