Spatiotemporal distribution of bacterial dimethylsulfoniopropionate producing and catabolic genes in the Changjiang Estuary

Hao Sun, Ji Liu, Siyin Tan, Yanfen Zheng, Xiaolei Wang, Jinchang Liang, Jonathan Todd, Xiao-Hua Zhang

Research output: Contribution to journalArticlepeer-review

Abstract

The osmolyte dimethylsulfoniopropionate (DMSP) is produced in petagram amounts by marine microorganisms. Estuaries provide natural gradients in salinity and nutrients, factors known to regulate DMSP production; yet there have been no molecular studies of DMSP production and cycling across these gradients. Here, we study the abundance, distribution and transcription of key DMSP synthesis (e.g. dsyB and mmtN) and catabolic (e.g. dddP and dmdA) genes along the salinity gradient of the Changjiang Estuary. DMSP levels did not correlate with Chl a across the salinity gradient. In contrast, DMSP concentration, abundance of bacterial DMSP producers and their dsyB and mmtN transcripts were lowest in the freshwater samples and increased abruptly with salinity in the transitional and seawater samples. Metagenomics analysis suggests bacterial DMSP-producers were more abundant than their algal equivalents and were more prominent in summer than winter samples. Bacterial DMSP catabolic genes and their transcripts followed the same trend of being greatly enhanced in transitional and seawater samples with higher DMSP levels than freshwater samples. DMSP cleavage was likely the dominant catabolic pathway, with DMSP lyase genes being ~4.3-fold more abundant than the demethylase gene dmdA. This is an exemplar study for future research on microbial DMSP cycling in estuary environments.
Original languageEnglish
Pages (from-to)7073-7092
Number of pages20
JournalEnvironmental Microbiology
Volume23
Issue number11
Early online date24 Oct 2021
DOIs
Publication statusPublished - Nov 2021

Keywords

  • DMSP
  • estuary
  • DMS

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