Comparison of Biomethane Yields of Two Different Methanogenic Bacteria Cultures at Different Temperature

摘要

The Research Question of the study is “How does the biogas production and biomethane content that are produced by the Methanosarcina thermophila and Methanobrevibacter ruminantium change at 37℃ (mesophilic temperature conditions); 55℃ (thermophilic temperature conditions) by using the same amount of 100.0 mL stock solutions of each methanogenic bacteria cultures by feeding with %8 dry matter content substrate every 16 hours until reaching twentieth day at constant conditions.’udIn this study, I aimed to compare the biomethane yields of two different methanogenic bacteria in thermophilic (55℃) and mesophilic (37℃) temperature conditions using pasteurized cow manure as substrate. Pasteurization via autoclaving was necessary to avoid contamination by native bacteria that is abundant in the digestive tract of the animal. The experiment was conducted with biodigesters with a working volumes of 1 liters, with stock cultures of bacteria kindly provided by the institution that this experiment took place. The substrate solution which were given every sixteen hours until reaching twentieth day and recorded the volume of biogas in liters. Then by the help of the results (volume of biogas) that were taken every sixteen hours, the cumulative biogas production was calculated of each different types of bacteria Methanosarcina thermophila and Methanobrevibacter ruminantium, were compared statistically and the hypothesis was supported.udThe result of the experiment showed that, improvement of biogas production and biomethane content at thermophilic conditions, Methanosarcina thermophila produced the highest amount of biogas in liters. At mesophilic conditions, Methanobrevibacter ruminantium produced the highest amount of biogas in liters. Overall biomethane content per given volume of biogas did not changed significantly according to T-test by considering the results of experiment. Theudp value for Mesophilic Conditions (37℃) is 7.04239×10-15. p value of the investigation were calculated as 2.46299×10-8 for Thermophilic Condition. As a result of the P value those two bacteria Methanosarcina thermophila and Methanobrevibacter ruminantium are able to produce highest volume of biogas at their optimum conditions.