A new method for assessing soil microorganism diversity and evidence of vitamin deficiency in low diversity communities

Summary

A proposed new method for assessing the diversity of a soil microbial community is based on the species-typical ester-linked phospholipid fatty 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 fatty-acid diversity in nine soils from Central Switzerland was calculated using Shannon's formula. By means of a respiration test, it was further established that the low-diversity soils responded significantly and positively (respiration increase) to small additions of a vitamin mixture containing thiamin, pyridoxin, calpan, folic acid, and biotin. The results indicate a connection between microbial diversity and a yet unspecified vitamin deficiency within the population. Whether the vitamin deficiency is the cause or the effect of the reduced diversity remains to be established.