Effect of Organic Acid Treatment on Microalgae Lipid Extraction†

doi:10.7503/cjcu20140707

Abstract

Abstract:

Developing an advanced cell treatment technology is very important for promoting microbial oils as the feedstock for biodiesel production. The traditional inorganic acid-heat treatment process has some problems such as difficulty in recycling inorganic acid, serious environmental pollution and so on. This paper explores using organic acid which is easy to recycle, to treat cells for lipid extraction from microalgae. Effect of formic acid treatment on lipid extraction from Chlorella protothecoides was investigated systematically. The results showed that formic acid was very effective in treating microalgae cells and the total lipid yield and fatty acid methyl esters(FAME) yield were comparable with those obtained from inorganic acid-heat treatment process. It was found that formic acid concentration, temperature, treatment time and liquid/solid ratio(l/s) had a significant influence on micro-algae lipid extraction. Under the optimum condition of formic acid concentration 88%, temperature 100 ℃, treatment time 30 min and ratio of liquid to solid 6:1, the total lipid yield and FAME yield reached 49.2% and 92.1%, respectively. There was no obvious difference in fatty acid composition in the microbial oils obtained from organic acid treatment and inorganic acid-heat treatment process. There were 5 kinds of fatty acid in the microbial oil from Chlorella protothecoides, among which the content of C18:1 was the highest. Then, the adaptation of formic acid treatment to different microalgae material was investigated. The results showed that the total lipid yield and FAME yield of Nannochlorum sp and Nannochloropsis Oceanic were comparable with those obtained from inorganic acid-heat treatment process.

Key words: Microalgae, Formic acid, Lipid extraction, Biodiesel

CLC Number:

TrendMD:

WANG Songmei, KUAN Dingyaw, DU Wei, ZHAO Xuebing, LIU Dehua. Effect of Organic Acid Treatment on Microalgae Lipid Extraction^†[J]. Chem. J. Chinese Universities, 2015, 36(3): 499.

Figures/Tables 7

Table 1 Lipid extraction efficiency according to cell disruption method from Chlorella protothecoides*

Method	Bead-beating	Microwaves	Sonication	Steam explosion	HCl	Formic acid^*	No disruption
Total lipid yield(mass fraction, %)	28.9±3.1	6.0±0.5	15.4±1.1	7.4±0.8	47.2±2.6	46.7±0.8	5.7±0.4
FAME yield(mass fraction, %)	54.0±5.8	NA	27.1±1.9	NA	91.0±5.1	83.9±1.5	NA

Fig.1 Effects of formic acid concentrations on total lipid yield(a) and FAME yield(b) from Chlorella protothecoides Ratio of liquid to solid: 10 mL/g, temperature: 100 ℃, time: 30 min, stirring rate: 250 r/min.

Fig.2 Effect of temperature on total lipid yield(a) and FAME yield(b) from Chlorella proto-thecoides Mass fraction of formic acid: 88%, ratio of liquid to solid: 10 mL/g, time: 30 min, stirring rate: 250 r/min.

Fig.3 Effect of time on total lipid yield(A) and FAME yield(B) from Chlorella protothecoides Mass fraction of formic acid: 88%, ratio of liquid to solid: 10 mL/g, stirring rate: 250 r/min, temperature/℃: a. 75; b. 90; c. 100.

Fig.4 Effect of liquid/solid ratio on total lipid yield(A) and FAME yield(B) from Chlorella protothecoides Mass fraction of formic acid: 88%, ratio of liquid to solid: 100 ℃, time: 30 min, stirring rate: 250 r/min.

Table 2 Fatty acid composition of Chlorella protothecoides*

Fatty acid	Amount of fatty acid(%)		Fatty acid	Amount of fatty acid(%)
Fatty acid	Formic acid		HCl	Formic acid	HCl
C16:0	7.6±0.0	7.6±0.1	C18:2	15.9±0.1	16.0±0.0
C18:0	4.2±0.1	4.0±0.0	C20:0	1.7±0.0	1.6±0.0
C18:1	70.6±0.0	70.8±0.1

Table 3 Lipid extraction efficiency according to species with formic acid treatment method*

Series	Chlorella protothecoides		Nannochlorum sp		Nannochloropsis oceanic
Series	Formic acid	HCl	Formic acid	HCl	Formic acid	HCl
Total lipid yield(mass fraction, %)	49.2±0.0	47.2±2.6	21.3±0.7	14.7±0.4	26.0±0.0	21.7±0.1
FAME yield(mass fraction, %)	92.1±0.93	91.0±5.1	92.9±3.1	89.5±2.6	96.2±0.1	97.8±0.7

