Species Of Micromonospora Research Articles

Aspects of nitrogen-fixingActinobacteria, in particular free-living and symbioticFrankia

Studies of nitrogen-fixing properties among the Gram-positive Actinobacteria revealed that some species of Arthrobacter, Agromyces, Corynebacterium, Mycobacterium, Micromonospora, Propionibacteria and Streptomyces have nitrogen-fixing capacity. This is also valid for Frankia that fix nitrogen both in free-living and in symbiotic conditions. Frankia symbiosis results from interaction between the Frankia bacteria and dicotyledonous plants, that is, actinorhiza. These plants, which are important in forestry and agroforestry, form, together with the legumes (Fabales), a single nitrogen-fixing clade. It has been shown that a receptor-like kinase gene, SymRK, is necessary for nodulation in actinorhizal plants as well as in legumes and arbuscular mycorrhizal fungi. Recently, the involvement of isoflavonoids as signal molecules during nodulation of an actinorhizal plant was shown. The genome sizes of three Frankia species, Frankia EANpec, ACN14a and CcI3, are different, revealing a relationship between genome size and geographical distribution. Recent genomic sequencing data of Frankia represent genomes from cluster I to IV, indicating that the genome of DgI is one of the smallest genomes in Frankia. In addition, nonsymbiotic Frankiales such as Acidothermus cellulolyticus, Blastococcus saxoobsidens, Geodermatophilus obscurus and Modestobacter marinus have a variety of genome sizes ranging from 2.4 to 5.57Mb.

An effective method based on wet-heat treatment for the selective isolation of Micromonospora from estuarine sediments

Several methods for the isolation of Micromonospora from soil samples have been developed; however, it is unclear whether these methods are optimal for estuarine samples. In this study, we optimized the conditions of a wet-heat method for the selective isolation of Micromonospora from estuarine sediments. Sediments were collected from the Arakawa River (estuarine sediments) and Tokyo Bay (marine sediments). Sediment samples were wet-heated at 45, 55, or 65°C for 30min and then incubated at 27°C for 3weeks. After incubation, most of the actinomycete colonies were macroscopically determined to be of the genus Micromonospora or Streptomyces. In contrast to the treatment at 55°C, treatment at 65°C drastically reduced the number of Streptomyces colonies but increased the number of Micromonospora colonies from the estuarine sediments. This procedure allowed us to grow cultures that were composed of more than 90% Micromonospora. In addition, treatment at 65°C did not affect the diversity of Micromonospora species compared with treatment at 55°C. These results indicate that the wet-heat method, which involves pre-treating the sediment at 65°C for 30min, is a very simple and effective method for the selective enrichment of a large number of diverse Micromonospora from estuarine sediments. Our results may lead to the isolation of new Micromonospora species, which produce novel bioactive compounds, from different estuarine sediments.

Micromonospora halotolerans sp. nov., isolated from the rhizosphere of a Pisum sativum plant.

A filamentous actinomycete strain designated CR18(T) was isolated on humic acid agar from the rhizosphere of a Pisum sativum plant collected in Spain. This isolate was observed to grow optimally at 28 °C, pH 7.0 and in the presence of 5 % NaCl. Phylogenetic analyses based on the 16S rRNA gene sequence indicated a close relationship with the type strains of Micromonospora chersina and Micromonospora endolithica. A further analysis based on a concatenated DNA sequence stretch of 4,523 bp that included partial sequences of the atpD, gyrB, recA, rpoB and 16S rRNA genes clearly differentiated the new strain from recognized Micromonospora species compared. DNA-DNA hybridization studies further supported the taxonomic position of strain CR18(T) as a novel genomic species. Chemotaxonomic analyses which included whole cell sugars, polar lipids, fatty acid profiles and menaquinone composition confirmed the affiliation of the new strain to the genus Micromonospora and also highlighted differences at the species level. These studies were finally complemented with an array of physiological tests to help differentiate between the new strain and its phylogenetic neighbours. Consequently, strain CR18(T) (= CECT 7890(T) = DSM 45598(T)) is proposed as the type strain of a novel species, Micromonospora halotolerans sp. nov.

