Studies on protein adsorption in a vortex flow reactor

Has the time finally come for green oleochemicals and biodiesel production using large-scale enzyme technologies? Current status and new developments

With the growth of the chemical industry over the last decade, the need for cheaper (and more environmentally friendly) alternatives to petrochemicals of ever-increasing cost has grown steadily. Oleochemicals and biodiesel (OC/BD) are considered as green alternatives to petroleum derivatives, because they come from renewable oils and fats. OC/BD are currently produced by the traditional energy intensive chemical catalyzed methods, which have several economic and environmental drawbacks. For these reasons, the enzymatic production of OC/BD has attracted a growing attention for their greener pathway with respect to the chemically catalyzed processes. Lipase-catalyzed processes have a low energy requirement, since reactions are performed under atmospheric pressure and mild temperature and without the creation of side reactions. Furthermore, utilization of enzyme catalysts offers many advantages such as reducing the initial capital investment due to simplified downstream processing steps. Despite all the previous advantages, however, the high cost of lipases restricted their large-scale utilization. In the past decade, efforts have been made to reduce the cost of the enzymatic-catalyzed synthesis of OC/BD. However, most previous studies have studied only the technical feasibility of the lipase-catalyzed reactions and overlocked the economic viability. This review critically discusses the factors affecting the promotion of the economic feasibility of the enzymatic processes from the lab to large scale. These include reactor configuration, type of feedstock, conditions optimization, immobilization, lipase-producing microorganisms, and substrate diversification. In addition, this review reports the recent advances in lipase-catalyzed production of fatty acids, fatty esters, monoglycerides, and biodiesel in the lab as well as in the large-scales. To the best of authors' knowledge, this is the first review article reports the recent global progress achieved in both lab- and large-scale for the enzymatic production of OC/BD.

Vortex flow reactor assessment for the purification of monoclonal antibodies from unclarified broths

The vortex flow reactor (VFR) can be used in many chemical engineering applications. This paper assesses its novel use in the purification of monoclonal antibodies from cell broth. To this end, the IgG2a antibody was purified from the unclarified fermentation broth of transgenic mouse 55/6 hybridoma cells. Visual experiments showed that the VFR worked in the laminar vortices flow regime and the vortices displaced slightly faster than the axial flow. The VFR has the advantage of creating two sorts of flows: axial flow to produce the expanded bed and an extra vortex flow to avoid channeling and stabilize the expanded bed, the hydrodynamic behavior of which is plug flow with an experimental Pèclet number higher than 20. The pH was adjusted in the untreated fermentation broth, which was directly introduced into the reactor thus reducing the number of stages. The IgG2a purification was carried out in a single device via two steps: antibody adsorption in the expanded bed and antibody elution in the settled bed using Streamline rProtein A. A thirty-fold increase in the high-purity antibody concentration was achieved at the top of the pH5 elution peak with a total recovery of 93.1% (w/w) between elution peaks pH 5 and 3.