• 미생물학회지
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• 제21권3호
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• pp.143-148
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• 1983

Streptococcus sanguis와 여타 구강세균의 PZ-peptidase의 생산을 연구하였다. 세척한 온전한 세균세포를 효소윈으로, 그리고 PZ-pentapeptide를 효소의 기질로 사용하였다. 이 연구에서 책택한 균의 배양조건에서, S. sanguis에서는 넓은 범위의 효소활성도가, 실험실 균주와 신선한 분리균주에서 검출되었는데, 그 값은 O.5~7.9Unit/mg protein 이었다. Streptococcus mµtans와 Lactobacilli는 낮은 효소활성을 보였고 S. mutans의 경우 그 값은 0~0.5Unit/mg protein이었다. Streptococcus mitis와 Streptococcus salivarius는 다른 세균과 비교할 때 중등도의 효소활성을 갖고 있었고, Actiηomyces의 균주들은 S. sanguis처럼 넓은 범위의 활성도 (0~9.8 unit/mg protein)를 지니고 있었다. 본 논운에서 취급한 구강세균이 생성하는 PZ-peptidase가 사람의 타액단백질의 분해에 참여할 수 있는 가능성을 더불어 고찰하였다.

• Journal of Dairy Science and Biotechnology
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• 제41권1호
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• pp.34-43
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• 2023

Hydrolysis of whey-derived proteins using lactic acid bacteria (LAB) utilizes the mass culture method and fermentation of LAB to produce effective bioactive peptides. Whey protein has the biological potential of its precursors, but the active fragments may not be released depending on the hydrolysis method. As an alternative to these problems, the nutritional and bioactive functionality of the hydrolysis method have been reported to be improved using LAB for whey protein. Peptide fractions were obtained using a sample fast protein liquid chromatography device. Antioxidant activity was verified for each of the five fractions obtained. In vitro cell experiments showed no cytotoxicity and inhibited nitric oxide production. Cytokine (IL [interleukin]-1α, IL-6, tumor necrosis factor-α) production was significantly lower than that of lipopolysaccharides (+). As a result of checking the amino acid content ratio of the fractions selected through the AccQ-Tag system, 17 types of amino acids were identified, and the content of isoleucine, an essential amino acid, was the highest. These properties show their applicability for the production of functional products utilizing dietary supplements and milk. It can be presented as an efficient method in terms of product functionality in the production of uniform-quality whey-derived peptides.

• 미생물학회지
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• 제16권4호
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• pp.170-179
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• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Genomics & Informatics
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• 제8권2호
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• pp.63-69
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• 2010

Monofunctional biosynthetic peptidoglycan transglycosylase (MBPT) catalyzes the formation of the glycan chain in bacterial cell walls from peptidoglycan subunits: N-acetylglucosamine (NAG) and acetylmuramic acid (NAM). Bifunctional glycosyltransferases such as the penicillin binding protein (PBP) have peptidoglycan glycosyltransferase (PGT) on their C terminal end which links together the peptidoglycan subunits while transpeptidase (TP) on the N terminal end cross-links the peptide moieties on the NAM monosaccharide of the peptide subunits to create the bacterial cell wall. The singular function of MBPT resembles the C terminal end of PBP as it too contains and utilizes a similar PGT domain. In this article we analyzed the infectious and non infectious protein sequences of MBPT from 31 different strains of bacteria using a variety of bioinformatic tools. Motif analysis, dot-plot comparison, and phylogenetic analysis identified a number of significant differences between infectious and non-infectious protein sequences. In this paper we have made an attempt to explain, analyze and discuss these differences from an evolutionary perspective. The results of our sequence analysis may open the door for utilizing MBPT as a new target to fight a variety of infectious bacteria.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1321-1334
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• 2020

