Water Science & Technology—WST Vol 59 No 6 pp 1185–1194 © IWA Publishing 2009 doi:10.2166/wst.2009.035

Actinomycetes and earthy-musty odorous compounds in brackish fishponds in Tianjin, China

Yong Pan, Lipu Xu, Wenxuan Cao, Shouren Yin, Zongwei Wang and Qiaohong Zhou

The presence of the odorous compounds, 2-methylisoborneol (MIB) and geosmin, as well as causative microorganisms in brackish intensive cultivation fishponds in Tianjin, China that had a severe earthy-musty odor were evaluated. The results revealed that MIB was the primary odorous compound present in the Tianjin fishponds, with a concentration ranging from 0.53–5302.7 ng·L^-1. Furthermore, the concentration of MIB was found to be closely correlated with the gross biomass of actinomycetes in the water, which ranged from 10.67–1528.24 × 10⁶ cfu·ml^-1. Therefore, the sequences of the 16 SrRNA and morphological characteristics of the actinomycetes in the brackish fishponds were investigated. The results revealed that the actinomycetes in the brackish fishponds included 9 species of common and dominant actinomycetes belonging to 4 genera. Of these genera, Streptomyces were the dominant species, and Streptomyces, Nocardioides and Micromonospora were the most common species in the fishponds evaluated. Next, the ability of each of the isolated Streptomyces to produce MIB was measured under laboratory culture conditions. Streptomyces Sp2 was found to have a strong ability to produce MIB, which indicates that this strain may be the primary source of the earthy-musty odor reported in brackish intensive cultivation fishponds in Tianjin, China.

Keywords: actinomycetes; brackish intensive cultivation fishponds; earthy-musty odor; 2-methylisoborneol (MIB)

Full article (PDF Format)