Phylotype diversity of forest and grassland soils as well as of the corresponding enrichments. Phylotype diversity of forest, grassland soils and enrichment cultures

The phylotype diversity of five topsoils (four forest soils, one grassland soil) sampled in the vicinity of Jena (Germany) was analyzed via Illumina MiSeq technology to gain knowledge on the distribution of methylotrophic bacteria in soils, focussing especially on genera known to utilize lignin-borne methoxylated aromatics as growth substrates. These analyses revealed that Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the main phyla in the initial soil samples, and that methylotrophs such as acetogens remained largely absent. Therefore, it was attempted to enrich these under represented organisms by using the O-demethylation of a methoxylated aromatic compound (syringate) as the growth-selective process in enrichment cultures. The experiments showed that organisms initially present in soil are outcompeted by Firmicutes upon addition of syringate as growth substrate. The main Firmicutes genera identified were acetogens such as Alkalibaculum, Clostridium, Sporobacterium and Tissierella.