One of the strategies for diminishing greenhouse gass emissions is gradual
substitution of fossil fuels with biofuels made of plant biomass. Nowadays, lignocellulosic waste, the side product of agriculture, represents the most attractive feedstock for sustainable biofuel production. However, its recalcitance to biodegradation and associated high costs of pretreatment are major drawbacks to its application in biofuel production. Traditionally, biofuels production is a two-steps process which includes lignocellulose pretreatment and microbal bioconversion of sugars to biofuels. With metabolic engineering, more efficient metabolic pathways for major biofuels produced from carbohydrates are being established. The promissing strategy for more effective conversion of biomass to biofuels is the construction of cells suitable for consolidated bioprocesses, where hydrolisis and fermentation are performed in a single bioreactor. The following work reviews the most common strategies and recent achievements in metabolic engineering of microbial cells oriented towards more efficient production of first, second and third generation of biofuels.