Efficient Separation of a Novel Microbial Chassis, Vibrio natriegens, from High-Salt Culture Broth Using Ceramic Ultrafiltration Membranes

<i>Vibrio natriegens</i> is widely used as a production host for biotechnological processes due to its superior maximum glucose consumption rate, high growth rate, and abundant ribosomes. Most bioprocesses also need a scalable biomass separation step. This can be achieved by cross-flow filtration with ceramic membranes, although the membrane pores are susceptible to fouling. However, the fouling characteristics of <i>V. natriegens</i> culture broth have not been investigated in detail. We therefore characterized membrane fouling during the separation of <i>V. natriegens</i> biomass from culture broth using a cross-flow filtration plant with ceramic membranes. The resistance in series model was used to quantify the fouling-induced resistance caused by the different components of the culture broth. The total fouling resistance was 4.1·10⁹ ± 0.6·10⁹ m^-1 for the culture broth and 5.4·10⁹ ± 0.7·10⁹ m^-1 for the summed broth components. Reversible resistance accounted for 86% and 81% of these totals, respectively. We then applied Hermia's adapted filtration laws to determine the dominant fouling mechanism induced by the different broth components. In a further step, we established a setup to determine the compressibility index of the cells during cross-flow filtration, resulting in an estimated value of 0.55 ± 0.04. These results will facilitate the design of economic filtration plants and will help to establish <i>V. natriegens</i> as a production host for large-scale industrial processes.