scholarly journals Immobilization of Baeyer-Villiger monooxygenase from acetone grown Fusarium sp.

2021 ◽  
Author(s):  
Michio Takagi ◽  
Kotchakorn T.sriw ◽  
Ayaka Masuda ◽  
Nozomi Kawaguchi ◽  
Shusuke Fukui ◽  
...  
Keyword(s):  
Carbon Source ◽  
Substrate Specificity ◽  
Soil Sample ◽  
Preparative Scale ◽  
E Coli ◽  
Catalytic Activities ◽  
Formation Method ◽  
Fusarium Sp ◽  
Nanocrystal Formation ◽  
Villiger Oxidation

Abstract ObjectiveA novel biocatalyst for Baeyer–Villiger oxidations is necessary for pharmaceutical and chemical industries, so this study aims to find a Baeyer–Villiger monooxygenase (BVMO) and to improve its stability by immobilization. ResultsAcetone, the simplest ketone, was selected as the only carbon source for the screening of microorganisms with a BVMO. A eukaryote, Fusarium sp. NBRC 109816, with a BVMO ( F BVMO), was isolated from a soil sample. F BVMO was overexpressed in E. coli and successfully immobilized by the organic-inorganic nanocrystal formation method. The immobilization improved the thermostability of F BVMO. Substrate specificity investigation revealed that both free and immobilized F BVMO were found to show catalytic activities not only for Baeyer–Villiger oxidation of ketones to esters but also for oxidation of sulfides to sulfoxides. Furthermore, a preparative scale reaction using immobilized F BVMO was successfully conducted. ConclusionsFBVMO was discovered from an environmental sample, overexpressed in E. coli , and immobilized by the organic-inorganic nanocrystal formation method. The immobilization successfully improved its thermostability.

Existence and Decontamination of HVC, Infectious Enteric Bacteria and Parasites in Sewaged Soils

2014 ◽  
Vol 3 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Mohey A. Hassanain ◽  
Nawal A. Hassanain ◽  
Esam A. Hobballa ◽  
Fatma H. Abd- El Zaher ◽  
Mohamed Saber M. Saber
Keyword(s):  
Soil Sample ◽  
Potassium Permanganate ◽  
Enteric Bacteria ◽  
Sewage Effluent ◽  
Calcium Hypochlorite ◽  
Sand Soil ◽  
E Coli ◽  
Surface Sample ◽  
Loamy Sand Soil ◽  
Sewage Farm

A surface sample representing a high contaminated loamy sand soil irrigated with sewage effluent since 30 years and was cultivated with artichoke was collected from Abu-Rawash sewage farm. The existence of HVC, enteric infectious bacteria and parasites in sewaged soil found to be negative for the forward and positive for the latter's. Out of the 30 samples separated from the sewaged soil sample, only 3 samples contained parasitic fauna of developed and undeveloped Ascaris (10%) and five samples contained Entamoeba coli. Results showed that the number of Ascaris eggs/gm soil was 0.017 and the number of E. coli/gm was 0.26. Decontamination of soil parasites was effective using either calcium hypochlorite or potassium permanganate. Salmonella, Vibrio and Campelobacter were detected in the high contaminated sewaged soil and survived for 120 days in the sewaged soil under all control and bioremediated treatments irrigated with either sewage effluent or water.

scholarly journals Public-good driven release of heterogeneous resources leads to genotypic diversification of an isogenic yeast population in melibiose.

2021 ◽  
Author(s):  
Anjali Mahilkar ◽  
Phaniendra Alugoju ◽  
Vijendra Kavatalkar ◽  
Rajeshkannan E. ◽  
Jayadeva Bhat ◽  
...  
Keyword(s):  
Carbon Source ◽  
Public Good ◽  
Molecular Basis ◽  
Model System ◽  
Microbial Populations ◽  
Adaptive Diversification ◽  
E Coli ◽  
Hydrolysis Of ◽  
Convenient Model ◽  
Heterogeneous Resources

Adaptive diversification of an isogenic population, and its molecular basis has been a subject of a number of studies in the last few years. Microbial populations offer a relatively convenient model system to study this question. In this context, an isogenic population of bacteria (E. coli, B. subtilis, and Pseudomonas) has been shown to lead to genetic diversification in the population, when propagated for a number of generations. This diversification is known to occur when the individuals in the population have access to two or more resources/environments, which are separated either temporally or spatially. Here, we report adaptive diversification in an isogenic population of yeast, S. cerevisiae, when propagated in an environment containing melibiose as the carbon source. The diversification is driven due to a public good, enzyme α-galactosidase, leading to hydrolysis of melibiose into two distinct resources, glucose and galactose. The diversification is driven by a mutations at a single locus, in the GAL3 gene in the GAL/MEL regulon in the yeast.

