Monitoring of cell growth using the focused beam reflectance method

Abstract

In this paper the use of a focused beam reflectance measurement (FBRM) particle characterisation probe was investigated as a tool for monitoring the growth of the filamentous bacteria Streptomyces natalensis. The optimum operating parameters of the probe were identified, and it was found that the sample agitation rate had the largest effect on the mean value of a number of statistics of the chord length distribution (CLD) measured by the FBRM probe. A series of fractions of the particle size distribution was generated by sieving. It was found that the mean chord length measured by the probe responded to changes in the size distribution examined, increasing from 57.2 µm to 69.9 µm with an increase in the upper particle size from 180 µm to 300 µm. It was also found that the average total counts measured by the probe also increased with increasing sample concentration. This relationship was further investigated and it was found that in the normal range of biomass levels experienced in a fermentation (up to 4.0 g dm −3 ) there was an apparently linear relationship between counts and concentration. However, as concentration was increased further the relationship became increasingly non-linear.

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

“…Thus, the development of suitable methods to characterise the morphology of submerged cultures has been the subject of several studies. Whereas earlier efforts mainly involved digital image analysis [177,182,202,221], more recent studies focused on different techniques, including laser diffraction and focused beam reflectance [222]. Microscopic image acquisition and the subsequent analysis of the pictures provide an extensive quantitative description of the fungal morphology, both microand macro-morphological, and, furthermore, the application of advanced imaging techniques such as CLSM [223].…”

“…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.…”

“…However, it is not possible to directly correlate FBRM data to image analysis results. Additionally, it was proven that FBRM is a valid measurement method for biomass concentrations in cultivations involving filamentous microorganisms [222]. Furthermore, Grimm et al deployed FBRM for studying the agglomeration kinetics of spores [228,229].…”

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.…”

A review of non-invasive optical-based image analysis systems for continuous bioprocess monitoring

“…Since the probe cannot be placed into a sterilizable bioreactor without canceling sterility, applications in cell culture are rare so far. Offline investigations were performed in relation to morphological characteristics of Streptomyces natalensis [18,19]. The growth of plant cells was monitored by the FBRM Ò [20,21].…”