Linking alpha-diversity estimates between community fingerprinting and high-throughput 16S rRNA gene amplicon sequencing

Question: Microbial diversity screening by means of high throughput 16S rRNA gene sequencing has become a gold standard procedure for examining changes in community composition and structure. However, a large amount of data on α-and β-diversity has been produced through community fingerprinting methods or 16S clone libraries. Recent studies have shown that β-diversity measured by community fingerprinting is comparable to the estimates through high-throughput 16S rRNA gene sequencing. However, no link is established between the α-diversity estimates of the two methodological categories yet. Methods: Here, we analyze a large set of data generated by high-throughput 16S rRNA gene sequencing from a variety of habitats, for which community fingerprinting, i.e. denaturant gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (T-RFLP) and clone library profiles are also available. We have used publicly available as well as experimentally- and in-silico-generated data accounting for more than 20 different habitats. Results: We observed a significant, positive correlation between richness estimates deduced from community fingerprinting methods and evenness estimates from high throughput 16S rRNA gene sequencing. Conclusions: Our results suggest that these two components of α-diversity are directly comparable. That enables the use of evenness estimates from a vast number of past studies for comparison to upcoming studies, as well as the use of community fingerprinting for accurate estimations of evenness. Our results also highlight the need for re-assessment of past studies that were based on richness estimates of low-resolution community fingerpinting methods