title: Valorization of residual bacterial biomass waste after polyhydroxyalkanoate isolation by hydrothermal treatment.
abstract: Hydrothermal treatment (HTT) was used to convert residual bacterial biomass (RBB), recovered from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production, into valuable bioproducts. The effect of processing temperatures (150, 200, and 250°C) on the bioproducts (water-solubles (WSs), bio-oil, insoluble residue, and gas) was investigated. The yields of bio-oil and gas were higher at higher temperatures. The maximum WS content (28 wt%) was obtained at 200°C. GCMS analysis showed higher content of aromatics and N-containing compounds with increasing temperature. ESI-MS revealed chemical compounds (e.g. protein, carbohydrate, lipids, and lignin) associated with RBB are fragmented into smaller molecules (monomers) at higher HTT temperatures. The WS fraction contained totally 838, 889 and 886mg/g acids and 160, 31 and 21 mg/g carbohydrate for HTT at 150, 200, and 250°C, respectively. The solid residues contain unconverted compounds, especially after HTT at 150°C. The WS products (acids and carbohydrates) could be used directly for PHA biosynthesis.
authors.affiliation: Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844-1132, USA.
authors.forename: Liqing
authors.initials: L
authors.lastname: Wei
authors.affiliation: Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844-1132, USA.
authors.forename: Shaobo
authors.initials: S
authors.lastname: Liang
authors.affiliation: Department of Civil Engineering, University of Idaho, Moscow, ID 83844-1022, USA.
authors.forename: Erik R
authors.initials: ER
authors.lastname: Coats
authors.affiliation: Renewable Materials Program, Department of Forest, Rangeland and Fire Sciences, University of Idaho, Moscow, ID 83844-1132, USA. Electronic address: armandm@uidaho.edu.
authors.forename: Armando G
authors.initials: AG
authors.lastname: McDonald
mesh_terms: D020155:3-Hydroxybutyric Acid; D056804:Biofuels / Q000032:analysis* / Q000191:economics; D018533:Biomass; D002241:Carbohydrates / Q000032:analysis; D006358:Hot Temperature; D006885:Hydroxybutyrates; D007220:Industrial Waste / Q000032:analysis* / Q000191:economics; D008031:Lignin / Q000032:analysis; D010421:Pentanoic Acids; D054813:Polyhydroxyalkanoates / Q000302:isolation & purification
chemical_list: D056804:Biofuels; D002241:Carbohydrates; D006885:Hydroxybutyrates; D007220:Industrial Waste; D010421:Pentanoic Acids; D054813:Polyhydroxyalkanoates; C013056:beta-hydroxyvaleric acid; D008031:Lignin; D020155:3-Hydroxybutyric Acid
keywords: Bioproducts distribution; Hydrothermal treatment; Polyhydroxyalkanoate; Residual bacterial biomass