Escherichia ruysiae sp. nov., a novel Gram-stain-negative bacterium, isolated from a faecal sample of an international traveller.

The genus Escherichia comprises five species and at least five lineages currently not assigned to any species, termed 'Escherichia cryptic clades'. We isolated an Escherichia strain from an international traveller and resolved the complete DNA sequence of the chromosome and an IncI multidrug resistance plasmid using Illumina and Nanopore whole-genome sequencing (WGS). Strain OPT1704T can be differentiated from existing Escherichia species using biochemical (VITEK2) and genomic tests [average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH)]. Phylogenetic analysis based on alignment of 16S rRNA sequences and 682 concatenated core genes showed similar results. Our analysis further revealed that strain OPT1704T falls within Escherichia cryptic clade IV and is closely related to cryptic clade III. Combining our analyses with publicly available WGS data of cryptic clades III and IV from Enterobase confirmed the close relationship between clades III and IV (>96 % interclade ANI), warranting assignment of both clades to the same novel species. We propose Escherichia ruysiae sp. nov. as a novel species, encompassing Escherichia cryptic clades III and IV (type strain OPT1704T=NCCB 100732T=NCTC 14359T).

Short- and long-term redox regulation of photosynthetic light energy distribution and photosystem stoichiometry by acetate metabolism in the green alga, Chlamydobotrys stellata.

The effect of acetate metabolism on the light energy distribution between the two photosystems, on the PS II/PS I stoichiometry and on the expression of psbA and psbB and psaA genes was investigated in the green alga, Chlamydobotrys stellata during autotrophic (CO(2)), mixotrophic (CO(2) plus acetate) and photoheterotrophic (only acetate) cultivation. It was observed that acetate assimilation in the glyoxylate cycle resulted in a large drop in the ATP content and a concomitant increase in the NADPH content of the cells. The combined effect of high NADPH concentration and linear electron transport brought about an over-reduction of the inter-photosystem electron transport components. The reduced state of the inter-photosystem components initiated a state 1/state 2 transition of LHC II and a decrease in the PS II/PS I ratio. The PS II/ PS I ratio was reduced because the synthesis of PS II reaction centers was repressed and that of the PS I reaction centers was slightly enhanced by acetate cultivation. The amount of PsbA and PsbB proteins of PS II and the abundance of psbA mRNA decreased. The abundance of PS I PsaA protein and psaAmRNA were only slightly increased. All of the acetate-induced effects were reversible when the cells were transferred back to an acetate-free medium. Our observations demonstrate that the expression of the PS II psbA and psbB and PS I psaA genes is regulated by the redox state of the inter-photosystem components at the transcriptional level. Experiments carried out in the presence of DBMIB which facilitates the reduction of plastoquinone pool indicate that the expression of genes encoding the components of PS II and PS I are controlled by the redox state of a component (cytochrome b/f complex) located behind the plastoquinone pool.

Involvement of the donor tyrosine-D1 (Y d) in Photosystem II electron transport in the green alga, Chlamydobotrys stellata.

The light-induced oxidation of the accessory donor tyrosine-D (YD) has been studied by measurements of the EPR Signal IIslow at room temperature in the autotrophically and photoheterotrophically cultivated alga Chlamydobotrys stellata. After illumination and dark adaptation, YD Signal IIslow was observed only in autotrophic algae, i.e. under conditions of a linear photosynthetic electron transfer from water to NADP(+). The addition of artificial electron acceptors phenyl-p-benzoquinone (PPQ) or dichloro-p-benzoquinone (DCQ) to the autotrophic cells caused an almost negligible increase of this signal. When photosynthetic electron flow and oxygen evolution were diminished by removal of the carbon source CO2 and addition of acetate (photoheterotrophy), a pronounced YD Signal IIslow was seen only in presence of DCQ or PPQ. Several possibilities are discussed to explain the absence of YD Signal IIslow in photoheterotrophic Chl. stellata such as the existence of a cyclic PS II electron flow very effectively reducing P680 and thereby preventing the possibility of YD oxidation. Artificial electron acceptors withdraw electrons from this cycle thus keeping the primary quinone acceptor, QA, oxidized and thereby diminishing the reduction of P680 (+) by cyclic PSII. This leads to the appearance of the YD Signal IIslow also in the photoheterotrophically grown algae.

Hydrogen Photoevolution Indicates an Increase in the Antenna Size of Photosystem I in Chlamydobotrys stellata during Transition from Autotrophic to Photoheterotrophic Nutrition.

The changes in the light-harvesting antenna size of photosystem I were investigated in the green alga Chlamydobotrys stellata during transition from autotrophic to photoheterotrophic nutrition by measuring the light-saturation behavior of hydrogen evolution following single turnover flashes. It was found that during autotrophic-to-photoheterotrophic transition the antenna size of photosystem I increased from 180 to 250 chlorophyll. The chlorophyll (a + b)/P700 ratio decreased from 800 to 550. The electron transport of photosystem I measured from reduced 2,6-dichloro-phenolindophenol to methylviologen was accelerated 1.4 times. In the 77K fluorescence spectra, the photosystem II fluorescence yield was considerably lowered relative to the photosystem I fluorescence yield. It is suggested that the increased light-harvesting capacity and redistribution of absorbed excitation energy in favor of photosystem I is a response of photoheterotrophic algae to meet the ATP demand for acetate metabolism by efficient photosystem I cyclic electron transport when the noncyclic photophosphorylation is inhibited by CO(2) deficiency.

