• Environmental Engineering Research
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• 제19권4호
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• pp.387-393
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• 2014

The purpose of this study is to evaluate integrated anaerobic hydrogen fermentation and membrane bioreactor (MBR) for on-site domestic wastewater treatment and resource recovery. A synthetic wastewater (COD 17,000 mg/L) was used as artificial brown water which will be discharged from urine diversion toilet and fed into a continuous stirred tank reactor (CSTR) type anaerobic reactor with inclined plate. The effluent of anaerobic reactor mixed with real household grey water (COD 700 mg/L) was further treated by MBR for reuse. An optimum condition maintained in anaerobic reactor was HRT of 8 hrs, pH 5.5, SRT of 5 days and temperature of $37^{\circ}C$. COD removal of 98% was achieved from the overall system. Total gas production rate and hydrogen content was 4.6 L/day and 52.4% respectively. COD mass balance described the COD distribution in the system via reactor byproducts and effluent COD concentration. The results of this study asserts that, anaerobic hydrogen fermentation combined with MBR is a potent system in stabilizing waste strength and clean hydrogen recovery which could be implemented for onsite domestic wastewater treatment and reuse.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1084-1093
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• 2000

An in vitro gas production system was used to investigate the influence of various substrate mixtures on a natural mix of rumen microbes by measurement of fermentation end-products. The treatments were combinations of cassava (15.0, 30.0 and 45.0%) with different roughage sources (ruzi grass, rice straw or urea treated rice straw). Microbial biomass, net $^{15}N$ incorporation into cells, volatile fatty acid production, gas volume and rate of gas production increased linearly with increasing levels of cassava inclusion. There was also an effect of roughage source, with rice straw being associated with the lowest values for most parameters whilst similar values were obtained for ruzi grass and urea treated rice straw. The results suggest that microbial growth and fermentation rate increase as a function of readily available carbohydrate in the substrate mixture. A strong linear relationship between $^{15}N$ enrichment, total volatile fatty acid production and gas production kinetics support the suggestion of the use of the in vitro gas production system as a tool for screening feedstuffs as an initial stage of feed evaluation.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.358-362
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• 1988

세포외 효소를 효율적으로 생산하기 위한 새로운 발효시스템으로서 수성 2상계를 시험하였다. 실험대상으로는 Bacillus amyloliquefaciens 균주에 의하여 $\alpha$-amylase를 생산하는 시스템을 선정하였다. Polyethylene glycol 5%, dextran 7%, 그리고 발효액이 88% 포함된 수성 2상계 발효시스템에 의하여 $\alpha$-amylase의 생합성은 25% 정도 증가하였으며 효소의 비활성화는 관찰되지 않았다. 또한 Polyethylene glycol 이 효소의 생합성을 증진시키는 것으로 관찰되었다. 효소의 생합성을 증가시키며 동시에 효소를 발효액으로부터 분리하기 위하여는 polyethylene glycol을 성장도중에, dextran은 효소의 활성이 최고에 달한 후에 발효액에 가하는 발효방법이 바람직하다.

• 한국미생물·생명공학회지
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• 제48권1호
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• pp.32-37
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• 2020

We improved on a unified saccharification and fermentation (USF) system for the direct production of ethanol from agarose by increasing total agarase activity. The pGMFα-NGH plasmid harboring the NABH558 gene encoding neoagarobiose hydrolase and the AGAG1 and AGAH71 genes encoding β-agarase was constructed and used to transform Saccharomyces cerevisiae 2805. NABH558 gene transcription level was increased and total agarase activity was increased by 25 to 40% by placing the NABH558 gene expression cassette upstream of the other gene expression cassettes. In the 2805/pGMFα-NGH transformant, three secretory agarases were produced that efficiently degraded agarose to galactose, 3,6-anhydro-L-galactose (AHG), neoagarobiose, and neoagarohexaose. During the united cultivation process, a maximum of 2.36 g/l ethanol from 10 g/l agarose was produced over 120 h.

• 센서학회지
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• 제17권2호
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• pp.151-155
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• 2008

In this paper, it was investigated that the pattern recognition of multiplication environment of lactic acid bacteria in the process of curd yogurt preparation using household fermentation system, which was manufactured by combining incubator with sensor module, data processing circuit and computer. It will be sufficiently applicable to determine the maximum ratio of the amount of air to mixed milk for preparation of high quality yogurt.

