• Title/Summary/Keyword: microbial enzyme

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Biochemical Characterization of a GDSL-Motif Esterase from Bacillus sp. K91 with a New Putative Catalytic Mechanism

  • Ding, Junmei;Yu, Tingting;Liang, Lianming;Xie, Zhenrong;Yang, Yunjuan;Zhou, Junpei;Xu, Bo;Li, Junjun;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1551-1558
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    • 2014
  • The esterase gene Est8 from the thermophilic bacterium Bacillus sp. K91 was cloned and expressed in Escherichia coli. The monomeric enzyme exhibited a theoretical molecular mass of 24.5 kDa and an optimal activity around $50^{\circ}C$ at pH 9.0. A model of Est8 was constructed using a hypothetical YxiM precursor structure (2O14_A) from Bacillus subtilis as template. The structure showed an ${\alpha}/{\beta}$-hydrolase fold and indicated the presence of a typical catalytic triad consisting of Ser-11, Asp-182, and His-185, which were investigated by site-directed replacements coupled with kinetic characterization. Asp-182 and His-185 residues were more critical than the Ser-11 residue in the catalytic activity of Est8. A comparison of the amino acid sequence showed that Est8 could be grouped into the GDSL family and further classified as an SGNH hydrolase. Est8 is a new member of the SGNH hydrolase subfamily and may employ a different catalytic mechanism.

Purification and Characterization of Six Fibrinolytic Serine-Proteases from Earthworm Lumbricus rubellus

  • Cho, Il-Hwan;Choi, Eui-Sung;Lim, Hun-Gil;Lee, Hyung-Hoan
    • BMB Reports
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    • v.37 no.2
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    • pp.199-205
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    • 2004
  • The six lumbrokinase fractions (F1 to F6) with fibrinolytic activities were purified from earthworm Lumbricus rubellus lysates using the procedures of autolysis, ammonium sulfate fractionation, and column chromatography. The proteolytic activities on the casein substrate of the six iso-enzymes ranged from 11.3 to 167.5 unit/mg with the rank activity orders of F2 > F1 > F5 > F6 > F3 > F4. The fibrinolytic activities of the six fractions on the fibrin plates ranged from 20.8 to 207.2 unit/mg with rank orders of F6 > F2 > F5 > F3 > F1 > F4. The molecular weights of each iso-enzyme, as estimated by SDS-PAGE, were 24.6 (F1), 26.8 (F2), 28.2 (F3), 25.4 (F4), 33.1 (F5), and 33.0 kDa (F6), respectively. The plasminogen was activated into plasmin by the enzymes. The optimal temperature of the six iso-enzymes was $50^{\circ}C$, and the optimal pH ranged from pH 4-12. The four iso-enzymes (F1-F4) were completely inhibited by PMSF. The two enzymes (F5 and F6) were completely inhibited by aprotinin, TLCK, TPCK, SBTI, LBTI, and leupeptin. The N-terminal amino acid (aa) sequences of the first 20 to 22 residues of each fraction had high homology. All six isoenzymes had identical aa residues 2-3 and 13-15. The N-terminal 21-22 aa sequences of the F2, F3, and F4 isoenzymes were almost the same. The N-terminal aa sequences of F5 and F6 were identical.

Studies on Acetanilide p-Hydroxylase in Streptomyces spp. (Streptomyces 속 중의 Acetanilide p-Hydroxylase에 관한 연구)

