Correction: Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing.

[This corrects the article DOI: 10.1371/journal.pone.0194876.]

Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing - Fig 9

<p><b>Networks of microbial interaction for bacteria (a) and fungi (b) in the samples</b>. Each node represents a bacterial or fungal genus, edges denote significant correlations between phylotypes (Spearman’s ρ> 0.6). Positive correlations colored in green indicate co-occurrence, whereas negative correlations in red indicate mutual exclusion.</p

Heatmap of clustering analysis based on the top 50 functional genes in the samples.

<p>Heatmap of clustering analysis based on the top 50 functional genes in the samples.</p

Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing

<div><p>Douchi has been consumed as a flavoring ingredient for centuries. During production of douchi, numerous microorganisms play important roles in the hydrolysis and conversion of proteins and starch, which are related to the quality and flavor of the end product. Therefore, in the present study, the microbial diversity in two types of home-made traditional bacterial douchi from Gansu province in northwest China was studied by high-throughput sequencing, and a corresponding analysis of the bacterial and fungal communities were conducted. The results showed that geography may have impacted the fungal diversity and the bacterial and fungal species richness in the samples. The results also showed that the microbial community was significantly different in samples of different origin and the difference in the microbial community at the genus level was greater than at phylum level. Two dominant bacterial genera (<i>Bacillus</i> and <i>Ignatzschineria</i>) were common to the two samples, both of which had a relative abundance of more than 1%. Four bacterial genera (<i>Staphylococcus</i>, <i>Aerococcus</i>, <i>Geobacillus</i>, and <i>Jeotgalicoccus</i>) were dominant only in the sample from Qingyang, while another four (<i>Carnobacterium</i>, <i>Proteus</i>, <i>Aneurinibacillus</i>, and <i>Enterococcus</i>) were dominant only in the sample from Longnan. Two dominant fungal genera (<i>Pichia</i> and <i>Candida</i>) were shared by the two samples. Additionally, two genera (<i>Rhodosporidium</i> and <i>Yarrowia</i>) were dominant only in samples from Longnan. The functional genes of the bacteria present in samples indicated that a significant difference was observed in the bacterial community between samples of different origin. We also found that microbial interactions between bacterial and fungal communities in the samples were very complex. This study provides previously unknown information regarding the impact of the environment on microbial communities in douchi and lays a foundation for further investigations into food ecology in bacterial douchi.</p></div

Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing - Fig 1

<p><b>Rarefaction curves for Shannon diversity indices of bacteria (a) and fungi (b)</b>.</p

Other functional genes from bacteria in the samples.

<p>Other functional genes from bacteria in the samples.</p

Type of douchi and soybean, producers and origins of douchi samples.

<p>Type of douchi and soybean, producers and origins of douchi samples.</p

OTUs, Good's Coverage, Chao1, Simpson and Shannon's index for 16S r RNA and 18S r RNA sequencing of the samples.

<p>OTUs, Good's Coverage, Chao1, Simpson and Shannon's index for 16S r RNA and 18S r RNA sequencing of the samples.</p

Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing - Fig 5

<p><b>Relative abundance of fungal phyla (a) and genera (b) in the samples</b>.</p

Microbial diversity in two traditional bacterial douchi from Gansu province in northwest China using Illumina sequencing - Fig 4

<p><b>Linear discriminant analysis of microbial community compositions in douchi samples for bacteria (a) and fungi (b)</b>. The node size represents the difference in relative abundance. Green or red nodes indicate OTUs with significant differences of relative abundance, yellow nodes indicate OTUs with no significant differences in relative abundance.</p