A NEW METHOD FOR ASSESSING SOIL MICROORGANISM DIVERSITY AND EVIDENCE OF VITAMIN DEFICIENCY IN LOW DIVERSITY COMMUNITIES

A proposed new method for assessing the diversity of a soil microbial community is based on the species-typical ester-linked phospholipid fa tty acids in the membranes of living cells. Soils that support only a few dominant species (bacteria, fungi, protozoa or algae) are expected to show few dominant fatty acids and vice versa. The phospholipid fat ty-acid diversity in nine soils from Central Switzerland was calculate d using Shannon's formula. By means of a respiration test, it was furt her established that the low-diversity soils responded significantly a nd positively (respiration increase) to small additions of a vitamin m ixture containing thiamin, pyridoxin, calpan, folic acid, and biotin. The results indicate a connection between microbial diversity and a ye t unspecified vitamin deficiency within the population. Whether the vi tamin deficiency is the cause or the effect of the reduced diversity r emains to be established.