  • Kim, Jung-Ae;Lee, Sang-Sup
    • YAKHAK HOEJI
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    • v.32 no.5
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    • pp.295-303
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    • 1988
  • For microbial production of acetaminophen, a popular analgesic-antipyretic from aniline, we screened various fungi and bacteria. And we succeeded to some extents in acetaminophen production by successful protoplast fusion between S. lividans and S. globisporus and also between S. rimosus and S. aureofaciens. However, more fertile results might be brought via performing the cloning of acetanilide p-hydroxylation genes of Streptomyces in yeast. This study was initiated to determine whether the acetanilide p-hydroxylase of Streptomyces is cytochrome P-450 species or non-heme iron protein species. The p-hydroxylationactivity on acetanilide in S. aureofaciens ATCC 10762 was found to be unstable on exposing to the air. However, 100,000xg supernatant of the cell free extracts which were prepared in $N_2$ atmosphere showed the p-hydroxylation activity. Characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was not observed in the region of 450nm. Moreover, metyrapone and 2, 6-dichloroindophenol did not affect this enzyme activity, but sodium azide, sodium cyanide, cupric sulfate, cadmium chloride, ${\alpha}$, ${\alpha}'-dipyridyl$, and o-phenanthroline reduced p-hydroxylase activity considerably. S. fradiae NRRL 2702 was shown to have strong p-hydroxylation activity in intact cells. This activity disappeared in its cell free extracts. In its 100,000xg supernatant, however, characteristic absorption peak of cytochrome P-450 after reduction with dithionite and addition of CO was observed at 446nm. Thus, the results herein presented suggest that acetanilide p-hydroxylase of Streptomyces aureofaciens is not related to cytochrome P-450 and may include non-heme iron protein for its activity. However, it is not clear whether acetanilide p-hydroxylase in S. fradiae belongs to the same category of S. aureofaciens.

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Effect of Extract of Fermented Dropwort on Intestinal Bacteria and Enzymes In Vitro (미나리발효액이 장내 유해세균 및 유익균의 In Vitro 생육 및 효소활성에 미치는 영향)

  • Lee, Kyung-Ae;Kim, Moo-Sung;Cho, Hong-Bum
    • Korean Journal of Microbiology
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    • v.44 no.4
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    • pp.358-361
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    • 2008
  • Effect of extract of fermented dropwort (Oenanthe stolonifera) on growth of intestinal harmful/useful bacteria and enzyme activity were investigated in vitro. The extract showed strong inhibition on harmful microbes including Vibrio and Salmonella, but mild inhibition on Bifidobacterium longum in both agar plate and liquid cultivation. Minimum inhibitory concentration (MIC) value of B. longum was the highest among tested microbes. Inhibition effect of fermented extract on harmful microbes increased according to fermentation period. Extract of fermented dropwort showed inhibitory effects on activity of microbial ${\beta}$-glucuronidase and tryptophanase. The inhibitory effects were also proportional to fermentation period. As consequence, it is assumed that the uptake of fermented dropwort might be useful for human intestinal health.

Bacterial Abundances and Enzymatic Activities under Artificial Vegetation Island in Lake Paldang (팔당호에 설치된 인공식물섬에서의 세균 수와 체외효소 활성도의 변화)

  • Byeon, Myeong-Seop;Yoo, Jae-Jun;Kim, Ok-Sun;Choi, Seung-Ik;Ahn, Tae-Seok
    • Korean Journal of Ecology and Environment
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    • v.35 no.4 s.100
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    • pp.266-272
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    • 2002
  • For analyzing function of a microbial ecosystem which was created under the artificial vegetation island (AVI) installed at Lake Paldang, zooplankton and bacterial numbers and exoenzyme activities (${\beta}$-glucosidase and phosphatase) were measured biweekly from 3 November 2()()1 to 20 April 2002 at AVI site and control site. Under the AVI, the water quality was worse than control site in term of comparing the environmental parameters. But, zooplankton number of AVI site was 25 times higher than that of control site. Respiratory active bacterial numbers were 3-8 times higher at AVI site. In addition, enzymatic activities were higher at AVI site than those of control site. These results suggest that the zooplankton-phytoplankton-bacteria relationships are closely coupled with each other and organic materials are eliminated by respiration of zooplankton and bacterial activities.

