Ingrid Groth

Agrococcus jenensis gen. nov., sp. nov., a new genus of actinomycetes with diaminobutyric acid in the cell wall

Two strains of a new gram-positive coryneform bacterium isolated from soil and from a sandstone surface are described. Strain 2002-39/1T (T = type strain) is a coccoid, nonmotile, non-acid-fast, microaerophilic organism. The menaquinones of this strain are MK-12 and MK-11, and the main components of the whole-cell sugars are glucose and rhamnose. No mycolic acids are present. The G+C content of the DNA is 74 mol%. Comparative 16S ribosomal DNA studies and a cell wall analysis revealed that this strain represents a new genus belonging to the group of actinomycetes that have diaminobutyric acid in their peptidoglycans. The second strain, strain ST54, which was isolated from a sandstone surface, had the same characteristic features as strain 2002-39/1T. The name Agrococcus jenensis gen. nov., sp. nov., is proposed for these organisms. The type strain is strain 2002-39/1, which has been deposited in the German Collection of Microorganisms and Cell Cultures as strain DSM 9580.

Demetria terragena gen. nov., sp. nov., a new genus of actinomycetes isolated from compost soil.

A novel actinomycete was isolated from compost soil and was studied taxonomically and phylogenetically. Cells of this organism were gram positive, not acid fast, nonmotile, nonsporulating, irregular coccoid to short rod shaped, and microaerophilic. The cell wall peptidoglycan contained lysine and was cross-linked via an L-Lys<--L-Ser<--D-Asp interpeptide bridge. The major menaquinone was MK-8(H4). The polar lipids were phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, and two unknown phospholipids. Mycolic acids were absent. The cellular fatty acid profile was complex, with large amounts of saturated and monounsaturated straight-chain acids and smaller amounts of iso and anteiso branched-chain acids. The G+C content of the DNA was 66 mol%. Comparative 16S ribosomal DNA studies revealed that strain HKI 0089T represents a novel lineage within Actinobacteria (32) distinct from all previously described genera and most closely related to members of the genera Kytococcus, Dermacoccus, and Dermatophilus of the family Dermatophilaceae. On the basis of our results, we suggest that strain HKI 0089 should be classified in a new genus and species, for which we propose the name Demetria terragena. The type strain and the only strain of the genus and species is HKI 0089 (DSM 11295).

Janibacter limosus gen. nov., sp. nov., a new actinomycete with meso-diaminopimelic acid in the cell wall

New gram-positive bacteria were isolated from 1-year-old sludge from a wastewater treatment plant. The isolates are coccoid to rod-shaped, nonmotile aerobes that form neither spores nor mycelia. They are characterized by a peptidoglycan with directly cross-linked meso-diaminopimelic acid (type A1 gamma), by the presence of menaquinone MK-8(H4), and by the lack of mycolic acids. The strains have complex fatty acid patterns with i-C16:0 and straight-chain saturated and unsaturated fatty acids as major components. The G + C content of the DNA is 70 mol%. The results of chemotaxonomic studies and a 16S ribosomal DNA sequence comparison support our proposal to assign these bacteria to a new genus, the genus Janibacter gen. nov.; the type species is Janibacter limosus sp. nov., and the type strain of J. limosus is strain HKI 83 (= DSM 11140).

Bogoriella caseilytica gen. nov., sp. nov., a new alkaliphilic actinomycete from a soda lake in Africa

A new gram-positive, alkaliphilic, nonsporulating, rod-shaped bacterium is described. The organism was isolated from soda soil (Lake Bogoria, Kenya) and has the following characteristics. It is nonmotile, not acid fast, halotolerant, and microaerophilic, and optimal growth occurs at pH values between 9 and 10. The peptidoglycan type is of type A4 alpha, with lysine as the characteristic diamino acid and glutamic acid as a component of the interpeptide bridge. The major menaquinone is MK-8(H4). The polar lipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, and an unknown phospholipid. 12-Methyltetradecanoic acid is the predominant fatty acid. The G + C content of the DNA is 70 mol%. The results of 16S ribosomal DNA sequence comparisons revealed that strain HKI 0088T represents a new lineage in the order Actinomycetales. Therefore, we concluded that strain HKI 0088T should be assigned to a new genus and species, for which we propose the name Bogoriella caseilytica gen. nov., sp. nov. The type strain and only strain of this genus and species is HKI 0088 (= DSM 11294).

