Objectives
To protect our precious water and soil environments, it is important to remove toxic organopollutants from wastewaters and remediate polluted environments. We are studying a wastewater treatment and remediation technologies with biocatalysts produced from white-rot fungi. Understanding hazardous chemicals-degradation by the white-rot fungi at a molecular level might be useful for future applications of the organisms to bioremediation. In order to understand the responses of fungi to environmental stress and to identify changes in gene expression, we used the differential-display technique to identify genes that are differentially expressed in chemically stressed Coriolus versicolor.
Results
Differential display patterns from control and PCP-stressed C. versicolor indicated that many bands were common to both samples and the remainder were specific either to the control or to the PCP-treated sample. Five cDNA fragments were cloned and the sequence of one fragment (DD123) were analyzed in further detail. The amino acid sequence deduced from the nucleotide sequence of FDD123 was similar to that of heat shock protein 30 of Saccharomyces cerevisiae (HSP30) (31.7% identity for the entire amino acid sequence), and to that of YRO2 of S. cervisiae (34.1% identity). Alignment of the predicted amino acid sequence of FDD123 with those of HSP30 and YRO2 revealed strong conservation of domains that are conserved among the small HSPs from S. cerevisiae (Fig.). Analysis by RT-PCR of total RNA from C. versicolor cells was performed with primers specific for the FDD123. The level of FDD123 mRNA appeared to increase approximately 9.7-fold at 4 hr after the start of treatment with PCP. Considering the level of FDD123 mRNA detected under control conditions, we can surmise that the gene is expressed at a very low constitutive levele. Consitutive expression has been recognized for the genes of many major heat shock proteins, and such stress proteins are often essential for cell growth
Selected Publications
| 1) | Dechlorination of tetrachloroguaiacol by laccase of white-rot basidiomycete Coriolus versicolor. Appl. Microbiol Biotechnol, 45, 434-439, 1996 |
| 2) | Role of peroxidase and chitosan in removing chlorophenols from aqueous
solution. Wat. Sci. Tech., 34, 151-159, 1996 |
