Effects of media component and age on Aspergilli mycelia protoplast release

Effects of media component and age on the mycelia protoplast release of Aspergillus niger and Aspergillus oryzae was studied.The results showed that protoplast release related to closely media component and mycelia age;decrease of carbohydrate or nitrogen component could effectively prompted protoplast release from mycelia,and the effect of the former was great than the later.The relationship between mycelia age and protoplast release varied with media,the growth curve of M70 mycelia grown on the solid complete media related negatively to their protoplast release.And the mycelia age most suitable for protoplast preparation was 12 hours under this research condition.On the contrary,the protoplast release for M4 was not related to its growth curve of mycelia grown on the solid limited media such as casein medium,a great deal of protoplasts were released from 12 to 26 hours of mycelia age.