1.Improvement of Transformation System in Filamentous Fungus Aspergillus oryzae.
Jae Won LEE ; Chan Do YUN ; Young Tae HAHM
Korean Journal of Medical Mycology 2001;6(1):1-8
Aspergillus oryzae is a filamentous fungus classified in the group Aspergillaceae Ascomycetes. A. oryzae is an important microorganism for industrial production of enzymes and fermented food products. It secrets large quantities of proteins or enzymes into the culture medium which makes this organism appealing for the production of heterologous proteins. Recently Electric field-mediated transformation method, electroporation, has been applied to fungal transformation. It is fast, simple to handle, and avoids the use of some chemicals. The optimum conditions for A. oryzae were determined with pILJ-16 and ~0.2 x 105 protoplast cell at various field strength. The survived population of protoplasts in the electric field were ~80% of nonprotoplast cell population at 1.3 KV/cm to ~50% at 6.3 KV/cm. The electrotransformation efficiency, expressed as transformants/microgram of input DNA/population of protoplast cells, increased with the increment of the field strength up to 6.3 KV/cm. The highest value, 14.35%, was obtained at 6.3 KV/cm and 1540ohm. Some antibiotics for the dominant selectable makers were applied to A. oryzae and Tolypocladium inflatum. Whereas phleomycin was very effective on T. inflatum, hygromycin B and phleomycin were not effective on A. oryzae. Protoplasts were obtained with hemicellulase and celluclast, instead of novozyme234. More than 104 transformants/microgram of DNA with hemicellulase-treated protoplasts were obtained by using electroporation at the condition of 2,500 voltage, 1,540 ohm and 0.50 capacitance. Less than 102 transformants/microgram of DNA were obtained with Novozyme234- and celluclast-treated protoplasts.
Anti-Bacterial Agents
;
Ascomycota
;
Aspergillus oryzae*
;
Aspergillus*
;
DNA
;
Electroporation
;
Fungi*
;
Hygromycin B
;
Oryza
;
Phleomycins
;
Protoplasts
2.Transformation of the Edible Basidiomycete, Pleurotus ostreatus to Phleomycin Resistance.
Beom Gi KIM ; Jung Ho JOH ; Young Bok YOO ; Yumi MAGAE
Mycobiology 2003;31(1):42-45
For transformation of Pleurotus ostreatus, two novel vectors, pPhKM1 and pPhKM2, were constructed, using the regulatory sequences of the P. sajor-caju beta-tubulin gene (TUB1) and the ble gene encoding phleomycin binding protein. pPhKM1 contains ble fused to the TUB1 promoter and the Schizophyllum commune GPD terminator. pPhKM2 contains ble fused to the promoter and terminator regions of P. sajor-caju TUB1. To confirm phleomycin-resistance activity, each vector was cotransformed with pTRura3-2 into the P. ostreatus homokaryotic ura - strain. The transforming DNA was stably integrated into the genomic DNA. Subsequently, phleomycin resistance was conferred on wild-type dikaryotic P. ostreatus by transformation with pPhKM1 or pPhKM2. This transformation system generated stable phleomycin-resistant transformants.
Basidiomycota*
;
Carrier Proteins
;
DNA
;
Phleomycins*
;
Pleurotus*
;
Schizophyllum
;
Terminator Regions, Genetic
;
Tubulin