Ref ID : 1110
Yoshihara Kazutoshi, Osajima Katuhiro, Fujio Yusaku, and Ueda Seinosuke; [Substrate removal properties of dominant bacteria isolated from biological film]. Hakkokogaku 58(4):187-195, 1980
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Substrate removal properties of six dominant bacteria isolated from biological film were studied by investigating COD and bacterial biomass in a rotary shaken culture using a synthetic wastewater consisting of glucose, Polypepton and KH2PO4. Total COD (CODt) of supernatant liquid after centrifugation was assumed to be composed of the following two components: CODc, originating from carbohydrates (glucose in this study) and calculated from the following stoichiometric relation: mg/l CODc = mg/l Glucose x (192/180) and CODn supposed to mainly originate from nitrogenous substrates (Polypepton in this study) and obtained by subtracting CODc from CODt. Flavobacterium sp. and Alcaligenes sp. removed CODn faster than CODc. The removal rate of CODc increased considerably after the removable CODn was removed almost completely. Triphasic CODt removal by these two kinds of bacterium was observed in the time-course of substrate consumption. On the contrary, Klebsiella sp. removed CODc completely and at the fastest rate among the six bacteria studied. It was noted that the presence of glucose blocked CODn removal until the former was completely consumed. Arthrobacter sp. removed only CODc during the logarithmic phase of growth and CODn was not removed until the phase of negative growth acceleration. The removal rate of CODc with Arthrobacter sp. was much slower than with Klebsiella sp.; however that of CODn was the fastest among the six bacteria. Pseudomonas sp. consumed CODc gradually, but both CODn and biomass remained almost constant throughout the cultivation period. Bacillus sp. was able to remove both CODc and CODn at considerable rapid rates. With mixed culture systems which were composed of heterogeneous bacterial populations, a cooperative effect was found in the substrate removal, hence both CODc and CODn decreased at greater rates than with any pure culture system. Together with the knowledge of the succession of dominant bacterial flora reported in the preceding paper, these results allow the following reasonable conclusion: bacterial floras in biological film are constantly composed of such complementary members because as much as possible of both the carbonaceous and nitrogenous compounds can be removed.