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Title: Harvesting the Microalga Chlorella sorokiniana by Fungal-Assisted Pelletization

Journal Article · · Journal of Biobased Materials and Bioenergy
 [1];  [2];  [2];  [2];  [2];  [3];  [2];  [4]
  1. Technological Inst. of Mexicali (Mexico)
  2. Univ. of Arizona, Tucson, AZ (United States)
  3. Autonomous Univ. of Baja California (Mexico)
  4. Technological Inst. of Conkal (Mexico)

Currently, the co-cultivation of fungal and microalgal cells is considered a potential technology to minimize the harvesting cost and energy inputs in the algae-to-biofuel approach. In the present study, the co-cultivation of five selected filamentous fungi and microalgae Chlorella sorokiniana to form cell pellets was evaluated under different conditions, such as organic carbon (glucose, fructose, sucrose, and maltose) and nitrogen (urea, peptone, yeast extract, and sodium nitrate) source content with and without the presence of an alternative carbon source (wheat straw), and initial fungal/microalgae cells ratio for mixotrophic growing. In addition, cellulase activity and zeta potential measurements were carried out to obtain a better understanding of the pelletization process. Aspergillus flavus was found most efficient for pelletizing in the nutrient supplemented spent BG-11 in spite of its alkaline pH (7.5–8.3) under mixotrophic growing, being able to harvest up to 96% of the microalgal cells (4.2 x 107 cells mL-1 initial algal concentration) within 48 h at supplementation of 5, 10, and 1 g L-1 of fructose, NaNO3, and KH2PO4, respectively. The harvesting efficiency in terms of optical density at 750 nm as well as the variation of residual sugars, pH, and cellulase enzyme activity (2.3 U mL-1 maximum value) with time was also studied. A. flavus strain investigated in this work could emerge as an efficient and economically viable method in microalgae harvesting for biofuel production as well as in the production of other valuable compounds from extracellular fungal metabolites.

Research Organization:
Univ. of Arizona, Tucson, AZ (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office
Grant/Contract Number:
ee0006269
OSTI ID:
1581802
Journal Information:
Journal of Biobased Materials and Bioenergy, Vol. 12, Issue 6; ISSN 1556-6560
Publisher:
American Scientific PublishersCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science