Comparison of analysis methods for determination of the kinetic parameters in batch cultures (original) (raw)

Determination of biomass yield for growth of Candida utilis on glucose: Black box and metabolic descriptions

World Journal of Microbiology & Biotechnology - WORLD J MICROBIOL BIOTECHNOL, 1999

Similar to some complex chemical systems, many reactions are involved in a microbial process. One of the initial tasks for both systems consists of considering the stoichiometric relations among the different chemical reactants. In the present work, a methodology to establish the stoichiometric relations in microbial processes is shown. The yield of biomass from the C-source can be calculated from these relations by using two types of system descriptions found in the literature, the black box model and metabolic description. The former represents microbial growth by means of a chemical reaction which contains the accumulating compounds. The description is based on element, electric charge and Gibbs energy balances. The metabolic model also describes the intracellular biochemical reactions. The model is based on the specification of a set of reactions which contain all the accumulating and catalytic species. In the present work, the biomass yield is calculated for the Candida utilis–...

Comparative Study of Yeast Growth Kinetics in Different Reactors

2016

This study aims at investigating three different reactors (air-lift fermenter, bubble column reactor, continuous stirred-tank reactor) to evaluate their performance with respect to baker’s yeast (Active Dry Yeast powder) growth using YDM (Yeast Dextrose Media) in shake flask culture in the B.O.D incubator under optimum conditions. Conventional methodologies were implemented to investigate different parameters of yeast growth kinetics in the reactors viz., dry cell mass concentration, residual glucose concentration and cell count. It was finally estimated that among the three bioreactors, in the CSTR, running with an agitator speed of 650 rpm, the final dry cell mass concentration attained after 48 hours was 0.162gm/100 ml and almost all of the initial glucose (0.6 gm/100ml) was utilized within first 12 hours

Kinetics of microbial growth with mixtures of carbon sources

Antonie van Leeuwenhoek, 1993

Several investigations have shown that during growth in carbon-limited chemostats the simultaneous utilisation of carbon substrates which usually provoke diauxie under batch conditions, i.e., ‘mixed substrate growth’, is probably the rule under ecologically relevant growth conditions. In contrast, the models presently available for the description of the kinetics of microbial growth are all based on the use of single substrates. Systematic studies in chemostat culture have shown that steady-state residual concentrations of individual compounds were consistently lower during mixed substrate growth than during growth with the single substrates. This effect is clearly demonstrated for the case ofEscherichia coli growing with mixtures of glucose plus galactose. The data presented indicate that the extent of reduction of steady-state residual substrate concentration is dependent on the proportions of the substrates in the mixture, the nature of substrates mixed and the regulation pattern of enzymes involved in their breakdown. If this behaviour can be shown to be typical for growth under environmental conditions, it may provide an explanation why microbes still grow relatively fast at the low substrate concentrations encountered in nature.