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BioMed Research International
Volume 2014 (2014), Article ID 819474, 8 pages
Research Article

Fermentative Polyhydroxybutyrate Production from a Novel Feedstock Derived from Bakery Waste

1School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
2Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
3College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
4Department of Chemical Engineering, Gebze Institute of Technology, 41400 Gebze, Kocaeli, Turkey

Received 17 February 2014; Revised 19 May 2014; Accepted 30 June 2014; Published 20 July 2014

Academic Editor: Ramkrishna Sen

Copyright © 2014 Daniel Pleissner et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.