Year: 2017
Type: dissertation
Abstract: Botryococcus braunii is a green alga with high long chain hydrocarbon content suitable as a source of biofuel.Due to its external hydrocarbon production, mass cultivation of B. braunii can potentially reduce biofuel production energy and water requirements.However, if the aim is to mass produce biofuel, growing any microalgae with the conventional liquid based cultivation systems are found to be currently not economically viable.The alternative cultivation method is solid growth (biofilm) that can reduce energy and costs associated with harvesting and dewatering process.In the present work, I assessed the potential of successful biofilm growth and the overall lipid productivity of different B. braunii races, and conducted the preliminary economic assessment of B. braunii grown in biofilm compared to the liquid cultivation.In this project, I studied B. braunii (races A, B, L and S) growth on a biofilm for 10 weeks, under laboratory conditions (75 μmol photons m -2 s -1 and 25 o C).Growth, photosynthetic activity and biofilm structure were observed.Three out of four tested races (B, L and S) were successfully grown to stationary phase, with no contamination.However, B. braunii UTEX2441 (race A) cultures were heavily contaminated by fungi from Week 5, thus I stopped recording growth measurements for this strain.Amongst the another three races, B. braunii BOT22 (race B) culture showed higher biomass productivity (3.80 mg dry weight cm -2 d -1 ) and lipid yield (1.11 mg dry weight cm -2 ).Irrespective of the race, almost all photosynthetic parameters (FV/F0, PIABS and the OJIP curve) showed that the biofilm culture was more stressed when grown at lag and stationary phases compared to the logarithmic phase.The most reliable photosynthetic parameter for estimating B. braunii growth condition was FV/F0.
Author: Risa Swandari Wijihastuti
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
Funder: Murdoch University
OpenAlex ID: W2623593461