569 / 2024-09-18 14:08:07
Extracellular enzyme activity and microbial community structure in mariculture sediment
microbial diversity,extracellular enzyme,sediment,mariculture
Session 13 - Coastal Environmental Ecology under anthropogenic activities and natural changes
Abstract Accepted
Mariculture activities accumulate organic matter in sediment through feeding, putting seedling, biological feces and detritus. These processes shape the composition of microorganism in sediment, which, in turn, promote degradation of organic matter and release of nutrient. How sediment extracellular enzyme activity (EEA) and microbial composition are affected by mariculture still remain unclear. Here, we sampled sediment from three mariculture environment (non-culture area for reference, kelp culture area and large yellow croaker culture area) in Sansha Bay, which has the largest-scale mariculture in Fujian province. EEA related to sediment C (catalase), N (urease) and P (alkaline phosphatase) cycling were selected as indicators of the microbial mediated biogeochemical cycle in different mariculture area. High-throughput sequencing of the 16S rRNA gene amplicons (16S seq) was carried out to profile the sediment microbial community structure. The results revealed that the EEA related to C, N cycling in non-culture area was significantly higher than those in the mariculture area (p<0.01). Whereas, EEA associated with P cycling in large yellow croaker is lower than other area (p<0.01). The diversity of the sediment bacterial community in the non-culture area was also notably higher than culture areas (p<0.01). The microbial community is dominantly composed by Protebacteria, Desulfobacterota, Chloroflexi, Planctomycetota and Bacteroidota. However the mean proportions of predominant phyla varied significantly between non-culture area and culture area (p<0.01). These results showed that microbial diversity and EEA decline in the sediment affected by mariculture activities, which may lead to deceleration of biogenic elements exchange in sediment-water interface. Our study offer valuable insights to enhance understanding of the effect of mariculture activities in the coastal biogeochemical cycle.