References 24

[1]	Aransiola E. F., Ojumu T. V., Oyekola O. O., Madzimbamuto T. F., Ikhu-Omoregbe D. I. O., Biomass and Bioenergy,2014, 61, 276—297
[2]	Li S. H., Fang Y. M., Wang F., Li P., Li X. Y., Chem. J. Chinese Universities,2013, 34(7), 1714—1722
	(李树豪, 方亚梅, 王繁, 李萍, 李象远. 高等学校化学学报, 2013, 34(7), 1714—1722)
[3]	Chisti Y., Biotechnol. Advances, 2007, 25(3), 294—306
[4]	Rawat I., Ranjith R., Mutanda T., Bux F., Appl. Energy,2013, 103, 444—467
[5]	Tong M., Zhou Z.G., Agric. Eng. Technol.:New Energy Ind., 2009, (5), 19—26
	(童牧, 周志刚. 农业工程技术: 新能源产业, 2009, (5), 19—26)
[6]	Jiang X. M., Zheng Y. Z., Acta. Hydrob. Sin., 2003, 27(3), 243—247
	(蒋霞敏, 郑亦周. 水生生物学报, 2003, 27(3), 243—247)
[7]	Halim R., Harun R., Danquah M. K., Webley P. A., Appl. Energy,2012, 91(1), 116—121
[8]	Lee A. K., Lewis D. M., Ashman P. J., Biomass and Bioenergy,2012, 46, 89—101
[9]	Halim R., Danquah M. K., Webley P. A., Biotechnol. Adv., 2012, 30(3), 709—732
[10]	Lee J. Y., Yoo C., Jun S. Y., Ahn C. Y., Oh H. M., Bioresour. Technol., 2010, 101(1), 75—77
[11]	Zheng H. L., Yin J. L., Gao Zh., Huang H., Ji X. J., Dou C., Appl. Biochem. Biotechnol., 2011, 164(7), 1215—1224
[12]	Prabakaran P., Ravindran A. D., Lett. Appl. Microbiol., 2011, 53(2), 150—154
[13]	Neto A. M. P., Souza R. A. S., Leon-Nino A. D., Costa J. D. A., Tiburcio R. S., Nunes T. A., Mello T. C. S., Kanemoto F. T., Saldanha F. M. P., Gianesella S. M. F., Renew. Energy,2013, 55, 525—531
[14]	Kong F. M., Zhao X. Y., Tian Y. J., Guo T. Q., Liu J. J., China Brewing,2010, 29(5), 143—145
	(孔凡敏, 赵祥颖, 田延军, 国天庆, 刘建军. 中国酿造, 2010, 29(5), 143—145)
[15]	Xu J.Y., Microbial Conversion of Crude Glycerol to Lipids by Oleaginous Yeast Rhodosporidium. Toruloides, Tsinghua University, Beijing, 2013
	(徐静阳. 圆红冬孢酵母转化粗甘油合成油脂及其调控, 北京: 清华大学, 2013)
[16]	Zhang H., Tang B. K., Row K., Chem. Res. Chinese Universities,2014, 30(1), 37—41
[17]	Steriti A., Rossi R., Concas A., Cao G., Bioresour. Technol., 2014, 164, 70—77
[18]	Lam H. Q., Bigot Y. L., Delmas M., Avignon G., Ind. Crops Prod., 2001, 14, 65—71
[19]	Ligero P., Vega A., Bao M., Ind. Crops Prod., 2005, 21(2), 235—240
[20]	Zhao X. B., Wang L., Liu D. H., J. Chem. Technol. Biotechnol., 2007, 82(12), 1115—1121
[21]	Zhao X.B., Pulping and Pretreatment of Lignocellulosic Biomass with Organic Acids, Tsinghua University, Beijing, 2009
	(赵雪冰. 木质纤维原料的有机酸制浆及生物转化的预处理, 北京: 清华大学, 2009)
[22]	Bligh E. G., Dyer W. J., Can. J. Biochem. Physiol., 1959, 37, 911—917
[23]	Laurens L. M. L., Quinn M., Van W. S., David W. T., Edward J. W., Anal. Bioanal. Chem., 2012, 403(1), 167—178
[24]	Griffiths M. J., Van Hille R. P., Harrison S. T. L., Lipids,2010, 45(11), 1053—1060