• 한국미생물·생명공학회지
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• 제31권4호
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• pp.395-399
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• 2003

본 연구에서는 S. hindustanus ATCC 31218로부터 선별된 변이주를 사용하여 배양조건이 nebramycin 주요 생산물인 factor 2, factor 4, factor 5', kanamycin A 등의 구성비율과 역가에 미치는 영향을 조사하였다. 실험결과, nebramycin의 factor들이 구성비율은 온도 및 배지보다는 배양액량, 교반속도 등에 의해 크게 영향을 받는 것으로 나타났다. 따라서 플라스크와 발효조의 산소전달속도를 각각 측정하여 factor 5' 생산의 최적 산소전달조건을 검토한 결과, $0.50 mMO_2$/min으로 배양시 factor 5'의 역가가 가장 높았으며 구성비율도 70% 이상을 나타내었다. 한편 $0.9 mMO_2$/min 이상으로 배양시는 factor 2의 역가와 구성비율이 현저히 감소한 반면 factor 2의 역가와 구성비율이 급격히 증가하였다. 한편 본 연구에 사용된 변이주 S. hindustanus YHT-0001는 factor 5'의 역가는 16.4배, factor 5'구성비율은 약 11% 향상된 균주로 확인되었다. S. hindustanus 발효시 공급되는 산소량은 단지 hydroxyl기와 아미노기의 존재유무에 따라 구조가 결정되는 factor 5', factor 4, kanamycin A의 hydroxyl기 생성을 위한 산소공여자로 역할뿐 만 아니라 배당체 구조에 차이를 보이는 apramycin 생합성과정에 영향을 크게 준다고 사료되었다.

• Journal of Microbiology and Biotechnology
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• 제19권7호
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• pp.690-697
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• 2009

In the present study, production of compactin by Penicillium brevicompactum WA 2315 was studied. In the first step, various precultural parameters were studied by substituting one factor at a time. Subsequently, the effect of maltodextrin DE 18 on compactin production was studied. The optimized parameters gave maximum compactin production of 850 ${\mu}g/gds$as compared with 678 ${\mu}g/gds$before optimization. Statistical study was performed to further improve the production and develop a robust model. An improved yield of 950 ${\mu}g/gds$was obtained using the conditions proposed by the experimental model. The present study emphasizes the importauce of precultural and nutritional parameters on the production of compactin, and further confirms the usefulness of solid-state fermentation for the production of industrially important secondary metabolites. It also confirms that complex nitrogen sources such as oil cakes can be used for the production of compactin.

• 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.

• Journal of Dairy Science and Biotechnology
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• 제40권1호
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• pp.23-34
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• 2022

In this study, to determine the importance of lactic acid bacteria (LAB) in Kombucha fermentation, biological functions, such as organic acid production and anti-inflammatory and antibacterial activities, of Kombucha, with or without LAB inoculation, were evaluated. Lactobacillus paracasei DK215, Saccharomyces cerevisiae C3, and Acetobacter pasteurianus P2 were selected as the inoculants. Organic acids were measured every 3 days from the end of fermentation using HPLC; the organic acid content of LAB-inoculated Kombucha was relatively high. Samples with or without LAB inoculation showed high antibacterial activity against Escherichia coli. The MTT assay results indicated no significant difference in concentration difference and cell death. In the NO production test, compared with the uninoculated Kombucha sample, the LAB-inoculated Kombucha sample exhibited a value similar to that of the group without LPS treatment. The levels of cytokine (IL-1α, IL-6, TNF-α) production were significantly lower than those of the LPS(+) group, indicating the anti-inflammatory activity potential of the Kombucha sample. This improvement in the biological function of the LAB-inoculated Kombucha further verifies the value of LAB in the fermented food and beverage industry.

• Animal Bioscience
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• 제37권2_spc호
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• pp.360-369
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• 2024

Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including Sharpea, uncharacterized Succinivibrionaceae, and certain Prevotella phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel Prevotella species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.227-230
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• 2000

Batch cultivations of Anaerobiospirillum succiniciproducens have been systematically studied for the economical production of succinic acid from wood hydrolysate with corn steep liquor(CSL) as a nitrogen source. CSL was found to be an alternative complex nitrogen source for A. succiniciproducens when glucose and wood hydrolysate were used as carbon sources. Compared with polypeptone and/or yeast extract, CSL had similar effects on fermentation performance such as succinic acid yield and a ratio of succinic acid to acetic acid in the fermentation of wood hydrolysate as well as glucose. This means that succinic acid can be produced more economically from wood hydrolysate and CSL than relatively expensive carbon and nitrogen sources. Besides its low cost, the alternative medium served as a green technology for succinic acid production because it gives a net-zero effect on global warming.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.615-621
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• 1993

In order to maximize the riboflavin production by a mutant strain Ashbya gosspyii, the optimization of medium and fed-batch fermentation were performed. As carbon sources, glucose and soybean oil were necessary for the riboflavin overproduction. Optimal concentrations of glucose and soybean oil in the flask cultures were found to be 3.0% and 0.5%, respectively, in a complex medium containing corn steep liquor(CLS) 1%. Among the various organic nitrogen sources tested, CSL was the most effective one both for the cell growth and riboflavin overproduction.

• 한국수산과학회지
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• 제11권4호
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• pp.213-217
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• 1978

Henri-Michaelis-Menten model for predicting the behavior of culture of Brevibacterium flavum under carbon limiting condition has been evaluated on a chemostat growing in the presence of the phenol derivatives: guaiacol, o-vanillin and vanillin. It is found that Henri-Michaelis-Menten model could be applicable to the evaluation of the growth rate of cells in the phenol derivatives. The marked enhancing abilities of the cells treated by the phenol derivatives during fermentation were ascribed to the formation of charge-transfer complex between the phenol-derivatives and oxygen which supplies oxygen effectively to the fermentation system.

• BMB Reports
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• 제45권7호
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• pp.377-389
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• 2012

Food fermentations have enhanced human health since the dawn of time and remain a prevalent means of food processing and preservation. Due to their cultural and nutritional importance, many of these foods have been studied in detail using molecular tools, leading to enhancements in quality and safety. Furthermore, recent advances in high-throughput sequencing technology are revolutionizing the study of food microbial ecology, deepening insight into complex fermentation systems. This review provides insight into novel applications of select molecular techniques, particularly next-generation sequencing technology, for analysis of microbial communities in fermented foods. We present a guideline for integrated molecular analysis of food microbial ecology and a starting point for implementing next-generation analysis of food systems.

• 미생물학회지
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• 제28권3호
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• pp.264-267
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• 1990

The objectives of the current studies were to establish the optimal conditions for the production of extracellular protease inhibitor in a strain of Streptomyces fradiae. As results, it was found that cell specific growth rate was very critical for the production of protease inhibitor and the optimum specific growth rate was found to be 0.05 h$^{-1}$ . Dissolved oxygen tension and pH were also important to regulate the inhibitor production. The inhibitory mode of the purified inhibitor to .alpha.-chymotrypsin was found to be competitive (K$_{i}$=5.5*10$^{-7}$ M). One mole of inhibitor could bind two moles of .alpha.-chymotrypsin and the complex has very low dissociation constant.t.