Reproducing shake flasks performance in stirred fermentors: production of alginates by Azotobacter vinelandii

Bioprocess scale‐up: quest for the parameters to be used as criterion to move from microreactors to lab‐scale

“…This behavior was possibly due to out-of-phase conditions, which could also account for the results obtained previously by Reyes et al 112 Penã et al 114 tried to reproduce the mean molecular mass of the alginates obtained in shake flasks, in a stirred reactor maintaining P/V constant. A 500 mL Erlenmeyer flask was used, containing 1/5 filling volume.…”

“…112 The study showed that when an initial power draw of 0.27 kW m −3 was applied, a specific growth rate of 0.16 h −1 was obtained in a stirred reactor, which roughly doubled the specific growth rate obtained in shake flasks (0.09 h −1 ). Moreover, differences in the broth viscosity, concentration profiles and molecular weight of the alginate were observed.…”

Optimization of Carbon and Nitrogen Sources for Extracellular Polymeric Substances Production by Chryseobacterium indologenes MUT.2

“…The effect of the different nitrogen sources on the C. indologenes MUT.2 growth and its extracellular polymeric substance (EPS) production during cultivation in shake-flasks for 96 hours at 30ºC.The highest cell mass, EPS and other related factors were observed when glutamic acid was used as nitrogen source Figure 3. Batch cultivation of the C. indologenes MUT.2 in the shake flasks using the optimized medium stirred tank bioreactors (13,14). Therefore, the bioreactor fermentation process was developed on the basis of data obtained from shake flasks cultivation experiments.…”

A fermentation system designed to independently evaluate mixing and/or oxygen tension effects in microbial processes: development, application and performance

“…Another potential application of the system deals with scale-up, particularly in processes where P/V is expected to decrease as a result of increased broth viscosity. For example, during Azotobacter vinelandii shake flask cultures, Reyes et al [26] showed that power drops (originated by increased alginate concentrations) were beneficial to the process as higher mean molecular weights were obtained compared to their stirred tank counterparts (developed at the same initial P/V) where power drops were not observed. According to the authors, the power drops observed in the shake flasks should be reproduced-in the stirred tanks-in order to achieve similar alginate quality yields.…”

“…However, relatively few reports have measured in situ power drawn during actual fermentation processes developed in pilot or production scales [14,[16][17][18], and even fewer at bench scale [19]. At such scale, most reports have either estimated (from published correlations [20][21][22]) or measured (using water and/or diluted, re-constituted or actual fermentation broths [23][24][25][26]), ex situ, power drawn, resulting in possible inaccuracies of the actual energy dissipation rates. The latter is of importance as most research concerning the effect of hydrodynamic conditions upon biological activity has been developed at such scale.…”