Estimation of cell volume and biomass of penicillium chrysogenum using image analysis

Abstract

A methodology for the estimation of biomass for the penicillin fermentation using image analysis is presented. Two regions of hyphae are defined to describe the growth of mycelia during fermentation: (1) the cytoplasmic region, and (2) the degenerated region including large vacuoles. The volume occupied by each of these regions in a fixed volume of sample is estimated from area measurements using image analysis. Areas are converted to volumes by treating the hyphae as solid cylinders with the hyphal diameter as the cylinder diameter. The volumes of the cytoplasmic and degenerated regions are converted into dry weight estimations using hyphal density values available from the literature. The image analysis technique is able to estimate biomass even in the presence of nondissolved solids of a concentration of up to 30 gL(-1). It is shown to estimate successfully concentrations of mycelia from 0.03 to 38 gL(-1). Although the technique has been developed for the penicillin fermentation, it should be applicable to other (nonpellected) fungal fermentations.

Production of indole diterpenes by Aspergillus alliaceus

“…There were no obvious morphological differences that were likely to have affected OUR growth patterns, such as tight compact pellets that might initially grow slowly. Non-dissolved solids (e.g., Pharmamedia) were present similar to what has been identified previously (Packer et al, 1992).…”

In situ microscopy for on-line determination of biomass

“…can be applied for cell analysis, providing a wide scope of information. The evaluation of cell images allows an estimation of the cell volume and therefore, of the biomass (Bjørnsen, 1986;Frame and Hu, 1990;Packer et al, 1992). The cell volume can be calculated nearly independent of the cell morphology (hyphae, spheres, aggregates).…”

Morphological characterization of filamentous microorganisms in submerged cultures by on-line digital image analysis and pattern recognition

“…Various methods for analyzing morphology and biomass of filamentous microorganisms has been evolved, which characterize the biomass more accurately than previous methods. On the one hand algorithms for quantifying morphology of dispersed mycelia were developed (Packer and Thomas, 1990;Packer et al, 1992;. On the other hand, the pellet morphology was characterized by means of digital image analysis (Cox and Thomas, 1992;Reichl et al, 1992).…”