Culture Conditions and Investigation of Bioreactor Configurations for Lipase Production by Rhizopus oryzae

Abstract

Lipolytic enzymes are the subject of great industrial and academic interest. For this reason, a detailed study of lipolytic enzyme production by the fungus Rhizopus oryzae is tackled, and several steps from plate to shake flasks and bioreactor cultures are investigated in order to propose an optimized strategy to perform the biological process. The suitability of several lipidic compounds and surfactants is assessed. Triton X-100 (5 g/L) gives the highest activities with a maximum value of 6320 U/L which is 10-fold the value attained in cultures without addition of lipidic compounds. As there are almost no studies on bench-scale bioreactors, two bioreactor configurations, stirred tank and air-lift, are investigated to determine the most suitable one to carry out the biological reaction. It is demonstrated that the lipolytic activity is strongly enhanced when a stirred-tank bioreactor is used with a maximum value of 3521 U/L within two days which is clearly higher than the values produced by other recently reported species.

Isolation and characterization of novel thermophilic lipase-secreting bacteria

“…Therefore in this study, a medium was designed according to a literature review present on this subject. According to our literature review, it seems that the most significant factor in medium optimization to improve lipase productivity is type of carbon and nitrogen source (Kumari et al , 2009; Lopez et al , 2010; Lima et al , 2003; Treichel et al , 2010; Wang et al , 2008). Therefore, this medium was designed so that the olive oil was the sole carbon source and ammonium sulfate was mineral nitrogen source.…”

“…Therefore, this medium was designed so that the olive oil was the sole carbon source and ammonium sulfate was mineral nitrogen source. Different studies indicate that using oils such as plant oils, fatty acids and triglyceride as inducer or the sole carbon source increases the total lipase activity and productivity (Kumari et al , 2009; Lopez et al , 2010; Lima et al , 2003; Treichel et al , 2010; Wang et al , 2008). This issue is also confirmed by our results.…”