Comparison of lipase production by Geotrichum candidum in stirring and airlift fermenters

Abstract

The production of lipase by Geotrichum candidum in both, stirred tank and airlift bioreactors were compared. G candidum an imperfect filamentous fungus, grows well in liquid medium, and produces a lipase with specific affinity for long-chain fatty acids with cis-9 double bonds but, lipase production is generally not efficient because the optimum medium composition and fermentation conditions are not known. Response surface methodology was used to optimize the agitation speed (100-500 rpm) and aeration (0.2-1.8 vvm) for production of lipase by G candidum in a bench-scale stirred fermenter. A Central Composite Rotatable Design (CCRD) was used to optimize lipase activity and productivity. Lipase production in an airlift fermenter was also studied with aeration ranging from 1 to 3 vvm. A previously optimized culture medium containing 3.58% of peptone, 0.64% of soy oil and an initial pH of 7.0, was used in the experiments, incubating at 30• C. In the stirred reactor the optimum conditions of agitation and aeration for lipase production and productivity were 300 rpm and 1 vvm, leading to an activity of 20 U cm −3 in 54 h of fermentation and 0.3900 (U cm −3 h −1 ) of productivity. The best aeration condition in the airlift fermenter was 2.5 vvm, which yielded similar lipase activity after 30 h of fermentation, resulting in a productivity of 0.6423 (U cm −3 h −1 ). In the absence of mechanical agitation similar lipase yields were achieved but in less time, resulting in productivity, about 60% greater than in a stirred fermenter; the lower energy demand for the same lipase yield offers economic advantages.

The Brazilian Way to Consume acai: Do guarana Extract and Sugar Concentrations Influence on Acceptance?

“…Dependent variables flavor, texture and overall liking were analyzed by multivariate regressions and significances of the models were tested (Burkert et al, 2005) quadratic model terms while sugar caused no influence (p > 0.05) in these terms. A better understanding of the influence of the sensory descriptive attributes on the açaí samples with different concentrations of guaraná and sugar would be achieved applying a descriptive technique.…”

Isolation of Lipase-Producing Yeasts from Industrial Oily Residues in Different Culture Media

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A Review on Geotrichum Lipases: Production, Purification, Immobilization and Applications

“…Burket et al and Maldonado et al showed that 3.58 % w/w of peptone is enough to obtain a high level of lipase activity from G. candidum. They demon- 52,61 . Ginalska et al showed that 0.4 % w/w of urea was the best condition of nitrogen source for lipase production compared to other organic sources.…”

“…Soybean oil also shows similar results due to its similar composition to olive oil, and its low cost is a strong appeal for its application. Concentrations of 1.0 % w/w are frequently utilized, but optimized studies showed that lower concentrations (0.5 to 0.7 % w/w) are enough to induce the lipase production, and concentrations above 1.0 % w/w do not have significant effects on the increase in lipase activity [52][53][54]56,[60][61][62] . Glucose is the most used carbon source for the growth of G. candidum and the utilized concentration is usually 1.0 % w/w.…”