Interactive comment on “Molecular analysis of the microbial community structures in water-flooding

General comments: This paper (bg-2012-148) carefully studied about the bacterial and archaeal community structures in six water-flooding petroleum reservoirs with different temperatures (20 to 63 degree C). The microbial communities shifted from high-temperature (e.g. archaea: Thermococcus, Methanothermobacter, Thermoplasmatales, bacteria: Firmicutes, Thermotogae, Thermodesulfobacteria) to lowtemperature (e.g. archaea: Methanobacterium, Methanoculleus, Methanocalculus, bacteria: Proteobacteria, Bacteroidetes, Actinobacteria), which was a valuable information for microbial pertroleum researchers. Canonical correspondence analysis (CCA) revealed that temperature showed correlation with the microbial community structures. Furthermore, the physical, chemical, and geochemical characteristics (e.g.