• 유기물자원화
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• 제4권1호
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• pp.1-11
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• 1996

음식물 쓰레기의 고온 퇴비화 과정에서 종균 첨가가 미생물의 변화에 미치는 영향을 조사하였다. 실험실용 소형 퇴비화 장치에 선발한 고온성 세균, 효모 및 고온성 세균, 효모 복합종균을 첨가하여 $50^{\circ}C$에서 분해시키면서 고온성 세균과 효모의 생육 및 pH의 변화를 측정한 결과, 모든 실험구에서 효모가 우선적으로 생육하였으며 고온성 세균은 그보다 1일 또는 2일 후에 생육하였다. 종균으로 고온성 세균만 사용한 경우는 효과가 거의 없었으나 고온성 세균과 효모의 복합 종균을 첨가한 경우에는 고온성 세균의 생육이 현저히 촉진되었다. 특히 효모 종균을 단독으로 첨가한 경우에도 고온성 세균의 수가 반응 시작부터 급속히 증가하였다. 이러한 결과는 음식물 쓰레기의 분해시 고온성 세균의 증식에는 효모의 역할이 필수적인 것으로 나타났으며 그 이유는 효모가 세균의 생육을 저해하는 유기산을 제거하기 때문으로 밝혀졌다.

• 한국물환경학회지
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• 제21권5호
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• pp.490-495
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• 2005

Since there are very limited numbers of thermophilic anaerobic digesters being operated, it is often difficult to start up a new one using sludge from an existing reactor as a seed. However, for obvious reasons it seems few attempts have been made to compare the start-up performance of thermophilic anaerobic digestion using different sources of seed sludges. The purpose of this study was to evaluate the start-up performance of anaerobic digestion using aerobic Waste Activated Sludge (WAS) from a plant and mesophilic Anaerobic Digested Sludge (ADS) as the seed source at both mesophilic ($35^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures. In this study, two experiments were conducted. First, thermophilic anaerobic reactors were seeded with WAS (VSS = 4,400 mg/L) and ADS (VSS = 14,500 mg/L) to investigate start-up performance with a feed of acetate as well as propionate. The results show that WAS started to produce $CH_4$ soon after acetate feeding without a lag time, while ADS had a lag time of 10 days. When the feed was changed to propionate, WAS removed propionate down to below the detection limit of 10 mg/L, while ADS removed little propionate and produced little $CH_4$. Second, in order to further compare the methanogenic activity of WAS and ADS, both mesophilic and thermophilic reactors were operated. WAS acclimated to anaerobic conditions shortly and after acclimating it produced more $CH_4$ than ADS. WAS at mesophilic temperature biodegraded acetate at the same rate as for thermophilic. However WAS at mesophilic temperature biodegraded propionate at a much faster rate than at thermophilic. WAS as the seed source of anaerobic digestion resulted in much better performance than ADS at both mesophilic and thermophilic temperatures for both acetate and propionate metabolism.

• 한국환경보건학회지
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• 제10권1호
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• pp.107-117
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• 1984

This study was made to evaluate the temperature effects on anaerobic digestion of swine manure. A laboratory single-stage, high-rate, anaerobic digester was operated at 10, 20 and 30 day's HRT at the temperature of 35$\circ$C or 55$\circ$C. The conclusions from this study are as follows: (1) COD and BOD reductions were similar in both the mesophilic and thermophilic digestions. (2) With thermophilic digestion, volatile reduction increased to 67%, as compared with 60% of mesophilic digestion. With thermophilic digestion, the pH increased to 8.5 as compared with 8.0 of mesophilic digestion. With thermophilic digestion, the concentration of volatile acid increased to 763 mg/l, as compared with 250 mg/l of mesophilic digestion. While the gas was produced by mesophilic digestion at 0.74m$^3$/kg of VS fed, it increased to 0.87 m$^3$/kg VS fed by thermophilic digestion. The refractory VS was about 25% of the infiuent VS.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1976-1982
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• 2007