Knoellia sinensis gen. nov., sp. nov. and Knoellia subterranea sp. nov., two novel actinobacteria isolated from a cave

Two novel strains of the class Actinobacteria were isolated from a cave in China. Cells of both strains were gram-positive, non-motile, non-spore-forming and not acid-fast and exhibited a rod/coccus growth cycle. Both isolates grew well on complex organic media under aerobic conditions. Their cell wall peptidoglycan contained meso-diaminopimelic acid as diagnostic diamino acid. The acyl type of the glycan chain of peptidoglycan was acetyl. The major respiratory quinone was MK-8(H4). The cellular fatty acid profile was characterized by the predominance of 13-methyltetradecanoic (i-C15:0), 15-methylhexadecanoic (i-C17:0), 14-methylpentadecanoic (i-C16:0) and 14-methylhexadecanoic (ai-C17:0) acids. The major polar lipids were phosphatidylethanolamine, phosphatidylinositol and diphosphatidylglycerol. Mycolic acids were absent. The DNA G+C composition was 68-69 mol%. 16S rDNA-based phylogenetic analysis revealed an intermediate phylogenetic position of the cave isolates between the genera Janibacter and Tetrasphaera, which did not permit their unambiguous affiliation to either genus. Differences in morphological, physiological and chemotaxonomic properties between the two isolates and their closest phylogenetic neighbours support the proposal of a new genus and two novel species, Knoellia sinensis gen. nov., sp. nov. and Knoellia subterranea sp. nov. The type and only strains of the species are respectively HKI 0119T (= DSM 12331T = CIP 106775T) and HKI 0120T (= DSM 12332T = CIP 106776T).

Ornithinicoccus hortensis gen. nov., sp. nov., a soil actinomycete which contains L-ornithine

Two Gram-positive coccoid, non-motile bacteria with L-ornithine as diagnostic diamino acid of the peptidoglycan and an interpeptide bridge of L-Orn<--Gly(1,2)<--D-Glu were isolated from a sample of garden soil. The major menaquinone is MK-8(H4). 13-methyl and 12-methyl tetradecanoic acids are the predominant fatty acids. The polar lipids are phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine and two unknown phospholipids. Mycolic acids are absent. The DNA base composition is 72 mol% G + C. Recent comparative 16S rDNA studies revealed that strains HKI 0125T and HKI 0131 represent a novel lineage adjacent to the family Intrasporangiaceae of the order Actinomycetales but distinct from the previously described genera of this family. On the basis of the genotypic, chemotaxonomic, morphological and physiological characteristics of these two isolates it is proposed to classify HKI 0125T and HKI 0131 in a new genus and species for which the name Ornithinicoccus hortensis gen. nov., sp. nov. is proposed. The type strain is HKI 0125T (= DSM 12335T).

New and bioactive compounds from Streptomyces strains residing in the wood of Celastraceae

Abstract. Wood from three different plants of the Celastraceae growing in their natural habitats in Brazil (Maytenus aquifolia Mart.) and South Africa [Putterlickia retrospinosa van Wyk and Mostert, P. verrucosa (E. Meyer ex Sonder) Szyszyl.] was established as a source of endophytic bacteria using a medium selective for actinomycetes. Two isolates were identified as Streptomyces setonii and S. sampsonii whereas two others were not assignable to any of the known Streptomyces species. They were preliminarily named Streptomyces Q21 and Streptomyces MaB-QuH-8. The latter strain produces a new chloropyrrol and chlorinated anthracyclinone. The chloropyrrol showed high activity against a series of multiresistent bacteria and mycobacteria.

Beutenbergia cavernae gen. nov., sp. nov., an L-lysine-containing actinomycete isolated from a cave.