scholarly journals E. coli hypoxia-inducible factor ArcA mediates lifespan extension in a lipoic acid synthase mutant by suppressing acetyl-CoA synthetase

2010 ◽  
Vol 391 (10) ◽  
Author(s):  
Stavros Gonidakis ◽  
Steven E. Finkel ◽  
Valter D. Longo
Keyword(s):  
Heat Shock ◽  
Carbon Source ◽  
Pyruvate Dehydrogenase Complex ◽  
Hypoxia Inducible Factor ◽  
Acetyl Coa ◽  
E Coli ◽  
Extended Lifespan ◽  
Shock Resistance ◽  
Survival Extension

Abstract We have previously shown that both the hypoxia-inducible transcription factor ArcA and the PoxB/Acs bypass of the pyruvate dehydrogenase complex contribute to extended lifespan in Escherichia coli. In agreement with studies in higher eukaryotes, we also demonstrated that long-lived E. coli mutants, including LipA-deficient cells, are stress resistant. Here, we show that ArcA contributes to the enhanced lifespan and heat shock resistance of the lipA mutant by suppressing expression of the acetyl-CoA synthetase (acs) gene. The deletion of acs reversed the reduced lifespan of the lipA arcA mutant and promoted the accumulation of extracellular acetate, indicating that inhibition of carbon source uptake contributes to survival extension. However, Acs also sensitized cells lacking ArcA to heat shock, in the absence of extracellular acetate. These results provide evidence for the role of Acs in regulating lifespan and/or stress resistance by both carbon source uptake-dependent and -independent mechanisms.

scholarly journals Heterologous Production of 6-Deoxyerythronolide B in Escherichia coli through the Wood Werkman Cycle

Metabolites ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 228
Author(s):  
R. Axayacatl Gonzalez-Garcia ◽  
Lars K. Nielsen ◽  
Esteban Marcellin
Keyword(s):  
Escherichia Coli ◽  
Natural Products ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Structural Diversity ◽  
Heterologous Production ◽  
E Coli ◽  
Anticancer Properties ◽  
Defined Media ◽  
Extender Unit

Polyketides are a remarkable class of natural products with diverse functional and structural diversity. The class includes many medicinally important molecules with antiviral, antimicrobial, antifungal and anticancer properties. Native bacterial, fungal and plant hosts are often difficult to cultivate and coax into producing the desired product. As a result, Escherichia coli has been used for the heterologous production of polyketides, with the production of 6-deoxyerythronolide B (6-dEB) being the first example. Current strategies for production in E. coli require feeding of exogenous propionate as a source for the precursors propionyl-CoA and S-methylmalonyl-CoA. Here, we show that heterologous polyketide production is possible from glucose as the sole carbon source. The heterologous expression of eight genes from the Wood-Werkman cycle found in Propionibacteria, in combination with expression of the 6-dEB synthases DEBS1, DEBS2 and DEBS3 resulted in 6-dEB formation from glucose as the sole carbon source. Our results show that the Wood-Werkman cycle provides the required propionyl-CoA and the extender unit S-methylmalonyl-CoA to produce up to 0.81 mg/L of 6-dEB in a chemically defined media.

scholarly journals Self-protection Mechanism in d-Cycloserine-producingStreptomyces lavendulae

2004 ◽  
Vol 279 (44) ◽  
pp. 46143-46152 ◽  
Author(s):  
Masafumi Noda ◽  
Yumi Kawahara ◽  
Azusa Ichikawa ◽  
Yasuyuki Matoba ◽  
Hiroaki Matsuo ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
Alanine Racemase ◽  
Protection Mechanism ◽  
E Coli ◽  
Catalytic Activities ◽  
Resistance Determinants ◽  
Streptomyces Lavendulae ◽  
Dependent Inactivation ◽  
Genes Encoding ◽  
Self Protection

