Sustainable Refining of Vegetable Oil Made Easy with a Designer Phospholipase C Enzyme

Abstract

The increasing demand pressures the vegetable oil industry to develop novel refining methods. Degumming with type C phospholipases (PLCs) is a green technology and provides extra oil. However, natural PLCs are not active under the harsh conditions used in oil refining plants, requiring additional unit operations. These upfront capital expenditures and the associated operational costs hinder the adoption of this method. Here, we present a process based on ChPLC, a synthetic PLC obtained by consensus sequence design, possessing superior thermal stability and catalytic properties. Using ChPLC, crude soybean oil degumming was completed at 80 °C in 30 min, the temperature and residence time imposed by the design of existing oil refining plants. Remarkably, an extra yield of oil of 2% was obtained using 60% of the dose recommended for PLCs marketed today, saving upfront investments and reducing the operational cost of degumming. A techno-economic analysis indicates that, for medium size plants, ChPLC reduces the overall cost of soybean oil enzymatic degumming by 58%. The process presented here facilitates the implementation of enzymatic technologies to oil producers, regardless of their processing capacity, bringing potential annual benefits in the billion-dollar range for the global economy.

Thermal Stabilization of a Bacterial Zn(II)-Dependent Phospholipase C through Consensus Sequence Design

“…The consensus variant showing the highest activity in the degumming assay at 80 °C makes it extraordinarily valuable for edible oil refinement. 17 Cooperative Effect of Consensus Residues. We modeled the structures of all variants produced by using AlphaFold2 in order to find a rationale for the stability of the consensus protein (Figure 2).…”

“…Finally, we probe particular sites and their influence on the stability of the consensus variant. Application of this novel consensus PLC in vegetable oil refining will result in the broad adaptation of enzymatic degumming with a high economic and environmental impact …”

A thermostable phospholipase C obtained by consensus design

“…In contrast, the consensus variant shows a slight increase in phosphate released up to 80 °C, lowering the efficiency at 90 °C but still releasing twice as much phosphate as the any of the other natural variants at this temperature. The consensus variant showing the highest activity in the degumming assay at 80 °C makes it extraordinarily valuable for edible oil refinement 11 .…”

“…We anticipate that this enhanced enzyme will find valuable applications within the edible oil industry. 11…”

“…Finally we probe particular sites and their influence in the stability of the consensus variant. Application of this novel consensus PLC in vegetable oil refining will result in the broad adaptation of enzymatic degumming with a high economic and environmental impact 11 .…”