Utilization of Alcohols by Rhodopseudomonas sp. No. 7 Isolated from n-Propanol–Enrichment Cultures

A purple non-sulfur bacterium, Rhodopseudomonas sp. No. 7, was isolated from n-propanol–enrichment cultures under anaerobic-light conditions. Strain No. 7 can produce hydrogen from alcohols. The rate of hydrogen production from n-propanol was 34 μl/hr/mg dry cells. Strain No. 7 showed multiplication by budding and the best growth on n-propanol among other organic compounds tested. But its growth on n-propanol was poor under aerobic-dark conditions. NAD-linked alcohol dehydrogenase, NAD-linked aldehyde dehydrogenase, acyl-CoA synthetase and malate synthetase were found in strain No. 7. These enzymes were constitutive. On the other hand, isocitrate lyase was induced in cells grown on ethanol but not on n-propanol. No activity of phenazine methosulfate-linked alcohol dehydrogenase was detected in strain No. 7.     

Nalidixic acid-resistant mutations of the gyrB gene of Escherichia coli

Summary DNA fragments of 3.4 kb containing the gyrB gene were cloned from Escherichia coli KL-16 and from spontaneous nalidixic acid-resistant mutants. The mutations (nal-24 and nal-31) had been determined to be in the gyrB gene by transduction analysis. Nucleotide sequence analysis of the cloned DNA fragments revealed that nal-24 was a G to A transition at the first base of the 426th codon of the gyrB gene, resulting in an amino acid change from aspartic acid to asparagine, and nal-31 was an A to G transition at the first base of the 447th codon, resulting in an amino acid change from lysine to glutamic acid. This indicates that mutations in the gyrB gene are responsible for nalidixic acid resistance.     

Isolation,functional characterization and stress responses of raffinose synthase genes in sugar beet

Raffinose (sucrosylgalactoside oligosaccharide) is a water soluble carbohydrate and accumulates in response to abiotic stresses in plants. Plant raffinose synthases are poorly characterized, and the genes involved in raffinose biosynthesis are unknown in sugar beet. Here, we report the isolation of two genes encoding raffinose synthase (BvRS1 and BvRS2) as well as a gene encoding galactinol synthase (BvGolS1) from sugar beet. BvRS1 and BvRS2 show high homologies to Arabidopsis raffinose synthase AtRS5. BvRS1 and BvGolS1 were expressed in Escherichia coli. Crude extracts showed the activities of raffinose synthase and galactinol synthase. The K _m values of BvRS1 for galactinol and sucrose and the K _m values of BvGolS1 for UDP-galactose and myo-inositol were determined. The expression levels of BvRS1 were significantly higher than that of BvRS2. The mRNA for BvRS1 was rapidly induced by cold stress whereas the mRNA for BvRS2 was slowly induced by cold and salt stresses. These data suggest that BvRS1 and BvRS2 encode raffinose synthase genes responsible to cold and salt stress, respectively.     

Coordinated ciliary beating requires Odf2-mediated polarization of basal bodies via basal feet

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Highlights? Mice expressing truncated Odf2 cough and sneeze due to primary ciliary dyskinesia ? Full-length Odf2 is needed for the formation of basal body-associated basal feet ? In the absence of basal feet, basal bodies fail to align with planar polarity cues ? Polarization of basal bodies by Odf2 is required for coordinated ciliary beating     

Activation of macrophage-stimulating protein by human airway trypsin-like protease

Macrophage-stimulating protein (MSP) circulates as a proform protein and requires proteolytic processing for activation. Respiratory ciliated cells express the MSP receptor, recepteur d'origine nantais (RON), at the apical surface, which reportedly has an important role in ciliary function. Like RON, human airway trypsin-like protease (HAT) is also expressed at the apical surface of ciliated cells. Here we show that HAT cleaves proMSP at the physiological activation site, Arg483-Val484. MSP processed by HAT could induce chemotactic responses and morphological changes of peritoneal macrophages. In human respiratory epithelial cells, knock down of HAT expression reduced proMSP processing and RON autophosphorylation. We suggest that HAT is important for MSP-RON signaling in the respiratory tract.     

Cytoplasmic incompatibility involving <Emphasis Type="Italic">Cardinium</Emphasis> and <Emphasis Type="Italic">Wolbachia</Emphasis> in the white-backed planthopper <Emphasis Type="Italic">Sogatella furcifera</Emphasis> (Hemiptera: Delphacidae)

Cytoplasmic incompatibility (CI) is a reproductive phenotype induced by bacterial endosymbionts in arthropods. Measured as a reduction in egg hatchability resulting from the crossing of uninfected females with bacteria-infected males, CI increases the frequency of bacteria-infected hosts by restricting the fertilization opportunities of uninfected hosts in populations. Wolbachia, a type of alpha-proteobacteria, is well known as a CI inducer in a wide range of arthropod species, while Cardinium, a member of the phylum Bacteroidetes, is known to cause CI in one wasp and three spider mite species. In this study, dual infection with Cardinium and Wolbachia induced strong CI in a single host, Sogatella furcifera (Horváth), a planthopper species that is naturally infected with both bacteria. Specifically, infection with Cardinium alone was found to cause a 76 % reduction in egg development, and dual infection with Cardinium and Wolbachia a 96 % reduction, indicating that Cardinium induces CI and the dual infection raises the CI level. This study was the first to document reproductive alteration by Cardinium in a diploid host species.     

