Citricoccus muralis gen. nov., sp. nov., a novel actinobacterium isolated from a medieval wall painting.

Abstract

A Gram-positive, aerobic, spherical actinobacterium, designated strain 4-0(T), was isolated from a medieval wall painting and characterized to determine its taxonomic position. The peptidoglycan of strain 4-0(T) was of type A4alpha, with lysine as the diagnostic cell wall diamino acid and an interpeptide bridge of Lys-Gly-Glu. Its quinone system contained predominantly MK-9(H2) (64%) and its polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, four unknown glycolipids, two unknown phospholipids and an unknown lipid. The fatty acid profile of strain 4-0(T) was represented by significant amounts of ai-C15:0 and moderate amounts of ai-C17:0, i-C16:0 and i-C15:0 fatty acids. Spermidine was predominant in the polyamine pattern. The G+C content of the genomic DNA was 68 mol%. Comparative 16S rDNA sequence studies revealed the highest similarity values (95.4-96.1%) between strain 4-0(T) and species of the genus Micrococcus and certain species of the genus Arthrobacter, including Arthrobacter pascens DSM 20545(T), Arthrobacter ramosus DSM 20546(T), Arthrobacterprotophormiae DSM 20168(T), Arthrobacternicotianae DSM 20123(T) and Arthrobacter globiformis DSM 20124(T). Phylogenetic analyses demonstrated that strain 4-0(T) branches deeply on the Micrococcus lineage. Because it is almost equidistant phylogenetically from the genera Micrococcus and Arthrobacter and possesses significant differences in chemotaxonomic characteristics from members of these genera, it is suggested that strain 4-0(T) be classified as a novel species in a new genus; the name Citricoccus muralis gen. nov., sp. nov. is proposed. The type strain is strain 4-0(T) (= DSM 11442(T) CCM 4981(T)).

Description of Citricoccus nitrophenolicus sp. nov., a para-nitrophenol degrading actinobacterium isolated from a wastewater treatment plant and emended description of the genus Citricoccus Altenburger et al. 2002

“…Menaquinone MK-9(H 2 ) was also found as the main respiratory quinone in the three other validly described Citricoccus species (Table 2). However in the original publication of Altenburger et al (2002a), major menaquinones in C. muralis were reported to be MK-9 (H 2 ) (64%) and MK-7(H 2 ) (24%)-the latter of which was not detected in the present study possibly as a result of difference in growth conditions.…”

“…Based on the additional chemotaxonomic data provided in the present study, the formal description given by Altenburger et al (2002a) remains correct except that either MK-9 or MK-8 may be the predominant menaquinones.…”

“…Subsequent phylogenetic analysis showed that strain PNP1 T forms a clade with the four validly described members of this genus, C. muralis DSM 14442 T (Altenburger et al 2002a), C. alkalitolerans DSM 15665 T , C. parietis CCUG 57388 T (Schäfer et al 2010) and C. zhacaiensis JCM 15136 T (Meng et al 2010) (Fig. 2).…”

“…In the original description of the genus (Altenburger et al 2002a) it was stated: ''The quinone system contains MK-9(H 2 ) as the predominant menaquinone and moderate amounts of MK-7(H 2 ) and MK-8 (H 2 ).'' Based on the additional chemotaxonomic data provided in the present study, the formal description given by Altenburger et al (2002a) remains correct except that either MK-9 or MK-8 may be the predominant menaquinones.…”

“…The strain was enriched and isolated on the basis of its ability to tolerate and grow on pNP. Currently, the genus Citricoccus, belonging to the family Micrococcineae within the class Actinobacteria, contains four validly described species: C. muralis, C. alkalitolerans, C. parietis and C. zhacaiensis which were isolated from a medieval wall painting, a desert soil in Egypt, a mould infected wall and a wastewater bioreactor, respectively (Altenburger et al 2002a;Li et al 2005;Schäfer et al 2010;Meng et al 2010).…”