RESUMO
During the summer period (1525°C), 34 strains of methylotrophic bacteria associated with different species of herbs, shrub, and trees in Pushchino (Moscow oblast, Russia) were isolated on the medium with methanol. Predominance of pink-colored Methylobacterium strains in the phyllosphere of many plants was confirmed by microscopy, enumeration of the colonies from grass leaves, and sequencing of the 16S rRNA genes. Colorless and yellow-pigmented methylotrophs belonged to the genera Methylophilus, Methylobacillus, Hansschlegelia, Methylopila, Xanthobacter, and Paracoccus. All isolates were able to synthesize plant hormones auxins from L-tryptophan (5−50 µg/mL) and are probably plant symbionts.
Assuntos
Biodiversidade , Florestas , Methylobacillus , Methylobacterium , Methylophilus , Paracoccus , Xanthobacter , Methylobacillus/classificação , Methylobacillus/crescimento & desenvolvimento , Methylobacillus/isolamento & purificação , Methylobacterium/classificação , Methylobacterium/crescimento & desenvolvimento , Methylobacterium/isolamento & purificação , Methylophilus/classificação , Methylophilus/crescimento & desenvolvimento , Methylophilus/isolamento & purificação , Paracoccus/classificação , Paracoccus/crescimento & desenvolvimento , Paracoccus/isolamento & purificação , Federação Russa , Xanthobacter/classificação , Xanthobacter/crescimento & desenvolvimento , Xanthobacter/isolamento & purificaçãoRESUMO
A facultative methylotrophic bacterium, strain Lp-1, which was isolated from root nodules of lupine (Lupinus polyphyllus L.) on the medium with methanol as a carbon and energy source, exhibited high similarity of the 16S rRNA gene sequences to Delftia strains (94â99.9%). The cells of Delftia sp. Lp-1 were motile gram-negative rods dividing by binary fission. Predominant fatty acids were C16:0 (34.2%), C16:1ω9 (14.5%), and C18:1ω7c (17.3%). Phosphatidylethanolamine, phosphatidylcholine, and phosphatidylglycerol were the dominant phospholipids. Q8 was the major ubiquinone. Optimal growth occurred at 24â26°C and pH 7.1â7.3; growth was inhibited by 1% NaCl. The organism oxidized methanol with the classical methanol dehydrogenase and used the ribulose bisphosphate pathway of C1 metabolism. Analysis of translated amino acid sequence of the large subunit of the MxaF methanol dehydrogenase revealed 85.5â94% similarity to the sequences of such autotrophic methylotrophs of the class Alphaproteobacteria as Angulomicrobium, Starkeya, and Ancylobacter, indicating the possible acquisition of the mxaF gene via horizontal gene transfer. Delftia sp. Lp-1 (VKM B-3039, DSM 24446), the first methylotrophic member of the genus Delftia, was shown to be a plant symbiont, stimulating plant growth and morphogenesis, increasing the level of photosynthetic pigments and specific leaf weight. It possesses the nifH gene of nitrogen fixation, is capable of phosphate solubilization, synthesis of auxins and siderophores, and is antagonistic to plant pathogenic fungi and bacilli.
Assuntos
Processos Autotróficos/fisiologia , Delftia , Lupinus/microbiologia , Nódulos Radiculares de Plantas/microbiologia , Simbiose/fisiologia , Delftia/classificação , Delftia/genética , Delftia/isolamento & purificação , Delftia/metabolismoRESUMO
The influence of colonization of the pea (Pisum sativum L.) by aerobic methylobacteria of five different species (Methylophilus flavus Ship, Methylobacterium extorquens G10, Methylobacillus arboreus Iva, Methylopila musalis MUSA, Methylopila turkiensis Sidel) on plant resistance to paraquat-induced stresses has been studied. The normal conditions of pea colonization by methylobacteria were characterized by a decrease in the activity of antioxidant enzymes (superoxide dismutase, catalase, and peroxidases) and in the concentrations of endogenous H2O2, proline, and malonic dialdehyde, which is a product of lipid peroxidation and indicator of damage to plant cell membranes, and an increase in the activity of the photosynthetic apparatus (the content of chlorophylls a, b and carotenoids). In the presence of paraquat, the colonized plants had higher activities of antioxidant enzymes, stable photosynthetic indices, and a less intensive accumulation of the products of lipid peroxidation as compared to noncolonized plants. Thus, colonization by methylobacteria considerably increased the adaptive protection of pea plants to the paraquat-induced oxidative stress.
Assuntos
Peroxidação de Lipídeos/fisiologia , Methylobacteriaceae/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Pisum sativum/fisiologia , Aerobiose/fisiologia , Catalase/biossíntese , Paraquat/farmacologia , Pisum sativum/efeitos dos fármacos , Pisum sativum/microbiologia , Peroxidases/biossíntese , Fotossíntese/fisiologia , Superóxido Dismutase/biossínteseRESUMO
Phosphate-solubilizing activity was found in 14 strains of plant-associated aerobic methylobacteria belonging to the genera Methylophilus, Methylobacillus, Methylovorus, Methylopila, Methylobacterium, Delftia, and Ancyclobacter. The growth of methylobacteria on medium with methanol as the carbon and energy source and insoluble tricalcium phosphate as the phosphorus source was accompanied by a decrease in pH due to the accumulation of up to 7 mM formic acid as a methanol oxidation intermediate and by release of 120-280 µM phosphate ions, which can be used by both bacteria and plants. Phosphate-solubilizing activity is a newly revealed role of methylobacteria in phytosymbiosis.
Assuntos
Bactérias Gram-Negativas/metabolismo , Methylobacterium/metabolismo , Fosfatos/metabolismo , Aerobiose , Fosfatos de Cálcio , Meios de Cultura , Delftia/crescimento & desenvolvimento , Delftia/metabolismo , Bactérias Gram-Negativas/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Metanol , Methylobacterium/crescimento & desenvolvimento , Methylophilus/crescimento & desenvolvimento , Methylophilus/metabolismo , Solubilidade , SimbioseRESUMO
OBJECTIVE: Local injections of botulinum toxin type A (BTA) are currently used in treatment of poststroke spasticity. We assessed the efficacy of botulinum treatment using different doses of BTA. MATERIAL AND METHODS: We studied 68 patients with early arm poststroke spasticity in the acute and early recovery stages of stroke (up to 3 months from disease onset), mean age of the patients was 60,3±11,4 years. RESULTS AND CONCLUSION: BTA used in half dose of the mean recommended dose reduced motor disorders thus promoting the prevention of severe spasticity, formation of early contractures and relief of painful shoulder syndrome.
Assuntos
Toxinas Botulínicas Tipo A/uso terapêutico , Espasticidade Muscular/tratamento farmacológico , Fármacos Neuromusculares/uso terapêutico , Reabilitação do Acidente Vascular Cerebral , Idoso , Braço , Toxinas Botulínicas Tipo A/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espasticidade Muscular/etiologia , Fármacos Neuromusculares/administração & dosagem , Acidente Vascular Cerebral/complicaçõesRESUMO
OBJECTIVE: Muscle tone disorders, including poststroke spasticity, is a frequent cause of disability. We studied the efficacy and safety of tizalud (tizanidine) in patients with arm poststroke spasticity. MATERIAL AND METHODS: Forty-four patients were treated with tizalud and botulotoxin A in different doses in complex with rehabilitation measures or without them. RESULTS AND CONCLUSION: The marked improvement (the decrease in spasticity, increase in muscle power and pain syndrome intensity) was noted in patients treated with the combination of tizalud and botulotoxin A.