The inconsistent microbiota of Budu, the Malaysian fermented anchovy sauce, revealed through 16S amplicon sequencing

Budu is a Malaysian fermented anchovy sauce produced by immersing small fishes into a brine solution for 6 to 18 months. Microbial enzymes are known to contribute to fermentation; however, not much is known about the microbial community in Budu. Therefore, a better understanding of the Budu microbiome is necessary to improve the quality, consistency, and safety of the Budu products. In this study, we collected 60 samples from 20 bottles of Budu produced by seven manufacturers. We analyzed their microbiota using V3–V4 16S rRNA amplicon sequencing when we first opened the bottle (month 0), as well as 3 and 7 months post-opening (months 3 and 7). Tetragenococcus was the dominant genus in many samples, reaching a maximum proportion of 98.62%, but was found in low abundance, or absent, in other samples. When Budu samples were not dominated by a dominant taxa, we observed a wider genera diversity such as Staphylococcus, Acinetobacter, Halanaerobium and Bacillus. While the taxonomic composition was relatively stable across sampling periods, samples from two brands showed a sudden increase in relative abundance of the genus Chromobacterium at month 7. Based on prediction of metagenome functions, non-Tetragenococcus-dominated samples were predicted to have enriched functional pathways related to amino acid metabolism and purine metabolism compared to Tetragenococcus-dominated samples; these two pathways are fundamental to fermentation quality and health attributes of fish sauce. Among the non-Tetragenococcus-dominated samples, contributions towards amino acid metabolism and purine metabolism were biased towards the dominant taxa when species evenness is low, while in samples with higher species evenness, the contributions towards the two pathways were predicted to be evenly distributed between taxa. Our results demonstrated that the utility of 16S sequencing to assess batch variation in fermented food production. The distinct microbiota was shown to correlate with characteristic metagenome function including functions potentially related to fermented food nutrition and quality.

Whole-Genome Sequencing of Lentibacillus sp. Strain JNUCC-1, Isolated from Fermented Anchovy Sauce (Myeolchi Aekjeot)

Lentibacillus sp. strain JNUCC-1 was isolated from Korean traditionally fermented anchovy sauce. The 16S rRNA sequence of JNUCC-1 showed 95.2% and 95.1% similarity to Lentibacillus populi WD4L-1T and Virgibacillus siamensis MS3-4T, respectively, indicating that it is a novel species. The whole-genome sequence, which contains 3,687,469 bp and 3,833 genes in 3 contigs, is reported.

The microbiota of Malaysian fermented fish sauce

ABSTRACTBudu is a Malaysian fermented anchovy sauce produced by immersing small fishes into brine solution for 6 to 18 months. Fermentation of the anchovy sauce is catalyzed by microbial enzymes, but little is known about the microbial community in Budu. A better understanding of the Budu microbiota is necessary to better control the quality, consistency and biological safety of this fermentation product. In this study, we sampled 20 bottles of Budu produced by 7 different manufacturers and analyzed their microbiota based on V3-V4 16S rRNA amplicon sequencing, at the time of opening as well as 3- and 7-months post-opening. In most samples, Tetragenococcus appears to be the most prevalent genus detected making up an average of 38.77 % relative abundance per sample (median = 19.56%, min = 0%, max = 98.62%). Furthermore, we also detected possible spoilage microbial genera such as Xanthomonas, Acinetobacter, Pseudomonas, Halanaerobium, and Psychrobacter. The microbial composition of majority of samples appears to be relatively stable even after seven months of bottle opening and storage at room temperature. Samples from two brands however showed a sudden increase in the number of reads belonging to the genus Chromobacterium in the 7th month.