Micromonospora avicenniae sp. nov., isolated from a root of Avicennia marina

Strain 268506(T) was isolated from a root of Avicennia marina collected at mangrove forest in Wengchang, Hainan province, China. The 16S rRNA gene sequence of strain 268506(T) showed the highest similarity with Micromonospora equina Y22(T) (98.8 %) and Micromonospora olivasterospora DSM 43868(T) (98.7 %). In addition, gyrB gene phylogeny clearly showed strain 268506(T) should be assigned to the genus Micromonospora but different from any established Micromonospora species. The predominant menaquinones are MK-9(H8) and MK-9(H6). The major fatty acids are iso-C16:0, iso-C15:0 and anteiso-C17:0. The characteristic whole-cell sugars are xylose, mannose and arabinose. The cell wall contains meso-DAP and glycine. Phosphatidylinositol, diphosphatidylglycerol and phosphatidylethanolamine are the characteristic polar lipids. The DNA G+C content is 70.3 mol%. Some physiological and biochemical properties combined with low DNA-DNA relatedness indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. On the basis of these phenotypic and genotypic data, strain 268506(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora avicenniae sp. nov. is proposed. The type strain is 268506(T) ( = CCTCC AA 2012010(T) = DSM 45758(T)).

Evaluation of the Gulf of California as a potential source of bioactive marine actinobacteria

Actinobacteria produce many bioactive compounds currently used as antibiotics and anticancer drugs. The objective of this project was to evaluate the Gulf of California as a novel source of bioactive actinobacterial strains. A total of 235 actinobacterial strains were isolated from marine sediment collected in Concepción and los Ángeles bays (Mexico). Based on their morphology, seawater requirements, and 16S rRNA sequencing, actinobacterial strains were classified as Streptomyces, Micromonospora, and Salinispora. Sixty-nine organic and aqueous extracts were obtained using liquid-liquid extraction with ethyl acetate; 17 showed cytotoxic activity against breast cancer cells (MCF7) and cervical cancer cells (HeLa). The highest activity values observed, expressed as survival percentage, were 20–25% against MCF7 cells (strains S-365, S-355, and S-361) and 24–25% against HeLa cells (strains S-165, S-361, and S-353). Only three aqueous extracts showed antibiotic activity towards methicillin-resistant Staphylococcus aureus, with activity values of 3% and 6% for strains S-370 and S-369, respectively. Molecular weights found by liquid chromatography-mass spectrometry analysis are reported for Micromonospora species isolated from soil, but no species specific secondary metabolite evidence was observed for Salinispora isolates. The biological activity observed in this work offers opportunities for further chemical studies to define the compounds responsible for this activity in order to contribute to the discovery of new drugs and to acknowledge the Gulf of California as a reservoir of marine bioactive actinobacteria strains that are important for human health.

Diversity and Biosynthetic Potential of Culturable Actinomycetes Associated with Marine Sponges in the China Seas

The diversity and secondary metabolite potential of culturable actinomycetes associated with eight different marine sponges collected from the South China Sea and the Yellow sea were investigated. A total of 327 strains were isolated and 108 representative isolates were selected for phylogenetic analysis. Ten families and 13 genera of Actinomycetales were detected, among which five genera represent first records isolated from marine sponges. Oligotrophic medium M5 (water agar) proved to be efficient for selective isolation, and “Micromonospora–Streptomyces” was proposed as the major distribution group of sponge-associated actinomycetes from the China Seas. Ten isolates are likely to represent novel species. Sponge Hymeniacidon perleve was found to contain the highest genus diversity (seven genera) of actinomycetes. Housekeeping gene phylogenetic analyses of the isolates indicated one ubiquitous Micromonospora species, one unique Streptomyces species and one unique Verrucosispora phylogroup. Of the isolates, 27.5% displayed antimicrobial activity, and 91% contained polyketide synthase and/or nonribosomal peptide synthetase genes, indicating that these isolates had a high potential to produce secondary metabolites. The isolates from sponge Axinella sp. contained the highest presence of both antimicrobial activity and NRPS genes, while those from isolation medium DNBA showed the highest presence of antimicrobial activity and PKS I genes.

