Characterization of product capture resin during microbial cultivations

Abstract

Various bioactive small molecules produced by microbial cultivation are degraded in the culture broth or may repress the formation of additional product. The inclusion of hydrophobic adsorber resin beads to capture these products in situ and remove them from the culture broth can reduce or prevent this degradation and repression. These product capture beads are often subjected to a dynamic and stressful microenvironment for a long cultivation time, affecting their physical structure and performance. Impact and collision forces can result in the fracturing of these beads into smaller pieces, which are difficult to recover at the end of a cultivation run. Various contaminating compounds may also bind in a non-specific manner to these beads, reducing the binding capacity of the resin for the product of interest (fouling). This study characterizes resin bead binding capacity (to monitor bead fouling), and resin bead volume distributions (to monitor bead fracture) for an XAD-16 adsorber resin used to capture epothilone produced during myxobacterial cultivations. Resin fouling was found to reduce the product binding capacity of the adsorber resin by 25-50%. Additionally, the degree of resin bead fracture was found to be dependent on the cultivation length and the impeller rotation rate. Microbial cultivations and harvesting processes should be designed in such a way to minimize bead fragmentation and fouling during cultivation to maximize the amount of resin and associated product harvested at the end of a run.

Fungal endophytes from arid areas of Andalusia: high potential sources for antifungal and antitumoral agents

“…It has been reported that the positive effects of resin additions to fermentation media are due to the adsorption of non-stable products or to the removal of a product involved in secondary metabolite pathway feedback repression 46 . The addition of polymeric resins to culture media during fungal fermentations induced and/or increased the production of bioactive molecules that were detected in all the assays tested in our screening (Fig.…”

Assessing the effects of adsorptive polymeric resin additions on fungal secondary metabolite chemical diversity

“…Several studies, on bacteria and fungi, have described the ability of adsorptive polymeric resins to increase the production titres of certain compounds of microbial origin (Frykman et al 2006 ), and the possible mechanisms of action for these have been reviewed (Phillips et al 2013 ). However, the question of whether one resin is consistently better than others for increasing metabolite chemical diversity has not been examined for any sets of strains.…”

Extractive production of microbial oil using hydrophobic adsorbents: A comparative study

“…20 However, high glucose binding observed with Osorb implies that the nutrient binding affects the substrate uptake rate and, therefore, the production and yield in the presence of organo-silica matrices. 26 Furthermore, it has also been reported earlier that organo-silica matrices are known to hinder mass transfer by limiting the rate of diffusion. 27 The pore radius of 90 A in the case of SP70 offers it with an extensive surface area, in contrast to 60 A of Osorb.…”