Fluorescent reporter proteins have revolutionized gene expression analysis, but their use is limited to more-or-less transparent systems, such as single cells or zebrafish larvae. For researchers studying organisms that live in soil, using these visual reporters is infeasible in any but the thinnest of samples, says environmental and synthetic biologist Jonathan Silberg of Rice University.
“We can analyze cultured microbes in exquisite detail,” adds biogeochemist Caroline Masiello, also at Rice. “But the question is—does it matter at the scale of an ecosystem?” Silberg, Masiello, and colleagues have devised a new gas reporter system that can be used to detect the presence and activity of microbes in opaque samples of any size.
Ecologists often use headspace gas analysis to measure common bacterially produced gases, such as carbon dioxide and methane, without disrupting the soil or sediment sample. If bacteria could be genetically engineered to produce unusual gases, the team reasoned, they ...