Micromonospora cremea sp. nov. and Micromonospora zamorensis sp. nov., isolated from the rhizosphere of Pisum sativum.

Three actinobacterial strains, CR30(T), CR36 and CR38(T), were isolated from rhizosphere soil of Pisum sativum plants collected in Spain. The strains were filamentous, Gram-stain-positive and produced single spores. Phylogenetic, chemotaxonomic and morphological analyses confirmed that the three strains belonged to the genus Micromonospora. 16S rRNA gene sequence analysis of strains CR30(T) and CR36 showed a close relationship to Micromonospora coriariae NAR01(T) (99.3% similarity) while strain CR38(T) had a similarity of 99.0% with Micromonospora saelicesensis Lupac 09(T). In addition, gyrB gene phylogeny clearly differentiated the novel isolates from recognized Micromonospora species. DNA-DNA hybridization, BOX-PCR and ARDRA profiles confirmed that these strains represent novel genomic species. The cell-wall peptidoglycan of strains CR30(T) and CR38(T) contained meso-diaminopimelic acid. Both strains had MK-10(H(4)) as the main menaquinone and a phospholipid type II pattern. An array of physiological tests also differentiated the isolates from their closest neighbours. Considering all the data obtained, it is proposed that strains CR30(T) and CR36 represent a novel species under the name Micromonospora cremea sp. nov. (type strain CR30(T) = CECT 7891(T) = DSM 45599(T)), whereas CR38(T) represents a second novel species, for which the name Micromonospora zamorensis sp. nov. is proposed, with CR38(T) ( = CECT 7892(T) = DSM 45600(T)) as the type strain.

Micromonospora haikouensis sp. nov., isolated from mangrove soil

An actinomycete strain 232617(T) was isolated from a composite mangrove sediment sample collected in Haikou, China. Phylogenetic analysis of the 16S rRNA gene sequence of strain 232617(T) indicated the highest similarity with Micromonospora siamensis TT2-4(T) (99.05%), Micromonospora krabiensis A-2(T) (98.99%) and Micromonospora carbonacea DSM 43815(T) (98.91%). The gyrB gene sequence analysis also indicated that 232617(T) should be assigned to the genus Micromonospora. The cell wall contains meso-DAP and glycine. The major menaquinones were MK-10(H(4)) and MK-10(H(6)), with MK-9(H(4)) as minor components. The characteristic whole-cell sugars are xylose, arabinose and glucose. The phospholipid profile comprises phosphatidylethanolamine, diphosphatidlglycerol and phosphatidylinositol mannoside. The DNA G+C content is 71.5mol%. Furthermore, a combination of DNA-DNA relatedness and some physiological and biochemical properties indicated that the novel strain could be readily distinguished from the closest related species. On the basis of these phenotypic and genotypic data, strain 232617(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora haikouensis sp. nov. is proposed. The type strain is 232617(T) (=CCTCC AA 201112 (T)=DSM 45626 (T)).

Micromonospora yangpuensis sp. nov., isolated from a sponge

An actinomycete, strain FXJ6.011(T), was isolated from a cup-shaped sponge collected at Dachan reef, Yangpu in the South China Sea. The strain had morphological characteristics of members of the family Micromonosporaceae. Phylogenetic analysis of the 16S rRNA gene sequence of strain FXJ6.011(T) indicated the highest similarity (98.7 %) to Micromonospora auratinigra JCM 12357(T), Micromonospora chaiyaphumensis JCM 12873(T) and Micromonospora echinofusca JCM 3327(T). Analysis of the gyrB gene sequence also showed that strain FXJ6.011(T) should be assigned to the genus Micromonospora. It contained DD-diaminopimelic acid as the major cell-wall diamino acid and MK-10(H(2)) as predominant menaquinone. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidyl mannosides and phosphatidylinositol dimannoside. The major cellular fatty acids were iso-C(16 : 0), C(17 : 1)ω8c and C(16 : 0). Physiological and biochemical data and low DNA-DNA relatedness values enabled the strain to be differentiated from members of closely related species. Based on phenotypic and genotypic data, strain FXJ6.011(T) represents a novel Micromonospora species, for which the name Micromonospora yangpuensis sp. nov. is proposed; the type strain is FXJ6.011(T) ( = CGMCC 4.5736(T) = NBRC 107727(T)).

