Abstract:
:Identification and design of new cellulolytic enzymes with higher catalytic efficiency are a key factor in reducing the production cost of lignocellulosic bioalcohol. We report here identification of a novel β-glucosidase (Gluc1C) from Paenibacillus sp. strain MTCC 5639 and construction of bifunctional chimeric proteins based on Gluc1C and Endo5A, a β-1,4-endoglucanase isolated from MTCC 5639 earlier. The 448-amino-acid-long Gluc1C contained a GH superfamily 1 domain and hydrolyzed cellodextrin up to a five-sugar chain length, with highest efficiency toward cellobiose. Addition of Gluc1C improved the ability of Endo5A to release the reducing sugars from carboxymethyl cellulose. We therefore constructed six bifunctional chimeric proteins based on Endo5A and Gluc1C varying in the positions and sizes of linkers. One of the constructs, EG5, consisting of Endo5A-(G(4)S)(3)-Gluc1C, demonstrated 3.2- and 2-fold higher molar specific activities for β-glucosidase and endoglucanase, respectively, than Gluc1C and Endo5A alone. EG5 also showed 2-fold higher catalytic efficiency than individual recombinant enzymes. The thermal denaturation monitored by circular dichroism (CD) spectroscopy demonstrated that the fusion of Gluc1C with Endo5A resulted in increased thermostability of both domains by 5°C and 9°C, respectively. Comparative hydrolysis experiments done on alkali-treated rice straw and CMC indicated 2-fold higher release of product by EG5 than that by the physical mixture of Endo5A and Gluc1C, providing a rationale for channeling of intermediates. Addition of EG5 to a commercial enzyme preparation significantly enhanced release of reducing sugars from pretreated biomass, indicating its commercial applicability.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Adlakha N,Sawant S,Anil A,Lali A,Yazdani SSdoi
10.1128/AEM.01386-12subject
Has Abstractpub_date
2012-10-01 00:00:00pages
7447-54issue
20eissn
0099-2240issn
1098-5336pii
AEM.01386-12journal_volume
78pub_type
杂志文章abstract::The methanotrophic bacterium Methylosinus trichosporium OB3b is unusually active in degrading recalcitrant haloalkanes such as trichloroethylene (TCE). The first and rate-limiting step in the degradation of TCE is catalyzed by a soluble methane monooxygenase (sMMO). This enzyme is not expressed when the cells are grow...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.58.11.3701-3708.1992
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abstract::Bacteriovorous protozoa harboring symbiotic algae are abundant in aquatic ecosystems, yet despite a recent interest in protozoan bacterivory, the influence of light on their ingestion rates has not been investigated. In this study, Paramecium bursaria containing endosymbiotic Chlorella was tested for the effect of lig...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.57.8.2312-2316.1991
更新日期:1991-08-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.46.3.758-761.1983
更新日期:1983-09-01 00:00:00
abstract::The culturability of three Campylobacter jejuni strains and their infectivity for day-old chicks were assessed following storage of the strains in saline. The potential for colonization of chicks was weakened during the storage period and terminated 3 to 4 weeks before the strains became nonculturable. The results fro...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.67.5.2388-2392.2001
更新日期:2001-05-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00592-14
更新日期:2014-08-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00218-12
更新日期:2012-08-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03399-16
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.47.5.895-900.1984
更新日期:1984-05-01 00:00:00
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pub_type: 杂志文章
doi:10.1128/AEM.48.1.41-42.1984
更新日期:1984-07-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.71.12.9008-9012.2005
更新日期:2005-12-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.56.7.2133-2141.1990
更新日期:1990-07-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01255-16
更新日期:2016-08-15 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.52.1.214-216.1986
更新日期:1986-07-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.67.7.3115-3121.2001
更新日期:2001-07-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01632-16
更新日期:2016-09-30 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02080-07
更新日期:2008-05-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.54.6.1595-1601.1988
更新日期:1988-06-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.60.5.1481-1486.1994
更新日期:1994-05-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.58.6.2011-2015.1992
更新日期:1992-06-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.64.2.509-514.1998
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
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更新日期:2019-03-22 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.65.8.3298-3303.1999
更新日期:1999-08-01 00:00:00
abstract::In this report, we describe the selective cloning of large DNA fragments from magnetotactic metagenomes from various aquatic habitats. This was achieved by a two-step magnetic enrichment which allowed the mass collection of environmental magnetotactic bacteria (MTB) virtually free of nonmagnetic contaminants. Four fos...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02701-08
更新日期:2009-06-01 00:00:00
abstract::Strain VeGlc2, an anaerobic ultramicrobacterium belonging to the Verrucomicrobiales lineage of bacterial descent, fermented glucose to acetate, propionate, succinate, and CO2. The distribution of radiolabel in the fermentation end products produced from position-labelled glucose and in vitro measurements of enzyme act...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.64.12.4830-4833.1998
更新日期:1998-12-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.40.2.429-430.1980
更新日期:1980-08-01 00:00:00
abstract::Laboratory strains of Saccharomyces cerevisiae have been widely used as a model for studying eukaryotic cells and mapping the molecular mechanisms of many different human diseases. Industrial wine yeasts, on the other hand, have been selected on the basis of their adaptation to stringent environmental conditions and t...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00602-08
更新日期:2008-10-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
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更新日期:2017-11-16 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.05539-11
更新日期:2011-10-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
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更新日期:2014-01-01 00:00:00
abstract::An investigation of the Hg2+ resistance mechanism of four freshwater and four coastal marine bacteria that did not hybridize with a mer operonic probe was conducted (T. Barkay, C. Liebert, and M. Gillman, Appl. Environ. Microbiol. 55:1196-1202, 1989). Hybridization with a merA probe, the gene encoding the mercuric red...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.56.6.1695-1701.1990
更新日期:1990-06-01 00:00:00