Induction, purification, and characterization of two extracellular α-L-arabinofuranosidases from Fusarium oxysporum

2003 ◽  
Vol 49 (10) ◽  
pp. 639-644 ◽  
Author(s):  
Gianni Panagiotou ◽  
Evagelos Topakas ◽  
Lina Economou ◽  
Dimitris Kekos ◽  
Basil J Macris ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Enzyme Induction ◽  
Enzyme Purification ◽  
Sole Carbon Source ◽  
Purification And Characterization ◽  
Optimal Activity ◽  
Molecular Masses

In the presence of L-arabinose as sole carbon source, Fusarium oxysporum produces two α-L-arabinofuranosidases (ABFs) named ABF1 and ABF2, with molecular masses of 200 and 180 kDa, respectively. The two F. oxysporum proteins have been purified to homogeneity. The purified enzymes are composed of three equal subunits and are neutral proteins with pIs of 6.0 and 7.3 for ABF1 and ABF2, respectively. With p-nitrophenyl α-L-arabinofuranoside (pNPA) as the substrate, ABF1 and ABF2 exhibited Km values of 0.39 and 0.28 mmol·L–1, respectively, and Vmax values of 1.6 and 4.6 µmol·min–1·(mg of protein)–1, respectively, and displayed optimal activity at pH 6.0 and 50–60 °C. ABFs released arabinose only from sugar beet arabinan and not from wheat soluble and insoluble arabinoxylans. The enzymes were not active on substrates containing ferulic acid ester linked to C-5 and C-2 linkages of pNPA showing that phenolic substituents of pNPA sterically hindered the action of ABFs.Key words: α-L-arabinofuranosidase, enzyme purification, enzyme induction.

scholarly journals Purification and Characterization of Thermostable Endo-1,5-α-l-Arabinase from a Strain of Bacillus thermodenitrificans

2002 ◽  
Vol 68 (4) ◽  
pp. 1639-1646 ◽  
Author(s):  
Makoto Takao ◽  
Kana Akiyama ◽  
Takuo Sakai
Keyword(s):  
Sugar Beet ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Thermophilic Bacterium ◽  
Size Exclusion ◽  
Purification And Characterization ◽  
Optimal Activity ◽  
End Products ◽  
Beet Pulp

ABSTRACT A strain of a thermophilic bacterium, tentatively designated Bacillus thermodenitrificans TS-3, with arabinan-degrading activity was isolated. It produced an endo-arabinase (ABN) (EC 3.2.1.99) and two arabinofuranosidases (EC 3.2.1.55) extracellularly when grown at 60°C on a medium containing sugar beet arabinan. The ABN (tentatively called an ABN-TS) was purified 7,417-fold by anion-exchange, hydrophobic, size exclusion, and hydroxyapatite chromatographies. The molecular mass of ABN-TS was 35 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the isoelectric point was pH 4.5. The enzyme was observed to be more thermostable than known ABNs; it had a half-life of 4 h at 75°C. The enzyme had optimal activity at 70°C and pH 6.0. The enzyme had apparent Km values of 8.5 and 45 mg/ml and apparent V max values of 1.6 and 1.1 mmol/min/mg of protein against debranched arabinan (α-1,5-arabinan) and arabinan, respectively. The enzyme had no pectin-releasing activity (protopectinase activity) from sugar beet protopectin, differing from an ABN (protopectinase-C) from mesophilic Bacillus subtilis IFO 3134. The pattern of degradation of debranched arabinan by ABN-TS indicated that the enzyme was an endo-acting enzyme and the main end products were arabinobiose and arabinose. The results of preliminary experiments indicated that the culture filtrate of strain TS-3 is suitable for l-arabinose production from sugar beet pulp at high temperature.

Purification and Characterization of Chitinases from Bacillus licheniformis Using Auricularia auricular Colloidal Substance as a Substrate

2011 ◽  
Vol 233-235 ◽  
pp. 1014-1017
Author(s):  
Yong Jun Zhang ◽  
Qiao Xian ◽  
Jie Min He ◽  
Meng Yao Zhao
Keyword(s):  
Carbon Source ◽  
Bacillus Licheniformis ◽  
Sole Carbon Source ◽  
Culture Supernatant ◽  
Purification And Characterization ◽  
Medium Ph ◽  
Molecular Weights ◽  
Sds Page ◽  
Optimized Conditions

A chitinase was purified from the culture supernatant of Bacillus licheniformis with Auricularia auricular colloidal substance as the sole carbon source. The optimized conditions of this species strain for the production of chitinases were found to be when the culture was shaken at 37°C for 3 days in medium (pH 7) containing 0.05% KH2PO4,0.5%NaNO3, 0.05% MgSO4·7H2O and 1.5% Auricularia auricular colloidal substance powder(w/v). The molecular weights of the chitinases determined by SDS-PAGE were approximately 52kDa. The chitinases was inhibited highly by Mg2+ and PMSF, whereas Co2+ and Mn2+ could increase highly the activity of the chitinase.

scholarly journals Expression, Purification, and Characterization of (R)-Sulfolactate Dehydrogenase (ComC) from the Rumen MethanogenMethanobrevibacter milleraeSM9

Archaea ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Yanli Zhang ◽  
Linley R. Schofield ◽  
Carrie Sang ◽  
Debjit Dey ◽  
Ron S. Ronimus
Keyword(s):  
Biosynthetic Pathway ◽  
Critical Role ◽  
Reduction Reaction ◽  
Coenzyme M ◽  
Purification And Characterization ◽  
The Third ◽  
Optimal Activity ◽  
Methyl Coenzyme M Reductase

