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Characterization of catechol 2,3-dioxygenase from Planococcus sp. strain S5 induced by high phenol concentration

100%

Hupert-Kocurek K., Guzik U., Wojcieszynska D.

Acta Biochimica Polonica

2012

tom 59

nr 3

This study aimed at characterization of a new catechol 2,3-dioxygenase isolated from a Gram-positive bacterium able to utilize phenol as the sole carbon and energy source. Planococcus sp. strain S5 grown on 1 or 2 mM phenol showed activity of both a catechol 1,2- and catechol 2,3-dioxygenase while at a higher concentrations of phenol only catechol 2,3-dioxygenase activity was observed. The enzyme was optimally active at 60°C and pH 8.0. Kinetic studies showed that the Km and Vmax of the enzyme were 42.70 µM and 329.96 mU, respectively. The catechol 2,3-dioxygenase showed the following relative meta-cleavage activities for various catechols tested: catechol (100%), 3-methylcatechol (13.67%), 4-methylcatechol (106.33%) and 4-chlorocatechol (203.80%). The high reactivity of this enzyme towards 4-chlorocatechol is different from that observed for other catechol 2,3-dioxygenases. Nucleotide sequencing and homology search revealed that the gene encoding the S5 catechol 2,3-dioxygenase shared the greatest homology with the known genes encoding isoenzymes from Gram-negative Pseudomonas strains.

Production and characterization of alpha-amylase from Aspergillus niger JGI 24 isolated in Bangalore

84%

Varalakshmi K. N., Kumudini B. S., Nandini B. N., Solomon J., Suhas R., Mahesh B., Kavitha A. P.

Polish Journal of Microbiology

2009

tom 58

nr 1

29-36

Five fungal isolates were screened for the production of α-amylase using both solid-state and submerged fermentations. The best amylase producer among them, Aspergillus niger JGI 24, was selected for enzyme production by solid-state fermentation (SSF) on wheat bran. Different carbon and nitrogen supplements were used to enhance enzyme production and maximum amount of enzyme was obtained when SSF was carried out with soluble starch and beef extract (1 % each) as supplements. Further attempts to enhance enzyme production by UV induced mutagenesis were carried out. Survival rate decreased with increase in duration of UV exposure. Partial purification of the enzyme using ammonium sulphate fractionation resulted in 1.49 fold increase in the enzyme activity. The enzyme showed a molecular weight of 43 kDa by SDS-PAGE. Metal ions Ca²⁺ and Co²⁺ increased the enzyme activity. The enzyme was optimally active at 30°C and pH 9.5.

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Polish Journal of Microbiology

1 Guzik U.

1 Hupert-Kocurek K.

1 Kavitha A. P.

1 Kumudini B. S.

1 Mahesh B.

1 Nandini B. N.

1 Solomon J.

1 Suhas R.

1 Varalakshmi K. N.

1 Wojcieszynska D.

1 2012

1 2009

Wyniki wyszukiwania

Characterization of catechol 2,3-dioxygenase from Planococcus sp. strain S5 induced by high phenol concentration

Production and characterization of alpha-amylase from Aspergillus niger JGI 24 isolated in Bangalore