title: Microbial production, ultrasound-assisted extraction and characterization of biopolymer polyhydroxybutyrate (PHB) from terrestrial (P. hysterophorus) and aquatic (E. crassipes) invasive weeds.
abstract: This study reports synthesis of biodegradable poly(3-hydroxybutyrate) (PHB) polymer from two invasive weeds, viz. P. hysterophorus and E. crassipes. The pentose and hexose-rich hydrolyzates obtained from acid pretreatment and enzymatic hydrolysis of two biomasses were separately fermented using Ralstonia eutropha MTCC 8320 sp. PHB was extracted using sonication and was characterized using FTIR,1H and13C NMR and XRD. PHB content of dry cell mass was 8.1-21.6% w/w, and the PHB yield was 6.85×10-3-36.41×10-3% w/w raw biomass. Thermal properties of PHB were determined by TGA, DTG and DSC analysis. PHB obtained from pentose-hydrolyzate had glass transition temperatures of 6°-9°C, while PHB from hexose-rich hydrolyzate had maximum thermal degradation temperatures of 370°-389°C. These thermal properties were comparable to the properties of commercial PHB. Probable causes leading to differences in thermal properties of pentose and hexose-derived PHB are: extent of crystallinity and presence of impurity in the polymer matrix.
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Sushobhan
authors.initials: S
authors.lastname: Pradhan
authors.affiliation: Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Arup Jyoti
authors.initials: AJ
authors.lastname: Borah
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Maneesh Kumar
authors.initials: MK
authors.lastname: Poddar
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Pritam Kumar
authors.initials: PK
authors.lastname: Dikshit
authors.affiliation: Department of Chemical Engineering, National Institute of Technology (NIT), Tiruchirappalli 620 015, Tamil Nadu, India.
authors.forename: Lilendar
authors.initials: L
authors.lastname: Rohidas
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India; Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India. Electronic address: vmoholkar@iitg.ernet.in.
authors.forename: Vijayanand S
authors.initials: VS
authors.lastname: Moholkar
mesh_terms: D001704:Biopolymers; D006885:Hydroxybutyrates; D057685:Plant Weeds; D011091:Polyesters; D000094122:Polyhydroxybutyrates
chemical_list: D001704:Biopolymers; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates
keywords: Eichhornia crassipes; Fermentation; PHB; Parthenium hysterophorus; Ralstonia eutropha