P31: Screening and identification of new isolates for lignocellulosic agricultural wastes bioconversion: thermophile Penicillum sp. and Thermomyces lanuginosus with novel thermostables cellulase and xylanase

A new cellulase-producing fungi strain and two new xylanase-producing fungi were isolated from soil samples collected from decaying organic matter in Brazil. It was identified as Penicillum sp. and Thermomyces lanuginosus species using the method of 16S rRNA combined with morphological and physiological tests. Penicillium sp. produced extracellular cellulases in solid-state fermentation using sugar cane bagasse  as the carbon source at 50°C. It was demonstrated that this fungus was capable of producing the three major components of the cellulases (carboxymethyl cellulase (CMCase), filter paper cellulase (FPase) and β-glucosidase) that were produced with maximal activities (10.2; 0.91 and 3.15 IU/ml) respectively. Maximum CMCase activity was measured at 50 °C and pH 5.0 and it retained more than 60% of its maximal activity for at least one hour at 50-70 °C. Thermomyces lanuginous was capable to produced 0.052; 0.93; 6.24 and 1.14 IU/ml of CMCase, FPase, β-glucosidase, β-xylosidase respectively and high level of xylanase with maximal activity of 65.2 IU/ml at 60 °C and pH 6.0. More importantly, the xylanase by Thermomyces lanuginous showed stable enzymatic activities within pH 5-8 and at temperatures between 60 and 70°C. These results showed that these highly thermostables enzymes could be applied in bioconversion of lignocellulosic agricultural wastes. Investigation of physical-chemical treatments of sugar cane bagasse that favor enzymatic hydrolysis for bioethanol has shown that glycerol treatment applied at concentration of 0.1M combined with ozone produced the lower level of phenols and reducing sugars of 0.78 mg of gallic acid/g and 1.09 mg glucose/g respectively.