Fig 3. Effect of various treatments on the enhancement effect of cattle saliva.

(a) Denatured and dialyzed cattle saliva. Denaturation of cattle saliva: Cattle saliva was autoclaved for 13 minites at 121°C to denature proteins. After that, the saliva was centrifuged at 20,400 x g for 10 min. The supernatant (called ‘Autoclaved saliva’) was collected and subsequently used in experiments. Dialysis of cattle saliva: Cattle saliva was dialyzed against distilled water for 72 h at room temperture. The water was exchanged every other day. (b) Proteinase K treatment. Twenty microliters cattle saliva was mixed with 20 μL proteinase K (20 mg/mL) and the mixture was incubated at 50°C for 12 h. After the incubation, the mixture was incubated at 96°C for 10 min to denature proteinase K. This mixture was called ‘Proteinase K Saliva’ and used in the cellulose degradation assay. The concentration of cattle saliva in the reaction mixture was 5%. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).