Species Of Saccharothrix Research Articles

Diversity and Bioactivity of Endophytic Actinobacteria Associated with the Roots of Artemisia herba-alba Asso from Algeria.

The isolation of endophytic actinobacteria from the roots of wild populations of Artemisia herba-alba Asso, a medicinal plant collected from the arid lands of Algeria, is reported for the first time. Forty-five actinobacterial isolates were identified by molecular analysis and in vitro evaluated for antimicrobial activity and plant growth-promoting (PGP) abilities (1-Aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, nitrogen fixation, phosphate and potassium solubilization, ammonia, and siderophores production). The phylogenetic relationships based on 16S rRNA gene sequences show that the genus Nocardioides (n = 23) was dominant in the sampled localities. The remaining actinobacterial isolates were identified as Promicromonospora (n = 11), Streptomyces (n = 6), Micromonopora (n = 3), and Saccharothrix (n = 2). Only six (13.33%) strains (five Streptomyces and one Saccharothrix species) were antagonistic in vitro against at least one or more indicator microorganisms. The antimicrobial activity of actinobacterial strains targeted mainly Gram-positive bacteria. The results demonstrate that more than 73% of the isolated strains had ACC deaminase activity, could fix atmospheric nitrogen and were producers of ammonia and siderophores. However, only one (2.22%) strain named Saccharothrix sp. BT79 could solubilize phosphorus and potassium. Overall, many strains exhibited a broad spectrum of PGP abilities. Thus, A. herba-alba provides a source of endophytic actinobacteria that should be explored for their potential biological activities.

A novel protein elicitor (PeSy1) from Saccharothrix yanglingensis induces plant resistance and interacts with areceptor-like cytoplasmic kinase in Nicotiana benthamiana.

Previously, we reported a rare actinomycete Saccharothrix yanglingensis Hhs.015 with strong biocontrol ability, which can colonize plant tissues and induce resistance, but the key elicitor and immune mechanisms were unclear. In this study, a novel protein elicitor screened from the genome of Hhs.015, PeSy1 (protein elicitor of S.yanglingensis 1), could induce a strong hypersensitive response (HR) and resistance in plants. The PeSy1 geneencodes an 11 kDa protein with 109 amino acids that is conserved in Saccharothrix species. PeSy1-His recombinant protein induced early defence events such as acellular reactive oxygen species burst, callose deposition, and the activation of defence hormone signalling pathways, which enhanced Nicotiana benthamiana resistance to Sclerotinia sclerotiorum and Phytophthora capsici,and Solanum lycopersicum resistance to Pseudomonas syringae pv. tomato DC3000. Through pull-down and mass spectrometry, candidate proteinsthat interacted with PeSy1 were obtainedfrom N.benthamiana. We confirmed theinteraction between receptor-like cytoplasmic kinase RSy1 (Response to PeSy1) and PeSy1 using co-immunoprecipitation, bimolecular fluorescence complementation, and microscale thermophoresis. PeSy1 treatment promoted up-regulation of marker genes in pattern-triggered immunity. The cell death it elicited was dependent on the co-receptors NbBAK1 and NbSOBIR1, suggesting that PeSy1 acts as a microbe-associated molecular pattern from Hhs.015. Additionally, RSy1 positively regulated PeSy1-induced plants resistant to S.sclerotiorum. In conclusion, our results demonstrated a novel receptor-like cytoplasmic kinase in the plant perception of microbe-associated molecular patterns, and the potential of PeSy1 in induced resistance provided a new strategy for biological control of actinomycetes in agricultural diseases.

Saccharochelins A-H, Cytotoxic Amphiphilic Siderophores from the Rare Marine Actinomycete Saccharothrix sp. D09.

Siderophores are secreted by microorganisms to survive in iron-depleted conditions, and they also possess tremendous therapeutic potential. Genomic-inspired isolation facilitated the identification of eight amphiphilic siderophores, saccharochelins A-H (1-8), from a rare marine-derived Saccharothrix species. Saccharochelins feature a series of fatty acyl groups appended to the same tetrapeptide skeleton. With the help of gene disruption and heterologous expression, we identified the saccharochelin biosynthetic pathway. The diversity of saccharochelins originates from the flexible specificity of the starter condensation (CS) domain at the beginning of the nonribosomal peptide synthetase (NRPS) toward various fatty acyl substrates. Saccharochelins showed cytotoxicity against several human tumor cell lines, with IC50 values ranging from 2.3 to 17 μM. Additionally, the fatty acid side chains of the saccharochelins remarkably affected the cytotoxicity, suggesting changing the N-terminal acyl groups of lipopeptides may be a promising approach to produce more potent derivatives.

