OYSTER BIO DEPOSITION ENHANCED THE FUNCTIONAL POTENTIAL OF LABILE AND RECALCITRANT CARBON IN SHENZHEN BAY’S SEDIMENTS

Abstract

Oysters are typical aquatic animals with their special biological property of filter feeding in the water column. However, the biodeposition of oysters may change the sediment chemistry and also may affect the biogeochemical processes. We conducted research work to determine the effect of Oyster Biodeposition (OBD) on the sediments microbes, and their metabolic abilities on carbon at the site rich with oyster culture area of Shenzhen Bay China. After biochemical and Geochip5 analysis, we found that the genes coding the metabolic enzymes pullulanase, glucoamylase, exoglucanase, cellobiase, xylanase, etc. were highly abundant in oyster farming place compared to reference place.  Meanwhile, the functional genes cda (6%), pectinase (5%), and xyla (5%) were greatly abundant at the surface oyster area and they were showing significantly higher ( P= <0.05) normalized gene intensities compared to bottom sediment site. These genes were mostly involved in the degradation of labile and recalcitrant forms of carbon. These detected genes were mainly involved in the carbon degradation process and they were showing more tendency towards the degradation of labile carbon. Small abundance of enzymes such as glyoxal oxidase and phenol oxidase were also found which were involved in the degradation of recalcitrant carbon. Taken together, our results indicated that the OBD enhanced the degrading capacity of both labile and recalcitrant forms of carbon, it has a positive stimulating effect on sediment carbon metabolism.