Primary metabolites from overproducing microbial system using sustainable substrates

Abstract

Primary (or secondary) metabolites are produced by animals, plants, or microbial cell systems either intracellularly or extracellularly. Production capabilities of microbial cell systems for many types of primary metabolites have been exploited at a commercial scale. But the high production cost of metabolites is a big challenge for most of the bioprocess industries and commercial production needs to be achieved. This issue can be solved to some extent by screening and developing the engineered microbial systems via reconstruction of the genome‐scale metabolic model. The predicted genetic modification is applied for an increased flux in biosynthesis pathways toward the desired product. Wherein the resulting microbial strain is capable of converting a large amount of carbon substrate to the expected product with minimum by‐product formation in the optimal operating conditions. Metabolic engineering efforts have also resulted in significant improvement of metabolite yields, depending on the nature of the products, microbial cell factory modification, and the types of substrate used. The objective of this review is to comprehend the state of art for the production of various primary metabolites by microbial strains system, focusing on the selection of efficient strain and genetic or pathway modifications, applied during strain engineering.

Neural networks and genetic algorithm as robust optimization tools for modeling the microbial production of poly‐β‐hydroxybutyrate (PHB) from Brewers’ spent grain

“…In the final analysis, the ANN tool output represents the amount of PHB, and it was directed to get the best combination of independent variables using GA. The fitness value of an individual (i.e., solution) in a population was shown by Equation (2).…”

“…Therefore, biodegradable biopolymers, exhibiting similar or better mechanical and physical properties/characteristics, are desirable substitutes for example poly-β hydroxybutyrate (PHB). 1,2 PHB is a promising alternative to synthetic polymers because it is biodegradable, nontoxic, and possesses the same properties as petrochemical-based plastics. The microbial production of PHB is commonly performed by a two-stage fermentation using a variety of different microbial genera such as Alcaligenes or Azotobacter, Bacillus, and Pseudomonas species.…”

“…Accumulation of nondegradable petroleum‐derived synthetic polymers is a severe problem throughout the world. Therefore, biodegradable biopolymers, exhibiting similar or better mechanical and physical properties/characteristics, are desirable substitutes for example poly‐β hydroxybutyrate (PHB) 1,2 . PHB is a promising alternative to synthetic polymers because it is biodegradable, nontoxic, and possesses the same properties as petrochemical‐based plastics.…”

Removal and recovery of nutrients and value-added products from wastewater: technological options and practical perspective

“…At wastewater dosing frequencies (i.e., the feed) of once or twice every two days have shown ~ 80% biohydrogen production. Besides, biogas production and 97% carbon recovery in the form of biomethane are reported from vegetable market wastes in an anaerobic baffled reactor (ABR) [43,44]. In an ABR, the waste is added in the form of a slurry, and effluent recirculation is done to utilize the volatile fatty acids (VFA) formed during the process.…”

Special Section on Genome Editing and Engineering: For November/December 2020 Issue

“…To demonstrate this, Srivastava et al. [3] provide a comprehensive review on recent developments in microbial engineering to produce primary metabolites. The relative success in the production of engineered primary metabolites can be attributed to the native high carbon flux toward these metabolites and the kinetic improvement through genetic tools.…”