Comparative analysis of DNA extraction methods to study the body surface microbiota of insects: a case study with ant cuticular bacteria

High-throughput sequencing of the 16S rRNA gene has considerably helped revealing the essential role of bacteria living on insect cuticles in the ecophysiology and behavior of their hosts. However, our understanding of host-cuticular microbiota feedbacks remains hampered by the difficulties to working with low bacterial DNA quantities as in individual insect cuticle samples, which are more prone to molecular biases and contaminations. Herein, we conducted a methodological benchmark on the cuticular bacterial loads retrieved from two Neotropical ant species of different body size and ecology: Atta cephalotes (~15 mm) and Pseudomyrmex penetrator (~5 mm). We evaluated the richness and composition of the cuticular microbiota, as well as the amount of biases and contamination produced by four DNA extraction protocols. We also addressed how bacterial communities’ characteristics would be affected by the number of individuals or individual body size used for DNA extraction. Most extraction met...