The effect of glycerol mixed substrate on the heterologous production of a Rhizopus oryzae lipase in Pichia pastoris system

作者：Arnau Carolina; Casas Carles; Valero Francisco^*

来源：Biochemical Engineering Journal, 2011, 57: 30-37.

DOI：10.1016/j.bej.2011.08.004

• Pichia pastoris
• Mixed substrate
• Fed-Batch culture
• Glycerol
• Rhizopus oryzae lipase
• Bioprocess monitoring

A recombinant Rhizopus oryzae lipase producing Mut(s) Pichia pastoris strain was used as a model organism to study the effect of mixed substrates (glycerol and methanol) on the specific product productivity. Different fed-batch cultivations were performed under three constant specific growth rates (0.02, 0.05 and 0.1 h(-1)), maintaining a constant methanol concentration of 2 g l(-1).
At the lowest mu tested (0.02 h(-1)), the specific productivity was 1.23 and 1.61 fold higher and the specific methanol consumption rate (q(sMeOH)) was 3 and 3.5 fold higher than values obtained when p was 0.05 and 0.1 h(-1), respectively. This implies a relation between the q(sMeOH) and the specific productivity, yielding higher specific productivities whenever the consumption of methanol is higher. Although glycerol was maintained under limiting conditions in all mu tested, when the relation between the mu(Gly) and mu(MeOH) was larger than 4, an important decrease on the maximal activity value was observed.
Finally, a comparison under the same conditions using glycerol or sorbitol as co-substrates was also performed, obtaining better specific productivity when sorbitol was used. In addition, protease activity was detected when glycerol was used as co-substrate.

• 出版日期2011-11-15