Optimization of Agrobacterium tumefaciens-mediated transformation method of oleaginous filamentous fungus Mortierella alpina on co-cultivation materials choice

The Agrobacterium tumefaciens-mediated transformation (ATMT) method is commonly applied in the oleaginous filamentous fungus Mortierella alpina. During the ATMT process, the spores of M. alpina have traditionally been used as a co-cultivation material, but their long spore-producing cycle and low sporulation rate make the transformation process tedious. This study explores the use of germinating spores, mycelium and single solid colonies of uracil auxotrophic M. alpina CCFM501 as a co-cultivation material with A. tumefaciens AGL1. The results show that A. tumefaciens AGL1 can successfully transform the germinating spores, mycelium and single solid colonies of M. alpina. In addition, the transformation rate of the germinating spores was 50% higher than that of the fresh spores. Due to its concise preparation process, the mycelium was chosen as a co-cultivation material for two plasmids of different lengths and proven to be an efficient co-cultivation material for M. alpina.