• IMMUNE NETWORK
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• 제23권1호
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• pp.6.1-6.24
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• 2023

Intestinal microorganisms interact with various immune cells and are involved in gut homeostasis and immune regulation. Although many studies have discussed the roles of the microorganisms themselves, interest in the effector function of their metabolites is increasing. The metabolic processes of these molecules provide important clues to the existence and function of gut microbes. The interrelationship between metabolites and T lymphocytes in particular plays a significant role in adaptive immune functions. Our current review focuses on 3 groups of metabolites: short-chain fatty acids, bile acids metabolites, and polyamines. We collated the findings of several studies on the transformation and production of these metabolites by gut microbes and explained their immunological roles. Specifically, we summarized the reports on changes in mucosal immune homeostasis represented by the Tregs and Th17 cells balance. The relationship between specific metabolites and diseases was also analyzed through latest studies. Thus, this review highlights microbial metabolites as the hidden treasure having potential diagnostic markers and therapeutic targets through a comprehensive understanding of the gut-immune interaction.

• KSBB Journal
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• 제14권2호
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• pp.205-211
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• 1999

본 연구에서는 A.cycloclast ATCC 21921 균주를 사용하여 $\gamma$-butyrobetaine으로부터 L-carnitine을 생산하는 최적 조건에 대한 연구를 수행하였다. 배양액 내에 $\gamma$-butyrobetaine 만을 포함하였을때는 최대 L-carnitine 생산량이 29g/L이었고 전환수율도 30.9 mol%로 매우 낮았다. L-carmtine 생산에 미치는 탄소원의 영향을 관찰한 결과 glycerol을 첨가할 경우 L-carnitine 생산량이 4.6g/L 그리고 전환수율이 88.2 mol%로 $\gamma$-butyrobetaineaks을 포함하였을 때보다 월등히 향상되었다. Betaine, chohne와 같은 quaternary ammonium compounds 들이 L-carnitine 생산에 미치는 영향을 조사해본 결과, 이들에 의하여 L-carntine 생산 속도가 빨라지고 전환수율도 증가함을 알 수 있었다. 한편, 기질인 $\gamma$-butyrobetaine 농도 3% 이상에서 세포 생장은 저해되고 L-carnitine 생산은 기질 농도 2-3%에서 가장 우수함을 알 수 있었다. 본 연구에서 구한 최적 생산 조건, 다시 말해서 glycerol과 choline을 배양액에 포함하고 기질의 농도를 2%^로 하여 플라스크에서 회분식 배양을 하였을 때, 배양 4일 만에 최대 7.2g/L의 L-carrutine을 생산할 수 있었고 이때 $\gamma$-butyrobetaine으로부터 L-carnitine에로의 전환수율은 98.7mol%이었다.

• Journal of Microbiology and Biotechnology
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• 제28권7호
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• pp.1217-1224
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• 2018

Seaweeds produce antioxidants to counteract environmental stresses, and these antioxidant genes are regarded as important defense strategies for marine algae. In this study, the expression of Pyropia yezoensis (Bangiales, Rhodophyta) ascorbate peroxidase (PyAPX) and manganese-superoxide dismutase (PyMnSOD) was examined by qRT-PCR in P. yezoensis blades under abiotic stress conditions. Furthermore, the functional relevance of these genes was explored by overexpressing them in Chlamydomonas. A comparison of the different expression levels of PyAPX and PyMnSOD after exposure to each stress revealed that both genes were induced by high salt and UVB exposure, being increased approximately 3-fold after 12 h. The expression of the PyAPX and PyMnSOD genes also increased following exposure to $H_2O_2$. When these two genes were overexpressed in Chlamydomonas, the cells had a higher growth rate than control cells under conditions of hydrogen peroxide-induced oxidative stress, increased salinity, and UV exposure. These data suggest that Chlamydomonas is a suitable model for studying the function of stress genes, and that PyAPX and PyMnSOD genes are involved in the adaptation and defense against stresses that alter metabolism.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.684-689
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• 2012

In the present study, an efficient mercury-tolerant bacterial strain (RS-5) was isolated from heavy-metalcontaminated industrial effluent. Under shake flask conditions, 97% of the supplemented mercuric chloride was sequestered by the biomass of RS-5 grown in a tryptone soy broth. The sequestered mercuric ions were transformed inside the bacterial cells, as an XRD analysis of the biomass confirmed the formation of mercurous chloride, which is only feasible following the reaction of the elemental mercury and the residual mercuric chloride present within the cells. Besides the sequestration and intracellular transformation, a significant fraction of the mercury (63%) was also volatilized. The 16S rRNA gene sequence of RS-5 revealed its phylogenetic relationship with the family Bacillaceae, and a 98% homology with Lysinibacillus fusiformis, a Gram-positive bacterium with swollen sporangia. This is the first observation of the sequestration and volatilization of mercuric ions by Lysinibacillus sp.