An antibiotic,d-cycloserine (DCS), inhibits the catalytic activities of alanine racemase (ALR) andd-alanyl-d-alanine ligase (DDL), which are necessary for the biosynthesis of the bacterial cell wall. In this study, we cloned both genes encoding ALR and DDL, designatedalrSandddlS, respectively, from DCS-producingStreptomyces lavendulaeATCC25233. Each gene product was purified to homogeneity and characterized.Escherichia coli, transformed with a pET vector carryingalrSorddlS, displays higher resistance to DCS than the same host carrying theE. coliALR- or DDL-encoded gene inserted into the pET vector. Although theS. lavendulaeDDL was competitively inhibited by DCS, theKivalue (920 μm) was obviously higher (40∼100-fold) than those forE. coliDdlA (9 μm) or DdlB (27 μm). The highKivalue of theS. lavendulaeDDL suggests that the enzyme may be a self-resistance determinant in the DCS-producing microorganism. Kinetic studies for theS. lavendulaeALR suggest that the time-dependent inactivation rate of the enzyme by DCS is absolutely slower than that of theE. coliALR. We conclude that ALR from DCS-producingS. lavendulaeis also one of the self-resistance determinants.

The Characteristics and Kinetic Equation of 4-CP Biodegradation by Fusarium sp. HJ01

2012 ◽  
Vol 554-556 ◽  
pp. 1925-1928 ◽  
Author(s):  
Ji Wu Li ◽  
Xiao Hong Zhu ◽  
Jun Ya Pan
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Degradation Rate ◽  
Order Equation ◽  
First Order ◽  
Haldane Model ◽  
Effects Of Ph ◽  
Fusarium Sp ◽  
Ph Range ◽  
Kinetics Of

The stain of Fusarium sp. HJ01 used in 4-chlorophenol (4-CP) degradation was isolated in our laboratory. The effects of pH, temperature, 4-CP concentration, carbon source on 4-CP degradation rate were studied. It was concluded that Fusarium sp. HJ01 could grow with 4-CP as the sole carbon and energy source. 4-CP concentration of 100mg/L in the pH range of 4~10 and temperature range of 25°C~35°C could be degraded completely. The capacity of 4-CP degradation was effectively enhanced by the addiction of sucrose. The kinetics of 4-CP degradation could well accord with the Haldane model for 4-CP as the sole carbon source and with first order equation for added other sucrose.

scholarly journals Engineering of a Xylose Metabolic Pathway in Corynebacterium glutamicum

2006 ◽  
Vol 72 (5) ◽  
pp. 3418-3428 ◽  
Author(s):  
Hideo Kawaguchi ◽  
Alain A. Vert�s ◽  
Shohei Okino ◽  
Masayuki Inui ◽  
Hideaki Yukawa
Keyword(s):  
Carbon Source ◽  
Corynebacterium Glutamicum ◽  
Xylose Isomerase ◽  
Mineral Medium ◽  
Gene Encoding ◽  
Xylose Consumption ◽  
E Coli ◽  
High Copy Number Plasmid ◽  
Sugar Mixture ◽  
Pentose Sugar

ABSTRACT The aerobic microorganism Corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar xylose, which is commonly found in agricultural residues and other lignocellulosic biomass. We demonstrated the functionality of the corynebacterial xylB gene encoding xylulokinase and constructed two recombinant C. glutamicum strains capable of utilizing xylose by cloning the Escherichia coli gene xylA encoding xylose isomerase, either alone (strain CRX1) or in combination with the E. coli gene xylB (strain CRX2). These genes were provided on a high-copy-number plasmid and were under the control of the constitutive promoter trc derived from plasmid pTrc99A. Both recombinant strains were able to grow in mineral medium containing xylose as the sole carbon source, but strain CRX2 grew faster on xylose than strain CRX1. We previously reported the use of oxygen deprivation conditions to arrest cell replication in C. glutamicum and divert carbon source utilization towards product production rather than towards vegetative functions (M. Inui, S. Murakami, S. Okino, H. Kawaguchi, A. A. Vert�s, and H. Yukawa, J. Mol. Microbiol. Biotechnol. 7:182-196, 2004). Under these conditions, strain CRX2 efficiently consumed xylose and produced predominantly lactic and succinic acids without growth. Moreover, in mineral medium containing a sugar mixture of 5% glucose and 2.5% xylose, oxygen-deprived strain CRX2 cells simultaneously consumed both sugars, demonstrating the absence of diauxic phenomena relative to the new xylA-xylB construct, albeit glucose-mediated regulation still exerted a measurable influence on xylose consumption kinetics.

Three UDP-hexose 4-epimerases with overlapping substrate specificity coexist in E. coli O86:B7

2007 ◽  
Vol 356 (3) ◽  
pp. 604-609 ◽  
Author(s):  
Hongjie Guo ◽  
Wen Yi ◽  
Lei Li ◽  
Peng George Wang
Keyword(s):  
Substrate Specificity ◽  
E Coli
Sign in / Sign up

Export Citation Format

Share Document