Rhodopseudomonas palustrisin effluent enhances the disease resistance, TOR and NF-kappa B signalling pathway, intestinal microbiota and aquaculture water quality ofPelteobagrus vachelli

摘要

The use of traditional bait and medicament in freshwater aquaculture exacerbates environmental pollution and leads to frequent occurrence of diseases. Effluent collected afterRhodopseudomonas palustris-mediated wastewater treatment could be reutilized as microbial feeds, medicament and aquaculture water to culturePelteobagrus vachelli. Therefore, a novel integrated system of wastewater treatment using effluent containingR. palustristhat improves yield, increases disease resistance and enhances the quality of aquaculture water forP. vachelliculture was proposed and investigated.P. vachellican grow well in effluent containingR. palustris(ER). The survival rate, yield and whole-body composition of the ER group were all increased compared to those of the control group (CK). The biochemical (B vitamin) and other substances in the effluent ofR. palustrisenhanced the activity of proteases, amylases, lipases, alkaline phosphatase (AKP), acid phosphatase (ACP), phagocytic, superoxide dismutase (SOD) and catalase (CAT) by up-regulating the expression ofAKP,ACP,SODandCATgenes. Theoretical analysis showed that biochemical substances regulated the expression of these genes and enzyme activities as stimulus signal, component and active centre. Moreover,R. palustrisand biochemical substances improved the target of rapamycin (TOR) and nuclear factor kappa B (NF-kappa B) signalling pathways and intestinal microbiota. Furthermore,R. palustrisinhibitedAeromonas hydrophila, which increased resistance to fish diseases and promoted the growth of intestinal probiotics. Meanwhile,R. palustrisin effluent also purified the quality of aquaculture water. Use of this technology simultaneously helped improve aquaculture water quality, reduce water pollution and wastewater discharge and increased the output and disease resistance ofP. vachelli.