Open AccessHRT and nutrients affect bacterial communities grown on recirculation aquaculture system effluents
Author(s) -
Schneider Oliver,
ChabrillonPopelka Mariana,
Smidt Hauke,
Haenen Olga,
Sereti Vasiliki,
Eding Ep H.,
Verreth Johan A. J.
Publication year - 2007
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2007.00282.x
Subject(s) - biology , effluent , flavobacterium , bacteria , nutrient , nitrate , population , recirculating aquaculture system , microbial population biology , hydraulic retention time , vibrio , aquaculture , food science , microbiology and biotechnology , ecology , environmental engineering , environmental science , fishery , pseudomonas , demography , sociology , fish <actinopterygii> , genetics
In a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. Because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. Bacteria were produced in growth reactors under different conditions: 7 h hydraulic retention time (HRT) vs. 2 h, sodium acetate vs. molasses, and ammonia vs. nitrate. The community of the drumfilter effluent was different from those found in the reactors. However, all major community components were present in the effluent and reactor broths. HRT influenced the bacteria community, resulting in a DGGE profile dominated by a band corresponding to an Acinetobacter sp.‐related population at 2 h HRT compared to 7 h HRT, where bands indicative of α‐proteobacterial populations most closely related to Rhizobium and Shinella spp. were most abundant. Molasses influenced the bacterial community. It was dominated by an Aquaspirillum serpens ‐related population. Providing total ammonia nitrogen (TAN) in addition to nitrate led to the occurrence of bacteria close to Sphaerotilus spp., Flavobacterium mizutaii and Jonesia spp. It was concluded from these results that a 6–7 h HRT is recommended, and that the type of substrate is less important, and results in communities with a comparably low pathogenic risk.