Study Of The Lignocelluloses Degradation Characteristics Of A Cladosporium Sp.stain Bio-1

Screening and genetic engineering of microorganism to obtain efficientlignocellulose degradation strains plays important role in the fields of bioenergy andenvironment protection. Bio-1, isolated from the soil of Yuelu mountain, could growby using alkali lignin as the sole carbon source. Combined with the analysis of itsculture characters, morphological characters and18s rDNA and ITS sequences, Bio-1was identified as a member of the genus Cladosporium.The highest extracellular and intracellular laccase activities of Bio-1were241U/L and187U/L on the eighth day, respectively. When0.5mmol/L copper was addedto the culture on the fourth day, lacccase activities of3800U/L and5352U/L wereobtained on the eighth day, higher than some typical fungi used for laccase production.Extracellular and intracellular cellulase activities of51U/mL and2.9U/mL wereobtained on the eighth day.Two preliminary work for the further genetic engineering of Bio-1were alsocarried out. Mediums which contained alkali lignin, carboxymethyl cellulose-Na andbirchwood xylan as sole carbon sources were used, respectively and Bio-1sporeswere inoculated with different concentrations. According to Bio-1’s growth conditions,a simple and effective method for screening the transformants which could degradealkali lignin, cellulose or xylan respectively was optimized: the inoculated sporeconcentration of transformants was chosen as108per liter and the colony which growswell in less than60hours would be the mutant that has better degradation abilitythan the wild type. Then a dual-tag vector with enhanced GFP (EGFP) andHygromycin B resistance (hph) was constructed, providing a powerful tool for thescreening of transformants of Bio-1. After being sequenced and expressed in theE.coli, the recombinant plasmid was confirmed to be able to express the EGFP andhph gene.This paper charactered and analyzed a lignocelluloses-degrading fungus. Thepreliminary work for further development and utilization of this fungus was finished,which laid the foundation for obtaining superior strains used in bioenergy andwastewater treatment industries.