Fig. 6

Growth and fermentation products on various substrates by monoculture and co-culture combinations. Cellulolytic and fermenting strains; A co-culture of cellulolytic Clostridium sp. strain DBT-IOC-C19 and the xylanolytic Clostridium sp. strain DBT-IOC-DC21, B co-culture of cellulolytic Clostridium sp. strain DBT-IOC-C19 and non-cellulolytic (fermenting) strain Thermoanaerobacter sp. strain DBT-IOC-X2, C co-culture of cellulolytic Clostridium sp. strain DBT-IOC-C19 and xylanolytic Clostridium sp. strain DBT-IOC-DC21 and fermenting strain Thermoanaerobacter sp. strain DBT-IOC-X2, D monoculture xylanolytic Clostridium sp. strain DBT-IOC-DC21, and E monoculture cellulolytic Clostridium sp. strain DBT-IOC-C19 were grown on various substrates in serum bottles without pH control at 60 °C. Each data point represents average with error bars (±) showing standard deviations calculated from samples collected from triplicate experiments. The metabolite concentrations produced by different mono and co-culture combinations varied with a statistical significance [ANOVA Tukey’s test, ***p < 0.001, ** 0.01 > p > 0.001 and * 0.05 > p > 0.01]. The concentrations that are not significantly different from each other in treatment condition described are labeled with same lowercase letters associated with a level of significance in the figure [Substrates for fermentation: a avicel, b xylan, c Mixture of avicel and xylan, d pretreated rice straw biomass, e native rice straw biomass]