• KSBB Journal
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• 제23권1호
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• pp.54-58
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• 2008

수소는 연료전지와 같은 친환경적인 용도로 인해 미래의 에너지로서 주목받고 있는데, 생물학적인 발효법은 수소의 생산을 위한 유망한 방법이다. 본 연구에서는 Enterobacter aerogenes KCCM 40146을 대상으로 수소 생산을 최대로 하기 위한 배지의 조건을 최적화하였다. 그 결과, 0.5M potassium phosphate buffer pH 6.5에서 glucose 30 g/L일 때 수소의 누적 농도가 431 $m{\ell}$로 최대값을 얻을 수 있었다. 질소원으로 peptone과 tryptone을 넣은 배지가 수소의 생산 뿐 아니라 균주의 성장에 가장 효율적이었다 한편, 미생물의 성장속도조절이 수소의 효율적 생산을 위해 중요한 실험변수임을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제5권5호
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• pp.292-296
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• 1995

Production of poly($\beta$-hydroxybutyrate-co-$\beta$-hydroxyvalerate)[poly(HB-co-HV) from glucose and propionic acid was studied in a two-stage fed-batch fermentation using Alcaligenes eutrophus NCIMB 11599. When either glucose became sufficient or the feeding rate of propionic acid decreased, production of poly(HB-co-HV) increased but concomitantly resulted in a reduced fraction of HV. During the copolymer accumulation stage, the specific production rate of hydroxyvalerate (HV) increased up to 0.013 (g-HV/g-RCM/h) but it decreased as propionic acid was accumulated. Control of the propionic acid concentration in the medium, therefore, is considered to be one of the most important operating parameters for production of poly(HB-co-HV) with a higher HV fraction. A high titre of poly(HB-co-HV) (85.6 g/I) with HV fraction of 11.4 mol$%$ could be obtained in 50 h by controlling the propionic acid concentration at 1 to 4 g/I.

• 동아시아식생활학회지
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• 제19권3호
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• pp.356-362
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• 2009

The objective of this study was to investigate the biological activities of fermented mugworts and their effects on the lipid metabolism in hyperlipidemia-induced rats. The proximate compositions of two kinds of mugwort, Artemisia capillaris Thumberg and Artemisiae asiaticae Nakai, were compared before and after fermentation. In both types of mugwort crude protein and amino nitrogen contents markedly increased with fermentation. Thrombolytic activity determined from the size of the clear zone on a fibrin plate was higher for the Artemisiae asiaticae Nakai, especially in the fermented sample. Antioxidative activity according to DPPH(1,1-diphenyl-2-picrylhydrazyl) radical scavenging effects was higher for Artemisia capillaris Thumberg but no significant differences were found between the samples after fermentation. The body weights of hyperlipidemia-induced rats that were fed the mugworts for 4 weeks were lower than those of the control group. In all the mugwort-fed rats serum total cholesterol and LDL-cholesterol levels remarkably decreased. Furthermore the fermented mugworts were found to be more effective at decreasing triglyceride (TG) levels. It is also noteworthy that the highest HDL-cholesterol levels were observed in the rats treated with the fermented Artemisiae asiaticae Nakai. And fatty liver weights were higher in the rats fed Artemisia capillaris Thumberg. In conclusion the feeding of fermented Artemisiae asiaticae Nakai was effective for increasing thrombolytic activity and HDL-cholesterol levels as well as reducing TG levels in rats.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.959-965
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• 2013

Monascus species have been used to produce fermented rice called Monascus-fermented rice (MFR). To improve a Monascus strain via activation of secondary metabolite (SM) gene clusters for use in the production of MFR, we overexpressed an ortholog of the laeA gene, which encodes a global positive regulator of secondary metabolism under the control of the strong heterologous Aspergillus nidulans alcA promoter in Monascus pilosus. The OE::laeA transformant produced more SMs, including those not detected under uninduced conditions. MFR produced using the M. pilosus OE::laeA strain contained 4 times more monacolin K, a cholesterol-lowering agent, than MFR produced using the wild-type strain. In addition, pigment production was remarkably increased, and the antioxidant activity was increased as well. The results from this study suggest that Monascus species, which are important industrial fermentative fungi in Asia, can be improved for the production of functional foods by overexpressing the laeA gene.

• 한국식품영양과학회지
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• 제29권1호
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• pp.30-34
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• 2000

김치의 저장성을 연장하기 위한 시도의 하나로 1,000 ppm 농도의 자몽종자추출물(grapefruit seed extrtact, GFSE)과 구연산 용액에 절임 배추를 각각 씻어서 김치를 담근 다음 숙성시키면서 품질 특성의 변화를 측정하였다. GFSE 및 구연산에 세척한 배추로 담근 김치는 대조구에 비하여 pH 저하 및 적정산도의 증가가 늦어지는 것으로 나타나 숙성 기간의 연장 효과가 있는 것으로 나타났다. 또한 환원장은 GFSE로 처리한 시험구가 숙성 20일까지 가장 높은 값을 나타내어 발효가 억제되는 것으로 나타났다. GFSE를 처리한 시험구는 숙성 10일까지 대조구에 비하여 총균수 및 유산균수가 낮은 것으로 나타났으나 구연산 처리구는 대조구와 큰 차이를 나타내지는 않았다.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.51-57
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• 2007

The effects of maesil extract addition on the palatability and quality of kochujang, a traditional Korean condiment, were investigated in terms of the microbial characteristics, enzyme activities, and taste components during 100 days of fermentation. Viable cell counts of bacteria and yeast in maesil extract-added kochujang (maesil kochujang) were increased in proportion to added maesil extract from 1 to 5% during fermentation, up to 80 and 20 days, respectively and maintained $5.0{\sim}14.5{\times}10^6$ CFU/g. Activities of α-amylase, $\beta$-amylase, and protease were also increased in proportion to added maesil extract up to 20, 20, and 60 days, respectively and were higher than those of control during the aging process. The major organic acids in maesil kochujang were citric and malic acid. Composition and content of free sugar were not changed remarkably in general by the addition of maesil extract except maltose. The major free sugars of maesil kochujang were in the order of glucose>sucrose>maltose, and glucose content decreased significantly as the ratio of maesil extract increased, while maltose content increased significantly (p<0.05).

