Bacterial Diversity and Abundance in the Rearing Water of Vertical Crab Farming Applied with Microbial-based Portable Urban Filter (P-PUF)

A portable urban filter (P-PUF), equipped with physical filtration materials and specialized aerobic and anaerobic bacteria, was integrated into vertical crab farming systems to maintain water quality throughout crab cultivation. To precisely monitor water quality, an auto-sensor water quality monitoring system (Asor WQM) was employed. The objective of this study was to assess bacterial diversity and abundance in the rearing water of vertical crab farming treated with the P-PUF and Asor WQM (T.P-PUF), in comparison to conventional filtration (C.K) system. Bacterial diversity and abundance were evaluated through 16S rRNA amplicon sequencing and culturable methods. Our results demonstrate a notably higher bacterial diversity in the T.P-PUF treatment compared to the C.K. The top five bacterial phyla in both treatments were Pseudomonadota, Bacteroidota, Bacillota, Actinomycetota, and Acidobacteriota. The differences were observed in the composition of Bacillota and Bacteroidota between the two treatments, with T.P-PUF showing an increased abundance of Bacillota and C.K exhibiting a higher prevalence of Bacteroidota. At the family level, the bacterial community in T.P-PUF was primarily composed of Vibrionaceae, whereas Pseudoalteromadaceae dominated in C.K. The culturable method revealed that T.P-PUF substantially increased the abundance of total bacteria, nitrifying bacteria, and denitrifying bacteria in the rearing water compared to C.K. These findings indicate that the application of T.P-PUF leads to a distinct and more diverse bacterial community in the rearing water of mud crab culture, potentially enhancing the overall health and quality of crab production