Thermomonas haemolytica gen. nov., sp. nov., a c-proteobacterium from kaolin slurry

Four aerobic, Gram-negative bacterial strains isolated from kaolin slurry used
in the production of paper were subjected to a polyphasic analysis and
characterization to determine their taxonomic position. Analysis of the 16S
rDNA sequences of the four strains revealed that they represent a new lineage
within the c-Proteobacteria, related to the genera Xanthomonas,
Pseudoxanthomonas, Stenotrophomonas, Luteimonas, Xylella and
Rhodanobacter. Analysis of the quinone system, the polyamines, the fatty
acids and the polar lipids revealed a combination of characteristics that is
unique and not described for the phylogenetic relatives. The four strains
contain a ubiquinone Q-8, spermidine as the major polyamine,
diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine
as the predominant polar lipids, and a fatty acid profile with predominantly
iso-branched fatty acids. The GMC content of the genomic DNA was determined
to be within the narrow range 67<1–68<7 mol%. Determination of DNA
relatedness, as well as riboprint band patterns and amplified fragment length
polymorphism profiles, clearly demonstrated that the four strains are
members of a single species. Antibiotic-susceptibility patterns were identical
for the four strains. Although showing a high degree of similarites in
physiological and biochemical patterns, each of the four strains could be
distinguished from the others on the basis of a few biochemical characteristics.
On the basis of the estimates of phylogenetic relationships derived from the
16S rDNA sequence analyses, the observed chemotaxonomic characteristics
and other phenotypic traits, a new genus, Thermomonas gen. nov., and species,
Thermomonas haemolytica sp. nov., are proposed for the strains A50-7-3T
(¯DSM 13605T¯LMG 19653T), B 50-7-1 (¯DSM 13598¯LMG 19655),
D50-7-1 (¯DSM 13610¯LMG 19656) and B50-8-1 (¯DSM 13599¯LMG 19654),
with strain A50-7-3T as the type strain.