Lipid Composition of a Green Alga,Botryococcus braunii

Abstract

Botryococcus braunii strain Austin and strain Berkeley cultured under the same conditions contained 27.4 g and 34.0 g of lipids per 100 g of dry alga, respectively. The lipids in the former strain were 25.5% hydrocarbons, 58.8% other nonpolar lipids, and 15.7% polar lipids, and those in the latter strain were 71.6%, 9.2%, and 19.2%, respectively. Distinct differences were also observed in the components of the nonpolar and polar lipids, especially in the latter, between the strains. The fatty acid composition of the nonpolar lipid fraction in Austin strain was unique, oleic acid being 81 % of the total acids.The colonial microalga Botryococcus braunii is a freshwater autotrophic species belonging to the Chlorophyceae and is known to produce unusually high levels of liquid hydrocarbons. The alga has been proposed as a renewable source of fuels from recent concern for future energy requirements. It occurs throughout the world in a wide variety of climates and includes several strains which are classified into two races, A and B.ll The A race accumulates linear olefins, odd numbered from 23 to 31, chiefly CZ7 , CZ9 ' and C31 dienes or trienes, whereas the B race produces polyunsaturated triterpenes of the general formula CnH2n-10, n = 30 ~ 37, termed botryococcenes. 1 -4) These findings suggest that the same strain is unable to yield successively the two types of hydrocarbons contrary to previous proposals. 5 ) Numerous reports have been published regarding hydrocarbons of this alga in relation to production and composition under different growth conditions,4-10) their chemical structures,Z,1l-15) and biosynthesis.1 6 -1 9 ) Largeau et al. 16J showed that [9,1O-3H]-palmitic acid was rapidly incorporated into the A race hydrocarbons and Templier et al.17) indicated that [1O-14C]-0Ieic acid was an efficient precursor of the hydrocarbons. These fatty acids seem to be key intermediate metabolites in the biosynthesis from carbon dioxide to alkadienes and trienes.Douglas et aeO) reported that fatty acids of a natural winter bloom of B. braunii Kiitzing belonging to the B race ranged from C 14 to C 30 , palmitic, oleic, octacosenoic acids being the major components. To our knowledge, however, no other information is available concerning the fatty acid composition of B. braunii.Such a situation prompted us to investigate lipid composition of this alga. In this study, we have chosen two B. braunii strains, one each from the A and B races, and compared their lipids. We report here their nonpolar and polar 494 K. YAMAGUCHI et al. lipid composition and fatty acid composition. MATERIALS AND METHODSMicroorganisms. Botryococcus braunii strain Austin belonging to the A race was obtained from the Austin culture collection (University of Texas) and B. braunii strain Berkeley belonging to the B race was originally isolated to unialgal culture by Dr. Arthur M. Nonomura from lilyculturing tanks in the Department of Botany greenhouse of the University of California, Berkeley.4) Henceforth, they are referred to as the A and B strai...

Development of a screening procedure for the characterization of Botryococcus braunii strains for biofuel application

“…For the fast-growing strains, TL content was comprised between 21 and 32% DW and was, surprisingly, dominated by TAG which ranged from 11 to 21% DW. PL accounted for 1-6% DW for all the tested strains, which was consistent to what was generally observed for other microalgae species [44]. Those results highlighted that B. braunii biofuel potential, so far mainly focused on HC, should also be investigated for its TAG content.…”

Metabolic survey of Botryococcus braunii: Impact of the physiological state on product formation

“…The relative abundance of oleic acid decreased within the polar lipid fraction in the time course of the cultivation from 46.2±1.2% (Phase II) to 34.1±4.3% (Phase IV) and even more within the non-polar lipid fraction from 41.3±4.6% (phase II) to up to 7% (phase III and IV) ( Fig 2D and 2E ; S1 Table ). Furthermore, oleic acid was observed as the most abundant fatty acid within the non-polar fraction during Phase II (linear growth phase) in accordance with previous studies [ 72 ], however their level decreased during further cultivation. Another noteworthy finding was the presence of very long chain fatty acids (VLCFA) such as hexacosenoate (C 26:1 ), octacosenoate (C 28:1 ), octacosadienoate (C 28:2 ), tricontenoate (C 30:1 ) in both polar and non-polar lipid fractions ( Fig 2D and 2E ), since these VLCFA were reported to originate from oleic acid and to function as precursor for rigid polymers associated with the structure of B .…”

Response of Esherichia Colii to the Alcoholic Extract of Green Alga Chlorococcum Humicola

“…The alga was cultured under constant laboratory conditions and temperature of 25±2°C, 3000 lux and 16:8 light: dark as photo system in Chu 13 media (Yamaguchi et al, 1987) (incubated in the incubation room for 18 days, harvested by centrifuge with of 3000 rpm speed for 15 min, the sedimentation dried in oven at 50°C for 48 h, all samples keeps in 25C° antal used (Jawad, 1982;Eppley et al, 1977).…”