高級脂肪酸の嫌気的分解過程における硫酸塩還元細菌とメタン生成細菌の基質競合 Competitive Interaction between Sulfate-Reducing Bacteria and Methane-Producing Bacteria in Anaerobic Degradation of a Long-Chain Fatty Acid
Competitive interaction between sulfate-reducing bacteria (SRB) and methane producing bacteria (MPB) for hydrogen and for acetate in anaerobic degradation of long chain fatty acids (LFAs) was investigated using two different sludge consortia: the one (referred to as R1) grown in a sulfate-free medium and the other (R2) in a sulfate-rich medium. Both sludges were cultivated in parallel for six months in a fill-and-draw mode on palmitate (C 16, saturated LFA).R1 sludge finally reached a very low sulfate-reducing activity (SRA, 0.019 gCOD·gVSS-1·d-1) and a very high methaneproducing activity (MPA, 10.1 gCOD·gVSS-1·d-1) for hydrogen-fed vial test: the ratio of SRA/MPA (both on the basis of COD equivalent) was only 0.0019. On the contrary, R2 sludge was characterized by a high hydrogen-fed SRA (1.15 gCOD·gVSS-1·d-1) and by a low hydrogen-fed MPA (0.0093 gCOD·gVSS-1·d-1): the SRA/MPA ratio was 123. The results of hydrogen-trophic MPN enumeration showed a similar tendency: the SRB/MPB ratios were 1/103.6 and 102.0 for R1 and R2 sludge, respectively. Therefore, degradation of palmitate into acetate was performed by a symbiosis between proton-reducing acetogenic bacteria (PRB) and MPB in R1 sludge, whereas by a syntrophic association between PRB and SRB in R2 sludge.
- 水環境学会誌 = Journal of Japan Society on Water Environment
水環境学会誌 = Journal of Japan Society on Water Environment 22(9), 755-762, 1999-09