Cofactor F tail length distribution in different environmental samples.

Cofactor F is an electron carrier playing a crucial role in a variety of microorganisms during redox reactions of the primary and secondary metabolism due to its low redox potential and thus arouses increasing interest. In this study, cofactor F glutamyl tail length spectra in various habitats like manure, compost, soil, and digester sludge samples and their respective microbial communities were investigated using high performance liquid chromatography and an amplicon sequencing approach A previous study was used to identify F producing microorganisms. The highest concentration of cofactor F could be achieved in the horse manure, digester sludge, and mixed manure samples, which was approximately 100-fold higher than in all the other samples. The high content of the cofactor in the samples with high O availability pointed to the important role of the cofactor not only in redox reactions of anaerobic but also for aerobic microorganisms and indicated its ubiquitous character. The most abundant derivate was F-3 comprising the largest part of the cofactor derivates in seven out of ten samples. The high abundance of F-3 in samples with distinct properties (e.g. O and HO availability) showed its important role in redox reactions of the primary and secondary metabolism among prokaryotes.