IMPROVED STAIN FOR VISUALIZATION OF
            <i>AZOTOBACTER</i>
            ENCYSTMENT

Vela, G. R.; Wyss, Orville

doi:10.1128/jb.87.2.476-477.1964

Cited by 53 publications

(23 citation statements)

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“…Strain SB2 was found to be Gram‐negative and non‐motile. Staining for Azotobacter ‐type cysts was negative using standard procedures (Vela and Wyss, 1964), and neither exospores nor rosettes were observed after 4‐week incubation. Phase‐contrast micrographs showed that they create large and tight aggregates of cells surrounded by a capsule (Fig.…”

Section: Resultsmentioning

confidence: 99%

Characterization of a novel facultative Methylocystis species capable of growth on methane, acetate and ethanol

Lee

Yoon

et al. 2010

Environ Microbiol Rep

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A non-motile strain of Methylocystis, strain SB2, isolated from a spring bog in southeast Michigan, had a curved rod morphology with a typical type II intracytoplasmic membrane system. This organism expressed the membrane-bound or particulate methane monooxygenase (pMMO) as well as a chalkophore with high affinity for copper and did not express the cytoplasmic or soluble methane monooxygenase (sMMO). Strain SB2 was found to grow within the pH range of 6-9, with optimal growth at 6.8. Growth was observed at temperatures ranging between 10°C and 30°C, with no growth at 37°C. The DNA G+C content was 62.9 mol%. Predominant fatty acids were 18:1ω7c (72.7%) and 18:1ω9c (24%) when grown on methane. Phylogenetic comparisons based on both pmoA and 16S rRNA sequences indicated that this organism belonged to the Methylocystis genus, and was closely related to Methylocystis rosea SV97(T) and Methylocystis echinoides IMET10491(T) (98% 16S rRNA gene sequence similarity to both strains). DNA : DNA hybridizations indicated that strain SB2 had 70% similarity with M. rosea SV97(T) . Unlike M. rosea SV97(T) , strain SB2 was able to utilize not only methane for growth, but also ethanol and acetate. Furthermore, the predominant fatty acids in strain SB2 were different from those found in M. rosea SV97(T) , i.e. 54.2% and 39.7% of fatty acids are 18:1ω8 and 18:1ω7 in M. rosea SV97(T) , while 18:1ω8 is completely absent in strain SB2.

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Section: Resultsmentioning

confidence: 99%

Characterization of a novel facultative Methylocystis species capable of growth on methane, acetate and ethanol

Lee

Yoon

et al. 2010

Environ Microbiol Rep

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“…Light microscopy was performed with a Leica DMLB microscope at 100¥ magnification. Prior to the examination of the cells in the microscope they were stained with neutral red and light green SF yellowish (Vela and Wyss, 1964). Electron transmission microscopy was performed with a Tecnai 12 BioTWIN electron microscope (FEI).…”

Section: Light and Electron Transmission Microscopymentioning

confidence: 99%

The Azotobacter vinelandii AlgE mannuronan C‐5‐epimerase family is essential for the in vivo control of alginate monomer composition and for functional cyst formation

Steigedal

Sletta

Moreno

et al. 2008

Environmental Microbiology

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The industrially widely used polysaccharide alginate is a co-polymer of beta-D-mannuronic acid and alpha-L-guluronic acid (G), and the G residues originate from a polymer-level epimerization process catalysed by mannuronan C-5-epimerases. In the genome of the alginate-producing bacterium Azotobacter vinelandii genes encoding one periplasmic (AlgG) and seven secreted such epimerases (AlgE1-7) have been identified. Here we report the generation of a strain (MS163171) in which all the algE genes were inactivated by deletion (algE1-4 and algE6-7) or interruption (algE5). Shake flask-grown MS163171 produced a polymer containing less than 2% G (algG still active), while wild-type alginates contained 25% G. Interestingly, addition of proteases to the MS163171 growth medium resulted in a strong increase in the chain lengths of the alginates produced. MS163171 was found to be unable to form functional cysts, which is a desiccation-resistant differentiated form developed by A. vinelandii under certain environmental conditions. We also generated mutants carrying interruptions in each separate algE gene, and a strain containing algE5 only. Studies of these mutants indicated that single algE gene inactivations, with the exception of algE3, did not affect the fractional G content much. However, for all strains tested the alginate composition varied somewhat as a response to the growth conditions.

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“…For studies of cytological structures by light microscopy, a Nikon Microphot-FXA photomicroscope was used. Culture sample (10±20 ml) was pipetted onto a microscope slide, and a droplet of Azotobacter cyst-speci®c staining solution containing neutral red and light green SF yellowish was added (Vela and Wyss, 1964). The resulting wet mount was subjected to light microscopy using a 100´oil immersion lens.…”

Section: Growth and Microscopy Of A Vinelandiimentioning

confidence: 99%

Mannuronan C‐5 epimerases and cellular differentiation of Azotobacter vinelandii

Høidal

Svanem

Gimmestad

et al. 2000

Environmental Microbiology

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Differentiation in Azotobacter vinelandii involves the encystment of the vegetative cell under adverse environmental circumstances and the germination of the resting cell into the vegetative state when growth conditions are satisfactory again. Morphologically, the encystment process involves the development of a protective coat around the resting cell. This coat partly consists of multiple layers of alginate, which is a copolymer of beta-D-mannuronic acid (M) and alpha-L-guluronic acid (G). Alginate contributes to coat rigidity by virtue of a high content of GG blocks. Such block structures are generated through a family of mannuronan C-5 epimerases that convert M to G after polymerization. Results from immunodetection and light microscopy, using stains that distinguish between different cyst components and types, indicate a correlation between cyst coat organization and the amount and appearance of mannuronan C-5 epimerases in the extracellular medium and attached to the cells. Specific roles of individual members of the epimerase family are indicated. Calcium and magnesium ions appear to have different roles in the structural organization of the cyst coat. Also reported is a new gene sharing strong sequence homology with parts of the epimerase-encoded R-modules. This gene is located within the epimerase gene cluster of Azotobacter vinelandii.

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IMPROVED STAIN FOR VISUALIZATION OF AZOTOBACTER ENCYSTMENT

Cited by 53 publications

References 0 publications

Characterization of a novel facultative Methylocystis species capable of growth on methane, acetate and ethanol

Characterization of a novel facultative Methylocystis species capable of growth on methane, acetate and ethanol

The Azotobacter vinelandii AlgE mannuronan C‐5‐epimerase family is essential for the in vivo control of alginate monomer composition and for functional cyst formation

Mannuronan C‐5 epimerases and cellular differentiation of Azotobacter vinelandii

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