Scalable, Robust and Highly Productive Novel Convecdiff Membrane Platform for mAb Capture.

The recombinant monoclonal antibody capture step represents the current bottleneck in downstream processing. Protein A resins are diffusion-limited chromatography materials which require low flow rates to achieve a binding capacity above 30 g L-1 with the result of low productivity. Here, we present a novel chromatography membrane combining superior binding capacities with high flow rates for high productivity while achieving comparable product quality as state-of-the-art protein A resins. Further, we demonstrate full scalability of this convecdiff technology with experimental data demonstrating suitability for bioprocessing at different scales. This technology results in more than 10-fold higher productivity compared to Protein A resins, which is maintained during scale up. We demonstrate the influence of residence times, feed titers and the cleaning regime on productivity and indicate optimal utilization of the convecdiff membrane based on feed titer availability. The underlying high productivity and short cycle times of this material enable the purification of monoclonal antibodies with 10-times less chromatography material used per batch and utilization of the membrane within one batch. Provided in disposable consumables, this novel technology will remove column handling in bioprocesses and resin re-use over multiple batches.

Kallikrein-related peptidases are activators of the CC chemokine CCL14.

Chemokine CCL14 is inactive in its proform. Here, we show that inflammation- and cancer-associated kallikrein-related peptidases KLK5 and KLK8 remove the N-terminal eight amino acids from the proform thereby converting CCL14 to its active state. Activity of the chemokine is demonstrated by migration of myeloid cells expressing relevant receptors.

Repeated fed-batch fermentation using biosensor online control for citric acid production by Yarrowia lipolytica.

Biosensor-controlled substrate feeding was used in a citric acid production process with the yeast strain Yarrowia lipolytica H222 with glucose as the carbon source. The application of an online glucose biosensor measurement facilitated the performance of long-time repeated fed-batch process with automated bioprocess control. Ten cycles of repeated fed-batch fermentation were carried out in order to validate both the stability of the microorganism for citric acid production and the robustness of the glucose biosensor in a long-time experiment. In the course of this fermentation with a duration of 553 h, a slight loss of productivity from 1.4 g/(L×h) to 1.1 g/(L×h) and of selectivity for citric acid from 91% to 88% was observed. The glucose biosensor provided 6,227 measurements without any loss of activity.