In the current studies, we characterized the degradation of a hot mixture of benzene and toluene (BT) gases by a thermophilic biofilter using polyurethane as a packing material and high-temperature compost as a microbial source. We also examined the effect of supplementing the biofilter with yeast extract (YE). We found that YE substantially enhanced microbial activity in the thermophilic biofilter. The degrading activity of the biofilter supplied with YE was stable during long-term operation (approximately 100 d) without accumulating excess biomass. The maximum elimination capacity ($1,650\;g{\cdot} m^{-3}{\cdot} h^{-1}$) in the biofilter supplemented with YE was 3.5 times higher than that in the biofilter without YE ($470\;g{\cdot} m^{-3}{\cdot} h^{-1}$). At similar retention times, the capacity to eliminate BT for the YE-supplemented biofilter was higher than for previously reported mesophilic biofilters. Thus, thermophilic biofiltration can be used to degrade hydrophobic compounds such as a BT mixture. Finally, 168 rDNA polymerase chain reaction-DGGE (PCR-DGGE) fingerprinting revealed that the thermophilic bacteria in the biofilter included Rubrobacter sp. and Mycobacterium sp.

• 미생물학회지
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• 제36권1호
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• pp.33-39
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• 2000

버섯을 재배하는데 있어 버섯 균사의 성장은 고온성 곰팡이의 성장과 밀접한 연관이 있다. 느타리버섯 재배용 배지의 후발효 과정에서 느타리균사에 대하여 성장촉진 효과를 나타내는 7종의 thermophilic fungi를 순수분리 하였다. 각 7종의 thermophilic fungi모두 PDA(potato dextrose agar) 배지, $50^{\circ}C$에서 균사의 최적성장을 나타내었으며, 그 중 S-1, S-2 균주가 균사성장률이 가장 높았다. 또한 느타리버섯 폐면 배지에서도 좋은 성장을 나타내 우수한 고온성 후발효 균주로의 사용 가능성이 기대되었다. 액체배양 시 배지의 최초 pH는 pH 7.0- pH 10.0까지 다양한 구간에서 최적상태를 나타내었으나, pH 8.0또는 pH 9.0의 약알칼리 환경에서 잘 자랐으며, 배양 후 배지의 pH는 pH 5.5-6.0의 약산성을 띄었다. 이러한 최적환경에서 성장률을 측정한 결과 S-2 균주가 높은 성장률(0.47-0.50g/10 days)을 나타내었다. 형태적인 분류법에 따라 분류한 결과 S-1 균류는 Trichophyton sp.으로 동정되었으며, 이 외의 6 균주는 Sepedonium sp으로 분류되었다. 느타리버섯 후발효 과정에서 나타난 고온성 곰팡이들의 분포는 양송이 배지 숙성과정에 나타나는 고온성 곰팡이들의 분포와는 매우 달랐다. 이는 배지 성분 차이에 따른 생태적 차이로 판단되었다.

• 한국식품저장유통학회지
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• 제10권1호
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• pp.70-74
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• 2003

벼의 산지 및 품종별로는 중온 및 고온성 세균의 분포에 큰 차이가 없었으며, 도정도가 낮을수록 저장기간이 길수록 각각의 균들이 많이 존재하였다. 전기밥솥에서 고온성 세균의 증식은 75$^{\circ}C$이하에서 보온온도가 낮을수록 빠르게 나타났으며, 보온 초기에는 나타나지 않았으나 18∼24시간 사이에 증식속도가 빨라지는 경향을 나타내었다. 전기밥솥 밥의 고온성 세균수와 이상취 발생의 상관성은 있었으며, 고온성 세균수는 오븐내 밥의 표면중앙이 중심이나 밑바닥에 비하여 약간 많게 나타났다. 백미밥의 휘발성 성분은 보온초기에는 쌀로부터 유래되는 hexanal이 주성분이었으며, 장시간보온 후는 이상취를 나타내는 furan을 포함한 고비점 물질이 많았다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.469-474
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• 2000