Saccharothrix isguenensis sp. nov., an actinobacterium isolated from desert soil.

A novel actinobacterial strain, designated MB27T, was isolated from a Saharan soil sample collected in Mzab region (Ghardaïa province, South Algeria). Strain MB27T was characterized following a polyphasic taxonomic approach. This strain produced a branched and fragmented substrate mycelium, which was found to have a yellowish orange colour. A white scanty aerial mycelium was produced on most media tested. Chemotaxonomic and phylogenetic studies clearly demonstrated that strain MB27T belongs to the family Pseudonocardiaceae and is closely related to the genus Saccharothrix. Cell-wall hydrolysates contained meso-diaminopimelic acid but not glycine, and whole-cell hydrolysates contained galactose, glucose, ribose and small amounts of mannose and rhamnose. The detected phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Mycolic acids were not detected while the predominant fatty acid was iso-branched hexadecanoate (iso-C16 : 0). The major menaquinone was MK-9(H4). Results of 16S rRNA gene sequence comparisons revealed that strain MB27T shairs the highest degree of similarity with Saccharothrix ecbatanensis DSM 45486T (99.8%), Saccharothrix hoggarensis DSM 45457T (99.3 %), Saccharothrix longispora DSM 43749T (98.6 %) and Saccharothrix yanglingensis DSM 45665T (98.6 %). However, it exhibited only 11-42 % DNA-DNA relatedness to the neighbouring Saccharothrixspecies. On the basis of phenotypic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridization, strain MB27T is shown to represent a novel species of the genus Saccharothrix, for which the name Saccharothrix isguenensis sp. nov. (type strain MB27T=DSM 46885T=CECT 9045T) is proposed.

Taxonomy and chemical characterization of new antibiotics produced by Saccharothrix SA198 isolated from a Saharan soil

Actinomycete strain SA198, isolated from a Saharan soil sample of Algeria, exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria, and phytopathogenic and toxinogenic fungi. The morphological and chemotaxonomic characteristics of the strain were consistent with those of the genus Saccharothrix. Analysis of the 16S rRNA gene sequence of strain SA198 showed a similarity level ranging between 97.2 and 98.8% within Saccharothrix species, S. australiensis being the most closely related. Two new active products were isolated by reverse HPLC using a C18 column. The ultraviolet–visible (UV–VIS), infrared (IR), mass, and 1H and 14C nuclear magnetic resonance (NMR) spectra showed that these products were new bioactive compounds. The minimum inhibitory concentrations of these antibiotics showed a strong activity against fungi and moderate activities against Gram-positive and Gram-negative bacteria.

Saccharothrix sp. PAL54, a new chloramphenicol-producing strain isolated from a Saharan soil

An actinomycete strain designated PAL54, producing an antibacterial substance, was isolated from a Saharan soil in Ghardaïa, Algeria. Morphological and chemical studies indicated that this strain belonged to the genus Saccharothrix. Analysis of the 16S rDNA sequence showed a similarity level ranging between 96.9 and 99.2% within Saccharothrix species, with S. longispora DSM 43749(T), the most closely related. DNA-DNA hybridization confirmed that strain PAL54 belonged to Saccharothrix longispora. It showed very strong activity against pathogenic Gram-positive and Gram-negative bacteria responsible for nosocomial infections and resistant to multiple antibiotics. Strain PAL54 secreted the antibiotic optimally during mid-stationary and decline phases of growth. One antibacterial compound was isolated from the culture broth and purified by HPLC. The active compound was elucidated by uv-visible and NMR spectroscopy and by mass spectrometry. The results showed that this compound was a D: (-)-threo chloramphenicol. This is the first report of chloramphenicol production by a Saccharothrix species.

Saccharothrix yanglingensis sp. nov., an antagonistic endophytic actinomycete isolated from cucumber plant

An endophytic actinomycete strain, designated Hhs.015(T), was isolated from roots of cucumber seedlings. The endophytic isolate was identified by means of a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence similarities, strain Hhs.015(T) was closely related to members of the genus Saccharothrix. DNA-DNA hybridization with the four closest relatives, Saccharothrix longispora NRRL B-16116(T), Saccharothrix xinjiangensis NRRL B-24321(T), Saccharothrix autraliensis CGMCC 4.1355(T) and Saccharothrix espanaensis CGMCC 4.1714(T), gave similarity values of 33.8, 28.2, 44.1 and 29.5%, respectively, which indicated that strain Hhs.015(T) represents a novel species of the genus Saccharothrix. This is consistent with the morphological, physiological and chemotaxonomic data. As a whole, these results suggest that strain Hhs.015(T) represents a novel Saccharothrix species. The name Saccharothrix yanglingensis sp. nov. is proposed, with the type strain Hhs.015(T) (=CGMCC 4.5627(T)=KCTC 19722(T)).

