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Lipid production in association of filamentous fungi with genetically modified cyanobacterial cells.

Miranda AF, Taha M, Wrede D, Morrison P, Ball AS, Stevenson T, Mouradov A - Biotechnol Biofuels (2015)

Bottom Line: For most of genetically modified strains the total lipid yields extracted from the fungal-cyanobacterial pellets were found to be higher than additive yields of lipids and total free fatty acids produced by fungal and Synechocystis components when grown in mono-cultures.The synergistic effect observed in fungal-Synechocystis associations was also found in bioremediation rates when animal husbandry wastewater was used an alternative source of nitrogen and phosphorus.Fungal assisted flocculation can complement and assist in large scale biofuel production from wild-type and genetically modified Synechocystis PCC 6803 strains by (1) efficient harvesting of cyanobacterial cells and (2) producing of high yields of lipids accumulated in fungal-cyanobacterial pellets.

View Article: PubMed Central - PubMed

Affiliation: School of Applied Sciences, Royal Melbourne Institute of Technology University, Bundoora, VIC 3083 Australia.

ABSTRACT

Background: Numerous strategies have evolved recently for the generation of genetically modified or synthetic microalgae and cyanobacteria designed for production of ethanol, biodiesel and other fuels. In spite of their obvious attractiveness there are still a number of challenges that can affect their economic viability: the high costs associated with (1) harvesting, which can account for up to 50 % of the total biofuel's cost, (2) nutrients supply and (3) oil extraction. Fungal-assisted bio-flocculation of microalgae is gaining increasing attention due to its high efficiency, no need for added chemicals and low energy inputs. The implementation of renewable alternative carbon, nitrogen and phosphorus sources from agricultural wastes and wastewaters for growing algae and fungi makes this strategy economically attractive.

Results: This work demonstrates that the filamentous fungi, Aspergillus fumigatus can efficiently flocculate the unicellular cyanobacteria Synechocystis PCC 6803 and its genetically modified derivatives that have been altered to enable secretion of free fatty acids into growth media. Secreted free fatty acids are potentially used by fungal cells as a carbon source for growth and ex-novo production of lipids. For most of genetically modified strains the total lipid yields extracted from the fungal-cyanobacterial pellets were found to be higher than additive yields of lipids and total free fatty acids produced by fungal and Synechocystis components when grown in mono-cultures. The synergistic effect observed in fungal-Synechocystis associations was also found in bioremediation rates when animal husbandry wastewater was used an alternative source of nitrogen and phosphorus.

Conclusion: Fungal assisted flocculation can complement and assist in large scale biofuel production from wild-type and genetically modified Synechocystis PCC 6803 strains by (1) efficient harvesting of cyanobacterial cells and (2) producing of high yields of lipids accumulated in fungal-cyanobacterial pellets.

No MeSH data available.


Biomass and lipid production in A. fumigatus-SD100 pellets grown in 25 % swine wastewater. Af-SD100: A. fumigatus-SD100 pellets. Significance levels: *p < 0.05
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Fig6: Biomass and lipid production in A. fumigatus-SD100 pellets grown in 25 % swine wastewater. Af-SD100: A. fumigatus-SD100 pellets. Significance levels: *p < 0.05

Mentions: We assessed the ability of A. fumigatus-SD100 pellets for growth and absorption the nitrogen and phosphorus (NH4+ and PO4−3) from swine wastewater (SWW) (Table 5; Additional file 10: Figure S9). For these experiments, the swine wastewater was diluted to either 10 or 25 % with tap water. After 48 h of growth of A. fumigatus-SD100 pellets in 25 % wastewater the concentration of NH4+-N reduced from 164.3 to 18.2 mg/L (89 %) and the concentration of PO4−3-P reduced from 38.7 to 9.8 mg/L (75 %). This removal efficiency was higher than achieved separately by Synechocystis SD100 (30 % for NH4+-N and 26 % for PO4−3-P) and by A. fumigatus (52 and 45 %, for NH4+-N and PO4−3-P respectively). In 10 % SWW both nutrients were almost completely removed after 48 h incubation with A. fumigatus-SD100 alone (98 % removal for NH4+-N and 84 % removal of PO4−3-P). Nutrient uptake by A. fumigatus-SD100 pellets led to 2.3-fold increase in their biomass production after 48 h of treatment and this correlated with a 1.5-fold increase in lipid yield (Fig. 6).Table 5


Lipid production in association of filamentous fungi with genetically modified cyanobacterial cells.

