Accessing the Relationship between archaeal and bacterial Tetraethers in the Pearl River Estuary and Coastal South China Sea

Abstract:

Microbial intact polar GDGTs with phosphate head groups (phospho IP-GDGTs) are powerful biomarkers for tracing interactions between living cells and their environments. The goal of this study was to examine the relationship between archaeal isoprenoid (iso-) GDGTs and bacterial branched (br-) in the Pearl River estuary and coastal South China Sea. Suspended particulate matter (SPM) was collected using 0.7 µm- and 0.2 µm-filters in winter and summer of 2012. The results exhibited that 1) the abundance of phospho IP-isoGDGTs is lower than phospho IP-brGDGTs in different seasons, and 2) phospho IP-brGDGTs collected from 0.2 µm-filter in winter are significantly higher than the summer. Linear regression analysis showed that the abundance of phospho IP-isoGDGTs and phospho IP-brGDGTs are significantly correlated, suggesting that the source archaea of the isoGDGTs may have functional relationship with the brGDGT-producing bacteria in the study area. Furthermore, the seasonal highest abundances of iso- and br-GDGTs always occurred in the transitional zone between river and estuary, indicating that the transitional area is a highly productive environment for the GDGT-producing organisms.