scholarly journals From roots to leaves: the capacity of Micromonospora to colonize different legume tissues

Author(s):  
Patricia Benito ◽  
Lorena Carro ◽  
Rodrigo Bacigalupe ◽  
Maite Ortuzar ◽  
Martha E. Trujillo

An important number of Micromonospora strains have been reported from nitrogen fixing root nodules of legume and actinorhizal plants. However, the question of whether this bacterium can also be found in other parts of these plants remains unanswered. Over 150 strains were recovered from different Lupinus angustifolius and Pisum sativum tissues including leaves, stems, roots, and nodules. Ninety-seven percent of the isolates were identified by 16S rRNA gene sequence in the target genus and were associated with 27 different Micromonospora species. Plant-polymer degrading enzymes are suspected to play a role in the colonization of plants. To this end, bacterial enzymatic activity assays for amylases, cellulases, chitinases, pectinases and xylanases were determined. All strains produced xylanases and pectinases, while 98.6%, 98%, and 94.6% of them produced amylases, cellulases, and chitinases, respectively. The most productive strains included seven isolates from P. sativum and one from L. angustifolius. Strain Micromonospora lupini ML01-gfp was used to determine its capacity to reach and colonize different plant organs using P. sativum as the plant model. Stem and leaf samples were monitored by optical and fluorescence microscopy to locate the tagged strain. These results strongly suggest that Micromonospora is able, not only to infect nitrogen-fixing nodules, but also of reaching other parts of the host plant, especially the leaves.

2011 ◽  
Vol 61 (6) ◽  
pp. 1350-1355 ◽  
Author(s):  
Hao-Jie Jin ◽  
Yu-Guang Zhou ◽  
Hong-Can Liu ◽  
San-Feng Chen

A nitrogen-fixing bacterium, designated strain Be17T, was isolated from rhizosphere soil of Begonia semperflorens planted in Beijing Botanical Garden, PR China. Phylogenetic analyses based on a segment of the nifH gene sequence and a full-length 16S rRNA gene sequence revealed that strain Be17T was a member of the genus Paenibacillus. High levels of 16S rRNA gene sequence similarity were found between strain Be17T and Paenibacillus graminis RSA19T (97.9 %), Paenibacillus sonchi LMG 24727T (97.8 %), Paenibacillus riograndensis CECT 7330T (96.2 %) and Paenibacillus borealis DSM 13188T (96.1 %), respectively. Levels of 16S rRNA gene sequence similarity between strain Be17T and the type strains of other recognized members of the genus Paenibacillus were below 96.0 %. However, the DNA–DNA hybridization values between strain Be17T and P. graminis RSA19T, P. sonchi LMG 24727T and P. riograndensis CECT 7330T were 47.9 %, 38.7 % and 37.5 %, respectively. The DNA G+C content of strain Be17T was 52.9 mol%. The major fatty acid component of strain Be17T was anteiso-branched C15 : 0 (30.92 %). The major isoprenoid quinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. On the basis of its phenotypic characteristics, 16S rRNA gene sequences, DNA G+C content, DNA–DNA relatedness, chemotaxonomic properties and nifH gene sequence, strain Be17T represents a nitrogen-fixing strain of a novel species of the genus Paenibacillus, for which the name Paenibacillus jilunlii sp. nov. is proposed. The type strain is Be17T ( = CGMCC 1.10239T = DSM 23019T).


2006 ◽  
Vol 56 (8) ◽  
pp. 1899-1903 ◽  
Author(s):  
Debasree Dutta ◽  
Ratan Gachhui

The four nitrogen-fixing bacteria so far described in the family Acetobacteraceae belong to the genera Gluconacetobacter and Acetobacter. Nitrogen-fixing bacterial strain RG1T was isolated from Kombucha tea and, based on the phylogenetic analysis of 16S rRNA gene sequence which is supported by a high bootstrap value, was found to belong to the genus Acetobacter. Strain RG1T differed from Acetobacter aceti, the nearest member with a 16S rRNA gene sequence similarity of 98.2 %, and type strains of other Acetobacter species with regard to several characteristics of growth features in culture media, growth in nitrogen-free medium, production of γ-pyrone from glucose and dihydroxyacetone from glycerol. Strain RG1T utilized maltose, glycerol, sorbitol, fructose, galactose, arabinose and ethanol, but not methanol as a carbon source. These results, along with electrophoretic mobility patterns of nine metabolic enzymes, suggest that strain RG1T represents a novel nitrogen-fixing species. The ubiquinone present was Q-9 and DNA G+C content was 64.1 mol%. Strain RG1T exhibited a low value of 2–24 % DNA–DNA relatedness to the type strains of related acetobacters, which placed it as a separate taxon. On the basis of this data, the name Acetobacter nitrogenifigens sp. nov. is proposed, with the type strain RG1T (=MTCC 6912T=LMG 23498T).


2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1090-1095 ◽  
Author(s):  
Sofie E. De Meyer ◽  
Margo Cnockaert ◽  
Julie K. Ardley ◽  
Ben-Erik Van Wyk ◽  
Peter A. Vandamme ◽  
...  

