Biomass estimation in solid state fermentation I. Manual biochemical methods

Abstract

We examined the changes in three biomass constituents (glucosamine, ergosterol, total sugar), sucrose consumption and conidia formation, during cultivation of Beauveria bassiana on agar plates or clay granules. We showed that glucosamine can be considered a good biomass indicator on condition that the media had the same constituents but not necessarily the same C/N.ratio. Total sugar was not constant during the different growth phases and cannot accurately represent biomass changes. The ergosterol amounts changed during the different growth phases but, for a fixed process, it can be a good indicator of conidiation. Good correlations were obtained between glucosamine and sucrose consumption allowing biomass yield calculations.

Intra‐particle oxygen diffusion limitation in solid‐state fermentation

“…Glucose rather than starch was used as a carbon source to prevent problems associated with the diffusion of starch-hydrolyzing enzymes that may camouflage other growth-limiting conditions (Mitchell et al, 1991). A major problem in studying SSF processes is the difficulty in quantifying biomass, because the mycelium penetrates into the solid matrix (Desgranges et al, 1991;Mitchell et al, 1991;Ooijkaas et al, 1998). In our model system, however, the mycelium grew as a film on top of the agar and hardly penetrated the solid substrate due to the medium composition chosen.…”

Production of streptomycin from chitin using Streptomyces griseus in bioreactors of different configuration

“…Desgranges et al (1991) reached the same conclusion when they evaluated a number of indirect methods for measuring biomass concentration including CO 2 evolution, and glucosamine and ergosterol assays. This was a useful finding as subsequent fermentations were carried out in the presence of solid chitin which effectively prevented the direct determination of cell dry weight.…”

Chitin in a dual role as substrate for Streptomyces griseus and as adsorbent for streptomycin produced during fermentation

“…This correlation was important and confirmed the validity of using exit gas CO 2 concentration as an indirect indication of microbial growth. CO 2 evolution is commonly used as an indicator of growth and has been preferred to other indirect methods such as assays for cell wall components [23]. Work conducted to characterise the effects of agitation on cell lysis in Streptomyces clavuligerus also revealed concomitant increases in the concentrations of biomass and CO 2 [18].…”