Project description:In the present study, we studied microbial composition and metabolic activity in the euphotic zone of the South China Sea. 8 samples were collected and subjected to metaproteomic analysis. Our results suggested that mixotrophic phototrophs-driven NDL carbon fixation along with phytoplankton-driven NRL carbon fixation determined primary production in the oligotrophic ocean’s euphotic zone.
Project description:We designed a new specific mRNA microarray targeting a subset of genes (748) of the diazotrophs Richelia intracellularis and Calothrix rhizosoleniae (genomes RintRC01, RintHH01, RintHM01 and CalSC01) which associate with diatom hosts. The aim was to be able to describe the gene expressions of genes related to several metabolic pathways and how they possibly differed between the closely related strains based on environment and host association. To better understand how the different environments might affect gene expressions, the samples were taken in depth profiles, at night and day, during a cruise in the South China Sea.
Project description:Marine microorganisms inhabiting the bathypelagic zone (1000 m - 4000 m) are pivotal to biogeochemical cycling. However, a comprehensive understanding of microbial community structure and their metabolic activities adaptations to the extreme deep-sea conditions remains elusive. In this study, we employed a metaproteomic approach to investigate the protein profiles of microbial communities spanning the surface and bathypelagic layers of the South China Sea (SCS) and performed a comparative analysis with metagenomic data. The metaproteome and metagenome showed low correlation in functional expression but a high correlation at the phylum level. High-abundance genes were more likely to be translated into proteins, with protein over-representation observed in energy conversion and matter transport processes. Short-chain amide porins facilitate substance exchange and maintain cellular homeostasis, enabling Methylococcales to adapt to deep-sea conditions and actively oxidize methane. Flexible energy utilization strategies, such as CO oxidation, enable Propionibacteriales to thrive in deep-sea environments. This study highlights the significance of microbial enzyme resources and offers valuable insights into the adaptations of deep-sea microorganisms, emphasizing their considerable application potential.