Continuous Culture of Yeast on Phenol

Abstract

SUMMARYDebaryomyces subgbbosw ( NCYC 459) was grown in continuous culture a t 30" in media containing 3,6.65,9 and 12 pmoles phenol/ml. as sole source of carbon. With each medium, wash-out of organisms occurred at dilution rates in the range 0-33-0.36 hr-l. The yeasts became quickly adapted to the medium with lowest phenol content and grew readily at dilution rates between 0.1 and 0-3 hr-l. At lower dilution rates, however, the endogenous metabolism of the yeasts tended to outstrip the rate at which phenol was supplied. With 9 pmoles phenol/ml. the best rate of output of yeast was achieved but at 6-65 pmoles phenol/ml., was most fully utilized, utilization being complete up to a dilution rate of 0.3 hr-1. At the highest contents of phenol in the medium, the yeast adapted less readily and produced considerable amounts of riboflavin. The population became heterogeneous, with some yeasts clumping and others large and fragile. There was some evidence that the latter were unable to metabolize phenol but could utilize catechol, a product of metabolism of the normal organisms.The appendix provides a comparison between the reported results and those calculated from the growth constants using classical mathematical treatment of continuous culture. Substantial deviations are attributed to high maintenance energy requirements, flocculation of the yeast and toxicity of the medium.

Biodegradation of toxic chemicals using commercial preparations

“…Since the Livingston mixed liquor contains such a wide variety of bacteria and fungi, the probability is high that an appropriate organism is present. Many of those found to be phenol and 2-chlorophenol tolerant have also been reported by other investigators [11][12][13][14][15][16][17][18]. Figures 1 to 3 show the substrate concentrations after successive shock loadings to the biological reactor.…”

“…Many of those found to be phenol and 2-chlorophenol tolerant have also been reported by other investigators [11][12][13][14][15][16][17][18]. Figures 1 to 3 show the substrate concentrations after successive shock loadings to the biological reactor.…”

A Simulation Model for Decomposition in Grasslands

“…The maintenance energy requirement takes values of 0.13, 0.76, and 2.8 at 10°C, 2SCC, and 37"C, respectively. It may be argued that E. coli, native to a warmer and wetter environment than the soil, would have a higher maintenance requirement than soil microbes, but similar values are reported for yeast (Wase and Hough 1966) and two species of Aerobacter (Pirt 1965).…”

A Simulation Model for Decomposition in Grasslands

“…It may be argued that E. coli, native to a warmer and wetter environment than the soil, would have a higher maintenance requirement than soil microbes, but similar values are reported for yeast (Wase and Hough 1966) and two species of Aerobacter (Pirt 1965). The maintenance energy requirement takes values of 0.13, 0.76, and 2.8 at 10°C, 2SCC, and 37"C, respectively.…”