Department of Biological Science, Florida State University, 32306-2043, Tallahassee, Florida, USA.
Microb Ecol. 1988 Jul;16(1):49-64. doi: 10.1007/BF02097404.
Surface-soil and subsurface microfloras at the site of a shallow aquifer in Oklahoma were examined and compared with respect to (1) total and viable cell numbers, (2) colony and cell types that grew on various plating media, (3) cell morphologies seen in flotation films stripped from sample particles, and (4) cellular ultrastructure. Appreciable numbers of microbial cells were present in the subsurface (total counts: 10(6)-10(7) cellsg(-1); viable counts up to 10(6) cells · g(-1)), but the subsurface microflora was considerably less populous than that of the surface soil (total counts: 10(9) cells·g(-1); viable counts: 10(7)-10(8) cells · g(-1)). The subsurface microflora (especially that of the saturated zone) also appeared to be much less diverse, containing fewer microbial types that would grow on enumeration plates (on nutrient-rich media, 3-4 colony types versus 19-22 for the surface soil) and fewer cell types that could be distinguished by direct microscopy (3-4 types versus 17 for the surface soil). The specific types of microorganisms that were numerically predominant in the aquifer sediments were entirely different from those that were predominant in the surface soil. Moreover, the predominant types varied from one depth to another within the saturated zone. The potential metabolic capability of the subsurface microflora, as indicated by its readiness to grow rapidly on nutrient-rich media, also varied with depth.
俄克拉荷马州浅层含水层现场的表土和地下微生物群进行了检查，并就以下方面进行了比较：(1)总细胞数和活菌数；(2)在各种平板培养基上生长的菌落和细胞类型；(3)从样品颗粒中剥离的浮选膜中观察到的细胞形态；(4)细胞超微结构。地下存在大量微生物细胞（总计数：10(6)-10(7) cellsg(-1)；活菌计数高达 10(6) cells · g(-1)），但地下微生物群的数量明显少于表土（总计数：10(9) cells·g(-1)；活菌计数：10(7)-10(8) cells · g(-1)）。地下微生物群（特别是饱和带）似乎也不那么多样化，在计数平板上生长的微生物类型较少（在营养丰富的培养基上有 3-4 种菌落类型，而表土有 19-22 种），通过直接显微镜观察可以区分的细胞类型也较少（3-4 种类型，而表土有 17 种）。在含水层沉积物中数量上占优势的微生物特定类型与在表土中占优势的微生物类型完全不同。此外，在饱和带内，从一个深度到另一个深度，主要类型也发生了变化。地下微生物群的潜在代谢能力，如其在营养丰富的培养基上快速生长的能力，也随深度而变化。
