(A) Array data for pure culture strain 195 included triplicate biological replicates that were clustered together for each experimental condition by PCA. All samples were used for subsequent data analysis. (B) D. mccartyi-specific array data for biological replicates of KB-1 mixed culture demonstrated variability owing to array type, experimental design, and complex interactions of organisms in the community. Subsequent data analyses, therefore, were conducted with the expression values of all 33 biological replicates. “EE” = early exponential phase, “LE” = late exponential phase, “TR” = transition phase, “ES” = early stationary phase, “LS” = late stationary phase, “HighB12” = higher concentration of vitamin B12 in the medium, “LowB12” = lower concentration of vitamin B12 in the medium, “ANASspent” = ANAS supernatant added medium, “ANASmedium” = growth medium of ANAS cultures, “TCEM” = trichloroethene and methanol, “cDCEM” = cis 1,2-dichloroethene and methanol, “VCM” = vinyl chloride and methanol, “VCH” = vinyl chloride and hydrogen, “M” = methanol only, “NA” = not amended.