Potential biomass yield per phosphorus and lipid accumulation property of seven microalgal species

The aim of the study was to explore the possibility of bioremediation of oil refinery wastewaters by the cyanobacterium Synechococcus sp. MK568070, isolated from the Adriatic Sea. The potential of biomass and lipid production was explored upon cultivation on oil refinery wastewater with excess CO2 after the removal of nutrients. The strain grew well in a wide range of salinities and ammonium concentrations, and was further tested on the wastewater from local oil refinery plant of various N-composition. Growth experiment under optimized conditions was used to analyze the lipid, carbohydrate and protein dynamics. The biomass yield was highly dependent on nutrient source and concentration, salinity and CO2 addition. Highest biomass yield was 767 mg/L of dry weight. Towards the end of the experiment the decline in carbohydrate to 18.9% is visible, whereas at the same point lipids, in particular saturated fatty acid methyl esters (FAME), started to accumulate within the cells. The content of lipids at the end of the experiment was 21.4%, with the unsaturation index 0.45 providing good biofuel feedstock characteristics. Fourier Transform Infrared (FTIR) spectroscopy analysis demonstrated a high degree of lipid accumulation in respect to proteins, along with the structural changes and biomass accumulation. In addition, the N-removal from the wastewater was >99% efficient. The potential of lipid accumulation, due to the functional photosynthesis even at the minimal cell quota of nutrients, is critical for the usage of excess industrial CO2 and its industrial transformation to biodiesel. These findings enable further considerations of Synechococcus sp. (MK568070) for the industrial scale biomass production and wastewater remediation.

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Physiology and lipid accumulation capacity of differentYarrowia lipolyticaandRhodosporidium toruloidesstrains on glycerol

10.1101/278523 ◽

2018 ◽

Cited By ~ 3

Author(s):

Suellen Patricia Held Azambuja ◽

Nemailla Bonturi ◽

Everson Alves Miranda ◽

Andreas Karoly Gombert

Keyword(s):

Process Parameters ◽

Lipid Accumulation ◽

Consumption Rate ◽

Biomass Yield ◽

Dry Weight ◽

Exponential Growth Phase ◽

Specific Substrate ◽

Significant Difference ◽

Accumulation Capacity ◽

Main Carbon

AbstractObjectiveTo compare physiological and process parameters, as well as lipid accumulation capacity, of six strains ofYarrowia lipolyticaand two strains ofRhodosporidium toruloidesin media containing glycerol as the main carbon and energy source.ResultsThe strainsY. lipolyticaIMUFRJ 50678, Po1g, W29 and CCT 5443 displayed very similar physiological parameters, with µmax,andaverage values of 0.31 h−1, 0.53 (g DW/g S), 0.60 (g S/g DW.h) and 0.46 (g DW/g S), respectively. The two strains ofR. toruloidespresented physiological and process parameters with no significant difference, with average values of 0.084 h−1, 0.53 (g DW/g S), 0.17 (g S/g DW.h) and 0.44 (g DW/g S). Among allY. lipolyticastrains,Y. lipolyticaCCT 5443 strain presented the highestYLip/S, 0.054 (g Lip/g S), andPLipof 0.040 (g Lip/l.h). Among all investigated strains (Y. lipolyticaandR. toruloides), the yeastR. toruloidesCCT 7815 displayed the highest lipid accumulation capacity, withYLip/Sequal to 0.11 (g Lip/g S) andPLipequal to 0.10 (g Lip/l.h).ConclusionAmong all strains investigated in our study, the yeast strainR. toruloidesCCT 7815 presents the most promising characteristics for industrial single cell oil production.List of abbreviationsDWdry weight (g/l)Liplipid (g/l)PLiplipid productivity (g Lip/l.h)maximum specific substrate consumption rate (g S/g DW.h)Ssubstrate (g/l)YLip/Slipid yield on substrate (g Lip/g S)biomass yield on substrate during the exponential growth phase (g DW/g S)global biomass yield on substrate (g DW/g S)µmaxmaximum specific growth rate (h−1)

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