TY - JOUR
T1 - Microbial characteristics of methanogenic sludge consortia developed in thermophilic U ASB reactors
AU - Uemura, Shigeki
AU - Harada, Hideki
PY - 1993/7/1
Y1 - 1993/7/1
N2 - The effect of temperature on granulation and microbial interaction of anaerobic sludges grown in thermophilic upflow anaerobic sludge bed (UASB) reactors was investigated at two different temperatures, 55°C (Run 1) and 65°C (Run 2). Each run consisted of two phases. Phase 1 was conducted by feeding acetate for a period of 200 days. In Phase 2, both reactors were fed a mixture of acetate and sucrose for a further 100 days. During Phase 1, no granulation occurred in the sludge of either run. Microscopic observation revealed that the predominant methanogen was Methanothrix in Run 1, whereas Methanobacterium-like bacteria existed to a significant extent in Run 2. The acetate-utilizing methanogenic activity of both sludges increased with increasing test temperature in the range 55-65°C. Since the acetate-grown sludges exhibited far higher H2-utilizing methanogenic activity than acetate-utilizing methanogenic activity, it is suggested that a syntrophic association of acetate-oxidizing bacteria with hydrogenotrophic methanogens was responsible for a considerable portion of the overall acetate elimination in thermophilic anaerobic sludge. During Phase 2, granules coated with either filamentous bacteria or cocci-type bacteria (both presumably acid-forming bacteria) were successfully established in Run 1 and Run 2, respectively. Since the acetate-utilizing methanogenic activities of the granular sludges were four to five times higher than those of the acetate-grown sludges (Phase 1), the co-existence of these "coating bacteria" appeared to contribute to the enclosing of acetate consumers inside granules.
AB - The effect of temperature on granulation and microbial interaction of anaerobic sludges grown in thermophilic upflow anaerobic sludge bed (UASB) reactors was investigated at two different temperatures, 55°C (Run 1) and 65°C (Run 2). Each run consisted of two phases. Phase 1 was conducted by feeding acetate for a period of 200 days. In Phase 2, both reactors were fed a mixture of acetate and sucrose for a further 100 days. During Phase 1, no granulation occurred in the sludge of either run. Microscopic observation revealed that the predominant methanogen was Methanothrix in Run 1, whereas Methanobacterium-like bacteria existed to a significant extent in Run 2. The acetate-utilizing methanogenic activity of both sludges increased with increasing test temperature in the range 55-65°C. Since the acetate-grown sludges exhibited far higher H2-utilizing methanogenic activity than acetate-utilizing methanogenic activity, it is suggested that a syntrophic association of acetate-oxidizing bacteria with hydrogenotrophic methanogens was responsible for a considerable portion of the overall acetate elimination in thermophilic anaerobic sludge. During Phase 2, granules coated with either filamentous bacteria or cocci-type bacteria (both presumably acid-forming bacteria) were successfully established in Run 1 and Run 2, respectively. Since the acetate-utilizing methanogenic activities of the granular sludges were four to five times higher than those of the acetate-grown sludges (Phase 1), the co-existence of these "coating bacteria" appeared to contribute to the enclosing of acetate consumers inside granules.
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U2 - 10.1007/BF00205070
DO - 10.1007/BF00205070
M3 - Article
AN - SCOPUS:0027235875
VL - 39
SP - 654
EP - 660
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
SN - 0175-7598
IS - 4-5
ER -