Proposal of Umezawaea gen. nov., a new genus of the Actinosynnemataceae related to Saccharothrix, and transfer of Saccharothrix tangerinus Kinoshita et al. 2000 as Umezawaea tangerina gen. nov., comb. nov.

In the course of phylogenetic analyses of the taxa within the suborder Pseudonocardineae, it was observed that Saccharothrix tangerinus MK27-91F2(T) was misplaced in the genus Saccharothrix. After a detailed examination of nucleotide signatures in the 16S rRNA gene sequence along with the morphological and chemotaxonomic characteristics of this strain, which are different from those of all species of Saccharothrix as well as the other genera within the suborder, it was concluded that this strain represents a new genus, for which the name Umezawaea gen. nov. is proposed. Pseudosporangia are produced on the aerial mycelium, the whole-cell sugar pattern consists of galactose, mannose and ribose, phosphatidylethanolamine, phosphatidylinositol and lyso-phosphatidylethanolamine are the predominant phospholipids and MK-9(H(4)) is the predominant menaquinone. The type species of the proposed new genus is Umezawaea tangerina gen. nov., comb. nov., with the type strain MK27-91F2(T) (=NRRL B-24463(T) =DSM 44720(T) =FERM P-16053(T) =JCM 10302(T) =NBRC 16184(T)).

Saccharothrix xinjiangensis sp. nov., a pyrene-degrading actinomycete isolated from Tianchi Lake, Xinjiang, China

A pyrene-degrading isolate, strain PYX-6(T), was obtained from Tianchi Lake, Xinjiang Uygur Autonomous Region, China, and was identified by means of polyphasic taxonomy. On the basis of 16S rRNA gene sequence similarity, strain PYX-6(T) was closely related to members of the genus Saccharothrix. Its 16S rRNA gene sequence similarity to each of Saccharothrix syringae, Saccharothrix australiensis, Saccharothrix algeriensis and Saccharothrix coeruleofusca was 98 %. Chemotaxonomic and physiological properties of strain PYX-6(T) further supported its affiliation to the genus Saccharothrix. DNA-DNA hybridization results and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain PYX-6(T) from recognized Saccharothrix species. Therefore, strain PYX-6(T) represents a novel species, for which the name Saccharothrix xinjiangensis sp. nov. is proposed, with type strain PYX-6(T) (=AS 4.1731(T)=JCM 12329(T)).

Saccharothrix algeriensis sp. nov., isolated from Saharan soil.

The taxonomic position of a soil isolate, strain SA 233T, recovered from Saharan soil from Algeria was established using a polyphasic approach. This isolate has been previously reported to produce three novel dithiolopyrrolone antibiotics, and preliminary chemotaxonomic and morphological characteristics suggested that it was representative of a member of the genus Saccharothrix. Phylogenetic analysis of the strain from 16S rDNA sequences, along with a detailed analysis of morphological, chemotaxonomic and physiological characteristics, indicates that it belongs to the genus Saccharothrix and represents a novel species that is readily distinguished from all recognized Saccharothrix species. The name Saccharothrix algeriensis sp. nov. is proposed for the isolate, with type strain SA 233T (=NRRL B-24137T=DSM 44581T).

Poly(L‐lactide)‐Degrading Activity in Various Actinomycetes

AbstractThe poly(L‐lactide) (PLA)‐degrading ability of actinomycetes obtained from culture collections was examined by the formation of clear zones on PLA‐emulsified agar plates. Using 41 genera (105 strains) of actinomycetes with phylogenetic affiliations based on 16S rRNA sequences, PLA degraders were found to be limited to members of the family Pseudonocardiaceae and related genera. They included Amycolatopsis, Saccharothrix, Lentzea, Kibdelosporangium, and Streptoalloteichus. A large number of PLA degraders were widely distributed within the genus Saccharothrix. Most strains forming clear zones on PLA‐emulsified agar plates also formed clear zones on silk fibroin agar plates. Saccharothrix species showed an ability to degrade PLA films and assimilate degradation products in liquid cultures. No significant change of the molecular weight and polydispersity (Mw/Mn) of the remaining film fragments was confirmed. After cultivation for two weeks, many irregular holes/pits on the surface of the film due to the colonization of microorganisms were observed by scanning electron microscopy.Scanning electron micrograph of the surface of PLA film: A. orientalis subsp. orientalis IFO 12362 after 14 d.magnified imageScanning electron micrograph of the surface of PLA film: A. orientalis subsp. orientalis IFO 12362 after 14 d.

