title: Fermentative polyhydroxybutyrate production from a novel feedstock derived from bakery waste.
abstract: In this study, Halomonas boliviensis was cultivated on bakery waste hydrolysate and seawater in batch and fed-batch cultures for polyhydroxybutyrate (PHB) production. Results demonstrated that bakery waste hydrolysate and seawater could be efficiently utilized by Halomonas boliviensis while PHB contents between 10 and 30% (w/w) were obtained. Furthermore, three methods for bakery waste hydrolysis were investigated for feedstock preparation. These include: (1) use of crude enzyme extracts from Aspergillus awamori, (2) Aspergillus awamori solid mashes, and (3) commercial glucoamylase. In the first method, the resultant free amino nitrogen (FAN) concentration in hydrolysates was 150 and 250 mg L(-1) after 20 hours at enzyme-to-solid ratios of 6.9 and 13.1 U g(-1), respectively. In both cases, the final glucose concentration was around 130-150 g L(-1). In the second method, the resultant FAN and glucose concentrations were 250 mg L(-1) and 150 g L(-1), respectively. In the third method, highest glucose and lowest FAN concentrations of 170-200 g L(-1) and 100 mg L(-1), respectively, were obtained in hydrolysates after only 5 hours. The present work has generated promising information contributing to the sustainable production of bioplastic using bakery waste hydrolysate.
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Daniel
authors.identifier: 0000-0003-0517-1370
authors.initials: D
authors.lastname: Pleissner
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Wan Chi
authors.initials: WC
authors.lastname: Lam
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Wei
authors.initials: W
authors.lastname: Han
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Kin Yan
authors.initials: KY
authors.lastname: Lau
authors.affiliation: Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Lai Chun
authors.identifier: 0000-0001-9798-8657
authors.initials: LC
authors.lastname: Cheung
authors.affiliation: Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Ming Wui
authors.identifier: 0000-0002-2826-2817
authors.initials: MW
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Ho Man
authors.initials: HM
authors.lastname: Lei
authors.affiliation: Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Kin Yu
authors.initials: KY
authors.lastname: Lo
authors.affiliation: Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Wai Yee
authors.initials: WY
authors.lastname: Ng
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong ; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Zheng
authors.identifier: 0000-0003-2690-8327
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Chemical Engineering, Gebze Institute of Technology, 41400 Gebze, Kocaeli, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Melikoglu
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Carol Sze Ki
authors.identifier: 0000-0002-8493-4307
authors.initials: CS
authors.lastname: Lin
mesh_terms: D061249:Batch Cell Culture Techniques; D003470:Culture Media; D005285:Fermentation; D019649:Food Industry; D020632:Halomonas / Q000254:growth & development / Q000378:metabolism*; D006868:Hydrolysis; D006885:Hydroxybutyrates / Q000737:chemistry / Q000378:metabolism*; D007218:Industrial Microbiology; D007220:Industrial Waste
chemical_list: D003470:Culture Media; D006885:Hydroxybutyrates; D007220:Industrial Waste