Detalle de: Validation of a new catalysed reporter deposition–fluorescence in situ hybridization probe for the accurate quantification of marine B acteroidetes populations

Summary Catalysed reporter deposition–fluorescence in situ hybridization ( CARD‐FISH ) is a powerful approach to quantify bacterial taxa. I n this study, we compare the performance of the widely used B acteroidetes CF 319 a probe with the new CF 968 probe. In silico analyses and tests with isolates demonstrate that CF 319 a hybridizes with non‐ B acteroidetes sequences from the R hodobacteraceae and A lteromonadaceae families. We test the probes’ accuracy in 37 globally distributed marine samples and over two consecutive years at the B lanes B ay M icrobial O bservatory ( NW M editerranean). We also compared the CARD‐FISH data with the B acteroidetes 16 S rRNA gene sequences retrieved from 27 marine metagenomes from the TARA Oceans expedition. We find no significant differences in abundances between both approaches, although CF 319 a targeted some unspecific sequences and both probes displayed different abundances of specific B acteroidetes phylotypes. Our results demonstrate that quantitative estimations by using both probes are significantly different in certain oceanographic regions ( M editerranean Sea, R ed Sea and A rabian Sea) and that CF 968 shows seasonality within marine B acteroidetes , notably large differences between summer and winter that is overlooked by CF 319 a . We propose CF 968 as an alternative to CF 319 a for targeting the whole B acteroidetes phylum since it has better coverage, greater specificity and overall better quantifies marine B acteroidetes .