Gordona hydrophobica sp. nov., Isolated from Biofilters for Waste Gas Treatment

Abstract

The taxonomic position of Gordona sp. strain DSM 44015T, isolated from the packing material of a biofilter used for biological odor abatement of animal rendering emissions, has been clarified by a polyphasic study comprising chemotaxonomic, sequencing, and phenotypic results. The strain possesses a wall chemotype IV, MK-9 (H2), as the predominant menaquinone; relatively long-chain mycolic acids (54 to 62 carbon atoms); and straight-chain, saturated, and monounsaturated fatty acids with considerable amounts of tuberculostearic acid. The polar lipids include phosphatidylethanolamine, and the G+C content of the DNA is 69 mol%. Similarity values for genes encoding 16s rRNA indicate that Gordopla sp. strain DSM 44015T represents a new species within the genus Gordopla for which the name Gordona hydrophobica is proposed.Actinomycetes containing mycolic acids have many common cell wall characteristics and form a suprageneric group (24,(32)(33)(34) comprising the genera Corynebacterium, Rhodococcus, Gordona, Nocardia, Mycobacteriurn, Tsukarnurella, and Dietzia (28). Numerical taxonomic, chemical, and molecular systematic methods (8, 9) have been used to differentiate among the taxa.Up to date, six species of the genus Gordona (33, 35) are known: Gordona bronchialis, Gordona rubropertincta, Gordona terrae (39, Gordona sputi (36,38), Gordona aichiensis (18,37), and Gordona amarue (18,21). The taxonomic history of the genus Gordona is confusing because of renamings of original isolates (36) and recent transfers of strains from the genus Rhodococcus or Nocardia to the genus Gordona (18). Polyphasic taxonomic studies, including chemotaxonomic, phylogenetic, and phenotypic properties, clearly separated the species of the genus Gordona from those of other actinomycete genera Until now, Gordona species have been regarded primarily as opportunistic pathogens isolated from sputum of humans (G. bronchialis, G. aichiensis, and G. sputi) suffering from pulmonary lesions (35)(36)(37). Compared with the number of isolates from sputum, few Gordona strains have been isolated from terrestrial or aquatic habitats where mycolic acid-containing actinomycetes are generally known to be widely distributed (9). Only two Gordona species, G. terrae and G. rubropertincta, derive from soil (35,36). Another strain that has recently been affiliated with the taxon Gordona, G. amarae (18), had been isolated from foam formed on the surface of aeration tanks in activated sludge-sewage-treatment plants (21). Gordona strains have also been isolated from the packing material (tree bark compost) of biofilters used for the treatment of malodorous animal rendering emissions (1,2). These strains were able to use readily volatile, poorly water-soluble carbonyl compounds such as aldehydes and ketones contained in the waste gases, thus suggesting a contribution of these bacteria to the deodorization of the off-gases (1). Furthermore, these strains were found to possess extremely hydrophobic cell surfaces, P9. which has been related to the presence of unshielde...

A New Glycosylated Lipopeptide Incorporated into the Cell Wall of a Smooth Variant of Gordona hydrophobica

“…One of them belonged to a saturated 3-OH fatty acid since its basal peak at m/z 103 originated from [CH(OH)CH 2 COOCH 3 ] ϩ . The other one was an unsaturated 3-OH fatty acid with a significant peak at m/z 103 and a basal peak at m/z 55 due to [H 3 C(CH) 2 CH 2 ] ϩ . The parental peaks of the methyl esters were difficult to detect by this ionization method and were only observed for the unsaturated fatty acid, but their molecular weight could be obtained from the peaks at m/z ϭ M-50, which are of significant height in the case of 3-OH fatty acids (17).…”

“…For structural analysis we used the glycolipid of the strain 1775/15s, which was confirmed to be G. hydrophobica by DNA-DNA hybridization with G. hydrophobica DSM 44015 T and that was the object of further physiological investigations. 2 …”

“…The isolation and classification of G. hydrophobica DSM 44015 T has been published previously (1,2). A detailed description of chemotaxonomical and physiological markers of G. hydrophobica DSM 44015 T r (ϭ1610/1b), G. hydrophobica DSM 44015 T s (ϭ1610/1a), G. hydrophobica 1775/15r and G. hydrophobica 1775/15s has been published (1) (s ϭ smooth variants, r ϭ rough variants).…”

“…As judged by GLC/MS analysis it was difficult to decide whether valine is ester-or amide-linked to the 20:0 (3-OH), since both derivatives exhibit identical molecular weights. To solve this problem, the peracetylated derivatives [(R)-3-hydroxy-tetradecanamido]-Dvaline methyl ester (2) (3) have been synthesized whereby the (R)-3-hydroxymyristic acid (14:0 (3-OH)) was used instead of 3-hydroxyeicosanoic acid (20:0 (3-OH)), since it was the only (R)-configurated 3-hydroxylated fatty acid available.…”

“…On the basis of chemotaxonomic differentiation they were able to identify strains of the genus Corynebacterium, Gordona, Mycobacterium, and Arthrobacter. Some biofilter isolates of Gordona hydrophobica (2) showed colony morphologies, which gave rise to different physicochemical properties of their cell surface. The rough variants possess an extremely hydrophobic cell surface due to a hydrophobic mycolic acid layer.…”