(R)-Sulfolactate dehydrogenase (EC 1.1.1.337), termed ComC, is a member of an NADH/NADPH-dependent oxidoreductase family of enzymes that catalyze the interconversion of 2-hydroxyacids into their corresponding 2-oxoacids. The ComC reaction is reversible and in the biosynthetic direction causes the conversion of (R)-sulfolactate to sulfopyruvate in the production of coenzyme M (2-mercaptoethanesulfonic acid). Coenzyme M is an essential cofactor required for the production of methane by the methyl-coenzyme M reductase complex. ComC catalyzes the third step in the first established biosynthetic pathway of coenzyme M and is also involved in methanopterin biosynthesis. In this study, ComC fromMethanobrevibacter milleraeSM9 was cloned and expressed inEscherichia coliand biochemically characterized. Sulfopyruvate was the preferred substrate using the reduction reaction, with 31% activity seen for oxaloacetate and 0.2% seen forα-ketoglutarate. Optimal activity was observed at pH 6.5. The apparentKMfor coenzyme (NADH) was 55.1 μM, and for sulfopyruvate, it was 196 μM (for sulfopyruvate theVmaxwas 93.9 μmol min−1 mg−1andkcatwas 62.8 s−1). The critical role of ComC in two separate cofactor pathways makes this enzyme a potential means of developing methanogen-specific inhibitors for controlling ruminant methane emissions which are increasingly being recognized as contributing to climate change.

scholarly journals Isolation and Characterization of a Novel p,p’-DDT-Degrading Bacterium: Aeromonas sp. Strain MY1 from Agricultural Soil

2020 ◽  
pp. 12-22
Author(s):  
Y. Murtala ◽  
B. C. Nwanguma ◽  
L. U. S. Ezeanyika
Keyword(s):  
Carbon Source ◽  
16S Rrna ◽  
Agricultural Soil ◽  
Sole Carbon Source ◽  
Phylogenetic Analyses ◽  
Inhibitory Effect ◽  
Aerobic Conditions ◽  
Degrading Bacterium ◽  
Isolation And Characterization

Background: Despite the banned on the use of dichlorodiphenyltrichloroethane (DDT) and other Persistent Organic Pollutants (POPs) by the Stockholm Convention for their toxicity, emerging shreds of evidence have indicated that DDT is, however, still in use in developing countries. This might increase the global burden of DDT contamination and its hazardous effects. Aim: This study focused on the isolation and characterization of p,p’-DDT-degrading bacterium from a tropical agricultural soil. Methodology: Standard isolation procedure was used for the screening and isolation of the strain. The 16S rRNA and phylogenetic analyses were used to identify the isolate and established protocols were followed to characterize the strain. Results: A new strain belonging to the genus Aeromonas was isolated from agricultural soil using minimal salt-p,p’-DDT enrichment medium. The 16S rRNA sequencing was used to identify the strain and the partial sequence was deposited in the NCBI GenBank as Aeromonas sp. Strain MY1. This mesophilic isolate was capable of utilizing up to 50 mgL-1 of p,p’-DDT as the sole carbon source at an optimum pH of 7.5 and optimum temperature of 35 °C within 120 h under aerobic conditions. Fe2+ (0.2 mgL-1) demonstrated a stimulatory effect on the p,p’-DDT degradation capacity by the strain MY1. However, Zn, Cu, Pb, Hg, Ag and Cr ions have demonstrated various patterns of inhibitory effect on the p,p’-DDT degradation capacity of the isolate at 0.2 mgL-1. The strain MY1 could be a promising candidate for the bioremediation of p,p’-DDT contaminant. Conclusion: Aeromonas sp. strain MY1 was capable of utilizing p,p’-DDT as a sole carbon source under aerobic conditions. The utilization capacity of the strain was influenced by some heavy metals. Fe was found to enhance the p,p’-DDT utilization capacity of the isolate at a lower concentration. While Zn, Cu, Pb, Hg, Ag and Cr showed various patterns of inhibitory effect.

Purification and characterization of a lectin from Xanthomonas campestris NCIM 5028

1996 ◽  
Vol 42 (6) ◽  
pp. 609-612 ◽  
Author(s):  
Bhagyashree Joshi ◽  
Jayant M. Khire ◽  
Hephzibah SivaRaman ◽  
M. Islam Khan
Keyword(s):  
Molecular Mass ◽  
Host Plant ◽  
Xanthomonas Campestris ◽  
Simple Procedure ◽  
Gel Filtration ◽  
Purification And Characterization ◽  
Ammonium Sulphate Precipitation ◽  
Molecular Masses ◽  
Lectin Purification

A lectin was isolated from culture filtrates of Xanthomonas campestris NCIM 5028, by a simple procedure of hydrophobic chromatography on phenyl-Sepharose after ammonium sulphate precipitation. The lectin was a heterodimer, with subunit molecular masses of 30 000 and 28 000. Gel filtration on S-300 column, calibrated with markers, showed its molecular mass to be approximately 70 000. Its isoelectric point was 7.2. The agglutination of the rabbit erythrocytes by the lectin was inhibited by fetuin glycopeptides and host plant (Brassica oleracea) extracts.Key words: Xanthomonas campestris, lectin, purification.

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