Fig. 2From: Diversity of alkane hydroxylase genes on the rhizoplane of grasses planted in petroleum-contaminated soilsRarefaction curves of retrieved a alkB genes at 856 days (C. dactylon and Z. japonica) or 891 days (unplanted soils, Z. matrella and dr-Z. japonica) and b CYP153 genes at 494 days from four rhizoplane samples and unplanted contaminated soil samples. The y axis shows the number of OTUs grouped at 85 % (alkB) and 93 % (CYP153) similarityBack to article page