In order to enhance the degradation efficiency of waste activated sludge (WAS) by thermophilic aerobic digestion, an ultrasonic pretreatment was examined. It was observed that ultrasonic pretreatment increased the solubilization of organic matter in the WAS and that the solubilization ratio of the organics increased during the first 30 min but did not extensively increase thereafter. Therefore, a pretreatment time of 30 min was determined to be the economical pretreatment time from the experimental results. From the digestion experiments, which was conducted using the WAS collected from an oil refinery plant in Inchon, Korea, investigating the effects of an ultrasonic pretreatment on thermophilic aerobic digestion, it was confirmed that the proposed ultrasonic pretreatment was effective at enhancing the release of the cellular components in WAS and the degradation of released components in the thermophilic aerobic digestion.

• 한국물환경학회지
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• 제23권6호
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• pp.906-912
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• 2007

A lab-scale thermophilic aerobic digestion (TAD) system was operated at $64^{\circ}C$ with mixed primary and secondary sludges taken from a large wastewater treatment plant. The semi-continuously operated reactor at HRTs of 1, 3 and 6 days indicated that longer HRT could stabilize sludge organics and solids comparable to anaerobic digestion. It has been found that reduced HRT of 3 and 1 day produced the effluent with highly biodegradable soluble organics, indicating the possibility of energy recovery in TAD. No proof of biological nitrification was observed at thermophilic operating temperature of $64^{\circ}C$, while nitrogen removal seemed due to nitrogen exertion during the aerobic thermophilic cell synthesis as well as ammonia stripping.

• 대한수의학회지
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• 제29권3호
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• pp.291-301
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• 1989

To investigate the epidemiological trait of intestinal diseases of animals caused by thermophilic Campylobacter spp., isolation of etiological agent was carried out. Isolated Campylobacter spp. were biotyped, serotyped and the susceptibility of the isolates to antimicrobial agents were examined. Th results were as follows. 1. Isolation rates of Campylobacter spp. from 649 fecal materials of 208 cattle, 300 pigs and 141 chickens were 25.5%, 23.7% and 38.3%, respectively. 2. The majority of the 130 isolates of C jejuni was classified as biotype I(50.6%) and biotype II (34.6%). Most of the 46 isolates of C coli were biotype I (71.7%). 3. Isolated C jejuni strains showed 14 different serotype, and serotype 4, 26, 36 were most frequent. Isolated C coli strains showed 5 different serotype and serotype 31 and 21 were relatively common. 4. Isolated Campylobacter spp. were highly susceptible to nalidixic acid, amikacin, gentamicin, colistin and chlorampehnocol.

• 한국환경과학회지
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• 제15권9호
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• pp.897-905
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• 2006

This study has been conducted to investigate biodegradation characteristics and optimum mixing ratio for co-digestion with thermophilic acid-fermented food waste and sewage sludge using batch anaerobic digester. As the basis operating conditions for anaerobic digestion, the reaction temperature was controlled $35{\pm}1^{\circ}C$ and stirrer was set 70rpm. Thermophilic acid-fermented food waste and sewage sludge were mixed at the ratio of 10:0, 7:3, 5:5, 3:7, 0:10 and 5;5(food waste : sewage sludge) as the influent substrates. In results of co-digestion according to mixing ratio of thermophilic fermented food wastes and sewage sludge in batch mesophilic anaerobic digestion reactor, $385mL\;CH_4/g\;VS_{added}$ of methane production rate at 1:1 mixing ratio was more than that of any other mixing ratios. Compared with $293mL\;CH_4/g\;VS_{added}$ of methane production rate at 1:1 mixing ratio of food wastes and sewage sludge, pretreatment of food wastes by thermophilic acid fermentation was more effective in co-digestion with sewage sludge.