Beef, pork, chicken and milk are considered representative protein sources in the human diet. Since the digestion of protein is important, the role of intestinal microflora is also important. Despite this, the pure effects of meat and milk intake on the microbiome are yet to be fully elucidated. To evaluate the effect of beef, pork, chicken and milk on intestinal microflora, we observed changes in the microbiome in response to different types of dietary animal proteins in vitro. Feces were collected from five 6-week-old pigs. The suspensions were pooled and inoculated into four different media containing beef, pork, chicken, or skim milk powder in distilled water. Changes in microbial communities were analyzed using 16S rRNA sequencing. The feces alone had the highest microbial alpha diversity. Among the treatment groups, beef showed the highest microbial diversity, followed by pork, chicken, and milk. The three dominant phyla were Proteobacteria, Firmicutes, and Bacteroidetes in all the groups. The most abundant genera in beef, pork, and chicken were Rummeliibacillus, Clostridium, and Phascolarctobacterium, whereas milk was enriched with Streptococcus, Lactobacillus, and Enterococcus. Aerobic bacteria decreased while anaerobic and facultative anaerobic bacteria increased in protein-rich nutrients. Functional gene groups were found to be over-represented in protein-rich nutrients. Our results provide baseline information for understanding the roles of dietary animal proteins in reshaping the gut microbiome. Furthermore, growth-promotion by specific species/genus may be used as a cultivation tool for uncultured gut microorganisms.

• 약학회지
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• 제46권1호
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• pp.24-29
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• 2002

Enoyl-Acyl Carrier Protein Reductase (Fabl) of bacteria is hem as an important target for new antibacterial drugs and plays a determinant role in completing cycles of elongation in type-H fatty acid synthase system. In this study, a fabI gene from Staphylococcus aureus 6538p cloned in pET-l4b vector and FabI protein was over-produced in Escherichaia coli BL2l (DE3). $NH_2$-terminal His-tagged FabI protein was purified by nickel-nitrilotriacetic acid (Ni-NTA) metalaffinity chromatography Purified 6xHis-tagged FabI showed a catalytic activity on tram - 2 - octenoyl - N -acethlcysteamine by utilizing NADPH as a cofactor. For the discovery of new FabI inhibitors from chemical libraries, a target-oriented screening system using a 96-well plate was developed. About 10,000 chemical libraries from Korea Chemical Bank wore tested in this screening system, and 26 chemicals (0.25%) among them showed an inhibitory activity against FabI enzyme. This result showed that a new screening system can be used for the discovery of new FabI inhibitors.

• Mass Spectrometry Letters
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• 제5권4호
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• pp.110-114
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• 2014

The method of direct mass spectrometry profiling is reliable and reproducible for the rapid identification of clinical isolates of bacteria and fungi. This is the first study evaluating the approach of MALDI-TOF mass spectrometry profiling for rapid identification of carbapenemase-resistant enterobacteriaceae (CRE). Proof of concept was achieved by the discrimination of CRE using MALDI Biotyper MS based on the protein. This profiling appears promising by the visual observation of consistent unique peaks, albeit low intensity, that could be picked up from the mean spectra (MSP) method. The Biotyper MSP creation and identification methods needed to be optimized to provide significantly improved differences in scores to allow for subspecies identification with and without carbapenemases. These spectra were subjected to visual peak picking and in all cases; there were pertinent differences in the presence or absence of potential biomarker peaks to differentiate isolates. We also evaluated this method for potential discrimination between different carbapenemases bacteria, utilizing the same strategy. Based on our data and pending further investigation in other CREs, MALDI-TOF MS has potential as a diagnostic tool for the rapid identification of even closely related carbapenemases but would require a paradigm shift in which Biotyper suppliers enable more flexible software control of mass spectral profiling methods.

