Composite Mutagenesis Budding Aureobasidium Pullulan Breeding High Strain

Aureobiasidium is a kind of yeast fungi, it belongs to Deuteromycota, Moniliales, Aureobasidium, the two forms of Aureobiasidium are the yeast and fungi mycelia. It can produce a variety of metabolism product, such as exocellular polysaccharide, enzymes, antibiotics, etc, and the scientists put their energy on pullulan. It is described as α-(1â†'6) linked polymer of maltotriose subunits. Pullulan is colorless, odorless, no any adverse effect to human body. Because of some special chemical and biological characters, such as water-solubility, plasticity, and ect. It is widely used in the field of medicine, food, cosmetics, tobacco and agriculture, etc. Therefore, it is muti-function biological products, which have economic value and potency.Study begin with Aureobiasidium A312,it is from Huazhong University of Science and Technology. By using UV-irradiated, nitrous acid mutagenesis, screen the high yield strains, and then using the ion beam, screening high yield strains. Screening method:By using UV-irradiated, nitrous acid mutagenesis and ion beam, mutations are inoculated to five milliliter medium, culture in28℃,200rpm for70hours. And then add ten milliliter ethanol, observe the production of pullulan. And then sieve to increase production of mutagenic sub-inoculated into fifty milliliter of culture do rescreening to determine the increase in production of mutants. Year and an half later, we got the mutants:UV-irradiated2600, nitrous acid mutagenesis800. UV-irradiated-nitrous acid mutagenesis800, the ion beam700.At last, we get five strains that pullulan relative to the strains A312are increased by7.8%,4.5%,33.7%,39.2%,15%.