enzymatic degradability of lignocellulosic biomass (Keller et al., 2003; Wan and Li, 2010; Pinto et al., 2012). Other applicable microbial consortia usually consist of 2-4 strains, among which bacteria of the genus Clostridium are most common. Mixed cultures of cellulolytic and non-cellulolytic bacteria are also used. These are very often cultivated under strictly anaerobic conditions, using pre-reduced media. Attempts were made to remove this inconvenience, e.g., by using strains with lower requirements and showing higher tolerance to oxygen.