Abstract：
:A beta-agarase gene, agaB34, was functionally cloned from the genomic DNA of a marine bacterium, Agarivorans albus YKW-34. The open reading frame of agaB34 consisted of 1,362 bp encoding 453 amino acids. The deduced amino acid sequence, consisting of a typical N-terminal signal peptide followed by a catalytic domain of glycoside hydrolase family 16 (GH-16) and a carbohydrate-binding module (CBM), showed 37-86% identity to those of agarases belonging to family GH-16. The recombinant enzyme (rAgaB34) with a molecular mass of 49 kDa was produced extracellularly using Escherichia coli DH5alpha as a host. The purified rAgaB34 was a beta-agarase yielding neoagarotetraose (NA4) as the main product. It acted on neoagarohexaose to produce NA4 and neoagarobiose, but it could not further degrade NA4. The maximal activity of rAgaB34 was observed at 30 degrees and pH 7.0. It was stable over pH 5.0-9.0 and at temperatures up to 50 degrees . Its specific activity and kcat/Km value for agarose were 242 U/mg and 1.7x106/sM, respectively. The activity of rAgaB34 was not affected by metal ions commonly existing in seawater. It was resistant to chelating reagents (EDTA, EGTA), reducing reagents (DTT, beta-mercaptoethanol), and denaturing reagents (SDS and urea). The E. coli cell harboring the pUC18-derived agarase expression vector was able to efficiently excrete agarase into the culture medium. Hence, this expression system might be used to express secretory proteins.
journal_name
J Microbiol Biotechnoljournal_title
Journal of microbiology and biotechnologyauthors
Fu XT,Pan CH,Lin H,Kim SMsubject
Has Abstractpub_date
2009-03-01 00:00:00pages
257-64issue
3eissn
1017-7825issn
1738-8872pii
8205journal_volume
19pub_type
杂志文章abstract：:VP7, an outer capsid protein of grass carp reovirus (GCRV), was expressed and displayed on the surface of Saccharomyces cerevisiae for developing an efficient vaccine against hemorrhagic disease of grass carp. The result of flow cytometry analysis indicated that protein VP7 could be displayed on the surface of yeast c...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1505.05041
更新日期：2015-12-28 00:00:00
abstract：:While searching for lactic acid bacteria that can restore aging-impaired immune responses, we isolated the Toll-like receptor (TLR) 2/NF-kappaB-activating strain Lactobacillus plantarum HY7712 from kimchi and investigated its immunomodulating effect in whole-body γ-irradiated mice. Exposure to HY7712 strongly activate...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1307.07001
更新日期：2014-01-01 00:00:00
abstract：:The thermophile Bacillus fordii MH602 was screened for stereospecifically hydrolyzing DL-5-substituted hydantoins to L-alpha-amino acids. Since the reaction at higher temperature, the advantageous for enhancement of substrate solubility and for racemization of DL-5-substituted hydantoins during the conversion were ach...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.0904.04048
更新日期：2009-12-01 00:00:00
abstract：:Metabolite profiles of seven commercial vinegars and two traditional vinegars were performed by gas chromatography time-of-flight mass spectrometry with multivariate statistical analysis. During alcohol fermentation, yeast, nuruk, and koji were used as sugars for nutrients and as fermentation substrates. Commercial an...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1408.08021
更新日期：2015-02-01 00:00:00
abstract：:Retrovirus tropism can be restricted by host cell factors such as Fv1, TRIM5alpha, and Lv1 that inhibit infection by targeting the incoming viral capsid. The Fv1 gene inhibits murine leukemia virus infection in mice, but the precise mechanism of Fv1-mediated restriction is poorly understood. Our previous studies had d...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2008-04-01 00:00:00
abstract：:The bioassay-guided fractionation of MeOH extract from Naematoloma fasciculare afforded a petroleum ether fraction (NFPF) and four known compounds, which showed good antitumor activities to inhibit MCF-7 cell line proliferation in vitro and tumor growth in H(22) implanted mice in vivo. In addition, a number of unsatur...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2009-10-01 00:00:00
abstract：:Extremophilic microorganisms have established a diversity of molecular strategies in order to survive in extreme conditions. Biocatalysts isolated by these organisms are termed extremozymes, and possess extraordinary properties of salt allowance, thermostability, and cold adaptivity. Extremozymes are very resistant to...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章,评审
doi：10.4014/jmb.1611.11006
更新日期：2017-04-28 00:00:00
