Table 4.

Summary of the selected samples used for shotgun metagenomic sequencing

Sample ID	Experiment	Day of passage/replicates	Sample name in Fig. 3	Fermentation substrate /products description
MLA-3-AC	MLA	3/pooled A+C	MLA 3 A and MLA 3 C	The main non-gaseous fermentation products of molasses were lactate and ethanol, concentration of butyrate was very low
MLA-9-AC	MLA	9/pooled A+C	MLA 9 A and MLA 9 C	The main fermentation product of molasses supplemented with acetate and lactate was butyrate; lactate as a substrate was efficiently utilized
LA-3-BC	LA	3/pooled B+C	LA 3 B and LA 3 C	Lactate as a substrate was partially metabolized
LA-18-AB	LA	18/pooled A+B	LA 18 A and LA 18 B	The main fermentation product of the medium containing exclusively lactate and acetate was butyrate; lactate as a substrate was efficiently utilized