Fishmeal Wastewater as A Low-Cost Nitrogen Source for γ-Polyglutamic Acid Production Using Bacillus subtilis

• Published in: Waste and biomass valorization 2019-04, Vol.10 (4), p.789-795
• Main Authors: Zhang, Chao, Wu, Dao-Ji, Jia, Jie, Yang, Hong-Qi
• Format: Article
• Language: English
• Subjects: Acid production; Acids; Bacillus subtilis; Cell culture; Cell growth; Chemical oxygen demand; Dilution; Engineering; Environment; Environmental Engineering/Biotechnology; Fish meal; Glucose; Glutamic acid; Industrial Pollution Prevention; Nitrogen; Optimization; Organic chemistry; Original Paper; Renewable and Green Energy; Waste disposal; Waste Management/Waste Technology; Wastewater
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-017-0100-1

Fishmeal wastewater, a fishmeal processing waste, was used as culture medium to study the effect of Bacillus subtilis A3 on the production of γ-polyglutamic acid (γ-PGA). The results showed that the optimum concentration of chemical oxygen demand (COD Cr ) for fishmeal wastewater was 15 g/L. Moreover, addition of 30 g/L glucose and 25 g/L glutamic acid in the medium was beneficial to cell growth and production of γ-PGA. The study also showed that the high salinity of wastewater had little effect on cell growth and production of γ-PGA after dilution. Thus, the optimal medium consisted of COD 15, 30 g/L glucose, 25 g/L glutamic acid, in which the average yield of γ-PGA (25.07 ± 0.34 g/L) was obtained. The study suggested that fishmeal wastewater can be a replacement for nitrogen source for γ-PGA production, and hence it can be the cost-effective alternative in γ-PGA production. Meanwhile, the process can offset the disposal costs of the wastes.