ISSN:
1432-0614
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract. The production and utilization of carboxylic acids during aerobic thermophilic treatment of a model sludge composed of bacterial cells were examined in a laboratory treatment system. Operation under a limited supply of O2, typical for such treatment systems, resulted in a distinct pattern of production and simultaneous utilization of low molecular weight carboxylic acids. Pulse-addition of a mixture of carboxylic acids at the end of a fed-batch cycle indicated that simultaneous utilization of acetate, propionate, isobutyrate, n-butyrate and isovalerate could occur, but only after a lag phase during which only acetate was utilized. In an attempt to differentiate between production and utilization of the carboxylic acids, a series of pulse experiments were performed using 14C-labelled acetate. The results indicated that production continued late into the fed-batch cycle whereas utilization could occur during the entire cycle. When acetate was pulsed to the process, only 11% of the acetate carbon was incorporated into new biomass, whereas 75% was converted into CO2. However, 14% of the original radioactivity persisted in the supernatant despite complete acetate utilization. This suggested that some of the acetate was metabolized into more slowly biodegradable products.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002530050089
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