Miranda AF, Taha M, Wrede D, Morrison P, Ball AS, Stevenson T, Mouradov A - Biotechnol Biofuels (2015)

Biomass and lipid production in A. fumigatus-SD100 pellets grown in 25 % swine wastewater. Af-SD100: A. fumigatus-SD100 pellets. Significance levels: *p < 0.05
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4635583&req=5

Fig6: Biomass and lipid production in A. fumigatus-SD100 pellets grown in 25 % swine wastewater. Af-SD100: A. fumigatus-SD100 pellets. Significance levels: *p < 0.05
Mentions: We assessed the ability of A. fumigatus-SD100 pellets for growth and absorption the nitrogen and phosphorus (NH4+ and PO4−3) from swine wastewater (SWW) (Table 5; Additional file 10: Figure S9). For these experiments, the swine wastewater was diluted to either 10 or 25 % with tap water. After 48 h of growth of A. fumigatus-SD100 pellets in 25 % wastewater the concentration of NH4+-N reduced from 164.3 to 18.2 mg/L (89 %) and the concentration of PO4−3-P reduced from 38.7 to 9.8 mg/L (75 %). This removal efficiency was higher than achieved separately by Synechocystis SD100 (30 % for NH4+-N and 26 % for PO4−3-P) and by A. fumigatus (52 and 45 %, for NH4+-N and PO4−3-P respectively). In 10 % SWW both nutrients were almost completely removed after 48 h incubation with A. fumigatus-SD100 alone (98 % removal for NH4+-N and 84 % removal of PO4−3-P). Nutrient uptake by A. fumigatus-SD100 pellets led to 2.3-fold increase in their biomass production after 48 h of treatment and this correlated with a 1.5-fold increase in lipid yield (Fig. 6).Table 5

Bottom Line: For most of genetically modified strains the total lipid yields extracted from the fungal-cyanobacterial pellets were found to be higher than additive yields of lipids and total free fatty acids produced by fungal and Synechocystis components when grown in mono-cultures.The synergistic effect observed in fungal-Synechocystis associations was also found in bioremediation rates when animal husbandry wastewater was used an alternative source of nitrogen and phosphorus.Fungal assisted flocculation can complement and assist in large scale biofuel production from wild-type and genetically modified Synechocystis PCC 6803 strains by (1) efficient harvesting of cyanobacterial cells and (2) producing of high yields of lipids accumulated in fungal-cyanobacterial pellets.

View Article: PubMed Central - PubMed

Affiliation: School of Applied Sciences, Royal Melbourne Institute of Technology University, Bundoora, VIC 3083 Australia.

ABSTRACT

Background: Numerous strategies have evolved recently for the generation of genetically modified or synthetic microalgae and cyanobacteria designed for production of ethanol, biodiesel and other fuels. In spite of their obvious attractiveness there are still a number of challenges that can affect their economic viability: the high costs associated with (1) harvesting, which can account for up to 50 % of the total biofuel's cost, (2) nutrients supply and (3) oil extraction. Fungal-assisted bio-flocculation of microalgae is gaining increasing attention due to its high efficiency, no need for added chemicals and low energy inputs. The implementation of renewable alternative carbon, nitrogen and phosphorus sources from agricultural wastes and wastewaters for growing algae and fungi makes this strategy economically attractive.

Results: This work demonstrates that the filamentous fungi, Aspergillus fumigatus can efficiently flocculate the unicellular cyanobacteria Synechocystis PCC 6803 and its genetically modified derivatives that have been altered to enable secretion of free fatty acids into growth media. Secreted free fatty acids are potentially used by fungal cells as a carbon source for growth and ex-novo production of lipids. For most of genetically modified strains the total lipid yields extracted from the fungal-cyanobacterial pellets were found to be higher than additive yields of lipids and total free fatty acids produced by fungal and Synechocystis components when grown in mono-cultures. The synergistic effect observed in fungal-Synechocystis associations was also found in bioremediation rates when animal husbandry wastewater was used an alternative source of nitrogen and phosphorus.

Conclusion: Fungal assisted flocculation can complement and assist in large scale biofuel production from wild-type and genetically modified Synechocystis PCC 6803 strains by (1) efficient harvesting of cyanobacterial cells and (2) producing of high yields of lipids accumulated in fungal-cyanobacterial pellets.

No MeSH data available.