Areal contrasts in the abundance of hydrocarbon oxidizing microbes in soils.

An abundance of hydrocarbon oxidizing microbes is found, not unexpectedly, in areas where extraordinary quantities of hydrocarbons exist in the biosphere. In particular, bacteria of the genus Mycobacterium develop in areas of oil and gas production and in areas of petroliferous gas seeps. One of these species, Mycobacterium paraffinicum n. sp., shows a high degree of specificity for petroleum hydrocarbons, as reported by Davis et al. (1956). Mlethods for demonstrating hydrocarbon oxidizing microbes in the soil strongly influence observed results. This paper describes some of the experimental field work performed by the Field Research Laboratory of the Magnolia Petroleum Company. Widely separated areas and a variety of soils were studied. Ethane and methane were employed for cultivating the hydrocarbon oxidizers in the laboratory. The objectives of this study were threefold: (a) to test various methods for detectinig hydrocarbon oxidizing microbes in the soil; (b) to determin-e the relative abundance of ethane oxidizers that exist in areas of petroliferous gas emanationi, particularly with respect to the magnitude of areal contrasts; anid (c) to observe the effect of seasonal soil moisture on the hydrocarbon oxidizing microflora.