Calcium Antagonist Isradipine Reduces Metabolic Alterations in Acute Cerebral Ischemia in Spontaneously Hypertensive Rats

The present study was designed to examine the effect of a calcium antagonist isradipine (PN200-110: PN) on local cerebral blood flow and brain tissue metabolism after 1-hour supratentorial ischemia induced by bilateral carotid artery ligation (BCL) in spontaneously hypertensive rats (SHR). PN, dissolved in ethanol plus polyethylene glycol 400, diluted with saline to make the final concentration of 0.25mg/ml and 2.5mg/ml, was administered subcutaneously either 30 min prior to BCL or just after the induction of incomplete cerebral ischemia (n = 7 in each group). Vehicle injection was served as a control group (n = 7). Cerebral blood flow in the parietal cortex (CBF) and the cerebellar cortex (CeBF) was measured by hydrogen clearance technique, and the supra- and infratentorial metabolites of the brain frozen in situ were determined by the enzymatic method. Blood pressure was lowered, but CBF was increased by PN administration in pre-BCL treatment study. After 1 hour of BCL, CBF decreased to around 10% or less of the resting value, being insignificant among the groups. Brain adenosine triphosphate was better preserved in PN-administered groups. The increase in lactate level tended to reduce dose dependently by PN treatment. PN also reduced the metabolic alterations in brain tissue with significance, even when administered just after the induction of forebrain ischemia. It is considered that pre- as well as post-BCL administration of PN is beneficial to attenuate the metabolic alterations in incomplete forebrain ischemia in SHR.     

Production of 2-phenylethanol in roses as the dominant floral scent compound from L-phenylalanine by two key enzymes, a PLP-dependent decarboxylase and a phenylacetaldehyde reductase

We investigated the biosynthetic pathway for 2-phenylethanol, the dominant floral scent compound in roses, using enzyme assays. L-[(2)H8] Phenylalanine was converted to [(2)H8] phenylacetaldehyde and [(2)H8]-2-phenylethanol by two enzymes derived from the flower petals of R. 'Hoh-Jun,' these being identified as pyridoxal-5'-phosphate-dependent L-aromatic amino acid decarboxylase (AADC) and phenylacetaldehyde reductase (PAR). The activity of rose petal AADC to yield phenylacetaldehyde was nine times higher toward L-phenylalanine than toward its D-isomer, and this conversion was not inhibited by iproniazid, a specific inhibitor of monoamine oxidase. Under aerobic conditions, rose petal AADC stoichiometrically produced NH3 together with phenylacetaldehyde during the course of decarboxylation and oxidation, followed by the hydrolysis of L-phenylalanine. Phenylacetaldehyde was subsequently converted to 2-phenylethanol by the action of PAR. PAR showed specificity toward several volatile aldehydes.     

Diversity of Helicobacter pylori cagA and vacA genes in Costa Rica: its relationship with atrophic gastritis and gastric cancer

BACKGROUND: Associations between Helicobacter pylori gene diversity and gastric cancer have not been reported on in Costa Rica, despite its being one of the countries with the highest gastric cancer incidence and mortality rates in the world. The aim of this study was to determine the prevalence of H. pylori cagA and vacA genes and investigate whether it could be correlated with atrophic gastritis (AG) and gastric cancer (GC) in Costa Rica. MATERIALS AND METHODS: Genomic DNAs from isolates of 104 patients classified into two groups: non-atrophic gastritis group (n = 68) and atrophic gastritis group (n = 36), were subjected to PCR-based genotyping of cagA and vacA genes and their correlation with clinical outcome was investigated. Total DNA extractions from gastric tissues of 25 H. pylori-infected gastric cancer patients were utilized for comparative purposes. RESULTS: The presence of cagA (75.3%), vacA s1b (75.3%), and vacA m1 (74.2%) was detected, and colonization by strains with different vacA genotypes in the same stomach was found in 9.7% of the patients. Age- and sex-adjusted vacA s1b and vacA m1 were associated with GC while only vacA m1 was significantly associated with AG. A tendency for association between cagA and vacA s1b, and AG was reported. CONCLUSIONS: The prevalence status of the cagA and vacA (s1/m1) genes in Costa Rica seems to fall between that found in European/North American and East Asian countries, and both cagA and vacA seem to have clinical relevance in this country.