The relationship of substrate, growth rate, and maintenance coefficient to single cell protein production

Various organic compounds were assessed as potential substrates for single cell protein production. Substrate evaluation was based on the costs associated with the substrate, oxygen, and heat yield coefficients: Y sub , Y o , and Y kcal , respectively. Y o , and Y kcal , were calculated from experimental values of Y sub , and from the elemental composition of bacterial cells. The dependence of the yield coefficients on the specific growth rate (μ) and maintenance coefficient ( m ) also was assessed. The analysis disclosed that m caused two‐ to threefold variations in the yield coefficients as μ was increased from 10% to 100% of μ max . The effect of different m values at constant specific growth rates also was determined. The value of m had a significant effect on the yield coefficients even at high specific growth rates. Assignment of cost factors to the yield coefficients provided an estimation of the impact m and μ on biomass production costs.