• Agricultural and Biosystems Engineering
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• 제5권2호
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• pp.50-54
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• 2004

The study aimed to develop a mechanized mushroom growing system for the substrate materials mixing and wetting, materials fermentation and pasteurisation through the design of integrated cultivation machine system for oyster mushroom. The power requirement of the prototype during fermentation operation was measured in the range of 31$\~$33 kg-m and the torque has not so much differ by the kinds and quantity of materials. The work efficiency of conventional method for stacking the heap and turning the heap of cotton waste by tractor rotavator and manual wetting required 78 hours. But the watering, fermentation and sterilisation by the prototype use same operation required 25.5 hours, which can save the operation labour by $67\%$. The machine can be saved the requirement of heating energy by $63\%$, and the machine can also be saved the material cost by $44\%$. It is envisaged that the machine can effectively be used for large mushroom growing farms or joint use mushroom growing group-farmers in a village.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.1047-1053
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• 2022

When ptsG, a glucose-specific phosphotransferase system (PTS) component, is deleted in Escherichia coli, growth can be severely poor because of the lack of efficient glucose transport. We discovered a new PTS transport system that could transport glucose through the growth-coupled experimental evolution of ptsG-deficient E. coli C strain under anaerobic conditions. Genome sequencing revealed mutations in agaR, which encodes a repressor of N-acetylgalactosamine (Aga) PTS expression in evolved progeny strains. RT-qPCR analysis showed that the expression of Aga PTS gene increased because of the loss-of-function of agaR. We confirmed the efficient Aga PTS-mediated glucose uptake by genetic complementation and anaerobic fermentation. We discussed the discovery of new glucose transporter in terms of different genetic backgrounds of E. coli strains, and the relationship between the pattern of mixed-acids fermentation and glucose transport rate.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.275-287
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• 2000

Fermentation strategies for recombinant protein production in Pichia pastoris have been investigated and are reviewed here. Characteristics of the expression system, such as phenotypes and carbon utilization, are summarized. Recently reported results such as growth model establishment, app58lication of a methanol sensor, optimization of substrate feeding strategy, DOstat controller design, mixed feed technology, and perfusion and continuous culture are discussed in detail.

• 한국식품과학회지
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• 제26권3호
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• pp.199-203
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• 1994

외기의 온도를 감지하여 김치의 품온을 유추함으로써 사계절에 관계없이 일정한 김장 김치맛을 감도록 하면서 소비자의 기호도를 고려하여 풋맛(key I), 김장맛(key II), 익은맛(key III)에 가까운 김치를 조기에 숙성시켜 장기간 저장할 수 있는 냉장고용 자동 제어시스템을 개발하였다. 이때 온도에 대한 micom의 디지털 출력값과의 상관관계식은 $T(^{\circ}C)$=-2.1516D+61.2037이었고 R은 0.9759로 나타났다. 자동제어시스템에 의한 김치 발효효과를 조사한 결과 key I에서는 식염농도 2%, 3% 및 5%의 경우 김치의 적숙기에 해당하는 pH4.5. 산도 0.6%에 이르는데 각각 약 $3{\sim}4$일, $4{\sim}5$일 및 $11{\sim}12$일, key II에서는 약 $2{\sim}3$일, $3{\sim}4$일 및 $10{\sim}11$일 그리고 key III에서는 약 2일, 3일 및 $9{\sim}10$일이 소요되었다. 그리고 발효 및 저장선택 3단계 key에서 저장효과는 모두 14일까지 식이 가능한 수준의 pH 및 산도범위로 유지되었고 pH 및 산도, 총균수 및 젖산균수, 환원당 함량의 변화 결과로 보아 저장효과가 어느정도 더 연장될 것으로 나타났다. 한편, 김치의 관능평가에서도 기호도면에서 뚜렷한 차이를 보였는데 특히 3% 시험구가 관능적으로 가장 좋았고 2%, 5% 순으로 나타났다. 더욱이 5% 시험구는 발효도 느리게 일어나고 관능적인 면에서도 바람직하지 못한 것으로 나타났다.

• 한국미생물·생명공학회지
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• 제16권3호
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• pp.213-218
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• 1988

섬유소 폐기물인 볏짚으로부터 butanol를 생산하기 위하여 Clostridium acetobutylicum KCTC1037 와 cellulase(from Trichoderma viride)을 발효액에 동시에 첨가하여 발효시키는 동시당화 발효법(Simultaneous saccharification and fermentation, SSF)을 수행하였다. Alkali 처리한 볏짚을 발효기질로 사용한 결과 그 농도를 25%로 사용하였을 때 최고 150mM의 butanol이 생산되었고, 15% 볏짚을 사용하였을 때는 97mM의 butanol이 생산되었다. 그러나 ball milled 볏짚의 경우 발효산물 중 대부분이 acetate와 butyrate로 주로 산이 생산되었으며 따라서 solventogenesis는 거의 일어나지 않았다. 또한 그 농도별 실험에서 보면 8%의 ball milled 볏짚 사용시 66mM의 butanol이 생산된 반면 그 이상의 농도에서는 butanol 생산량이 점차 감소하는 추세를 보였으며 acetate, butyrate 같은 산은 계속 증가 추세를 보였다. 이것으로 보아 ball milled 볏짚에는 butanol 발효 과정 중 acidogenesis에 서 solventogenesis로의 전이 (shift)를 방해하는 어떤 인자가 있으리라고 추측되었으며 alkali 처리방법에 의해서 이 방해자는 제거될 수 있는 것으로 관찰되었다.