Accumulation of microcystins, bacterial community composition and mlrA gene abundance in shrimp culture ponds

• Published in: Aquaculture Environment Interactions Vol. 16; pp. 163 - 174
• Main Authors: Wang, X, Dai, W, Bi, X, Zhang, X, Zhang, D
• Format: Journal Article
• Language: English
• Published: Oldendorf Ecology Institute 30-05-2024; Inter-Research
• Subjects: Abundance; Accumulation; Aquaculture; Bacteria; Biodegradation; Community composition; Composition; Cyanobacteria; Hepatopancreas; Intestine; Intestines; Microcystins; Ponds; Sediment; Sediments; Shrimp culture; Shrimps; Sphingobium; Toxins
• ISSN: 1869-215X; 1869-7534
• DOI: 10.3354/aei00479

Cyanobacteria blooms occur frequently in low-salinity shrimp culture ponds. To provide useful information about the potential harm and
in situ
biodegradation pathway of microcystins (MCs) in these ponds, we investigated accumulation of MCs in shrimp hepatopancreas and sediments, bacterial community composition and
mlrA
gene abundance in intestines and sediments in 11
Litopenaeus vannamei
culture ponds from 9 farms in China. MCs (MC-LR, MC-RR and MC-YR) accumulated in shrimp hepatopancreas and sediments in each sampled pond. Higher bacterial richness and diversity were observed in sediments than in intestines. Two MC-degrading genera (
Sphingobium
and
Roseomonas
) were detected in the intestine bacterial community, and 3 MC-degrading genera (
Sphingobium
,
Rhizobium
and
Acinetobacter
) were detected in the sediment bacterial community. The
mlrA
gene was easier to detect and more abundant in shrimp intestines than in sediments. These results suggest that there was a potential MC hazard in shrimp culture ponds, and the biodegradation pathway in shrimp intestines seemed to be more dependent on the
mlr
pathway than that in the sediments.