D. Haltrich et al., OPTIMIZATION OF A CULTURE-MEDIUM FOR INCREASED XYLANASE PRODUCTION BYA WILD STRAIN OF SCHIZOPHYLLUM-COMMUNE, Enzyme and microbial technology, 15(10), 1993, pp. 854-860
A culture medium for a wild strain of Schizophyllum commune was optimi
zed with regard to xylanase production by means of response surface me
thods. The medium components having the strongest influence on xylanas
e production were chosen for optimization and included microcrystallin
e cellulose (Avicel), yeast extract, and NH4NO3. The optimal region of
the medium composition was approached by factorial designs and by the
path of steepest ascent. The optimum concentrations were determined b
y a central composite design and were found to be 73.4 g l-1 Avicel, 5
5.4 g l-1 yeast extract, and 1.38 g l-1 NH4NO3. Additional factorial d
esigns for the medium components that were found to have less influenc
e on xylanase production further improved the medium composition. When
the strain was cultivated using the optimized medium in shake flasks,
a maximum production of 5,740 IU ml-1 (95,670 nkat ml-1) xylanase act
ivity was reached within 11 days. A laboratory fermentation (9.5 l wor
king volume) was performed with the optimized medium and yielded a max
imum xylanase activity of 4,839 IU ml-1 (80,650 nkat ml-1). Other enzy
me activities assayed during this cultivation included filter paper an
d carboxymethyl cellulase, beta-glucosidase, beta-xylosidase, beta-man
nanase, acetyl esterase, acetyl xylan esterase, alpha-arabinofuranosid
ase, and alpha-galactosidase.