Thermoluminescence study of the in vivo effects of bicarbonate depletion and acetate/formate presence in the two algae Chlamydobotrys stellata and Chlamydomonas reinhardtii.

We investigated the influence of CO2/HCO3 (-)-depletion and of the presence of acetate and formate on the in vivo photosynthetic electron transport in the two green algae Chlamydobotrys stellata and Chlamydomonas reinhardtii by means of thermoluminescence technique and mathematical glow curve analysis. The main effects of the removal of CO2 from the algal cultures was: (1) A shift of the glow curve peak position to lower temperatures resulting from a decrease of the B band and an increase of the Q band. (2) Treatment of CO2-deficient Chl. stellata with DCMU yielded two thermoluminescence bands in the Q band region peaking at around +12°C and +5°C; in case of Chl. reinhardtii DCMU treatment induced only one band with an emission maximum at +5°C. The presence of acetate or formate in CO2-depleted algal cultures lowered the intensities of all of the individual TL bands but that of a HT band (TL+37). The effects of CO2-depletion and of the presence of anions were fully reversible.

Flash oxygen yield patterns of autotrophically and photoheterotrophically grown Chlamydobotrys stellata in the presence and absence of lipophilic acceptors.

The obligate phototrophic green alga Chlamydobotrys stellata does not evolve oxygen when grown in CO2-free atmosphere on acetate. With the application of the lipophilic acceptor 2,6-dichloro-p-benzoquinone it was investigated whether this phenomenon is caused by the inactivation of the water-splitting system or by an inhibition of the electron transport chain. It was found that in the presence of DCQ, the photoheterotrophic alga exhibited a normal period-4 flash oxygen pattern, but the steady state yield was only 25% of that measured in the autotrophic cells. After DCQ addition, the initial distribution of S-states and the values of the transition probabilities proved to be the same in the autotrophic and photoheterotrophic algae. These results indicate that photoheterotrophic growth conditions inhibit the electron transport of Chl. stellata behind the acceptor site of DCQ, but the water-splitting system remains active with a reduced oxygen evolving capacity.

[Neurosarcoidosis. Comparative analysis of the clinical profile based on 537 cases from the world literature up to 1963 and from 1976-1988]. / Neurosarkoidose. Vergleichende Analyse des klinischen Profils anhand von 537 Beobachtungen aus der Weltliteratur bis 1963 und von 1976-1988.

Observation of neurosarcoidosis in a thirty-year-old black female characterised predominantly by bilateral facial nerve paralysis gave rise to a review of literature since 1978 and also to a comparison with an early study in 1963. As described 1963 the clinical picture is characterized by increased protein content of the CSF (33.8%), facial nerve paresis (25.5%), pleocytosis (23%), diabetes insipidus (21%), hemiparesis (17.2%), organic psychosis (16.9%), papilloedema (15.5%), ataxia (13%), convulsive seizures (12.5%), optic atrophy (12.5%), loss of hearing (12.2%), nystagmus (8.6%) and numerous other symptoms more rarely found. This corresponds to the symptoms of chronic basal meningitis with an infiltration in the neighbouring structures of brain and less frequently the spinal cord. In only 58.7% of the cases (presumably at the onset of sarcoidosis) was the bronchial tract (or the lungs) affected, in 11.5% the skin or the eyes. Although the clinical picture is clear enough the etiology has yet to be determined. Evidence of a pathogen or a pathogenic agent (analogous to berylliosis) has never been established to date. On the other hand there are some indications of a disturbance in the immune system, perhaps of a particular genetic foundation since sarcoidosis strikes black patients with conspicuous frequency. There exist more cases in one family. Exceeding expected random distribution, many patients have the HLA-Factor B 8 (on the chromosome 6) and DR 3. The Kveim-Test was in 71 cases positive, in 12 cases negative. The possibilities of carrying out studies of CSF - analogous to the studies of bronchial lavage - in the most cases of neurosarcoidosis have not been exhausted as to determine the activity of the T-lymphocytes, the interleucines, the angiotensin-converting enzyme while the Gallium 67 scintigraphy and other methods to determine the non-specific activity of the inflammation. The efficiency of the treatment with corticosteroids (Prednison or Triamcinolonacetonid) depends of the phase of the inflammatory process. 12% of the registered cases died.

Bicarbonate in vivo Requirement of Photosystem II in the Green Alga Chlamydobotrys stellata.

Flash induced 685 nm fluorescence emission of preilluminated and dark kept Chlamydobotrys stellata has been measured under conditions of CO(2)-deprivation. The difference in fluorescence intensity between dark kept and preilluminated cells is taken as a measure for the reduced state of the primary stable electron acceptor of photosystem II, Q, at the given intensity of preillumination. CO(2) removal from growing cultures of this alga for 15 min diminishes photosynthetic electron transport at the oxidizing side of this photosystem. Prolonged CO(2)-absence influences also its reducing side. Measurements of flash induced oxygen yields support the conclusion that both sides of photosystem II are affected in the absence of bicarbonate.