High yield and cost‐effective production of poly(γ‐glutamic acid) with Bacillus subtilis

Abstract

Poly(γ‐glutamic acid) (γ‐PGA) is a promising biopolymer with many potential industrial and pharmaceutical applications. To reduce the production costs, the effects of yeast extract and L‐glutamate in the substrate for γ‐PGA production were investigated systematically at shake flask scale. The results showed that lower concentrations of yeast extract (40 g/L) and L‐glutamate (30 g/L) were beneficial for the cost‐effective production of γ‐PGA in the formulated medium. By maintaining the glucose concentration in the range of 3–10 g/L via a fed‐batch strategy in a 10‐L fermentor, the production of γ‐PGA was greatly improved with the highest γ‐PGA concentration of 101.1 g/L, a productivity of 2.19 g/L·h and a yield of 0.57 g/g total substrate, which is about 1.4‐ to 3.2‐fold higher than those in the batch fermentation. Finally, this high‐density fermentation process was successfully scaled up in a 100‐L fermentor. The present work provides a powerful approach to produce this biopolymer as a bulk chemical in large scale.

Anticandidal effect of endophytic bacteria isolated from Equisetum arvense L. against Candida albicans and Candida glabrata

“…Numerous species of the Bacillus genus are reasonably considerable for the purposes, as they are functional for the production of numerous molecules and supplementary goods for foodstuff as well as in agricultural, biological and pharmaceutical industries 55,56 . In the pharmaceutical industry, there is high demand for Bacillus species because of its potential to produce a broad array of metabolites with antimicrobial activity [57][58][59][60][61] . Thus, the endophytic bacterias from E arvense, including Bacillus sp., could potentially be useful for pharmaceutical industries.…”

Poly-γ-glutamic acid: production, properties and applications

“…High-yield, cost-effective and large-scale production of c-PGA from B. subtilis ZJU-7 (B. subtilis CGMCC1250) has been reported by Huang et al (2011 …”

A New Method to Purify Poly-γ-glutamic Acid Using Gemini Quaternary Ammonium Salts and Characterization of its Ionic Complex

“…There are several studies that report the production of γ-PGA of more than 20 g/L (Luo et al, 2016). For example, when Bacillus subtilis was cultured using a 10-L bioreactor, the maximum production yield exceeded 100 g/L (Huang et al, 2011). However, the viscosity of the culture broth increases with an increase in γ-PGA production, whereby purification of γ-PGA becomes difficult.…”