Micromonospora humi sp. nov., isolated from peat swamp forest soil

A novel actinomycete, strain P0402(T), was isolated from peat swamp forest soil collected in Thailand. Its taxonomic position was determined by using a polyphasic taxonomic approach. The chemotaxonomic characteristics of this strain matched those of the genus Micromonospora, i.e. the presence of meso-diaminopimelic acid and N-glycolyl muramic acid in the peptidoglycan, whole-cell sugar pattern D, phospholipid type II, and cellular fatty acid type 3b. Phylogenetic analysis based on 16S rRNA gene sequences revealed a close relationship between strain P0402(T) and Micromonospora coxensis JCM 13248(T) (99.0 % similarity), Micromonospora eburnea JCM 12345(T) (99.0 %), Micromonospora marina JCM 12870(T) (98.9 %), Micromonospora halophytica JCM 3125(T) (98.7 %), Micromonospora chalcea JCM 3031(T) (98.7 %), Micromonospora purpureochromogenes JCM 3156(T) (98.6 %) and Micromonospora aurantiaca JCM 10878(T) (98.5 %). It could be clearly distinguished from these type strains based on low levels of DNA-DNA relatedness and phenotypic differences. On the basis of the data presented, strain P0402(T) is suggested to represent a novel species of the genus Micromonospora, for which the name Micromonospora humi sp. nov. is proposed. The type strain is P0402(T) ( = JCM 15292(T) = PCU 315(T) = TISTR 1883(T)).

Optimization of Culture Medium to Increase the Production of Desferrioxamine B (Desferal) in Streptomyces pilosus

The aim of this study was optimization of culture medium in direction of increasing the production rate of desferrioxamine B. Streptomycetes are the most widely studied and well known genus of the actinomycete family. Streptomycetes usually inhabit soil and are important decomposers. The genus Streptomyces are Gram-positive and GC rich bacteria that are important for production of many antibiotics and secondary metabolites. These metabolites are important in industrial and medical fields. Deferoxamines (also known as desferrioxamine B, desferoxamine B, DFO-B, DFOA, DFB or desferal) are low-molecular-weight, iron-chelating compounds (siderophores) produced and secreted by many actinomycetes, including species of Streptomyces, Nocardia and Micromonospora. Streptomyces pilosus synthesizes the siderofore desferrioxamine B. Desferrioxamine B is used clinically to treat disorders related to iron overload and pathological iron deposition in human. Our results revealed that the use of soybean as a base medium plus additives such as Na2HPO4.12H2O, NaH2PO4, MgSO4.7H2O, ZnSO4.7H2O, FeSO4.7H2O, CaCl2.2H2O, NaCl, MnSO4, NH4Cl, KH2PO4, K2HPO4, some of the amino acids and vitamins increased the production of desferrioxamine B about 8 times in comparison with the control.

Micromonospora rhizosphaerae sp. nov., isolated from mangrove rhizosphere soil

Strain 211018(T) was isolated from mangrove Excocaria agallocha rhizosphere soil. 16S rRNA gene sequence analysis showed the highest similarity to the type strains of Micromonospora olivasterospora DSM 43868(T) (98.6 %) and Micromonospora pattaloongensis TJ2-2(T) (98.4 %). gyrB gene sequence analysis also indicated that strain 211018(T) should be assigned to the genus Micromonospora. The characteristic whole-cell sugars are xylose, mannose and arabinose. The predominant menaquinone is MK-9(H(4)) and the major fatty acids are iso-C(15 : 0) (27.5 %), 10-methyl C(17 : 0) (14.2 %), C(17 : 1)ω8c (12.8 %), iso-C(16 : 0) (12.6 %), anteiso-C(15 : 0) (6.1 %), iso-C(17 : 0) (4.1 %) and anteiso-C(17 : 0) (4.0 %). The phospholipid profile comprises phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The DNA G+C content is 70.8 mol%. The chemotaxonomic data of the strain coincided with those of the genus Micromonospora. Furthermore, a combination of DNA-DNA hybridization results and some physiological and biochemical properties indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. On the basis of these phenotypic and genotypic data, strain 211018(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora rhizosphaerae sp. nov. is proposed. The type strain is 211018(T) (=CGMCC 4.5599(T) =DSM 45431(T)).

