To provide an elaborate understanding on the performance of Entererococcus sp. L1 in biogas production at different fermentation periods under controlled low temperature, biogas optimization experiments was undertaken. Specifically, microscopic and culture techniques, physiological and biochemical studies, and measurement of optical densities at 600 wavelengths (OD600) were undertaken to identify and characterize the Entererococcus sp. L1. The aim was to identify the strain and determine its optimum working conditions in biogas production at different fermentation periods under controlled low temperature. The result confirmed the strain as hydrogen-producing bacteria (Enteroccus sp. L1). It was also confirmed that the organic nitrogen source was significantly better than the inorganic nitrogen source in supporting the growth of the bacteria. The optimal pH and temperature for the growth and biogas production performance of the Entererococcus sp. L1 was 7 and 15 °C respectively. The Na₂HPO₄ concentration of 0.2% was confirmed to be best for the optimum growth of the bacteria, and addition of citric acid resulted to significant inhibitory effect on the growth of the Entererococcus sp. L1. The effect of adding different concentrations (0, 1%, 5%, 10%) of the L1 bacteria inoculum on cow dung at simulated low temperature (15 °C) biogas fermentation showed that 10% treatment had the highest gas production of 3121 ml, which was 89% higher than the control (0 concentration). The daily gas production rate was 0.02 m³/(m⁻³d⁻¹), which was 90% higher than the control. This showed that 10% treatment provided the best gas production result, with highest gas production occurring at 10% treatment within 31–60 days of fermentation (p < 0.05). The study therefore recommends application of the Entererococcus sp. L1 in biogas production under the above confirmed optimum working conditions for increased bigas quality and quantity.

详细了解肠球菌属的性能。L1在受控低温下不同发酵时期的沼气生产中，进行了沼气优化实验。具体而言，进行了显微和培养技术、生理和生化研究以及 600 波长 (OD600) 光密度的测量，以鉴定和表征肠球菌。L1。目的是鉴定菌株并确定其在受控低温下不同发酵时期生产沼气的最佳工作条件。结果证实该菌株为产氢菌（Enteroccussp. L1)。还证实有机氮源在支持细菌生长方面明显优于无机氮源。肠球菌生长和沼气生产性能的最佳 pH 值和温度。L1 分别为 7 和 15 °C。证实0.2%的Na ₂ HPO ₄浓度最适合细菌的最佳生长，添加柠檬酸对肠球菌的生长有显着抑制作用sp. L1。在模拟低温（15℃）沼气发酵下，添加不同浓度（0、1%、5%、10%）L1菌种对牛粪的影响表明，10%处理产气量最高，为3121 ml ，比对照（0 浓度）高 89%。日产气量为0.02 m ³ /(m ^-3 d ^-1 )，比对照高90%。这表明 10% 的处理提供了最好的产气结果，10% 的处理在发酵的 31-60 天内产生了最高的产气量（p < 0.05）。因此，该研究建议应用肠球菌sp. L1 在上述沼气生产中确认了提高沼气质量和数量的最佳工作条件。