Stable Isotope Probing the N Cycle: Current Applications and Future Directions
from: Metagenomics of the Microbial Nitrogen Cycle: Theory, Methods and Applications (Edited by: Diana Marco). Caister Academic Press, U.K. (2014)
Much of our understanding of microbial ecophysiology with respect to nitrogen cycling has been derived from cultivation based techniques, which are unable to capture a large proportion of microbial diversity in the environment. 15N DNA stable isotope probing (SIP) is a technology that allows experimental assessment of nitrogen uptake in systems where requisite organisms cannot be cultivated, by combining evidence for isotopic uptake with phylogenetic inferences via sequence based analysis. The technique has recently been applied in a variety of systems including enrichment cultures, soils, and marine environments. This chapter summarizes some historical perspective on 15N SIP methodology and reviews the available 15N SIP literature. Advantages and disadvantages of 15N SIP are discussed. Much of the potential of 15N SIP remains unrealized due to important experimental limitation. Recent technological developments that are likely to result in significant improvements in resolution and utility of stable isotope tracer techniques are also described read more ...