Production of laccase by a newly isolated deuteromycete fungus Pestalotiopsis sp. and its decolorization of azo dye

Abstract

The effect of various carbon and nitrogen sources on the production of laccase by newly isolated deuteromycete Pestalotiopsis sp. was tested under liquid-state fermentation. Twenty grams per liter of glucose and 10 g l(-1) ammonium tartrate were found to be the optimized concentrations of carbon and nitrogen sources, respectively. The influence of different inducers and inhibitors on the laccase production was also examined. Adding the Cu up to optimum concentration of 2.0 mM in medium (include 20 g l(-1) glucose and 10 g l(-1) ammonium tartrate), the highest laccase activity of 32.7 +/- 1.7 U ml(-l) was achieved. Cu had to be supplemented after 2 days of growth for its maximal effect, an addition after 6 days of growth, during which laccase activity was dominantly formed, resulted in distinctly reduced laccase activity. In addition, Direct Fast Blue B2RL can be effectively decolorized by crude laccase, the decolorization percentage of which was 88.0 +/- 3.2% at pH 4.0 within 12 h. The results suggest that Pestalotiopsis sp. is a high potential producer of the industrially important enzyme laccase.

Screening and induction of laccase activity in fungal species and its application in dye decolorization

“…Extracellular liquid from P. ostreatus degraded the two reactive dyes (50 μg/ml each) namely reactive blue 49 (66%) and reactive red 243 (55%) within 12 h. P. ostreatus secrete acid stable laccase, which are very useful for their application to the removal of dyes from acidic textile effluents such as those resulting from wool and polyester processing. Degradation from this study and those in literature was found to be high at acidic pH to our results, some workers have showed that the degradation of industrially important dyes by lignin peroxidase (Jadhav et al, 2008a;Jadhav et al, 2008b) and laccase (Wang et al, 2010;Hao et al, 2007;Couto and Herrera, 2006) was also more in the buffer of lower pH values. The above results show that the individual dye structures influence the decolorization extent obtained by laccase, indicating the specificity of laccase towards different dye structures.…”

“…As laccases oxidize various types of substrates, several different compounds have been used as indicators for laccase production. Common indicators used are guaiacol (Coll et al, 1993;Kiiskinen et al, 2004;Vishwanath et al, 2008;Ang et al, 2010), 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) (Floch et al, 2002;Wilkołazka et al, 2002;Hao et al, 2007), syringaldazine (Floch et al, 2002;Wilkołazka et al, 2002;Wang et al, 2010) and polymeric dyes like remazol brilliant blue-R (RBB-R) (Desouza et al, 2004).…”

Isolation, Identification And Characterisation Of Dye-Adapted Bacteria From Textile Effluents Mixed With Sewage Released Into The River Amaravathy, Karur, Tamilnadu, India.

“…Knowledge of the population density can be extrapolated to quantitative analysis of the kinetics of azo-dye decolourisation and mineralization [9]. Microorganisms have developed enzyme system for the decolourisation and mineralization of azo dyes under certain environmental conditions [9,10,11]. Preliminary characterization of the bacterial isolate regarding its morphological, biochemical characters and decolourisation activity as well as the molecular identity gives useful information with regard to the further application of strain for various purposes [12].…”

Enhancement of Laccase Production from Pleurotus ostreatus PVCRSP-7 by altering the Nutritional Conditions using Response Surface Methodology

“…Above or below this level, the production decreased. Increasing the glucose concentration above the optimum level inhibits the synthesis of laccase (Hao et al 2007;Periasamy and Palvannan 2010). This catabolic repression is already well-established in fungi and is believed to be an energy-conserving process (Ronne 1995).…”