Supercritical CO(2): a novel environmentally friendly mutagen.

In order to develop mutagenic methods, supercritical CO(2) was evaluated as a new environmentally friendly mutagen. During treatment by supercritical CO(2), the survival rate and the positive mutation rate of Flavobacterium sp. strain YY25 were strongly dependent on pressure, temperature, treatment time and additive (DMSO). 8 MPa, 35 degrees C, 30 min of supercritical CO(2) and 1% of DMSO were believed as the optimum doses. After the seed liquid was treated under these conditions, a mutant strain with about 44.2% increase in lipase yield comparing with the wild strain was acquired, indicating that the novel mutagenic method by supercritical CO(2) was feasible and promising in microbial breeding field.