Stable isotope probing with 18O-water to investigate microbial growth and death in environmental samples.

ABSTRACT

Growth and mortality of microorganisms have been characterized through DNA stable isotope probing (SIP) with 18O-water in soils from a range of ecosystems. Conventional SIP has been improved by sequencing a marker gene in all fractions retrieved from an ultracentrifuge tube to produce taxon density curves, which allow estimating the atom percent isotope composition of each microbial taxon's genome. Very recent advances in SIP with 18O-water include expansion of the technique to aquatic samples, investigations of microbial turnover in soil, and the first use of 18O-water in RNA-SIP studies.