• 한국미생물·생명공학회지
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• 제19권2호
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• pp.179-185
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• 1991

We examined optimum culture conditions of Rhodopseudomonas sphaeroides B5 for effective utilization of substrate and sunlight for hydrogen production. The optimum concentration range of DL-lactate as electron donor for hydrogen production by resting cells was from 5 to 50mM, and optimun CN ratio (lactate/glutamat) for maintenence of hydrogen production activity by growing cultures was from 5 to 6. Hydrogen production by the cultures of low cell density (0.36mg/ml dry cells) was saturated with 10 Klux light intensity. Under constant illumination of 50Klux which was set up as the average medium value of annual variation of sunlight intensity, hydrogen production with various cell densities in the culture resulted in highest production rate (132${\mu}$l/hr/mg dry cells) up to 0.64mg/ml dry cells. However, the amount of total hydrogen production was saturated with cell density of 2.1mg/ml dry cells. In addition to these, the optimum inner thickness pervious to light of the culture vessel for hydrogen production which was measured under sunlight was 5 cm.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1262-1270
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• 2008

The objective of this study was to investigate the effect of dietary supplementation with calcium salts of soybean oil fatty acids (CaSO) and linseed oil fatty acids (CaLO) on c9,t11-CLA production in ruminal fluid and milk fat from Holstein dairy cows. Rumen fermentation, lactational performances and fatty acid profiles in ruminal fluid and milk fat were also investigated. Twenty multiparous Holstein dairy cows were allotted randomly into two groups consisting of ten cows in each group according to calving date and average milk yield. The first group of cows was fed a control (without calcium salts) diet and a treatment as 1.0% of CaSO (on DM basis) for 30 days in each period. In the second group, cows were fed the same control diet and 1.0% of CaLO as a treatment in the same manner. The forage: concentrate ratio was 52:48, and diets were formulated to contain 17% crude protein (DM basis) for both groups. Ruminal pH, protozoal numbers and the concentration of total volatile fatty acids were unchanged, however, the ruminal ammonia-N decreased by feeding CaSO or CaLO treatment compared to the control diet. The vaccenic acid (trans-11 C18:1; VA) in rumen fluid increased (p<0.01) by 169% and 153%, and the c9,t11-CLA content of rumen fluid increased (p<0.01) by 214% and 210% in the CaSO and CaLO treatments, respectively, compared to the control diet. In milk fatty acids, the VA content increased by 130% and 132% in the evening and morning milking times, respectively, and the c9,t11-CLA content increased by 125% in both milking times for the CaSO supplementation than that of control diet. In the case of CaLO supplementation, the VA increased by 117% and 114%, and the c9,t11-CLA increased by 96% and 94% in the evening and morning milking times, respectively, compared to the control diet. The contents of VA and c9,t11-CLA of milk fatty acids were numerically higher in the evening milking time compared to the morning milking time for control and both treatments. Finally, these results indicated that the supplementation of CaSO or CaLO treatment increased the VA and the c9,t11-CLA in both ruminal fluid and milk fat of Holstein dairy cows.

• 한국분말재료학회지
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• 제17권6호
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• pp.435-442
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• 2010

• Asian-Australasian Journal of Animal Sciences
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• 제26권8호
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• pp.1111-1118
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• 2013

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.

• 청정기술
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• 제8권4호
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• pp.193-198
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• 2002

지식정보사회에서의 기술은 가장 귀중한 지식의 형태이며 매우 큰 경제적 가치를 갖는다. 기술가치는 기술성, 시장성 등의 평가요소와 평가시점에 따라 좌우되므로 일반적인 재화에 비하여 그 가치를 측정하기 어려운 측면이 있다. 궁극적으로 불확정적인 미래의 변화에 능동적으로 대처하고 신뢰성 있는 기술가치평가를 위해서 환경적 가치측면을 고려하는 것은 매우 중요하다.

