Co-Production of Fungal Biomass Derived Constituents and Ethanol from Citrus Wastes Free Sugars without Auxiliary Nutrients in Airlift Bioreactor
2016 (English)In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 17, no 3, article id 302
Article in journal (Refereed) Published
Sustainable development
The content falls within the scope of Sustainable Development
Abstract [en]
The potential of two zygomycetes fungi, Mucor indicus and Rhizopus oryzae, in assimilating citrus waste free sugars (CWFS) and producing fungal chitosan, oil, and protein as well as ethanol was investigated. Extraction of free sugars from citrus waste can reduce its environmental impact by decreasing the possibility of wild microorganisms growth and formation of bad odors, a typical problem facing the citrus industries. A total sugar concentration of 25.1 g/L was obtained by water extraction of citrus waste at room temperature, used for fungal cultivation in shake flasks and airlift bioreactor with no additional nutrients. In shake flasks cultivations, the fungi were only able to assimilate glucose, while fructose remained almost intact. In contrast, the cultivation of M. indicus and R. oryzae in the four-liter airlift bioreactor resulted in the consumption of almost all sugars and production of 250 and 280 g fungal biomass per kg of consumed sugar, respectively. These biomasses correspondingly contained 40% and 51% protein and 9.8% and 4.4% oil. Furthermore, the fungal cell walls, obtained after removing the alkali soluble fraction of the fungi, contained 0.61 and 0.69 g chitin and chitosan per g of cell wall for M. indicus and R. oryzae, respectively. Moreover, the maximum ethanol yield of 36% and 18% was obtained from M. indicus and R. oryzae, respectively. Furthermore, that M. indicus grew as clump mycelia in the airlift bioreactor, while R. oryzae formed spherical suspended pellets, is a promising feature towards industrialization of the process.[on SciFinder (R)]
Place, publisher, year, edition, pages
2016. Vol. 17, no 3, article id 302
Keywords [en]
mucor indicus, rhizopus oryzae, chitosan, citrus waste, ethanol, oil, pellet, protein
National Category
Industrial Biotechnology
Research subject
Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-11441DOI: 10.3390/ijms17030302ISI: 000373712800125PubMedID: 26927089Scopus ID: 2-s2.0-84959230541OAI: oai:DiVA.org:hb-11441DiVA, id: diva2:1056167
Note
MEDLINE AN 2016759271(Journal; Article; (JOURNAL ARTICLE); (RESEARCH SUPPORT, NON-U.S. GOV'T))
2016-12-142016-12-142022-02-10Bibliographically approved