Analysis of nifH DNA and RNA reveals a disproportionate contribution to nitrogenase activities by rare plankton-associated diazotrophs.

Background: Holobionts comprising nitrogen-fixing diazotrophs and phytoplankton or zooplankton are ubiquitous in the pelagic sea. However, neither the community structure of plankton-associated diazotrophs (PADs) nor their nitrogenase transcriptional activity are well-understood. In this study, we used nifH gene Illumina sequencing and quantitative PCR to characterize the community composition and nifH expression profile of PADs with > 100 μm size fraction in the euphotic zone of the northern South China Sea.

[Protective effects of exogenous HS to the recovery of hypoxia post-conditioning on aged H9C2 cells and the underling mechanisms].

Objective: To investigate the recovery of protective effects of exogenous hydrogen sulfide (HS) on hypoxia post-conditioning in aged H9C2 cells and its mechanism.

Methods: H9C2 cells (cardiomyocytes line) were treated with 30 μmol/L hydrogen peroxide (HO) for 2 hours, then cultured for 3 days in order to induce cellular aging. Aged H9C2 cells were randomly divided into 5 groups (=8):Control group (Control), hypoxia/reoxygenation group (H/R), H/R + NaHS group, hypoxia post-conditioning (PC) group, PC+NaHS group.

Illumina-based analysis the microbial diversity associated with Thalassia hemprichii in Xincun Bay, South China Sea.

In order to increase our understanding of the microbial diversity associated with seagrass Thalassia hemprichii in Xincun Bay, South China Sea, 16S rRNA gene was identified by highthrough sequencing method. Bacteria associated with seagrass T. hemprichii belonged to 37 phyla, 99 classes.

Responses of bacterial communities in seagrass sediments to polycyclic aromatic hydrocarbon-induced stress.

The seagrass meadows represent one of the highest productive marine ecosystems, and have the great ecological and economic values. Bacteria play important roles in energy flow, nutrient biogeochemical cycle and organic matter turnover in marine ecosystems. The seagrass meadows are experiencing a world-wide decline, and the pollution is one of the main reasons.

The diversity of coral associated bacteria and the environmental factors affect their community variation.

Coral associated bacterial community potentially has functions relating to coral health, nutrition and disease. Culture-free, 16S rRNA based techniques were used to compare the bacterial community of coral tissue, mucus and seawater around coral, and to investigate the relationship between the coral-associated bacterial communities and environmental variables. The diversity of coral associated bacterial communities was very high, and their composition different from seawater.