Soil as a Habitat of Vitamin-requiring Bacteria

Abstract

MOST of the B vitamins have been shown to occur in arable soil, their presence being attributable to release from vitamin-containing plant and animal residues, liberation from the roots of growing plants and synthesis by micro-organisms. It is therefore not surprising that bacteria are present for which certain vitamins are essential for growth. It has been previously shown^1,2 that among the indigenous soil bacteria are forms requiring one or more preformed vitamins, while other reports^3,4 have pointed to the need of other types for certain specific factors, namely vitamin B₁₂ and the terregens factor. However, apart from a recent report⁵ on the incidence of bacteria requiring vitamin B₁₂ and the terregens factor in soil and in the rhizosphere of certain plants, no information is available concerning the abundance in soil of bacteria requiring specific vitamins for growth.