원문정보
초록
영어
The acidogenesis was reported to be very important due to the fact that volatile fatty acids generated through this process, especially acetate and butyrate, were preferable substrates for methanogens. For this process of swine wastewaster with ca. 40,000 mg/L of COD, a series of experiments were carried out with laboratory-scale continuously stirred tank reactors to obtain short chain volatile fatty acids. The profile of total volatile fatty acids production was investigated with simultaneous variations in hydraulic retention time (HRT) (0.5 to 2.5 days) and temperature (40 to 60℃). Response surface methodolgy made an application successfully to approximate the responses of the production of total volatile fatty acids. The optimum physiological conditions the
production were 2.0 days HRT and 50℃ using the quadratic model. In the optimal condition, the DGGE analysis was carried out with extracted DNA using 16S rDNA primers which was used to compare the composition of bacterial communities in swine manure during the acidogenesis. The swine manure was initially dominated by Pseudomonas sp., Bacillus halodurans and then the existence of these species was kept to the steady state of acidogenesis; on the contrary, swine effluent bacterium which existed in the original sludge for seeding has disappeared as soon as the acidogenesis began. Moreover, Clostridium sp. and Gracilibacter thermotolerans which were known as the typical thermophilic acidogens have suddenly dominated when the continuous stirring reaction with the constant HRT (hydraulic retention time) was stated, which
means the microbial community has changed from mesophlic to thermophilic organisms
according to the increase of temperature with initially mesophilic sludge for seeding in
the acidogenesis.