Monitoring of Streptomyces peucetius cultivations using FTIR/ATR spectroscopy and quantitative models based on library type data.

Cultivations of Streptomyces peucetius in two types of medium were monitored on-line using a Fourier transform infrared (FTIR) spectrometer combined with an attenuated total reflection probe. The quantitative measurements of the glucose, starch and acetate concentrations were implemented using partial least squares calibration models. These were regressed on spectral and concentration information obtained by adding together single constituent spectra of the main constituents in the medium according to a full factorial design.

Factors affecting the production of L-xylulose by resting cells of recombinant Escherichia coli.

Factors affecting the production of the rare sugar L-xylulose from xylitol using resting cells were investigated. An E. coli BPT228 strain that recombinantly expresses a gene for xylitol dehydrogenase was used in the experiments.

Contributions of biotechnology to the production of mannitol.

Mannitol is a 6-carbon sugar alcohol that has been produced traditionally by chemical catalysis. Biotechnology has brought advances to the production in terms of substrate purity, process equipment requirements and safety. Enzymatic methods have improved the yields and the use of microbes has brought versatility to the range of substrates that can be used in the processes.

Biomass measurement online: the performance of in situ measurements and software sensors.

Biomass measurement is one of the most critical measurements in biotechnological processes. The technologies developed for the measurement of biomass in situ have developed over the years. Because it has been over 10 years since the last review concentrating on practical issues concerning biomass measurements, it is time to evaluate recent developments in the field.

A chemostat study of Streptomyces peucetius var. caesius N47.

The behavior of Streptomyces peucetius var. caesius N47 was studied in a glucose limited chemostat with a complex cultivation medium. The steady-state study yielded the characteristic constants mu (max) over 0.

Modeling and simulation of Streptomyces peucetius var. caesius N47 cultivation and epsilon-rhodomycinone production with kinetic equations and neural networks.

This study focuses on comparing different kinetic growth models and the use of neural networks in the batch cultivation of Streptomyces peucetius var. caesius producing epsilon-rhodomycinone. Contois, Monod and Teissier microbial growth models were used as well as the logistic growth modeling approach, which was found best in the simulations of growth and glucose consumption in the batch growth phase.

Optimization of a Bifidobacterium longum production process.

Bifidobacteria are used as probiotics mainly in the dairy industry as cell suspensions or as freeze-dried additives. So far there have been no reports on a thorough investigation on factors influencing the production process or a statistical approach to the optimization thereof. A 2(8-4) fractional factorial design was used in determining the critical parameters influencing bioreactor cultivations of Bifidobacterium longum ATCC 15707.

Scale-up of a new bacterial mannitol production process.

D-Mannitol is a sugar alcohol with applications in chemistry, food and pharmaceutical industries, and medicine. Commercially, mannitol is produced by catalytic hydrogenation. Although this process is widely used, it is not optimal for mannitol production.