Hydrocellulase of Aspergillus aculeatus

Conditions for extracellular production of vitamin B₆ compounds (B₆), especially pyridoxal 5'-phosphate (PLP) by Schizosaccharomyces pombe leu1 strain were examined. The productivity was dependent on concentration of L-leucine in the culture medium: 30 mg/l gave the highest concentrations of total B₆ and PLP. The viable cells harvested at different growth phases showed different productivity: middle and late exponential phase cells showed the highest productivity of total B₆ and PLP, respectively. D-Glucose (1%, w/v) among other sugars gave the best productivity. Supplementation of air and ammonium sulfate significantly increased extracellular production of PLP. Superoxide anion producers, menadione and plumbagin, and H₂O₂ increased the productivity of PLP. Cycloheximide inhibited the increase of PLP by the oxidative stress and in contrast, increased pyridoxine.