• 식물병연구
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• 제19권4호
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• pp.254-258
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• 2013

후자린산(FA)는 Fusarium 속 균이 생성하는 독소로서 다른 곰팡이독소보다 독성은 낮으나 다른 독소와 중복 오염시 전체 독성을 증진시키는 것으로 알려졌다. 현재까지 FA 생합성 관련 효소나 유전자가 Fusarium oxysporum에서 밝혀지지 않았기 때문에 본 연구에서는 관련 생합성 유전자의 발굴을 위해 제한효소를 통한 무작위 삽입 형질전환방법인 REMI를 이용하여 FA 생성 F. oxysporum 균주의 생합성유전자의 결손을 시도하였다. F. oxysporum 균주 2주를 대상으로 REMI를 시도한 결과, 평균 3.2주 ($1{\mu}g$ DNA 당)의 효율로 7,100주 이상의 형질전환체를 육성하였다. FA 미생성 형질전환체를 스크리닝 하기 위해 FA가 함유된 배양액에서 다양한 식물종자의 발아여부를 조사한 결과, 11종의 종자 중 가장 감수성인 배추종자를 선발하였다. 각 형질전환체는 Czapek-Dox broth에서 3주간 배양한 후 배양여액을 배추종자의 발아여부 검정에 사용하였다. 검정결과 총 5,000여 주의 REMI 형질전환체 중 53주의 배양여액에서 종자가 발아하지 않아, 이들을 FA 미(저) 생성 추정 형질전환체로 선발하였다. 이중 26주의 FA 생성량을 HPLC로 분석한 결과, 2주의 형질전환체에서 모균주 생성량의 1% 이하의 FA가 검출되었다. 이 중 형질전환체 1주로부터 REMI 벡터 삽입 부위 게놈 DNA의 염기서열(252 bp)을 확보하였으며, 이 부위는 F. fujikuroi의 미동정 게놈부위와 93% 유사성이 있음을 확인하였다. 이 부위의 FA생성 관련성 증명을 위해서는 추후 연구가 필요하다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.36-40
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• 1996

For the production of cis, cis-muconic acid via biocatalytic conversion reactions from a toxic cosubstrate, benzoic acid, a fed-batch process using computer-controlled DO-stat feeding was developed. The mutant strain of Pseudomonas putida BM014 produced cis, cis-muconic acid from benzoic acid with high conversion yield. More than 32 g/L of cis, cis-muconic acid was accumulated in 42h and a productivity of 1.4g/(L.h)was achieved.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2008년도 추계학술발표회
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• pp.123-124
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• 2008

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1150-1152
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• 2009

Geraniol (1) is the biogenetic precursor of a number of monoterpenes. We tested various marine-derived microorganisms to determine their ability to biotransform 1. Only Hypocrea sp. was capable of transforming 1 into its oxidized derivative, 1,7-dihydroxy-3,7-dimethyl-(E)-oct-2-ene (2). The structure of the metabolite obtained was assigned on the basis of detailed spectroscopic data analyses.

• Journal of Microbiology and Biotechnology
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• 제25권11호
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• pp.1773-1781
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• 2015

Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

• 한국해양바이오학회지
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• 제2권1호
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• pp.11-22
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• 2007

This aims to review natural products transformed by mimic intestinal metabolisms with microorganisms and hydrolytic enzymes, which exhibit enforced biological activity, higher extraction yield and identification of active components. In the process, transformation to the smaller active compounds with enzymes and microbes mimics the pharmacological action of natural products by intestinal bacteria. In order to establish conditions for the fermentation and enzyme reaction, it is required to choose several natural products for biotransformation and investigate the optimal conditions for the fermentation or the enzyme reaction such as composition, temperature, pH, inoculum, and cultivation time. It is expected an increase of the internal absorption of the active materials without regard to the intestinal microbes or its ability through biosynthesis of the active materials by the microbes and enzymes. And this techniques can be applied to biotransformation of natural products such as sesaminol, resveratrol, 1-deoxy nojirimycin, naringenin, quercetin, and baicalin and to the metabolism study using the animal model.