Solid-state fermentation with orange waste: optimization of Laccase production from Pleurotus pulmonarius CCB-20 and decolorization of synthetic dyes

Laccases are oxidoreductase enzymes that have the ability to oxidize phenolic substrates. Its biotechnological potential has been greatly explored in many areas as biotechnology industry, bioremediation of dyes, food industry and environmental microbiology. The aim of this study was maximize the laccase production by Pleurotus pulmonarius (Fr.) Quélet in solid-state fermentation (SSF) using orange waste as substrate. After optimization the capability of the crude laccase to decolorize dyes was analyzed. The fermentation medium in the solid-state was optimized by applying a factorial design. After statistics optimization, laccase activity increased two times. The laccase activity appears to be correlated with the ability of crude extract to decolorize some industrial dyes. The optimized laccase was characterized with respect to optimum pH, influence of temperature and salts. Our results demonstrate that P. pulmonarius was an efficient producer of an important industrial enzyme, laccase, in a cheap solid-state system using orange waste as substrate.

Pentachlorophenol removal by Pleurotus pulmonarius in submerged cultures

Pentachlorophenol (PCP) removal by Pleurotus pulmonarius grown in submerged cultures in the presence and absence of laccase inducers was studied in this work. When PCP was added to a final concentration of 25 mg·L-1 in submerged cultures actively producing laccase, 70 percent of the PCP was removed after 96 h. The removal of PCP was less than 20 percent in the cultures with low laccase activity. The results suggested that laccase played an important role in the biodegradation of PCP by P. pulmonarius and that for bioremediation purposes the fungus must be cultured under the conditions of active laccase production.

Production of hydrolytic enzymes by the plant pathogenic fungus Myrothecium verrucaria in submerged cultures

A capacidade do fungo fitopatogênico Myrothecium verrucaria produzir enzimas hidrolíticas extracelulares em culturas submersas foi estudada utilizando diversos substratos. O fungo foi capaz de produzir diferentes depolimerases e glicosidases, sendo xilanases, pectinases e proteases as mais importantes. Atividade lipase foi encontrada nos filtrados das culturas desenvolvidas na presença de óleo de oliva, enquanto atividade proteolítica foi detectada em todas as culturas. Xilanase e pectinase foram otimamente ativas em pH 4,5 a 5,5, enquanto protease foi ativa em ampla faixa de pH (3,5 a 11,0). As três enzimas foram otimamente ativas 40ºC e estáveis por várias horas a temperaturas até 50ºC.

Production of amylases by Aspergillus tamarii

A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, was able to produce both Ó-amylase and glucoamylase activities in mineral media supplemented with 1(per cent) (w/v) starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained using shaking culture. The production of amylases was tolerant to a wide range of initial culture pH values (from 4 to 10) and temperature (from 25 to 42degree C). Two amylases, once Ó-amylase and one glucoamylase, were separated by ion exchange chromatography. Both partially purified enzymes had optimal activities at pH values between 4.5 and 6.0 and were stable under acid conditions (pH 4.0-7.0). The enzymes exhibited optimal activities at temperatures between 50(degree) and 60(degree) C and wete stable for more than ten hours at 55(degree) C.