Microbial assemblages in terrestrial environments, such as soils, utilize hydrolytic enzymes to function biologically in various environments including for the degradation of organic carbon compounds and cycling of nutrients that eventually contributes to the ecological and agricultural productivity of such environments. In this study, 3 soil types (i.e., sandy, loamy and clayey) with varying characteristics were collected within the premises of Albion College in Michigan, with the goal of comparing the occurrences of indigenous bacterial populations and their respective hydrolytic enzyme activities in the soils. The soils were examined for their organic matter content (% OM), while bacterial abundance was determined by combinations of viable counts and nucleic acid staining, and enzymatic activities measured using fluorescein diacetate (FDA) analysis. Results from the study showed loamy soil to have a significantly higher % OM at 30% on average as compared to 2.5% and 6.6% recorded in the sandy and clayey soils. Comparatively, bacterial numbers (both viable and total counts) were also significantly higher in loamy soils than the other two soils. The same trend was observed for FDA analysis with higher fluorescein released in the loamy soil relative to the two other soils. Overall, clear differences were observed in the relationships between % OM and bacterial numbers and hydrolytic enzyme activities among the three soil types and between the two seasons examined. The results suggest that % OM strongly influences both bacterial abundance and hydrolytic enzyme activities in loamy soil and less so in both sandy and clayey soils examined in the study. This study in conclusion revealed potential strong relationships between soil organic carbon and indigenous bacterial populations as well as their FDA activities in various soil types.

中文翻译：

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土壤有机质含量与细菌水解酶活性的关系：季节比较

陆地环境（例如土壤）中的微生物群落利用水解酶在各种环境中发挥生物学功能，包括降解有机碳化合物和最终促进此类环境的生态和农业生产力的养分循环。在这项研究中，在密歇根州阿尔比恩学院的场地内收集了具有不同特征的 3 种土壤类型（即沙质、壤土和粘土），目的是比较土壤中土著细菌种群的出现情况及其各自的水解酶活性. 检查土壤的有机质含量 (% OM)，而细菌丰度由活菌计数和核酸染色的组合确定，和使用荧光素二乙酸酯 (FDA) 分析测量的酶活性。研究结果表明，与砂质和粘质土壤中记录的 2.5% 和 6.6% 相比，壤土的 OM 百分比显着更高，平均为 30%。相比之下，肥沃土壤中的细菌数量（活菌数和总计数）也明显高于其他两种土壤。与其他两种土壤相比，在肥沃土壤中释放的荧光素更高的 FDA 分析观察到了相同的趋势。总体而言，在三种土壤类型之间和两个季节之间观察到 OM 百分比与细菌数量和水解酶活性之间的关系存在明显差异。结果表明，% OM 强烈影响壤土中的细菌丰度和水解酶活性，而在研究中检查的沙质和粘质土壤中影响较小。该研究的结论揭示了土壤有机碳与本地细菌种群及其在各种土壤类型中的 FDA 活动之间潜在的密切关系。