Three strains of Gram-stain-negative, rod-shaped bacteria were isolated from Lebeckia ambigua root nodules and authenticated on this host. Based on the 16S rRNA gene sequence phylogeny, they were shown to belong to the genus Burkholderia , with the representative strain WSM3556T being most closely related to Burkholderia caledonica LMG 23644T (98.70 % 16S rRNA gene sequence similarity) and Burkholderia rhynchosiae WSM3937T (98.50 %). Additionally, these strains formed a distinct group in phylogenetic trees of the housekeeping genes gyrB and recA. Chemotaxonomic data, including fatty acid profiles and analysis of respiratory quinones, supported the assignment of our strains to the genus Burkholderia . Results of DNA–DNA hybridizations, MALDI-TOF MS analysis and physiological and biochemical tests allowed genotypic and phenotypic differentiation of our strains from their nearest neighbour species. Therefore, these strains represent a novel species, for which the name Burkholderia dilworthii sp. nov. is proposed, with the type strain WSM3556T ( = LMG 27173T = HAMBI 3353T).


2010 ◽  
Vol 60 (5) ◽  
pp. 1152-1157 ◽  
Author(s):  
Tomoko Aizawa ◽  
Nguyen Bao Ve ◽  
Mutsuyasu Nakajima ◽  
Michio Sunairi

Nitrogen-fixing bacteria, strains SA41T, SA42 and SA53, were isolated from an aquatic plant, Eleocharis dulcis, that grows in highly acidic swamps (pH 2–4) in actual acid sulfate soil areas of Vietnam. The isolates were Gram-negative, aerobic, non-spore-forming, rod-shaped bacteria, having a cell width of 0.6–0.7 μm and a length of 1.5–1.7 μm. They showed good growth between pH 3.0 and 7.0, and between 17 and 37 °C. The organisms contained ubiquinone Q-8 as the predominant isoprenoid quinone, and C16 : 0, C17 : 0 cyclo, C18 : 1 ω7c and summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH) as major fatty acids. Their fatty acid profiles are similar to those reported for other Burkholderia species. The DNA G+C content of these strains was 64 mol%. On the basis of 16S rRNA gene sequence similarity, these strains were shown to belong to the genus Burkholderia. Although their calculated 16S rRNA gene sequence similarity values to Burkholderia silvatlantica, Burkholderia mimosarum, Burkholderia ferrariae and Burkholderia tropica were 98.5, 98.2, 98.0 and 97.0 %, respectively, the isolates formed a distinct group in phylogenetic trees, and the DNA–DNA relatedness values of strain SA41T to these species were 39, 41, 39 and 33 %, respectively. The results of physiological and biochemical tests, including whole-cell protein pattern analysis, allowed phenotypic differentiation of these strains from the published Burkholderia species. Therefore, strains SA41T, SA42 and SA53 represent a novel species for which the name Burkholderia heleia sp. nov. is proposed. The type strain is SA41T (=NBRC 101817T=VTCC-D6-7T).


2006 ◽  
Vol 56 (4) ◽  
pp. 889-893 ◽  
Author(s):  
Cheng-Hui Xie ◽  
Akira Yokota

Three yellow-pigmented strains associated with rice plants were characterized by using a polyphasic approach. The nitrogen-fixing abilities of these strains were confirmed by acetylene reduction assay and nifH gene detection. The three strains were found to be very closely related, with 99·9 % 16S rRNA gene sequence similarity and greater than 70 % DNA–DNA hybridization values, suggesting that the three strains represent a single species. 16S rRNA gene sequence analysis indicated that the strains were closely related to Sphingomonas trueperi, with 99·5 % similarity. The chemotaxonomic characteristics (G+C content of the DNA of 68·0 mol%, ubiquinone Q-10 system, 2-OH as the only hydroxy fatty acid and homospermidine as the sole polyamine) were similar to those of members of the genus Sphingomonas. Based on DNA–DNA hybridization values and physiological characteristics, the three novel strains could be differentiated from other recognized species of the genus Sphingomonas. The name Sphingomonas azotifigens sp. nov. is proposed to accommodate these bacterial strains; the type strain is Y39T (=NBRC 15497T=IAM 15283T=CCTCC AB205007T).


Author(s):  
Shadi Khodamoradi ◽  
Richard L. Hahnke ◽  
Yvonne Mast ◽  
Peter Schumann ◽  
Peter Kämpfer ◽  
...  

