Using agro-industrial wastes for mixotrophic growth and lipids production by the green microalga Chlorella sorokiniana

Abstract

There has been growing interest in the use of microalgae for the production of biofuels, but production costs continue to be too high to compete with fossil fuel prices. One of the main limitations for photobioreactor productivity is light shielding, especially at high cell densities. The growth of the green microalga Chlorella sorokiniana, a robust industrial species, has been evaluated under different trophic conditions with traditional carbon sources, such as glucose and sucrose, and alternative low cost carbon sources, such as carob pod extract, industrial glycerol and acetate-rich oxidized wine waste lees. The mixotrophic cultivation of this microalga with wine waste lees alleviated the problems of light shielding observed in photoautotrophic cultures, improving specific growth rate (0.052 h-1) compared with the other organic sources. The fed-batch mixotrophic culture of Chlorella sorokiniana in a 2 L stirred tank reactor, with optimized nutritional conditions, 100 mM of acetate coming from the oxidized wine waste lees and 30 mM of ammonium, produced an algal biomass concentration of 11 gL-1 with a lipid content of 38% (w/w). This fed-batch strategy has been found to be a very effective means to enhance the biomass and neutral lipid productivity.

How Has the Wine Sector Incorporated the Premises of Circular Economy?

“…Number of papers References 2019 8 [8], [37], [38], [39], [40], [41], [42], [43] 2018 23 [3], [7], [31], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [ literature review. Fig.…”

Chemo-Enzymatic Saccharification Strategy of Microalgae Chlorella Sorokiniana

“…The microalgae Chlorella sorokiniana 211-32 [7] was obtained from the culture collection of the Institute of Plant Biochemistry and Photosynthesis, IBVF, (Seville, Spain). Microalgae was cultivated in 1M tris-acetate-phosphate medium [11] pH = 7.2, grown under continuous white light irradiation of 100 lE m −2 s −1 and aerated at 25°C.…”

“…Since microalgae have been reported to have no lignin composition, it can be categorized as a cellulosic based material allowing development of a cost-effective processes. In the present work, is used the green microalgae Chlorella sorokiniana, a robust industrial species, due to their fast growth rates and simple cultivation requirements under typical conditions and tolerant to high temperatures and levels of solar irradiance [7]. Our goal is to hydrolyze the carbohydrates present in the biomass of the microalgae Chlorella sorokiniana, in simple sugars, so that they can be fermented for bioethanol production.…”

Chemical and Physical Pretreatments of Microalgal Biomass

“…The non-axenic culture of Chlorella sorokiniana 211-32 [9] was obtained from the culture collection of the Institute of Plant Biochemistry and Photosynthesis, IBVF, (Seville, Spain). Tris-acetate-phosphate (TAP) medium at pH 7.2 was used for C. sorokiniana culturing [10].…”