Quantitative use of fluorescence in situ hybridization to detect syntrophic acetogenic bacteria in anaerobic environmental samples

Abstract:

Syntrophic acetogenic bacteria, an important functional one in anaerobic habitats, were detected and counted by fluorescence in situ hybridization (FISH) technology by using 16S rRNA-based oligonucleotide probes. For enumeration and quantification of the targeted bacteria, an attempt was made to optimize the hybridization conditions. The optimum conditions are as follows: a fixation time of 19h, a dehydrated time of 5min, and a formamide concentration of 55% in hybridized solution. The abundance of syntrophic acetogenic bacteria of different environmental samples were quantified by FISH and the results showed that Upflow Anaerobic Sludge Reactor (UASB) treating STHZ〗high-concentration organic wastewater and the digestive tract of some animals were the main habitats of syntrophic acetogenic bacteria. The numbers of syntrophic acetogenic bacteria in UASB and cattle manure were 1.70×10⁹ cells/mL sample and 6.50×10⁸ cells/mL sample, respectively. Meanwhile, the sediments of rivers and lakes existed less of the bacteria and the contents of them were just about 1.20×10⁸ cells/mL sample in Taihu lake.