Strain improvement of Acremonium cellulolyticus for cellulase production by mutation.
In the search for an efficient producer of cellulolytic enzymes, Acremonium cellulolyticus strain C-1 was subjected to mutagenesis using UV-irradiation and N-methyl-N'nitro-N-nitrosoguanidine (NTG) and strain CF-2612 was isolated. Strain CF-2612 exhibited higher filter paperase (FPase) activities (17.8 U/ml) than the parent strain C-1 (12.3 U/ml). Soluble protein production and beta-glucosidase activity from strain CF-2612 were also significantly improved. FPase activity, cellulase productivity and yield of CF-2612 using batch culture with 5% Solka Floc in a 2-l jar fermentor at 30 degrees C reached 18.0 U/ml, 150.0 FPU/l/h and 360.0 FPU/g carbohydrate, respectively; when fed-batch culture was used with Solka Floc, these values reached 34.6 U/ml, 240.3 FPU/l/h and 346.0 FPU/g carbohydrate, respectively. It was observed that more hydrolyzed glucose was released from pretreated eucalyptus with the enzyme of strain CF-2612, compared with that of the commercial cellulase GC-220. This result was attributed to the higher ratio of beta-glucosidase/FPase activity of strain CF-2612. Three distinguishable phases including the periods of primary or second mycelial growth and mycelial fragmentation were proposed in batch culture by A. cellulolyticus.
Fang
Xu
X
Biomass Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2-2-2 Hiro-suehiro, Kure 737-0197, Japan.
Yano
Shinichi
S
Inoue
Hiroyuki
H
Sawayama
Shigeki
S
D000164:Acremonium / Q000378:metabolism*; D019149:Bioreactors; D002241:Carbohydrates; D002480:Cellulase / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D005285:Fermentation; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D009154:Mutation / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D001617:beta-Glucosidase / Q000378:metabolism
D002241:Carbohydrates; D005656:Fungal Proteins; D001617:beta-Glucosidase; D002480:Cellulase; D005947:Glucose