ABSTRACT
In macro-ecological communities, the communities of bacteria and archaea in soil are almost invariably composed of a range of diverse types with different ecophysiological characteristics. The bacteria isolated from soil by culturing so far have been shown to collectively possess an immense diverse metabolic capacity. The traditional cultivation-based studies using dilution plating on standard agar media or cultivation/enrichment in liquid media have taught that a wide range of different bacteria, belonging to several different bacterial phyla, inhabit soil. Gene expression mechanisms in Archaea are often more related to those of eukaryotes than to those in the Bacteria. Based on the bacterial numbers and diversities in soil, soil appears to provide considerable hospitable niche space for a range of bacteria and archaea, despite the apparent limitations to their growth. One consequence of the nutrient starvation that bacteria and most likely archaea experience in soils is a reduction in their cell size.