• Journal of Microbiology and Biotechnology
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• 제20권7호
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• pp.1086-1091
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• 2010

This study explored the use of gellan gum as an immobilization matrix for the production of cyclosporin A (CyA) by immobilized spores and mycelia of Tolypocladium inflatum MTCC 557. Different carriers, such as gellan gum, sodium alginate, celite beads, and silica, were tested as immobilization carriers, along with the role of the carrier concentration, biomass weight, number of spore-inoculated beads, and repeated utilization of the immobilized fungus. The maximum CyA production was 274 mg/l when using gellan gum [1% (w/v)], and a mycelial weight of 7.5% (w/v) supported the maximum production of CyA. Additionally, the addition of a combination of $_L$-valine (6 g/l) and $_L$-leucine (5 g/l) after 48 h of fermentation produced 1,338 mg/l of CyA when using gellan gum. The immobilized mycelia beads were found to remain stable for four repetitive cycles, indicating their potential for semicontinuous CyA production.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.584-599
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• 2017

Biodiesel is renewable, eco-friendly, clean burning diesel replacement that is consisted of short chain alkyl ester. Biodiesel is derived from the transesterification of vegetables oils or animal fats with alcohol. The process has some technical problems that must be resolved to reduce the high operation cost. Eco-friendly physical technologies by using microwave have successfully improved the transesterification for biodiesel production. This paper attempts to extensively review microwave-assisted technology for biodiesel production. Additionally, different types of catalyst for biodiesel production have been summarized. It is concluded that the microwave-assisted technique improves the reaction rate significantly in comparison with conventional methods. Therefore it can be a suitable method of reducing the reaction time and can also decreases the cost of biodiesel production.

• 한국수소및신에너지학회논문집
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• 제22권5호
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• pp.741-748
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• 2011

Hydrogen is clean and renewable, and recognized as a very promising energy resource to solve both depletion of petroleum and environmental problems caused by the use of fossil fuels. Extensive researches have been performed worldwide on the production technologies of hydrogen. In this paper, the technology trend of photo-electrochemical (PEC) hydrogen production was scrutinized based on the patent and paper analysis. Open/registered patents of US, JP, EP, and KR and SCI Journals related to the PEC hydrogen production technology between 1996~2010 were reviewed. Patents and papers were gathered by using the key-words searching method and filtered by desirable filtering criteria. The technology trend was discussed by classifying each patent and paper based on the publishing year, country, and organization, and analyzing the core patents and papers.

• Environmental Engineering Research
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• 제13권2호
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• pp.93-97
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• 2008

Anaerobic co-digestion of swine manure and food waste for biogas production was performed in serum bottles at 2% volatile solids(VS) concentration and various mixing ratios of two substrates(swine manure: food waste = 100 : 0 $\sim$ 0 : 100). Through kinetic mode of surface methodology, the methane production was fitted to a Gompertz equation. The specific methane production potential of swine manure alone was lower than that of food waste. However, maximum methane production potential increased up to 1.09-1.22% as food waste composition increased up to the 80%. The maximum methane production value of food waste was 544.52 mL/g VS. It was observed that the maximum methane production potential of 601.86 mL/g VS was found at the mixing ratio of 40:60.

• Environmental Engineering Research
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• 제20권4호
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• pp.370-376
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• 2015

This study investigated the effects of various arsenite concentrations on bio-hydrogen production from molasses using a sequence batch reactor (SBR) operated in a series of three batch cycles. In the first batch cycle, hydrogen production was stimulated at arsenite concentrations lower than 2.0 mg/L, while inhibition occurred at arsenite concentration higher than 2.0 mg/L compared to the control. Hydrogen production decreased substantially during the second batch cycle, while no hydrogen was produced during the third batch cycle at all tested concentrations. The toxic density increased with respect to the increase in arsenite concentrations (6.0 > 1.6 > 1.0 > 0.5 mg/L) and operation cycles (third cycle > second cycle > first cycle). The presence of microorganisms such as Clostridium sp. MSTE9, Uncultured Dysgonomonas sp. clone MEC-4, Pseudomonas parafulva FS04, and Uncultured bacterium clone 584CL3e9 resulted in active stimulation of hydrogen production, however, it was unlikely that Enterobacter sp. sed221 was not related to hydrogen production. The tolerance of arsenite in hydrogen producing microorganisms decreased with the increase in induction time, which resulted in severing the inhibition of continuous hydrogen production.