title: Fermentative production of poly (γ-glutamic acid) from renewable carbon source and downstream purification through a continuous membrane-integrated hybrid process.
abstract: Experimental investigations were carried out on continuous and direct production of poly-(γ-glutamic acid) in a hybrid reactor system that integrated conventional fermentative production step with membrane-based downstream separation and purification. Novelty of the integrated system lies in high degree of purity, conversion, yield and productivity of poly-(γ-glutamic acid) through elimination of substrate-product inhibitions of traditional batch production system. This new system is compact, flexible, eco-friendly and largely fouling-free ensuring steady and continuous production of poly-(γ-glutamic acid) directly from a renewable carbon source at the rate of 0.91 g/L/h. Cross-flow microfiltration membrane modules ensured almost complete separation and recycle of cells without much fouling problem. Well-screened ultrafiltration membrane module helped to concentrate poly-(γ-glutamic acid) while ensuring recovery and recycle of 96% unconverted carbon source resulting in yield of 0.6g/g along with high product purity.
authors.affiliation: Environmental and Membrane Technology Laboratory, Department of Chemical Engineering, National Institute of Technology Durgapur, 713209, India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Environmental and Membrane Technology Laboratory, Department of Chemical Engineering, National Institute of Technology Durgapur, 713209, India. Electronic address: parimalpal2000@yahoo.com.
authors.forename: Parimal
authors.initials: P
authors.lastname: Pal
mesh_terms: D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000378:metabolism*; D005285:Fermentation; D008567:Membranes, Artificial; D010539:Permeability; D011099:Polyglutamic Acid / Q000096:biosynthesis*; D014462:Ultrafiltration; D014867:Water
chemical_list: D008567:Membranes, Artificial; D014867:Water; D011099:Polyglutamic Acid; D002244:Carbon
keywords: Cell recycle; Continuous system; Membrane-integrated system; Poly-(γ-glutamic acid); Ultrafiltration