Administration of antibiotics contributes to cholestasis in pediatric patients with intestinal failure via the alteration of FXR signaling

  • Xiao, Yongtao;Zhou, Kejun;Lu, Ying;Yan, Weihui;Cai, Wei;Wang, Ying
    • Experimental and Molecular Medicine
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    • v.50 no.11
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    • pp.14.1-14.14
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    • 2018
  • The link between antibiotic treatment and IF-associated liver disease (IFALD) is unclear. Here, we study the effect of antibiotic treatment on bile acid (BA) metabolism and investigate the involved mechanisms. The results showed that pediatric IF patients with cholestasis had a significantly lower abundance of BA-biotransforming bacteria than patients without cholestasis. In addition, the BA composition was altered in the serum, feces, and liver of pediatric IF patients with cholestasis, as reflected by the increased proportion of primary BAs. In the ileum, farnesoid X receptor (FXR) expression was reduced in patients with cholestasis. Correspondingly, the serum FGF19 levels decreased significantly in patients with cholestasis. In the liver, the expression of the rate-limiting enzyme in bile salt synthesis, cytochrome P450 7a1 (CYP7A1), increased noticeably in IF patients with cholestasis. In mice, we showed that oral antibiotics (gentamicin, GM or vancomycin, VCM) reduced colonic microbial diversity, with a decrease in both Gram-negative bacteria (GM affected Eubacterium and Bacteroides) and Gram-positive bacteria (VCM affected Clostridium, Bifidobacterium and Lactobacillus). Concomitantly, treatment with GM or VCM decreased secondary BAs in the colonic contents, with a simultaneous increase in primary BAs in plasma. Moreover, the changes in the colonic BA profile especially that of tauro-beta-muricholic acid ($T{\beta}MCA$), were predominantly associated with the inhibition of the FXR and further altered BA synthesis and transport. In conclusion, the administration of antibiotics significantly decreased the intestinal microbiota diversity and subsequently altered the BA composition. The alterations in BA composition contributed to cholestasis in IF patients by regulating FXR signaling.

Anti-inflammatory effect of Distylium racemosum leaf biorenovate extract in LPS-stimulated RAW 264.7 macrophages cells (LPS로 유도된 RAW 264.7 세포에 대한 조록나무 잎 Biorenovation 추출물의 항염증 활성)

  • Hong, Hyehyun;Lee, Kyung-Mi;Park, Taejin;Chi, Won-Jae;Kim, Seung-Young
    • Journal of Applied Biological Chemistry
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    • v.64 no.4
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    • pp.375-382
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    • 2021
  • Biorenovation is a microbial enzyme-based structural modification of component compounds in natural products and synthetic compounds including plant extracts with the potential benefits of improved biological activities compared with its reaction substrates. In this study, we investigated the anti-inflammatory activity of Distylium racemosum leaf extract and D. racemosum leaf biorenovation extract (DLB). As a result, DLB inhibited nitric oxide, prostaglandin E2, and inflammatory cytokines including tumor necrosis factor-α, interleukin-6, interleukin-1β at non-toxic concentrations. In addition, DLB significantly inhibited inducible nitric oxide synthase and cyclooxygenase-2 on LPS-treated RAW 264.7 macrophages. Based on these results, we suggest that the DLB could be used as a potent anti-inflammatory agents. It also suggests that the application of biological evolution has potential usefulness to increase the practical value of natural products.

Effects of dietary supplementation with different levels and molecular weights of fungal β-glucan on performances, health and meat quality in broilers

  • Kovitvadhi, Attawit;Chundang, Pipatpong;Tirawattanawanich, Chanin;Prathumpai, Wai;Methacanon, Pawadee;Chokpipatpol, Krith
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.10
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    • pp.1548-1557
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    • 2019
  • Objective: To investigate the effects of dietary supplementation with different levels and molecular weights of fungal ${\beta}$-glucan on productive performances, health, carcass traits and meat quality in broilers. Methods: Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in $2{\times}4$ factorial arrangement. These groups were supplemented with (0, 10, 30, and 60 ppm) of molecular weight 1-3, 1-6 ${\beta}$-glucan (low or high). High molecular weight ${\beta}$-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with ${\gamma}$-Irradiation treatment was performed to achieve low molecular weight ${\beta}$-glucan (L: 8 kDa). Results: There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (p>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (p<0.05). The increase of supplemental dose increased caecal amylase activity (p<0.05). Immunomodulatory effects from L was revealed by the marked increase of phagocytic activity, relative weight of thymus and bursa of fabricius (p<0.05). Similarly, the additive dose at 30 ppm provided the same results, whereas the only significant difference with supplementation at 60 ppm was an increase in phagocytic activity (p<0.05). Interestingly, villi height of broilers fed L was higher than other groups (p<0.05). The treatments did not influence haematology, blood chemistry, antibody production level against vaccination, carcass traits and meat quality (p>0.05). Conclusion: The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.

