Background: Microalgae is considered a promising source for biofuel and bioenergy production, bio-remediation and production of high-value bioactive compounds, but harvesting microalgae is a major bottleneck in the algae based processes. The objective of this research is to mimic the growth of natural lichen and develop a novel biofilm platform technology using filamentous fungi and microalgae to form a lichen type of biofilm "mycoalgae" in a supporting polymer matrix. Results: The possibility of co-existence of Chlorella vulgaris with various fungal cultures was tested to identify the best strain combination for high algae harvest efficiency. The effect of different matrices for cell attachment and biofilm formation, cell surface characterization of mycoalgae biofilm, kinetics of the process with respect to the algaefungi cell distribution and total biomass production was studied. Mycoalgae biofilm with algae attachment efficiency of 99.0 % and above was achieved in a polymer-cotton composite matrix with glucose concentration of 2 g/L in the growth medium and agitation intensity of 150 rpm at 27 ° C. The total biomass in the co-culture with the selected strain combination (Mucor sp. and Chlorella sp.) was higher than the axenic cultures of fungi and algae at the conditions tested. Conclusions: The results show that algae can be grown with complete attachment to a bio-augmenting fungal surface and can be harvested readily as a biofilm for product extraction from biomass. Even though, interaction between heterotrophic fungi and phototrophic algae was investigated in solid media after prolonged contact in a report, this research is the first of its kind in developing an artificial lichen type biofilm called "mycoalgae" biofilm completely attached on a matrix in liquid cultures. The mycoalgae biofilm based processes, propounds the scope for exploring new avenues in the bio-production industry and bioremediation.
Bibliographical noteFunding Information:
FTIR analysis was carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program. The authors acknowledge the UMN CharFac staff Dr.Bing Luo, Senior Research Associate for FTIR analysis. The authors acknowledge Tanner Barnharst for proofreading and Carlos Zamalloa for comments. The authors gratefully acknowledge The University of Minnesota, Biotechnology Institute-Synthetic Ecology Program for the support to develop pelletized microalgae cultivation via attraction between microalgae and fungal cells. Legislative-Citizen Commission on Minnesota Resources (LCCMR) - Environment and Natural Resources Trust Fund, Minnesota is providing funding support for developing this novel Mycoalgae biofilm technology for environmental applications.
- Filamentous fungi
- Mycoalgae biofilm