Strategies for Supplying Precursors to Enhance the Production of Secondary Metabolites in Solid-State Fermentation

Abstract

The production of secondary metabolites can be improved with the supply of precursors both in submerged and solid-state fermentation (SSF). Microorganisms assimilate the precursors and biotransform them to excrete compounds of commercial interest. The raw materials used in SSF, frequently agro-industrial residues, may contain molecules that serve as precursors for secondary metabolites. However, supplying a precursor can dramatically improve crop production. Commonly, precursors are added as part of the liquid with which the solid material to be fermented is moistened. However, recently it has been proposed to take advantage of the oxygen supply for the gradual supply of volatile precursors. It can help to avoid toxicity problems with the precursors. The present work reviews the strategies to supply precursors to improve the production of secondary metabolites in solid-state fermentation.

Fermentation: A Potential Strategy for Microbial Metabolite Production

“…Because of this, not all microbial species produce these substances. Secondary metabolic pathways are used to create secondary metabolites from primary metabolites like amino acids and acetyl-coenzyme A [60]. Figure 11 illustrates how primary and secondary metabolic pathways are related.…”

“…There are mevalonic acid pathways in yeast, fungi, animals, plants, archaea, and some eubacteria. Most bacteria, cyanobacteria, and plant plastids contain the methylerythritol phosphate pathway [60].…”

“…The microbial morphology is more appropriate for generating secondary metabolites in SSF, although SmF is a simpler procedure to perform. Thus, SSF has several benefits, including simple gaseous transport, low water consumption, utilization of cellulosic waste, pH control, and requirement for smaller fermenters, which reduces the work needed for downstream processing [60,65].…”