Екологічні особливості рідкісних родів актиноміцетів у ґрунтах Азербайджану

The results of the research of rare species of actinomycetes in some soils of Azerbaijan were studied. On the selective media the representatives of Streptomyces, Streptosporangium, Micromonospora, Actinomadura, Microbispora, Saccharopolyspora and Saccharomonospora were revealed. Species of Streptomyces and Micromonospora dominate in mountain-wood ecosystems (60 %.). It was established that among streptomyces species of Cinereus section of Violaceus series; Helvolo-Flavus sections of Helvolus series, Roseus sections of Fuscus series; Azureus sections of Coerulescens series. It was established that amount of termotolerant actinomycetes in the investigated desert soils of Azerbaijan depends on the incubation temperature. The species of Streptomyces, Micromonospora, Saccharopolyspora and Actinomadura genera were isolated from desert soils of Azerbaijan.

Micromonospora pisi sp. nov., isolated from root nodules of Pisum sativum.

A novel actinomycete, designated strain GUI 15(T), isolated from the root nodules of a Pisum sativum plant was characterized taxonomically by using a polyphasic approach. The 16S rRNA gene sequence of strain GUI 15(T) showed highest similarity to Micromonospora pattaloongensis TJ2-2(T) (98.7 %) and Polymorphospora rubra TT 97-42(T) (98.5 %). Phylogenetic analysis based on the gyrase B gene also supported the close relationship of these three strains, but indicated that strain GUI 15(T) should be assigned to the genus Micromonospora. Chemotaxonomic results confirmed the position of the isolate in the genus Micromonospora, but revealed differences at the species level. The novel strain could be distinguished from recognized Micromonospora species by using a combination of physiological and biochemical tests. Based on these observations, strain GUI 15(T) is considered to represent a novel species of the genus Micromonospora, for which the name Micromonospora pisi sp. nov. is proposed. The type strain is GUI 15(T) (=DSM 45175(T)=LMG 24546(T)).

Micromonospora pattaloongensis sp. nov., isolated from a Thai mangrove forest

An actinomycete, designated strain TJ2-2(T), was isolated from soil collected from a mangrove forest in Pattaloong Province, Thailand, and was subjected to morphological and chemotaxonomic analysis and phylogenetic investigation based on 16S rRNA gene sequences. The data from these analyses indicated that the novel strain should be classified as a member of the genus Micromonospora and that the closest relative was Micromonospora olivasterospora DSM 43868(T) (98.7 % gene sequence similarity). The DNA-DNA hybridization data and some physiological and biochemical properties indicated that the novel strain could be readily distinguished from its closest phylogenetic relatives. On the basis of these phenotypic and genotypic data, strain TJ2-2(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora pattaloongensis sp. nov. is proposed. The type strain is TJ2-2(T) (=JCM 12833(T)=TISTR 1559(T)).

Micromonospora chaiyaphumensis sp. nov., isolated from Thai soils

Three actinomycete strains, MC5-1T, MC7-1 and R1-1, were isolated from soil samples collected in Thailand. Their taxonomic positions were determined using a polyphasic approach. The chemotaxonomic characteristics of these strains coincided with those of the genus Micromonospora, i.e. meso-diaminopimelic acid and N-glycolyl muramic acid were present in the cell-wall peptidoglycan, the whole-cell sugars were of pattern D, the phospholipids were of type II and the cellular fatty acids were of type 3b. Phylogenetic analysis of the 16S rRNA gene sequences revealed a close relationship between strains MC5-1T, MC7-1 and R1-1 (99.8 % sequence similarity) and Micromonospora auratinigra JCM 12357T (99.3 %). The three novel strains were clearly distinguishable from M. auratinigra JCM 12357T from the low DNA-DNA relatedness (< or =43.4 %). On the basis of the data presented, strain MC5-1T represents a novel species of the genus Micromonospora, for which the name Micromonospora chaiyaphumensis is proposed. The type strain is MC5-1T (=KCTC 19332T=JCM 12873T=PCU 267T=TISTR 1564T).