• 농업과학연구
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• 제43권3호
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• pp.379-386
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• 2016

Four ruminally cannulated Holstein steers (BW $482.9{\pm}8.10kg$), fed low protein TMR (CP 11.7%) as a basal diet, were used to investigate changes in rumen fermentation and blood metabolism according to protein fraction, cornell net carbohydrates and protein system (CNCPS), and enriched feeds. The steers, arranged in a $4{\times}4$ Latin square design, consumed TMR only (control), TMR supplemented with rapeseed meal (AB1), soybean meal (B2), and perilla meal (B3C), respectively. The protein feeds were substituted for 23.0% of CP in TMR. Ruminal pH, ammonia-N, and volatile fatty acids (VFA) in rumen digesta, sampled through ruminal cannula at 1 h-interval after the morning feeding, were analyzed. For plasma metabolites analysis, blood was sampled via the jugular vein after the rumen digesta sampling. Different N fraction-enriched protein feeds did not affect (p > 0.05) mean ruminal pH except AB1 being numerically lower 1 - 3 h post-feeding than the other groups. Mean ammonia-N was statistically (p < 0.05) higher for AB1 than for the other groups, but VFA did not differ among the groups. Blood urea nitrogen was statistically (p < 0.05) higher for B2 than for the other groups, which was rather unclear due to relatively low ruminal ammonia-N. This indicates that additional studies on relationships between dietary N fractions and ruminant metabolism according to different levels of CP in a basal diet should be required.

• BMB Reports
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• 제38권3호
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• pp.294-299
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• 2005

In this report, we describe the high-yield secretory expression of the recombinant human anti-HBsAg Fab fragment from Pichia pastoris that was achieved by co-integration of the genes encoding the heavy and light chains (both under the control of alcohol oxidase promoter) into the genome of the yeast cells. The fed-batch fermentations were carried out in a 5 L scale. Both chains of the Fab were successfully expressed upon methanol induction. The absorbance ($OD_{600}$) of the broth can reach 350~500 at the end of fed-batch phase. After the induction, the expression level of the recombinant Fab (soluble) reached 420~458 mg/L. The recombinant Fab fragment was purified from the crude culture supernatant by ion exchange chromatography and the purity of the recombinant Fab fragment was over 95%. The affinity activities of the crude fermentation supernatant and the purified Fab were analyzed by indirect ELISA, which showed that the purified recombinant Fab fragment had high affinity activity with hepatitis B surface antigen.

• Journal of Ginseng Research
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• 제20권3호
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• pp.307-317
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• 1996

This study was undertaken to examine the effects of fresh ginseng addition on the chemical and sensory properties of dongchimi juice fermented under various conditions. The contents of free sugars in dongchimi juice during fermentation increased at the initial stage, but decreased at the palatable stage and then increased again thereafter. Free sugars were higher in dongchlml juice with 4% of ginseng addition than with Soye ginseng and without ginseng addition. Analyses of organic acid contents showed that all three groups contained relatively high amounts of citric, lactic and malic acids. It was also found that, as fermentation progressed, the amounts of tactic and acetic acids in- creased, while that of malic acid decreased at the palatable stage and increased again thereafter. Total saponins were highest in dongchimi juice fermented at 4$^{\circ}C$ with 4% of ginseng addition and panax atrlol ginsenosldes were found more than panaxadiol ginsenosides in dongchimi juice The results of sensory evaluation revealed that dongchimi juice prepared with the addition of $4^{\circ}C$ and 4% ginseng was lower in sour taste and moldy off flavor than the control, thus scoring high In total acceptability. Dongchimi juice with 4% of ginseng addition was best in most sensory characteristics.

• Food Science and Biotechnology
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• 제16권1호
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• pp.146-149
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• 2007

Dynamic rheological properties of hot pepper-soybean paste (HPSP) mixed with xanthan gum were evaluated at different gum concentrations (0.3, 0.6, and 0.9%) and fermentation times (12 and 24 week). Magnitudes of storage (G') and loss moduli (G") in the HPSP-xanthan gum mixture systems increased with an increase in frequency ($\omega$), while complex viscosity (${\eta}^*$) decreased. G' values were higher than the G" values over most of the frequency range (0.63-63 rad/sec), and were frequency-dependent. The dynamic moduli (G', G", and ${\eta}^*$) of the HPSP-xathan mixtures were lower than those of the control (0% gum). The differences between the dynamic moduli values at 12-week and 24-week fermentation decreased with increasing gum concentration, showing that xanthan gum can be used to stabilize and improve the viscoelastic rheological properties of HPSP. The G' value of the HPSP-xathan mixtures increased with an increase in gum concentration from 0.3 to 0.9%, whereas the G" decreased. The ability of xanthan gum to increase the elastic properties in the HPSP-xanthan mixture systems seemed to be the result of the incompatibility phenomena existing between xanthan gum and glutinous rice starch.