• 한국미생물·생명공학회지
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• 제7권2호
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• pp.65-70
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• 1979

SCP생산을 위하여 토양과 하수로부터 methanol을 탄소원 및 에너지원으로 이용하는 세균을 분리하여 이중 생육이 우수한 균주를 선별하였고, 이의 형태적 생리적 특성을 조사하여 동정하였다. 그리고 탄소원, 질소원, 금속이온, 생육인자 등이 생육에 미치는 영향을 조사하여 영양조건을 최적화한 결과를 다음과 같이 얻었다. 1) 우량균주로 선별한 균주는 탄소원으로서 methanol 이외의 다른 유기화합물에서는 생육이 되지않는 obligate methylotrophs로서 형태적 생리적 특성을 근거로 Methylomonas methanolica로 동정되었다. 2) 최적영양조건은 초기 methanol 농도 0.8% (v/v), 질소원은 (NH$_4$)$_2$ SO$_4$ 0.6%, 금속이온은 MgSO$_4$.7H$_2$ 0.1%이었다.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.776-783
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• 2018

The agarase gene gaa16a was identified from a draft genome sequence of Gilvimarinus agarilyticus JEA5, an agar-utilizing marine bacterium. Recently, three agarase-producing bacteria, G. chinensis, G. polysaccharolyticus, and G. agarilyticus, in the genus Gilvimarinus were reported. However, there have been no reports of the molecular characteristics and biochemical properties of these agarases. In this study, we analyzed the molecular characteristics and biochemical properties of agarases in Gilvimarinus. Gaa16A comprised a 1,323-bp open reading frame encoding 441 amino acids. The predicted molecular mass and isoelectric point were 49 kDa and 4.9, respectively. The amino acid sequence of Gaa16A showed features typical of glycosyl hydrolase family 16 (GH16) ${\beta}$-agarases, including a GH16 domain, carbohydrate-binding region (RICIN domain), and signal peptide. Recombinant Gaa16A (excluding the signal peptide and carbohydrate-binding region, rGaa16A) was expressed as a fused protein with maltose-binding protein at its N-terminus in Escherichia coli. rGaa16A had maximum activity at $55^{\circ}C$ and pH 7.0 and 103 U/mg of specific activity in the presence of 2.5 mM $CaCl_2$. The enzyme hydrolyzed agarose to yield neoagarotetraose as the main product. This enzyme may be useful for industrial production of functional neoagaro-oligosaccharides.

• 한국토양비료학회지
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• 제37권1호
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• pp.46-53
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• 2004

벼(Oryza sativa L.)에 서식하고 있는 메탄올 자화세균(methylotrophic bacteria)의 군집구조를 분석하기 위하여, 국내 3지역(청원, 익산, 밀양)의 경작지 논에서 재배되고 있는 4품종(일미, 동진, 남평, 오대) 벼의 잎, 줄기, 이삭, 뿌리 및 근권토양을 수집하였다. Methanol이 유일한 탄소원으로 첨가된 선택배지를 이용하여, 분홍색 색소체를 갖는 35균주와 무색소체의 5균주를 선별하였으며, 선별균주들의 형태학적, 생리 생화학적 특성을 조사하여 4개의 군집으로 구분하였다. 군집 I 및 IV 는 각각 nitrate와 nitrite reduction 특성에 의해 구별되었으며, pink pigment colony를 형성하는 또 다른 두 개의 군집들은 cellulase 생성유무에 의하여 구분되었다. 표준균주인 Methylobacterium extorquens AM1은 분리균주들과는 다른 군집으로 구분되었으며, M. fujisawaense KACC10744는 III 군집에 속하는 것으로 분석되었다. 분리된 모든 균주들은 urease, oxidase, catalase, pectinase 활성시험에서 양성반응을 나타냈으며, indole, MR-VP, $H_2S$, starch, casein 시험에서는 음성반응을 나타내었다. 또한, 모든 분리 균주들의 열 내성은 없었으며, $45^{\circ}C$ 이상에서는 성장하지 못하였다. 군집 I에서 두개의 분리균주가 각각 gelatin 가수분해와 methane 이용능을 나타내었으며, 대부분의 균주들은 탄소원으로 monosaccharides, disaccharide, polyols를 이용하여 성장하였다. 분리 및 선별되어진 균주들 중 6 균주만이 $86.2-809.9nmol\;C_2H_4\;h^{-1}\;mg^{-1}$ protein 범위의 질소고정능을 나타내었다.