AbstractStrain M2T was isolated from the beach of Cuxhaven, Wadden Sea, Germany, in course of a program to attain new producers of bioactive natural products. Strain M2T produces litoralimycin and sulfomycin-type thiopeptides. Bioinformatic analysis revealed a potential biosynthetic gene cluster encoding for the M2T thiopeptides. The strain is Gram-stain-positive, rod shaped, non-motile, spore forming, showing a yellow colony color and forms extensively branched substrate mycelium and aerial hyphae. Inferred from the 16S rRNA gene phylogeny strain M2T affiliates with the genus Streptomonospora. It shows 96.6% 16S rRNA gene sequence similarity to the type species Streptomonospora salina DSM 44593 T and forms a distinct branch with Streptomonospora sediminis DSM 45723 T with 97.0% 16S rRNA gene sequence similarity. Genome-based phylogenetic analysis revealed that M2T is closely related to Streptomonospora alba YIM 90003 T with a digital DNA-DNA hybridisation (dDDH) value of 26.6%. The predominant menaquinones of M2T are MK-10(H6), MK-10(H8), and MK-11(H6) (> 10%). Major cellular fatty acids are iso-C16:0, anteiso C17:0 and C18:0 10-methyl. The polar lipid profile consisted of diphosphatidylglycerol phosphatidyl glycerol, phosphatidylinositol, phosphatidylcholine, phosphatidylethanolamine, three glycolipids, two unknown phospholipids, and two unknown lipids. The genome size of type strain M2T is 5,878,427 bp with 72.1 mol % G + C content. Based on the results obtained from phylogenetic and chemotaxonomic studies, strain M2T (= DSM 106425 T = NCCB 100650 T) is considered to represent a novel species within the genus Streptomonospora for which the name Streptomonospora litoralis sp. nov. is proposed.


2014 ◽  
Vol 64 (Pt_11) ◽  
pp. 3877-3884 ◽  
Author(s):  
Celine De Maesschalck ◽  
Filip Van Immerseel ◽  
Venessa Eeckhaut ◽  
Siegrid De Baere ◽  
Margo Cnockaert ◽  
...  

Strains LMG 27428T and LMG 27427 were isolated from the caecal content of a chicken and produced butyric, lactic and formic acids as major metabolic end products. The genomic DNA G+C contents of strains LMG 27428T and LMG 27427 were 40.4 and 38.8 mol%. On the basis of 16S rRNA gene sequence similarity, both strains were most closely related to the generically misclassified Streptococcus pleomorphus ATCC 29734T. Strain LMG 27428T could be distinguished from S. pleomorphus ATCC 29734T based on production of more lactic acid and less formic acid in M2GSC medium, a higher DNA G+C content and the absence of activities of acid phosphatase and leucine, arginine, leucyl glycine, pyroglutamic acid, glycine and histidine arylamidases, while strain LMG 27428 was biochemically indistinguishable from S. pleomorphus ATCC 29734T. The novel genus Faecalicoccus gen. nov. within the family Erysipelotrichaceae is proposed to accommodate strains LMG 27428T and LMG 27427. Strain LMG 27428T ( = DSM 26963T) is the type strain of Faecalicoccus acidiformans sp. nov., and strain LMG 27427 ( = DSM 26962) is a strain of Faecalicoccus pleomorphus comb. nov. (type strain LMG 17756T = ATCC 29734T = DSM 20574T). Furthermore, the nearest phylogenetic neighbours of the genus Faecalicoccus are the generically misclassified Eubacterium cylindroides DSM 3983T (94.4 % 16S rRNA gene sequence similarity to strain LMG 27428T) and Eubacterium biforme DSM 3989T (92.7 % 16S rRNA gene sequence similarity to strain LMG 27428T). We present genotypic and phenotypic data that allow the differentiation of each of these taxa and propose to reclassify these generically misnamed species of the genus Eubacterium formally as Faecalitalea cylindroides gen. nov., comb. nov. and Holdemanella biformis gen. nov., comb. nov., respectively. The type strain of Faecalitalea cylindroides is DSM 3983T = ATCC 27803T = JCM 10261T and that of Holdemanella biformis is DSM 3989T = ATCC 27806T = CCUG 28091T.


1999 ◽  
Vol 65 (7) ◽  
pp. 2942-2946 ◽  
Author(s):  
Carlos R. Osorio ◽  
Matthew D. Collins ◽  
Alicia E. Toranzo ◽  
Juan L. Barja ◽  
Jesús L. Romalde

ABSTRACT The causative agent of fish pasteurellosis, the organism formerly known as Pasteurella piscicida, has been reclassified asPhotobacterium damselae subsp. piscicida on the basis of 16S rRNA gene sequence comparisons and chromosomal DNA-DNA hybridization data; thus, this organism belongs to the same species asPhotobacterium damselae subsp. damselae(formerly Vibrio damselae). Since reassignment of P. damselae subsp. piscicida was based on only two strains, one objective of the present work was to confirm the taxonomic position of this fish pathogen by sequencing the 16S rRNA genes of 26 strains having different geographic and host origins. In addition, a nested PCR protocol for detection of P. damselae based on 16S rRNA was developed. This PCR protocol was validated by testing 35 target and 24 nontarget pure cultures, and the detection limits obtained ranged from 1 pg to 10 fg of DNA (200 to 20 cells). A similar level of sensitivity was observed when the PCR protocol was applied to fish tissues spiked with bacteria. The PCR approach described in this paper allows detection of the pathogen in mixed plate cultures obtained from asymptomatic fish suspected to be carriers of P. damselae subsp. piscicida, in which growth of this bacterium cannot be visualized. Our results indicate that the selective primers which we designed represent a powerful tool for sensitive and specific detection of fish pasteurellosis.


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