Identifying Community Structure of Lactic Acid Bacteria (LAB) Using Environmental DNA (eDNA) in IMTA System at Enclosed Sea (Hangzhou Bay) East China Sea
Dyah Muji Rahayu1, Elya Mufidah2, Peimin He3*, Kejun Li3, Jinlin Liu3,4,5

1Department of Fisheries Product Technology, Faculty of Animal Husbandary, Universitas Jambi, 3636, Indonesia
2Bioprocess Engineering, Department of Biosystem Engineering, Faculty of Agricultural Technology, Brawijaya University, 65145, Indonesia
3College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
4North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266061, China
5The Key Laboratory of Zoological Systematics and Application, Hebei University, Baoding 071002, China

Abstract

Aquaculture practices employing the IMTA system in China have experienced rapid development in recent decades. This expansion is driven by the growing demand for the fisheries sector, both domestically and internationally. Biomonitoring of Lactic Acid Bacteria (LAB) communities is necessery to supppose as biocontrol through bacteriocins. However, information regarding LAB communities within the IMTA system, especially concerning bacteriocin potential, remains limited. Hence, the purpose of this study employs eDNA analysis to determine the taxonomic composition and abundance of LAB communities at various sites and seasons. Samples were collected at a depth of 2.5 meters with a volume of 5 liters during winter, spring, summer, and autumn at IMTA system encompassing fish farming, control, and algae cultivation area. Illumina sequencing successfully identified 18,736 OTUs, with LAB being represented by 740 OTUs and the abundance all LAB species was 881,962 individuals. Taxonomically, dominating LAB species include phylum Actinomycetota and class Actinomycetes, each with 467 OTUs, order Kitasatosporales, family Streptomycetaceae, and genus Streptomyces, each with 464 OTUs. Genus Streptomyces exhibited the highest abundance, totaling 612,327 individuals, while Escherichia coli was the most dominant species, with abundance of 28,595 individuals. Escherichia coli was found to be most abundant during autumn (11,170 individuals) and at the control location (6,447 individuals). The use of eDNA proved to be an effective tool for biomonitoring LAB communities at the species level, providing spatial and temporal insights into their abundance.

Keywords: eDNA- IMTA- LAB- structure community

Topic: Waste and environmental management