An Introduction to the Thermodynamics Calculation of PHA Production in Microbes

Abstract

The large variance in food availability is not uncommon in the natural environment and microbes have evolved strategies to minimize the impact of food scarcity and starvation. The universal methods include sporulation with low metabolic rate, and intracellular storage of energy or nutrient source. The capability to synthesize polyhydroxyalkanoate (PHA) provides the microbe with a competitive advantage in combating starvation. Simultaneously, the microbial PHA metabolism also means that PHA is readily biodegradable. This chapter aims to introduce the concept of thermodynamics to PHA production along with cell synthesis and energy production. Specific cases with common substrates under aerobic and anaerobic conditions are examined. The chapter applies thermodynamics to assess potential microbial PHA synthesis scenarios under aerobic and anaerobic conditions. This provides new perspectives for PHA production and enhances understanding of rarely reported scenarios such as anaerobic PHA production.