Microbial Biosynthesis and Applications of Gentamicin: A Critical Appraisal

Gentamicin is an aminoglycoside antibiotic produced by various species of the genus Micromonospora and has received much attention in the recent years as a broad-spectrum antibiotic for treatment of various infections. It exists as a complex of closely related aminoglycoside structures and the clinically significant one is the gentamicin C complex. This review article focuses attention on the present status of knowledge and the main advancements achieved in the last few decades on the subject of gentamicin with regard to its production, biosynthetic pathway, mode of action, and uses. The various nutritional and environmental parameters affecting gentamicin production and the factors affecting the release of bound gentamicin are discussed. Further, strain improvement using UV and/or chemical mutagenesis can be applied to augment the efficiency of the producer strain and a number of case studies are presented. Different detection and quantitative methods for gentamicin estimation and the mode of action of gentamicin are discussed in detail. This antibiotic finds extensive use in combination chemotherapy and as a drug for different delivery agents for treatment of osteomyelitis and other recent applications in gene therapy.

Micromonospora rifamycinica sp. nov., a novel actinomycete from mangrove sediment

An actinomycete strain, AM105(T), that produces rifamycin, was isolated from mangrove sediment samples collected from the South China Sea. The strain showed closest 16S rRNA gene sequence similarity to Micromonospora matsumotoense (98.0%). Chemotaxonomic characteristics of the isolate coincided with members of the genus Micromonospora. The value of DNA-DNA relatedness to M. matsumotoense (53.6%) and phenotypic differences from phylogenetically related Micromonospora species indicated that this isolate belongs to a novel species, for which the name Micromonospora rifamycinica sp. nov. is proposed. The type strain is AM105(T) (=CGMCC 4.2495(T)=DSM 44983(T)).

Eight new species of the genus Micromonospora, Micromonospora citrea sp. nov., Micromonospora echinaurantiaca sp. nov., Micromonospora echinofusca sp. nov. Micromonospora fulviviridis sp. nov., Micromonospora inyonensis sp. nov., Micromonospora peucetia sp. nov., Micromonospora sagamiensis sp. nov., and Micromonospora viridifaciens sp. nov.

A previous phylogenetic study on type strains of the genus Micromonospora and Micromonospora species bearing non-validly published names has pointed towards the species status of several of latter strains. Subsequent studies on morphological, cultural, chemotaxonomic, metabolic, and genomic properties, and on whole cell mass spectrometric analyses by matrix adsorbed laser desorption/ionization time-of-flight (MALDI-TOF) confirmed the species status, leading to the proposal of eight new Micromonospora species: Micromonospora citrea sp. nov., type strain DSM 43903 T, Micromonospora echinaurantiaca sp. nov., type strain DSM 43904 T, Micromonospora echinofusca sp. nov., type strain DSM 43913 T, Micromonospora fulviviridis sp. nov., type strain DSM 43906 T, Micromonospora inyonensis sp. nov., type strain DSM 46123 T, Micromonospora peucetia sp. nov., type strain DSM 43363 T, Micromonospora sagamiensis sp. nov., type strain DSM 43912 T and Micromonospora viridifaciens sp. nov., type strain DSM 43909 T.

Micromonospora eburnea sp. nov., isolated from a Thai peat swamp forest

Two actinomycete strains, LK2-10T and LK2-5, which produced single, non-motile spores, were isolated from peat swamp forest soil in Yala Province, Thailand. A polyphasic study was carried out to establish the taxonomic position of these strains. Morphological and chemotaxonomic characteristics of these strains coincided with those of the genus Micromonospora. Phylogenetic analysis using 16S rRNA gene sequences also indicated that these strains should be classified in the genus Micromonospora and clearly separated from their closest relative, Micromonospora nigra DSM 43818T. Furthermore, a combination of DNA-DNA hybridization results and physiological and biochemical properties indicated that these strains were distinguished from all recognized Micromonospora species. These strains therefore represent a novel species, for which the name Micromonospora eburnea sp. nov. is proposed. The type strain is LK2-10T (=JCM 12345T=PCU 238T=DSM 44814T=TISTR 1531T).