title: Influence of feeding strategies of mixed microbial cultures on the chemical composition and microstructure of copolyesters P(3HB-co-3HV) analyzed by NMR and statistical analysis.
abstract: NMR spectroscopy was applied for quantitative and qualitative characterization of the chemical composition and microstructure of a series of poly(3-hydroxybutyrate-co-3-hydoxyvalerate) copolymers, P(3HB-co-3HV), synthesized by mixed microbial cultures at several different feeding strategies. The monomer sequence distribution of the bacterially synthesized P(3HB-co-3HV) was defined by analysis of their high-resolution 1D (13)C NMR and 2D (1)H/(13)C HSQC and (1)H/(13)C HMBC NMR spectra. The results were verified by employment of statistical methods and suggest a block copolymer microstructure of the P(3HB-co-3HV) copolymers studied. Definitive distinction between block copolymers or a mixture of random copolymers could not be achieved. NMR spectral analysis indicates that the chemical composition and microstructure of the copolymers can be tuned by choosing a correct feeding strategy.
authors.affiliation: REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Ivanova
authors.forename: L S
authors.initials: LS
authors.lastname: Serafim
authors.forename: P C
authors.initials: PC
authors.lastname: Lemos
authors.forename: A M
authors.initials: AM
authors.lastname: Ramos
authors.forename: M A M
authors.initials: MA
authors.lastname: Reis
authors.forename: E J
authors.initials: EJ
authors.lastname: Cabrita