Profile Analysis of Bacteria in Human Hands Using the Terminal Restriction Fragment Length Polymorphism (T-RFLP) Analysis (제한효소 절편길이 다형성(T-RFLP) 분석기법을 이용한 손에 서식하는 세균의 군집조성 분석)

  • Park, Jisun;Kim, Seung Bum
    • Journal of Science Criminal Investigation
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    • v.11 no.4
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    • pp.276-282
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    • 2017
  • As evidence that can be obtained at the crime scene, the importance of micro-evidences has been recognized in recent years with the development modern molecular-level analytical techniques. These micro-evidences include substances useful for personal identification such as DNA, but it is difficult to collect only the evidences showing individual characteristics every time at the crime scene. Therefore, development of new research approaches for the discovery and application of micro-evidence candidates is in increasing demand. For this purpose, skin microbial communities of bacteria inhabiting the palms of 16 people were collected and terminal-restriction enzyme fragment length polymorphism (T-RFLP) analysis was carried out to examine the potential for the application in personal identification. As a result, 16 different electropherograms were obtained, and various taxa including Staphylococcus and Bacillus were shown to produce different T-RF profiles among individuals. These results were analyzed with the factors affecting the microbiota such as sex and working environment of individuals.

Production performances and antioxidant activities of laying hens fed Aspergillus oryzae and phytase co-fermented wheat bran

  • Huang, Chung Ming;Chuang, Wen Yang;Lin, Wei Chih;Lin, Li Jen;Chang, Sheng Chang;Lee, Tzu Tai
    • Animal Bioscience
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    • v.34 no.3_spc
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    • pp.371-384
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    • 2021
  • Objective: Wheat bran (WB) was co-fermented with Aspergillus oryzae and phytase (Phy) to determine whether co-fermentation improve WB phosphorus and fiber utilization in Isa-brown layers. Methods: A total of 112 Isa brown layer were randomly divided into 7 treatments with 8 replicates per a treatment and 2 hens per a replicate. The treatments included basal diet (control), basal diet supplemented with 250 unit/kg Phy (control+Phy), diet with 10% WB (10% WB), diet with 5% WB and 250 unit/kg Phy (5% WB+Phy) diet with 10% WB and 250 unit/kg Phy (10% WB+Phy), diet with 5% fermented WB supplemented with molasses and phy (PCFWH) and 125 unit/kg Phy (5% PCFWH), and diet with 10% PCFWH (10% PCFWH). The intestinal microbial population, intestinal morphology, serum antioxidant enzyme activities, and excreta phosphorus content were assessed. Results: In PCFWH, spore counts, protease activity, xylanase activity, and ferulic acid were 8.50 log/g dry matter (DM), 190 unit/g DM, 120 unit/g DM, and 127 ㎍/g, respectively. Xylobiose and xylotriose were released in PCFWH, while they were not detectable in WB. Antioxidant capacity was also enhanced in PCFWH compared to WB. The 10% WB+Phy and 10% PCFWH groups produced higher egg mass, but hens fed 5% WB+Phy had the lowest amount of feed intake. Eggs from 10% PCFWH had better eggshell weight, eggshell strength, and eggshell thickness. Birds fed with 10% PCFWH also had higher serum superoxide dismutase and catalase activities. Compare to control, 10% PCFWH significantly reduced excreta phosphorus content. Conclusion: Diet inclusion of 10% PCFWH improved egg quality, antioxidant status, and excreta phosphorus content of laying hens.