Assessment and optimization of xylanase production using co-cultures of Bacillus subtilis and Kluyveromyces marxianus.

Co-cultures of Bacillus subtilis and Kluyveromyces marxianus were investigated in submerged fermentation for xylanase production at shake-flask scale. Xylanase production markedly increased when arabinose, xylose, or hazelnut shells were used as the single carbon source. Maximal xylanase of 49.5 IU/mL was achieved with 4% B. subtilis, 4% K. marxianus, 40% solid load of hazelnut shells, and pH 7.0. Overall, xylanase was enhanced by 4.4-fold compared to initial un-optimized monoculture production and 2.8-fold compared to initial un-optimized co-cultured production, after optimization by response surface method.