Growth of Candida utilis on Enzymatically Hydrolyzed Potato Waste

Abstract

Attempts to grow mixed cultures of Endomycopsis fibuligera and Candida utilis on waste material obtained from a potato processing plant were only partially successful; poor amylase production by Endomycopsis resulted in slow growth of the Candida. There was extensive conversion of starch to glucose when waste, which had been treated with a high speed shear/disintegrator, was hydrolyzed by industrial amylases derived from Aspergillus niger and Bacillus licheniformis. Growth of C. utilis on the separated liquid phase of the hydrolysate, supplemented with inorganic nitrogen, proceeded normally; the yields and growth rates were similar to those obtained with conventional substrates.

Cultivation of Candida utilis on Cassava Peel Hydrolysates for Single-cell Protein Production

“…The presence of yeast extract enhanced the maximum specific growth rate significantly, even though the biomass yield coefficients (Y x/s ) differed little in the two media. These yields were similar to those previously reported [34,35]. As the cultivation proceeded, the pH of both media decreased.…”

“…The above yields and growth rates (Table 3) are in accordance with values found by others for C. utilis. The biomass yield coefficients on glucose reported in the literature range from 0.45 to 0.55 [29,34,39], whereas Moreton [35] reported Y x/s values of 0.51 to 0.58 for the growth of C. utilis on enzymatically hydrolysed potato waste starch.…”

Production of Microbial Biomass Protein from Potato Processing Wastes by Cephalosporium eichhorniae

“…In the Swedish Symba process (9) the amylolytic fungus Saccharomycopsis fibuligera is grown together with C. utilis; the former species hydrolyzes the starch, and the latter grows rapidly on the sugars released. More recent evaluations of this process (10,14,19) suggest that this process is only partially successful when applied to potato wastes. An amylolytic strain of Canadida tropicalis has been reported to convert starchy substrates into cell mass in a single stage (24), but its use on potato wastes has not been described.…”

The Use of Selected Strains of Yeasts in the Treatment of Processing Wastewater From Lye-Peeled and Steam-Peeled Potatoes

“…However, a symbiotic relationship of these organisms may reach a stage whereby the Candida removes the glucose at a faster rate t h a n the S. fibuliger can hydrolyze starch, thereby suppressing the growth of S. fibuliger, which would then release insufficient glucose from the starch of wastewater for optimum growth of both organisms. Thus, as suggested by many researchers (Jar1 1969; Moreton 1978;Lemmel et al 1979) it would be best to grow C. utilis and S. fibuliger separately on potato processing wastewater, whereby S. fibuliger could be grown in the first stage to produce amylases and the mixed culture in the second stage to produce single-cell protein. Preliminary experiments were conducted in which S. fibuliger was grown first to break down the starch, followed by treatment with other yeasts to produce protein.…”