Two aerobic, Gram-positive bacteria, strains HKI 0122T and HKI 0132, were isolated from a cave. Cells are not acid-fast, non-motile, non-spore-forming and exhibit a rod-coccus growth cycle. The cell wall peptidoglycan contains lysine in position 3 of the peptide subunit and an interpeptide bridge of L-Lys<--L-Glu. The major menaquinone is MK-8(H4), 13-methyl and 12-methyl tetradecanoic acids are the predominating fatty acids. The polar lipids consist of phosphatidylinositol, diphosphatidylglycerol and three unknown phospholipids. Mycolic acids are absent. The DNA base composition is 71 mol% G + C. Phylogenetic analysis revealed that strain HKI 0122T forms a novel taxon among the families and unassigned genera of the suborder Micrococcineae, within the order Actinomycetales. On the basis of the genotypic, chemotaxonomic, morphological and physiological characteristics of these two isolates it is proposed to assign strains HKI 0122T and HKI 0132 to a new genus and species for which the name Beutenbergia cavernae gen. nov., sp. nov. is proposed. The type strain is HKI 0122T (= DSM 12333T).

Ornithinimicrobium humiphilum gen. nov., sp. nov., a novel soil actinomycete with L-ornithine in the peptidoglycan

A Gram-positive bacterium originating from garden soil was taxonomically studied. Cells are non-motile, non-sporulating, irregular rods and cocci. The cell wall peptidoglycan contains L-ornithine as diagnostic diamino acid and an interpeptide bridge consisting of L-Orn<--L-Ala<--Gly<--D-Asp. The major menaquinone is MK-8(H4). 13-Methyl tetradecanoic acid and 14-methyl pentadecanoic acid are the predominant fatty acids. The polar lipids are phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, three unknown glycolipids and three unknown phospholipids. Mycolic acids are absent. The DNA G+C composition is 70 mol%. The acyl type of the glycan chain of peptidoglycan is acetyl. Glucose is the dominating whole cell sugar; arabinose, rhamnose and xylose are present in traces. Results of 16S rDNA sequence comparisons revealed that strain HKI 0124T represents a novel lineage within the suborder Micrococcineae of the order Actinomycetales adjacent to the recently described genus Ornithinicoccus. On the basis of the clearly pronounced morphological, physiological, chemotaxonomic and phylogenetic differences between strain HKI 0124T and all members of the suborder Micrococcineae, it is proposed to assign strain HKI 0124T to a new genus and species, Ornithinimicrobium humiphilum gen. nov., sp. nov. The type and only strain is HKI 0124T (= DSM 12362T = CIP 106634T).

Arousing sleeping genes: shifts in secondary metabolism of metal tolerant actinobacteria under conditions of heavy metal stress

Numerous microbial habitats are strongly influenced by elevated levels of heavy metals. This type of habitat has developed either due to ore mining and metal processing or by pedogenesis above metal-rich base rocks. Most actinobacteria are soil-borne microbes with a remarkable capability for the synthesis of a broad variety of biologically active secondary metabolites. One major obstacle in identifying secondary metabolites, however, is the known phenomenon of sleeping gene clusters which are present, but silent under standard screening conditions. Here, we proceed to show that sleeping gene clusters can be awakened by the induction in heavy metal stress. Both, a chemical and a biological screening with extracts of supernatant and biomass of 10 strains derived from metal contaminated and non-contaminated environments was carried out to assay the influence of heavy metals on secondary metabolite patterns of metal tolerant actinobacteria. Metabolite patterns of cultures grown in complex and minimal media were compared to nickel (or cadmium) spiked parallels. Extracts of some strains grown in the presence of a metal salt displayed intense antibiosis against Escherichia coli, Mycobacterium smegmatis, Staphylococcus aureus and Candida albicans. Contrarily to the widely held opinion of metals as hindrance in secondary metabolism, metals thus can induce or enhance synthesis of possibly potent and medically relevant metabolites in metal tolerant strains. Hence, re-screening of existing strain libraries as well as identification of new strains from contaminated areas are valid strategies for the detection of new antibiotics in the future.