The study of communities of microbes (microbiomes) in a variety of environments, including the human body, has deep roots in disciplines like microbial ecology and environmental engineering, but the generalized realization that microbiomes play roles of relevance to our natural and built environment, has emerged only during the last decade as one of the scientific grand challenges of our century. To help create and advance this discipline of Microbiomics, many have argued, developing novel techniques, often falling under the “omics” rubric has been necessary. Yet, after application of these techniques one is often left with under-examined large datasets, trivial conclusions, or merely correlative forms of evidence. An integrated, systems understanding of microbiomes, one that establishes general functional principles that are both explanatory and predictive (and hence applicable and translatable) of the behavior of communities of microorganisms remains a disciplinary aspiration. Part of the path forward relies clearly in technical and bioinformatic advances, but we argue, on the basis of our own work with biological soil crusts microbiomes, that a faster pace can be achieved by the use of concurrent multiple “omics” approaches in combination with traditional cultivation based microbial ecology approaches. A strategy we call combinomics.
Results/Conclusions
In areas where plant cover is restricted and plant litter scarce, light reaches unimpeded the soil surface, creating a habitat for microbial phototrophs. These in turn support plant-independent complex soil communities known as biological soil crusts because of the physical effect they have on soil surface consolidation. It is now known that they account for a sizeable fraction of the global microbial primary producer biomass, and that they are globally relevant contributors to the nitrogen cycle. At the local scale, they become important ecosystem components, particularly in arid lands, as agents of C and N fertility, as well as in erosion control.
Biological soil crusts constitute optimal organo-sedimentary soil systems to apply a variety of high throughput “omic” approaches to understand their function and environmental role, such as (meta)genomics, (meta)trasncriptomics or (exo)metabolomics. I will review the use of combinomics in our lab to understand the biogeography, carbon and nitrogen cycling of biological soil crusts in North American arid lands, and will also introduce how the information obtained is robust enough to be translatable and applicable to large-scale efforts in aridland soil restoration.