• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.68-78
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• 2006

The purpose of this study was to estimate the identification of thermophilic hacterial with fermentation of pig manure. To identify the characters of thermophilic bacteria related to fermentation at a high temperature condition, we selected 28 different kinds of original settling thermophilic bacteria that were sampled at different 23 areas. They were distributed 1$1{\times}10^5{\sim}10^8CFU$ at medium and the enzyme activity at $55^{\circ}C$ incubation condition, especially cellulase and a-amylase, were higher than those of $30^{\circ}C$. Partial sequencing data for 165 rDNA region were obtained from 28 samples representing 15 different genera. Bacillus subcilis, one of those bacteria, has endodermic spores at high fermented condition.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1049-1057
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• 2012

The study investigated the biochemical methane potential (BMP) assay of pig slurry supplemented with mixed methanogens and cellulolytic bacteria to improve anaerobic digestion for methane production. For the BMP assay, 7 different microbial supplementation groups consisted of the cultures of mixed methanogens (M), Fibrobacter succinogenes (FS), Ruminococcus flavefaciensn (RF), R. albus (RA), RA+FS, M+RA+FS, and control. The cultures were added in the batch reactors with the increasing dose levels of 1% (0.5 mL), 3% (1.5 mL) and 5% (2.5 mL). Incubation for the BMP assay was carried out for 60 days at $38^{\circ}C$ using anaerobic digestate obtained from an anaerobic digester with pig slurry as inoculum. In results, 5% RF and RA+FS increased total biogas up to 8.1 and 8.4%, respectively, compared with that of control (p<0.05). All 5% microbial culture supplements significantly increased methane production up to 12.1~17.9% compared with that of control (p<0.05). Total solid (TS) and volatile solid (VS) digestion efficiencies showed no relationship to the increased supplementation levels of microbial cultures. After incubation, pH values in all treatment groups ranged between 7.527 and 7.657 indicating that methanogensis was not inhibited during the incubation. In conclusion, the results indicated that both hydrolysis and methanogenesis stages for methane production in anaerobic batch reactors were influenced by the supplemented microorganisms due to the chemical characteristics of pig slurry, but only the 5% supplementation level of all microbial culture supplements used in the experiment affected methane production.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.515-523
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• 2012

The study investigated the biochemical methane potential (BMP) assay of cellulose supplementing with mixed methanogens and cellulolytic bacteria to improve anaerobic digestion for methane production. For the BMP assay, 7 different microbial supplementation groups were consisted of the cultures of mixed methanogens (M), Fibrobacter succinogenes (FS), Ruminococcus flavefaciensn (RF), R. albus (RA), RA+FS and M+RA+FS including control. The cultures were added in the batch reactors with the increasing dose levels of 1% (0.5 mL), 3% (1.5 mL) and 5% (2.5 mL). Incubation for the BMP assay was carried out for 40 days at $38^{\circ}C$ and anaerobic digestate obtained from an anaerobic digester with pig slurry as inoculum was used. In results, 5% FS increased total biogas and methane production up to 10.4~22.7% and 17.4~27.5%, respectively, compared to other groups (p<0.05). Total solid (TS) digestion efficiency showed a similar trend to the total biogas and methane productions. Generally the TS digestion efficiency of the FS group was higher than that of other groups showing at the highest value of 64.2% in the 5% FS group. Volatile solid (VS) digestion efficiencies of 68.4 and 71.0% in the 5% FS and the 5% RF were higher than other groups. After incubation, pH values in all treatment groups were over 6.4 indicating that methanogensis was not inhibited during the incubation. In conclusion, the results indicated that the hydrolysis stage for methane production in anaerobic batch reactors was the late-limiting stage compared with the methanogenesis stage, and especially, as the supplementation levels of F. succinogenes supplementation increased, the methane production was increased in the BMP assay compared with other microbial culture addition.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.388-395
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• 1987

In order to obtain a regulatory mutant strain with high cellulase activity, a newly isolated Penicillium verrculosum, strain F-3 was used as parental strain since it was proved to be an efficient cellulase producer. A number of experiments were conducted to determine the optimum conditions to in-duce mutagenesis and isolate the desirable mutant strains. Out of several restriction compounds tested, 1.5% oxgall was found to be most effective to restrict the colony size by suppressing overgrowth. Derepression of catabolites was employed as a criterion in selecting mutant strains with high cellulase productivity. Production of cellulase by Penicillium venculosum F-3 was suppressed when cultured on the media with more than 1% of glucose or glycerol. It was found that either irradiation with UV light for 19 mins or treatment with nitrosoguanidine at 200$\mu\textrm{g}$/m1 for 60 mins, induced mutagenesis at desired level, when the survival rate of the spore was 0.2% and 48%, respectively. Three mutant strains of F-3, UV-9, UV-10, and NTG-3 that had the highest cellulase productivity were finally selected, based on filter paper degradation rate, size of clearing zone on the screening plate and cellulase activity in the medium containing cellulose powder. When the mutant strains were compared with parental strain F-3, on the KC-M-W medium containing cellulose powder, the filter paper activities of UV-9, UV-10, and NTG-3 were increased by 34%, 55%, and 41%, respectively. However, the assimilation of cellobiose octaacetate by UV-9 or NTG-3 was markedly reduced. When the mutant UV-10 was grown on cellobiose octaacetate medium (CCA-4) in shaking flasks, the cellulase activities of the mutant increased by 20 to 50% compared to the parental strain. Excreation of soluble protein from the mutant also elevated up to 30%. The mutant also constitutively produced both CMCase and $\beta$-glucosidase, though at relatively low level, in the presence of glucose or cellobiose as carbon sources.