• Journal of Life Science
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• v.21 no.11
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• pp.1599-1606
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• 2011

To evaluate the effects of microorganism agents on oil biodegradation, treatability and microcosm studies were conducted. Petroleum oil degrading bacteria were isolated from enriched cultures of oil-contaminated sediment samples using a mineral salts medium (MSM) containing 0.5% Arabian heavy crude oil as the sole carbon source. After a 5 day-incubation period using MSM, mixed microorganisms of three species (strains BS1, BS2 and BS4) degraded 48.4% of aliphatic hydrocarbons and 30.5% of aromatic hydrocarbons. Treatability and microcosm tests were performed in the three different treatment conditions (AO: Arabian heavy crude oil, AO+IN: Arabian heavy crude oil+inorganic nutrient, AO+IN+MM: Arabian heavy crude oil+inorganic nutrient+mixed microorganism agents). Among these, significantly enhanced biodegradation of aliphatic hydrocarbons were observed in AO+IN and AO+IN+MM conditions, without showing any different biodegradation rates in either condition. However, the degradation rates of aromatic hydrocarbons in an AO+IN+MM condition were increased by 50% in the treatability test and by 13% in the microcosm test compared to those in an AO+IN condition. Taken together, it can be concluded that mixed microorganism agents enhance the biodegradation of aliphatic and aromatic hydrocarbons in laboratory, a treatability test, and a microcosm test. This agent could especially be a useful tool in the application of bioremediation for removal of aromatic hydrocarbons.

• Korean Journal of Microbiology
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• v.21 no.3
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• pp.109-114
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• 1983

Physiological conditions for hydrogen evolution by Rhodopseudomonas sphaeroides K-7 are examined. Larger amount of molecular hydrogen was evolved at $30^{\circ}C$, pH6.8-7.0 under anaerobically illuminated condition of about 12, 000 lux by the organism. The heighest rates of hydrogen evolution were observed in the culture with the organic acids such as acetate, DL-lactate or DL-malate in media containing L-glutamate as a nitrogen source. Hydrogen was also evolved from glucose with the rate of $178.9\;{\mu}l/hr/mg$ cells (dry weight). When glucose was adopted a a sole carbon source, however, conside erable time lag of about 20hours was required for hydrogen evolution. The resting cells stored at $30^{\circ}C$ under argon maintained the rate of hydrogen evolution in nearly about 90% of initial one even 40 days of storation.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.703-712
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• 2010

This study performed to extract operation factors of major organic wastes, which were food wastes and waste activated sludge generated in industries in order to use them as a substrate for bio-H2 production. According to the results of experimental analysis for hydrogen production capacity by various organic concentrations, the hydrogen production yield was the highest at 80 g/L, and the efficiency was improved by the pretreatment of waste activated sludge (acid treatment, alkali treatment). Hydrogen production efficiency was improved by mixing food wastes and waste activated sludge if waste activated sludge was below than 30%, however, it was decreased when it was more than 50%. The impacts of heavy metals on the hydrogen production shows that the inhibition level depends on the concentration of Cr, Zn, and Cu, Fe was able to enhance the hydrogen production.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.211-216
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• 1983

Rhodopseudomonas sphaeroides K-7 evolves large quantities of molecular hydrogen under anaerobic and light illuminated conditions in the presence of utilizable organic compounds as electron donors. Photoevolution of molecular hydrogen was strictly dependent on light as the activity of nitrogenase in this organism. Both of these were inhibited to the nearly same extent at varying concentrations of ammonium ion which also depressed nitrogenase synthesis. In the reaction mixtures devoid of molybdenum ion which is known as the component of nitrogenase, hydrogen evolution also decreased similarly like nitrogenase activity. Photoevolution of molecular hydrogen appeared to have no relationship with hydrogenase activity and bacteriocholophyll content and it was markedly inhibited under the atmosphere of $C_2$H$_2$, $N_2$ or $O_2$. The results strongly indicate that hydrogen evolution by R. sphaeroides K-7 might be catalyzed by nitrogenase. Both hydrogen evolution and nitrogenase activity were largely influenced by the nutritional history of the resting cells. From which we propose that glutamate might play an important role in the regulation of nigrogenase activity in vivo.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.903-906
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• 2008

To analyze the growth of SOB (Thiobacillus novellus) and biochemical corrosion of concrete, simulation test method and device were developed. And two types of simulation tests were conducted according to a transplant method and a concentration of H2SO4. As a result, the SOB growth in distinct manners and antibiosis of specimen were observed. In the case of the specimens indirectly transplanted with SOB through culture solution submersion at a hydrogen sulfide level of 120ppm, the rapid activation of SOB and the resulting sulfuric acid production were observed. However, SOB were shown to grow rapidly and then die out in a relative short period of time. Meanwhile, in the case of the specimens directly transplanted with SOB at a hydrogen sulfide level of 50ppm, the long-term growth of SOB was possible, but the production of sulfuric acid by SOB did not progress. In the case of the antibiotic metal-mixed specimens, SOB with destroyed cell membranes and internal organizations were observed.

• Journal of Biosystems Engineering
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• v.23 no.1
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• pp.31-48
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• 1998

가축분뇨, 음식쓰레기 둥의 유기성 고형 폐기물의 퇴비화처리 과정의 성능 향상과 암모니아 가스 발생을 저감화 하려는 연구의 일환으로서 파이로트 규모의 원통형 회분식 분해조 및 숙성조를 설계, 제작하여 퇴비화 성능과 탈취 효과를 분석하였다. 고형퇴비화 처리에 미치는 주요요인은 초기재료의 수분, 탄질비, 수소이온농도, 발효온도 및 통기조건 등이다. 돈분에 부자재인 톱밥을 혼합하여 초기 재료의 수분, 탄질비, 수소이온농도 등을 동일한 재료로서 같은 수준에 유지하고 연속통기와 간헐통기 방식으로 퇴비화하는 동안에 분해 및 숙성단계의 부위별 발효온도의 변화, 산소흡수 및 탄산가스 배출농도의 변동, 평균통기량, 재료의 평균온도 변화, 암모니아가스 배출농도의 변화 등을 분해 및 숙성 전기간을 통해 측정하고 초기재료와 숙성재료의 주요 이화학적 성분을 분석하여 퇴비화 성능과 회비 탈취 효율을 비교하였다. 주요 연구결과는 다음과 같다. 1. 숙성과정 8일 이후의 암모니아가스 탈취효율은 연속통기법이 90%이고, 간헐통기법이 70%였으며, 분해 및 숙성과정의 발효온도, 탄산가스 발생, 암모니아가스 배출농도 및 숙성회비의 성분 둥의 결과로서 판단할 때 에 퇴비 화 소요기 간은 6주간이었다. 2. 탄산가스 배출농도 변화로서 간헐통기 퇴비화 방식은 연속통기법에 비하여 분해과정이 7일 정도 빠르고, 숙성과정이 10일 정도 단축되었으며 암모니아가스 농도도 적게 나타나고 있었다. 3. 퇴비화 분해과정이 지난 후 숙성과정 도입단계에서 퇴비재료의 혼합 교반에 따른 재료의 고온상승으로 인한 암모니아가스의 고농도화 현상의 억제대책이 필요하다고 판단되었다.