Higher diversity of sulfur-oxidizing bacteria based on soxB gene sequencing in surface water than in spring in Wudalianchi volcanic group, NE China.

Abstract

Sulfur-oxidizing bacteria (SOB) play a key role in the biogeochemical cycling of sulfur. To explore SOB diversity, distribution, and physicochemical drivers in five volcanic lakes and twosprings in the Wudalianchi volcanic field, China. This study analyzed microbial communities in samples via high-throughput sequencing of the soxB gene. Physical-chemical parameters were measured, and QIIME 2 (v2019.4), R, Vsearch, MEGA7, and Mothur processed the data. Alpha diversity indices and UPGMA clustering assessed community differences, while heat maps visualized intra-sample variations. Canoco 5.0 analyzed community-environment correlations, and NMDS, Adonis, and PcoA explored sample dissimilarities and environmental factor correlations. SPSS v.18.0 tested for statistical significance. The diversity of SOB in surface water was higher than in springs (more than 7.27 times). We detectedSOB affiliated to β-proteobacteria (72.3 %), α-proteobacteria (22.8 %), and γ-proteobacteria (4.2 %) distributedwidely in these lakes and springs. Rhodoferax and Cupriavidus were most frequent in all water samples, whileRhodoferax and Bradyrhizobium are dominant in surface waters but rare in springs. SOB genera in both habitatswere positively correlated. Co-occurrence analysis identified Bradyrhizobium, Blastochloris, Methylibium, andMetyhlobacterium as potential keystone taxa. Redundancy analysis (RDA) revealed positive correlations betweenSOB diversity and total carbon (TC), Fe2+, and total nitrogen (TN) in all water samples. The diversity and community structure of SOB in volcanic lakes and springs in the Wudalianchivolcanic group were clarified. Moreover, the diversity and abundance of SOB decreased with the variation of wateropenness, from open lakes to semi-enclosed lakes and enclosed lakes.