Carboxymethylcellulose (CMC) medium (Bushnell and Haas, 1941) was used for isolation of hydrolytic bacteria, estimation of endoglucanase activity and optimization of culture conditions. CMC-Congo Red agar plates (Hendricks et al., 1995) were used for screening for hydrolytic activity. All the isolated strains and the control Escherichia coli strain were routinely grown in Luria-Bertani (LB) medium (Sambrook and Russell, 2001) at 30°C and 37°C, respectively. For the strains carrying pGEM-T Easy vector, LB was supplemented with ampicillin at the concentration of 100 g/mL.
Maize silage obtained from a farm in Trzebieszow Pierwszy (Poland) was mixed with low-mineral water (Eden Springs, Poland) and used as a substrate for biological pretreatment and anaerobic digestion processes (maize silage-water medium, MSW).