Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • harvard-cite-them-right
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Thorough Investigation of the Effects of Cultivation Factors on Polyhydroalkanoates (PHAs) Production by Cupriavidus necator from Food Waste-Derived Volatile Fatty Acids
University of Borås, Faculty of Textiles, Engineering and Business. (Swedish Centre for Resource Recovery)ORCID iD: 0000-0002-7619-6295
University of Borås, Faculty of Textiles, Engineering and Business. (Swedish Centre for Resource Recovery)ORCID iD: 0000-0001-6280-4483
MagSol, Tuhkanummenkuja 2, 00970 Helsinki, Finland.
National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia.
Show others and affiliations
2022 (English)In: Fermentation, E-ISSN 2311-5637, Vol. 8, no 11, article id 605Article in journal (Refereed) Published
Sustainable development
According to the author(s), the content of this publication falls within the area of sustainable development.
Abstract [en]

Volatile fatty acids (VFAs) have become promising candidates for replacing the conventional expensive carbon sources used to produce polyhydroxyalkanoates (PHAs). Considering the inhibitory effect of VFAs at high concentrations and the influence of VFA mixture composition on bacterial growth and PHA production, a thorough investigation of different cultivation parameters such as VFA concentrations and composition (synthetic and waste-derived VFAs) media, pH, aeration, C/N ratio, and type of nitrogen sources was conducted. Besides common VFAs of acetic, butyric and propionic acids, Cupriavidus necator showed good capability for assimilating longer-chained carboxylate compounds of valeric, isovaleric, isobutyric and caproic acids in feasible concentrations of 2.5–5 g/L. A combination of pH control at 7.0, C/N of 6, and aeration of 1 vvm was found to be the optimal condition for the bacterial growth, yielding a maximum PHA accumulation and PHA yield on biomass of 1.5 g/L and 56%, respectively, regardless of the nitrogen sources. The accumulated PHA was found to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with the percentage of hydroxybutyrate in the range 91–96%. Any limitation in the cultivation factors was found to enhance the PHA yield, the promotion of which was a consequence of the reduction in biomass production.

Place, publisher, year, edition, pages
MDPI, 2022. Vol. 8, no 11, article id 605
Keywords [en]
biopolymer, polyhydroalkanoates, volatile fatty acids, food waste, acidogenic fermentation
National Category
Bioprocess Technology
Research subject
Resource Recovery; Resource Recovery; Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-28962DOI: 10.3390/fermentation8110605ISI: 000882197500001Scopus ID: 2-s2.0-85141746651OAI: oai:DiVA.org:hb-28962DiVA, id: diva2:1712900
Available from: 2022-11-23 Created: 2022-11-23 Last updated: 2023-04-28Bibliographically approved
In thesis
1. Volatile Fatty Acids as a Key to Sustainability and Circularity in Polyhydroxyalkanoates Production
Open this publication in new window or tab >>Volatile Fatty Acids as a Key to Sustainability and Circularity in Polyhydroxyalkanoates Production
2023 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The negative consequences of plastic pollution on both environmental and socio-economic aspects have motivated the development of sustainable and renewable materials to replace the petroleum-based plastic. Polyhydroxyalkanoates (PHAs), which are bioplastics, having an outstanding biodegradability and rather comparable thermal and mechanical properties, are potential alternatives for the replacement of conventional plastics. However, one of the hurdles on the way to PHA commercial production is the cost of conventional feedstock, which can constitute up to 50% of the production cost. In this regard, volatile fatty acids (VFAs) derived from acidogenic fermentation of organic waste can be a promising substrate to increase the cost-competitiveness of PHA production. Therefore, in this thesis, VFAs were utilized and developed to be a key carbon feedstock for the sustainable and economically feasible production of PHAs. The applicability of individual and mixed VFAs as potential substrates was initially investigated through the cultivation of two different PHA-bearing bacteria of Bacillus megaterium and Cupriavidus necator, providing an average PHA yield on biomass of 10 and 55%, respectively. Further thorough studies, in terms of VFAs loading and inhibition thresholds and operating parameters, were conducted to improve the conversion efficiency of VFAs by C. necator. Consequently, a biomass yield on VFAs of up to 82% was obtained, rendering a PHA accumulation of 1 g/L using actual waste derived VFA effluent. In addition, in order to tackle the inherent issue of low productivity in batch and/or fed-batch cultivations under high VFA containing feed, a novel approach of immersed membrane reactor (iMBR) was introduced and applied in this thesis. With the assistance of membrane filtration, the PHA production was conducted in semi-continuous mode (up to 128 h), yielding a maximum biomass and PHA production of 6.6 and 2.8 g/L, respectively. The outcomes achieved, furthermore, were 32.1 and 28.5%, respectively, higher than that from a continuous stirred tank (CSTR), in which the cultivation was affected by the washout effect. Moreover, considering the insufficiency of the current recycling methods of PHA-based products in terms of resource recovery, a novel attempt of acidogenic fermentation has been conducted to valorize the PHA-based composites through conversion into precursor VFAs. Afterwards, the recovered VFAs could be recirculated into PHA production, fulfilling the concept of a circular bioeconomy.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2023
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 137
Keywords
bioplastics, food waste, polyhydroxyalkanoates, volatile fatty acids, immersed membrane bioreactor, acidogenic fermentation
National Category
Environmental Biotechnology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-29578 (URN)978-91-89271-92-0 (ISBN)978-91-89271-93-7 (ISBN)
Public defence
2023-05-26, C203, Allégatan 1, Borås, 10:00 (English)
Opponent
Supervisors
Available from: 2023-05-04 Created: 2023-03-28 Last updated: 2023-04-28Bibliographically approved

Open Access in DiVA

fulltext(2133 kB)210 downloads
File information
File name FULLTEXT01.pdfFile size 2133 kBChecksum SHA-512
39f17133c68ab3c0de990032dd1b75a2d070fe098de70ad4726c87724124119d0a9fff10d22b226277ec25e5eee90c90c5240fff4d496fa9e8c3feb23be2e15a
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Authority records

Vu, Hoang DanhMahboubi, AmirTaherzadeh, Mohammad JÅkesson, Dan

Search in DiVA

By author/editor
Vu, Hoang DanhMahboubi, AmirTaherzadeh, Mohammad JÅkesson, Dan
By organisation
Faculty of Textiles, Engineering and Business
Bioprocess Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 210 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 86 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • harvard-cite-them-right
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf