LH-PCR fingerprinting. Bacterial communities from continuous dark fermentation at 24 and 210 h (A) and frozen sediment used as inoculum (B). The x-axis shows the LH amplicons with the following size (bp): a = 330 to 331, b = 334, c = 336 to 337, d = 343 to 344, e = 346 to 348, f = 353 to 355, and g = 360 to 362. The y-axis shows the average of the relative ratios with the standard error bars of four replicate DNA extractions, with two PCR each. Amplicons with a relative ratio ≤1 are not included.