Pluraflavins, potent antitumor antibiotics from Saccharothrix sp. DSM 12931.

The new pluramycin-type antibiotics pluraflavin A, C43H54N2O14, pluraflavin B, C43H56N2O15, and pluraflavin E, C36H41NO14 were isolated from cultures of the Saccharothrix species DSM 12931. The structures of the novel compounds were elucidated with the aid of 2D NMR and mass spectrometric investigations. The characteristic structural element of pluraflavins A and B is an additional 4-epi-vancosamine unit at position 13 of the anthraquinone-gamma-pyrone ring system. Pluraflavin E has a carboxyl group in this position. Pluraflavin A has a reactive dimethyl epoxide side chain at position 2 of the anthraquinone-gamma-pyrone aglycon, which may explain the high activity of the antibiotic. The outstanding biological characteristic of pluraflavin A is its powerful, organ-dependent cytostatic action: the IC50 in the colon carcinoma proliferation assay is in the subnanomolar range.

Saccharomicins, Novel Heptadecaglycoside Antibiotics Effective against Multidrug-Resistant Bacteria

Two novel heptadecaglycoside antibiotics, saccharomicins A (1) and B (2), were isolated from a new species of Saccharothrix. Their structures were determined by a combination of chemical degradation and spectroscopic methods. Saccharomicin B (2) was identified as N-(m,p-dihydroxycinnamoyl) taurine p-O-[α-4-epi-vancosaminopyranosyl(1→4)-α-4-epi-vancosaminopyranosyl(1→4)-α-digitoxopyranosyl(1→4)-α- 4-epi-vancosaminopyranosyl(1→4)-α-digitoxopyranosyl(1→3)-β-fucopyranosyl(1→4)-β-saccharosaminopyranosyl(1→4)-α-digitoxopyranosyl(1→3)]-[α-4-epi-vancosaminopyranosyl(1→4)]-β-fucopyranosyl(1→4)-β- saccharosaminopyranosyl(1→4)-α-rhamnopyranosyl(1→3)-β-fucopyranosyl(1→4)-β-saccharosaminopyranosyl(1→4)-β-fucopyranosyl(1→4)-β-saccharosaminopyranosyl(1→4)-β-2-sulfate-fucopyranoside. Saccharomicin A (1) differs from saccharomicin B (2) only in the 10th sugar residue, where α-digitoxopyranosyl(1→3) is replaced with α-rhamnopyranosyl(1→3). The novel amino sugar residue, designated saccharosamine, was identified by NMR spectroscopy and X-ray crystallography. Both saccharomicins A (1) and B (2) showed antimicrobial activity against Gram-positive bacteria.

Carbocyclic nucleosides from a species of Saccharothrix

Investigation of a herbicidally active fermentation broth from a species of Saccharothrix has led to the isolation of three novel nucleosides based on a carbocyclic analogue of coformycin. Two other known carbocyclic nucleosides (adecypenol and aristeromycin) were also isolated from the same fermentation.

3-O-isobutyrylkinamycin C and 4-deacetyl-4-O-isobutyrylkinamycin C, new antibiotics produced by a Saccharothrix species.

3-O-isobutyrylkinamycin C and 4-deacetyl-4-O-isobutyrylkinamycin C, new antibiotics produced by a Saccharothrix species.

Transfer of "Nocardia aerocolonigenes" (Shinobu and Kawato 1960) Pridham 1970 into the Genus Saccharothrix Labeda, Testa, Lechevalier, and Lechevalier 1984 as Saccharothrix aerocolonigenes sp. nov.

I propose that “Nocardia aerocolonigenes” be placed in the genus Saccharothrix as Saccharothrix aerocolonigenes because it exhibits the following chemotaxonomic properties characteristic of this genus: Whole-cell hydrolysates contain the meso isomer of diaminopimelic acid, rhamnose and galactose are the characteristic sugars, and mycotic acids are absent. This species is phenotypically different from the type species of Saccharothrix, Saccharothrix australiensis (strain NRRL 11239), and deoxyribonucleic acid from the type strain of S. aerocolonigenes was determined to be only 10% homologous to deoxyribonucleic acid isolated from S. australiensis NRRL 11239. A description of the species is presented. The type strain is strain NRRL B-3298 (= ISP 5034 = ATCC 23870 = IFO 3837 = Shinobu No. 701).