Document Type : Review Paper
Authors
1
Biorefinery Group, Food Research Department, Faculty of Chemistry Sciences, Autonomous University of Coahuila, 25280, Saltillo, Coahuila, Mexico.
2
Cluster of Bioalcohols, Mexican Centre for Innovation in Bioenergy (Cemie-Bio), Mexico.
3
Laboratory of Fermentations, Graduate Program in Food Science and Technology, University of Passo Fundo, Campus I, Passo Fundo, Rio Grande do Sul, Brazil.
4
Department of Organic Chemistry, Faculty of Chemistry Sciences, Autonomous University of Coahuila, 25280 Saltillo, Coahuila, Mexico.
5
CEB-Centre of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal.
Abstract
Biofuels derived from microalgae biomass have received a great deal of attention owing to their high potentials as sustainable alternatives to fossil fuels. Microalgae have a high capacity of CO2 fixation and depending on their growth conditions, they can accumulate different quantities of lipids, proteins, and carbohydrates. Microalgal biomass can, therefore, represent a rich source of fermentable sugars for third generation bioethanol production. The utilization of microalgal carbohydrates for bioethanol production follows three main stages: i) pretreatment, ii) saccharification, and iii) fermentation. One of the most important stages is the pretreatment, which is carried out to increase the accessibility to intracellular sugars, and thus plays an important role in improving the overall efficiency of the bioethanol production process. Diverse types of pretreatments are currently used including chemical, thermal, mechanical, biological, and their combinations, which can promote cell disruption, facilitate extraction, and result in the modification the structure of carbohydrates as well as the production of fermentable sugars. In this review, the different pretreatments used on microalgae biomass for bioethanol production are presented and discussed. Moreover, the methods used for starch and total carbohydrates quantification in microalgae biomass are also briefly presented and compared.
Graphical Abstract

Highlights
- An overview on different aspect of 3rd generation bioethanol producted is presented.
- Different pretreatment methods used for microalgae biomass are reviwed and discussed.
- Different methods for starch and carbohydrates quantification are described.
Keywords