Kinetics of Mycoprotein Production from Alternative Carbon Substrates

TL;DR

This study investigates the biokinetics of F. venenatum A3/5 cultivation on various alternative carbon sources, revealing how substrate type influences growth dynamics, yield, and byproduct formation, with implications for optimizing mycoprotein production.

Contribution

The paper provides a comprehensive analysis of how different carbon substrates affect the growth kinetics and metabolic behavior of F. venenatum A3/5, including the use of an expired functional drink as a novel substrate.

Findings

Rapid sugars support high growth rates but produce more byproducts.

Fructose and xylose lead to slower growth but higher biomass yield.

Expired functional drink enhances growth and reduces overflow compared to synthetic controls.

Abstract

High throughput screening was used to study of the biokinetics of F. venenatum A3/5 cultivation on alternative carbon substrates, including monosaccharides, disaccharides and mixtures relevant to food & beverage, dairy and agricultural waste streams. Expired functional drink from the beverage sector was also assessed as the primary carbon source for mycoprotein production. Growth data was analysed using modified single and multiphase Gompertz models for comparison of maximum specific growth rate and progression milestones across diverse growth regimes. Time-series substrate and byproduct data was analysed using comparative metrics, providing an explanatory basis for the different growth phenotypes observed. Substrate type strongly influenced the apparent carbon allocation strategies, with rapidly consumed sugars such as glucose and sucrose supporting high growth rates, low biomass yield and a high degree of fermentative byproduct formation. Fructose and xylose cultivations led to slower overall growth but higher biomass yield and lower byproduct formation. Galactose and lactose showed distinct dynamics that suggested co-existence of transport and metabolic induction limitations. In all dual-substrate systems, sequential utilisation was observed. However, metabolic inheritance and environmental shift effects were highlighted as potential kinetic limitations. These conditions exhibited stunted diauxic growth and low yield from secondary sugars, with glucose-dominated primary growth significantly reshaping secondary substrate efficiencies relative to their study in silo. The expired functional drink supported highly rapid growth and achieved the highest maximum specific growth rate and biomass titre of all conditions examined, alongside reduced fermentative overflow and enhanced ethanol reassimilation relative to a compositionally matched synthetic control.