abstract：:Polyhydroxyalkanoate (PHA) synthase is a key enzyme for PHA production in microorganisms. The class IV PHA synthase is composed of two subunits: PhaC and PhaR. The PhaR subunit, which encodes the phaR gene, is only present in class IV PHA synthases. Therefore, the phaR gene is used as a biomarker for bacteria that con...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1907.07045
更新日期：2019-01-28 00:00:00
abstract：:Tuberculosis, which is caused by Mycobacterium tuberculosis (Mtb), is among the most pressing worldwide problems. Mtb uniquely interacts with innate immune cells through various pattern recognition receptors. These interactions initiate several inflammatory pathways that play essential roles in controlling Mtb pathoge...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章,评审
doi：10.4014/jmb.1908.08057
更新日期：2019-10-28 00:00:00
abstract：:With emphasis on thermal behavior in presence of different pH conditions and salts, the kinetic and thermodynamic parameters of purified polygalacturonase (PG) of E. carotovora subsp. carotovora (Ecc) BR1 were studied since characterization of an enzyme is significant in the context of burgeoning biotechnological appl...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.0908.08008
更新日期：2010-07-01 00:00:00
abstract：:The present study shows that DR1114 (Hsp20), a small heat shock protein of the radiationresistant bacterium Deinococcus radiodurans, enhances tolerance to hydrogen peroxide (H2O2) stress when expressed in Escherichia coli. A protein profile comparison showed that E. coli cells overexpressing D. radiodurans Hsp20 (EC-p...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1403.03006
更新日期：2014-08-01 00:00:00
abstract：:The fungal cell wall is a major target of antifungals. In this study, we report the antifungal activity of an ethanol extract from Aucklandia lappa against Candida albicans. We found that the extract caused cell wall injury by decreasing chitin synthesis or assembly and (1,3)-β-D-glucan synthesis. A sorbitol protectio...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.2002.02025
更新日期：2020-07-28 00:00:00
abstract：:The symbiotic nature of the relationship between algae and marine bacteria is well-studied among the complex microbial interactions. The mutual profit between algae and bacteria occurs via nutrient and vitamin exchange. It is necessary to analyze the genome sequence of a bacterium to predict its symbiotic relationship...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1911.11006
更新日期：2020-04-28 00:00:00
abstract：:Ingredients of soy and fermented soy products have been widely utilized as food supplements for health-enhancing properties. The aim of this study was to evaluate the effects of fermented soymilk (FSM) and soymilk (SM) on free fatty acid-induced lipogenesis in the hepatocellular steatosis model. HepG2 cells were incub...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1707.07061
更新日期：2018-02-28 00:00:00
abstract：:Infections by herpes simplex viruses have an immense impact on humans, ranging from selflimiting, benign illness to serious, life-threatening diseases. While nucleoside analog drugs are available, resistance has been increasing and currently no vaccine exists. Ginsenosides derived from Panax ginseng have been document...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1908.08047
更新日期：2020-01-28 00:00:00
abstract：:The pharmacokinetics of decursin and decursinol angelate (D/DA) was investigated in male SD rats following oral and intravenous administration. D/DA and metabolites obtained from in vitro samples were evaluated by LC/MS. The level of D/DA and metabolized decursinol in the blood following oral and intravenous administr...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.0905.05028
更新日期：2009-12-01 00:00:00
abstract：:In biological wastewater treatment high lipid concentration is known to inhibit microorganisms and cause active biomass flotation. To reduce lipid inhibition, a two-phase anaerobic system, consisting of an anaerobic sequencing batch reactor (ASBR) and an upflow anaerobic sludge blanket (UASB) reactor, was applied to s...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2010-01-01 00:00:00
abstract：:Effects of various industrially important carbon sources (glucose, sucrose, xylose, gluconate, and glycerol) on shikimic acid (SA) biosynthesis in Escherichia coli were investigated to gain new insight into the metabolic capability for overproducing SA. At the outset, constraints-based flux analysis using the genome-s...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2008-11-01 00:00:00
