Organic matter and microbial fluid analysis are rarely considered in the geothermal industry and research. However, they can have a significant impact on the efficiency of geothermal energy production. We found a high diversity of organic compound compositions in our samples and were able to differentiate them with respect to different sources (e.g. artificial and biogenic). Furthermore, the microbial diversity undergoes significant changes within the flow path of a geothermal power plant.