Candida curvata

Whey permeate may also be fermented anaerobically to fuel gas. Studies have also been reported on the production of ammonium lactate by continuous fermentation of deproteinized whey to lactic acid followed by neutralization with ammonia. Conversion of whey and whey permeate to oil and single-cell protein with strains of Candida curvata and Trichosporon cutaneum have been examined. Production of the solvents n-butanol and acetone by Clostridium acetobutylicum or C. butyricum is under investigation in New Zealand. Whey permeate also has potential for citric acid and acrylic acid manufacture. Extracellular microbial polysaccharide production from whey permeate has... 

This yeast was initially known as Candida curvata, then was renamed Apiotrichum curvatum, and now is regarded as Cryptococcus curvatus. 

Figure 18.2 Candida curvata grown with limiting nitrogen. Totai iipid content approximately 40%. M, mitochondrion and L, iipid droplets. (From [64] with permission, 2007 Elsevier B.V.)...

Table 9.1 Estimates of the model parameters for Candida curvata Apiotrichum curvatum) growing on glucose in continuous culture (from Ykema et aL, 1986)...

Although Candida curvata strains D and R are often referred to as Apiotrichum curvatum, this name is not recognized as such. Barnett et al. (1990) considers C. curvata to be a synonym of Cryptococcus curvatus which is now the recommended name. 

In this work, Candida curvata, now renamed Apiotrichum curvatum (but see also Table 9.2), was mutated and auxotrophic mutants were isolated that required oleic acid to be added to the culture media to allow them to grow. Such mutants were then unable to synthesize oleic acid themselves and thus would presumably be devoid of A9-desaturase activity (Figure 9.5). One of the isolated mutants, Ufa 33 (Table 9.5), now contained 50% stearic acid residues in its lipid. Nevertheless, the added oleic acid was still being converted to linoleic and linolenic acids which are regarded as undesirable fatty acids in any potential cocoa butter equivalent. To remove the A12- and A15-desaturases would have required a further, and much more extensive, mutation programme. 

The possible design of a SCO-producing process has been considered in some detail by Davies (1988,1992a,b) and Davies and Holdsworth (1992) for the development of a cocoa butter equivalent (CBE) process using Candida curvata. Davies (1992a) has identified three key areas that require successful development before large-scale production can be achieved. These are ... 

Evans, C.T. and Ratledge, C. (1983) A comparison of the oleaginous yeast, Candida curvata, grown on different carbon sources in continuous and batch culture. Lipids 18, 623-629. 

Candida curvata Single-stage continuous Glucose 13.5 29 0.16 Evans and Ratiedge (1983)... 

In the 1980s, Davies (1992) reported an economic analysis for SCO production ( 0.80— 1.00/kg MO) from waste lactose (200,000 m whey per year), utilizing the yeast strain Candida curvata. Based on this cost and using an order-of-magnitude approximation, the SCO production cost in 2008 would have been 1.4—1.8/kg (this value does not include the biodiesel production cost from SCO) in the case that whey is used as carbon source. Ratledge and Cohen (2008) reported that the minimum price of microbial oil produced from yeast or fungi could be 3/kg. 

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