abstract：:Clostridium difficile causes mucosal damage and diarrhea by releasing two exotoxins: toxin A and toxin B. C. difficile colitis is associated with alterations in bowel flora and the failure to mount an effective antibody response. The aim of the current study was to investigate whether antitoxin sera prevent toxin-A-in...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1401.01059
更新日期：2014-05-01 00:00:00
abstract：:TolC is an outer membrane porin protein and an essential component of drug efflux and type-I secretion systems in Gram-negative bacteria. TolC comprises a periplasmic alpha- helical barrel domain and a membrane-embedded beta-barrel domain. TdeA, a functional and structural homolog of TolC, is required for toxin and dr...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2008-05-01 00:00:00
abstract：:Based on its α-amylase activity at pH 5.0 and optimal pH of the crude enzyme, a strain (named B-5) with acid α-amylase production was screened. The B-5 strain was identified as Bacillus amyloliquefaciens through morphological, physiological, and biochemical characteristics analysis, as well as 16S rDNA phylogenetic an...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1409.09094
更新日期：2015-06-01 00:00:00
abstract：:Heat-resistant microbial hosts are required for bioprocess development using high cell density cultivations at the industrial scale. We report that the thermotolerance of Escherichia coli can be enhanced by overexpressing ybeD, which was known to encode a hypothetical protein of unknown function. In the wild-type E. c...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1901.01036
更新日期：2019-03-28 00:00:00
abstract：:The bioactivities of boxthron fruits, a source of oriental medicine, are well known, whereas phytochemical studies of the boxthorn stem are rare. In this study, the stem extract of boxthorn (Lycium chinense Miller) and its subfractions were evaluated for their effects on nitric oxide (NO) inhibition and procollagen ty...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1702.02004
更新日期：2017-08-28 00:00:00
abstract：:PineXol, extracted from Korean red pine bark, has beneficial effects, such as antioxidant, antiinflammatory, and antilipogenic activities in vitro. We tested the hypothesis that PineXol supplementation could have anti-obesity effects on mice fed a high-fat diet (HFD). Four-week-old male C57BL/6 mice were fed normal ch...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1612.12037
更新日期：2017-04-28 00:00:00
abstract：:Five fusion proteins between Z domains derived from Staphylococcal Protein A and Green Fluorescent Protein or Human Proinsulin were produced on the periplasm of Escherichia coli. The effects of the molecular weight and amino acid composition of the translocated peptide, culture medium composition, and growth phase of ...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2007-08-01 00:00:00
abstract：:Glucose dehydrogenase (GDH) is an oxidoreductase enzyme and is used as a biocatalyst to regenerate NAD(P)H in reductase-mediated chiral synthesis reactions. In this study, the glucose 1-dehydrogenase B gene (gdhB) was cloned from Bacillus thuringiensis subsp. kurstaki, and wild-type (GDH-BTWT) and His-tagged (GDH-BTN-...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1603.03021
更新日期：2016-10-28 00:00:00
abstract：:Bacillus amyloliquefaciens Pc3 was isolated from Antarctic seawater with antifungal activity. In order to investigate the metabolic regulation mechanism in the biosynthesis of lipopeptides in B. amyloliquefaciens Pc3, GC/MS-based metabolomics was used when exogenous indole was added. The intracellular metabolite profi...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1712.12014
更新日期：2018-05-28 00:00:00
abstract：:Cryptomonads are unicellular, biflagellate algae. Generally, cryptomonad cells cannot be preserved well because of their fragile nature, and an improved methodology should be developed to identify cryptomonads from natural habitats. In this study, we tried using several cytological fixatives, including glutaraldehyde,...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：10.4014/jmb.1203.03057
更新日期：2013-03-01 00:00:00
abstract：:The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones wer...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2007-01-01 00:00:00
abstract：:Two alternative pathways for methionine biosynthesis are known in Corynebacterium glutamicum: one involving transsulfuration (mediated by metB and metC) and the other involving direct sulthydrylation (mediated by metY). In this study, MetB (cystathionine gamma-synthase) and MetY (O-acetylhomoserine sulfhydrylase) from...
journal_title：Journal of microbiology and biotechnology
pub_type： 杂志文章
doi：
更新日期：2007-06-01 00:00:00
