Increased riboflavin production from activated bleaching earth by a mutant strain of Ashbya gossypii.
The production of riboflavin from vegetable oil was increased using a mutant strain of Ashbya gossypii. This mutant was generated by treating the wild-type strain with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Riboflavin production was 10-fold higher in the mutant compared to the wild-type strain. The specific intracellular catalase activity after 3 d of culture was 6-fold higher in the mutant than in the wild-type strain. For the mutant, riboflavin production in the presence of 40 mM hydrogen peroxide was 16% less than that in the absence of hydrogen peroxide, whereas it was 56% less for the wild-type strain. The isocitrate lyase (ICL) activity of the mutant was 0.26 mU/mg of protein during the active riboflavin production phase, which was 2.6-fold higher than the wild-type strain. These data indicate that the mutant utilizes the carbon flux from the TCA cycle to the glyoxylate cycle more efficiently than the wild-type strain, resulting in enhanced riboflavin production. This novel mutant has the potential to be of use for industrial-scale riboflavin production from waste-activated bleaching earth (ABE), thereby transforming a useless material into a valuable bioproduct.
Tajima
Satoshi
S
Department of Applied Biological Chemistry, Shizuoka University, Ohya, Suruga-ku, Japan.
Itoh
Yoko
Y
Sugimoto
Takashi
T
Kato
Tatsuya
T
Park
Enoch Y
EY
D001203:Ascomycota / Q000235:genetics / Q000378:metabolism*; D001412:Bacillus subtilis / Q000378:metabolism; D002175:Candida / Q000378:metabolism; D002952:Citric Acid Cycle; D005486:Flavin Mononucleotide / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006038:Glyoxylates / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D010938:Plant Oils / Q000378:metabolism; D012256:Riboflavin / Q000096:biosynthesis*; D012988:Soil Microbiology; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism
D006038:Glyoxylates; D010938:Plant Oils; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide; D012256:Riboflavin