Comparison of Morphological Characteristics of Streptomyces natalensis by Image Analysis and Focused Beam Reflectance Measurement

Abstract

A morphological interpretation is presented for data collected during growth of a filamentous organism, using a focused beam reflectance measurement (FBRM) system. The morphology of the organism was also obtained using conventional semiautomatic image analysis to support the interpretation of the FBRM data. The model organism employed is the filamentous soil-borne actinomycete Streptomyces natalensis, which produces the antifungal agent pimaricin. The organism was cultivated both in shake flasks and in a bench-scale stirred tank bioreactor. It was found that FBRM could be used to track changes in the morphology of the organism throughout the course of its growth on both scales. These changes were highlighted using both the median chord length and length-weighted mean chord length obtained from the chord length distribution measured with the FBRM probe. The ability of the FBRM probe to respond to changes in both the size and morphology of mycelial aggregates was supported by standard image analysis parameters, including equivalent diameter, convex area, and compactness.

The Taming of the Shrew - Controlling the Morphology of Filamentous Eukaryotic and Prokaryotic Microorganisms

“…Additionally, there have been efforts to investigate the application of the focused beam reflectance method (FBRM) for monitoring the growth [222] and morphological characteristics [227]. A focused laser beam is rapidly rotated to scan the particle suspension, in this case, the culture broth.…”

“…Different from most image analysis techniques, FBRM is suitable for online monitoring. Pearson et al [227] compared FBRM with traditional image analysis techniques for cultivations of S. natalensis. It was found that whereas FBRM is not applicable for characterising filamentous morphology through shape descriptors such as roughness and aspect ratio, the obtained chord length distributions enable a characterisation of morphology to some extent.…”

Optimization of Insect Cell Based Protein Production Processes - Online Monitoring, Expression Systems, Scale Up

“…Although the probe has already been utilized for offline characterization of microbial [95][96][97][98] and plant cell systems [99][100][101], applications in cell culture processes are not yet reported. The latest version of the G400 FBRM system distributed by Mettler-Toledo is fully autoclavable and therefore allows the integration of this technology even in cell culture processes.…”

Real-time monitoring and control of microbial bioprocesses with focus on the specific growth rate: current state and perspectives

“…The first has received a lot of attention over the past two decades (Davey et al 1993;Nicholson et al 1996;Carvell and Dowd 2006;O'Reilly and Hilton 2006), while the latter is still underexploited (Hall et al 1996;Finn et al 2006). Three other direct biomass quantification techniques that have only received marginal attention so far are real-time optical density and turbidity measurements and focused beam reflectance measurements (Pearson et al 2003). Viscosity measurements, RNA content, and real-time measurements of NADH by fluorescence spectroscopy could be alternative techniques to indirectly correlate process information with biomass concentration.…”