Optimization of lipase production by Staphylococcus warneri EX17 using the polydimethylsiloxanes artificial oxygen carriers

Abstract

In this research, the combined effects of polydimethylsiloxane (PDMS) and different conditions of oxygen volumetric mass transfer coefficient (k(L)a) on lipase production by Staphylococcus warneri EX17 were studied and optimized in bioreactor cultures. Raw glycerol from biodiesel synthesis was used as the sole carbon source. Full-factorial central composite design and the response surface methodology were employed for the experimental design and analysis of the results. The optimal polydimethylsiloxane concentration and mass coefficient transfer (k(L)a) were found to be 13.5% (v/v) and 181 h(-1), respectively. Under these conditions, the maximal cell production obtained was 10.0 g/l, and the volumetric lipase activities of approximately 490 U/l, after 6 h of cultivation. These results are in close agreement with the model predictions. Results obtained in this work reveal the positive effects of PDMS on oxygen volumetric mass transfer coefficient (k(L)a) in the Staphylococcus warneri EX17 cultivation and lipase production.

Modelling and Optimization Studies on a Novel Lipase Production by Staphylococcus arlettae through Submerged Fermentation

“…The nonlinear relationship of fermentation process variables, namely, inoculum concentration and temperature on lipase yield from Geobacillus thermoleovorans CCR11 has been also found through the RSM approach [19]. Significant and combined effects of polydimethylsiloxane (PDMS) and oxygen volumetric mass transfer coefficient through RSM have been acknowledged by Rech et al [20] for lipase production by Staphylococcus warneri EX17.…”

The effects of emulsified polydimethylsiloxane FG‐10 on the oxygen transfer coefficient (kLa) and lipase production byStaphylococcus warneriEX17

“…The author observed a 3‐fold increase in the oxygen uptake rate of immobilized T. versicolor in polyurethane foam with the addition of 0.5% silicone to cultures. Finally, Rech et al 28 studied the impact of adding non‐emulsified poly‐dimethylsiloxane (PDMS) to S. warneri cultures and reported the positive effects of this chemical concerning the production of lipases, which was around 50% higher when compared with cultivations without PDMS. Moreover, the authors reported a reduction in time to enzyme peak production of one‐half, while enhancing the oxygen transfer rates of cultures.…”