Search results for "Microbio"
showing 10 items of 8741 documents
Changes in the Pi uptake and polyP accumulation in Saccharomyces cerevisiae strains deficient in the synthesis of trehalose and/or glycerol
2007
Abstract The intracellular level of free inorganic orthophosphate (P i ) in yeast cells generally depends on the P i uptake capacity, energy state of the cells in respect to the activity of the membrane-associated ATPases and on the activity of metabolic pathways involved in the production of glycerol and trehalose. Batch fermentation was performed to investigate the carbon substrate consumption, the P i uptake capacity and product formation by four Saccharomyces cerevisiae strains differing in their ability to produce glycerol and/or trehalose. The consumption of P i in mutant strains with a lack of the synthesis of the trehalose and/or glycerol exceeded the level for a wild type strain ab…
Molar growth yields ofZymomonas mobilis on glucose after the transition from anaerobic to aerobic continuous growth
1999
An increase in the molar growth yield (Y X/S = 14.3-20.3 g/mol) on glucose (25 mM) was achieved after the transition of Zymomonas mobilis ATCC 29191 from anaerobic to aerobic steady state growth at dilution rates of D = 0.31-0.40 1/h and under oxygen-unlimited conditions. The transfer of anaerobically or aerobically grown steady state cells into a fresh medium resulted in the higher values of Y X/S . A positive correlation was established between biomass and acetaldehyde yield within the range of 5-9 mM acetaldehyde in the medium. An inhibitory effect of the exogenously added acetaldehyde (Kj = 16.7 ± 2.8 mM) on the ATPase activity was observed in vitro, using cell-free extracts of anaerobi…
Magnaporthe oryzae as an expression host for the production of the unspecific peroxygenase AaeUPO from the basidiomycete Agrocybe aegerita.
2021
Abstract The filamentous fungus Magnaporthe oryzae has the potential to be developed as an alternative platform organism for the heterologous production of industrially important enzymes. M. oryzae is easy to handle, fast‐growing and unlike yeast, posttranslational modifications like N‐glycosylations are similar to the human organism. Here, we established M. oryzae as a host for the expression of the unspecific peroxygenase from the basidiomycete Agrocybe aegerita (AaeUPO). Note, UPOs are attractive biocatalysts for selective oxyfunctionalization of non‐activated carbon‐hydrogen bonds. To improve and simplify the isolation of AaeUPO in M. oryzae, we fused a Magnaporthe signal peptide for pr…
The L-tartrate/succinate antiporter TtdT (YgjE) of L-tartrate fermentation in Escherichia coli.
2007
ABSTRACT Escherichia coli ferments l -tartrate under anaerobic conditions in the presence of an additional electron donor to succinate. The carrier for l -tartrate uptake and succinate export and its relation to the general C 4 -dicarboxylate carriers DcuA, DcuB, and DcuC were studied. The secondary carrier TtdT, encoded by the ttdT (previously called ygjE ) gene, is required for the uptake of l -tartrate. The ttdT gene is located downstream of the ttdA and ttdB genes, encoding the l -tartrate dehydratase TtdAB. Analysis of mRNA by reverse transcription-PCR showed that ttdA , ttdB , and ttdT are cotranscribed. Deletion of ttdT abolished growth by l -tartrate and degradation of l -tartrate c…
Utilizing genetically engineered bacteria to produce plant-specific glucosides
2001
Plant-derived glucosides have attracted much attention due to their widespread applications. This class of products is difficult to isolate or to synthesize in pure form because of the resulting low yields. Thus, simple approaches for the generation of such glucosides would be highly beneficial. We purified and characterized a novel glucosyltransferase from plant cell suspension cultures of Rauvolfia serpentina, which showed rather low substrate specificity. We obtained its cDNA and expressed the active recombinant protein in bacteria (Escherichia coli) with excellent plant-specific glucosylation efficiencies. Compared with the plant system, the bacteria delivered the new enzyme, which was …
Chemical composition and antimicrobial activity of the essential oil ofCurcuma leucorhizaRoxb
2012
The essential oils obtained by hydrodistillation from the rhizomes and leaves of Curcuma leucorhiza Roxb. were analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS) for the first time. A total of forty-nine compounds were identified in both oils. The main compounds in the rhizome and leaf oils were germacrone (9.6–19.7%), curdione (19.1–19.5%), camphor (7.2–8.1%), 1,8-cineole (4.0–7.4%), curzerene (3.0–5.7%), linalool (5.2–5.4%), neo-curdione (2.8–4.6%) and isoborneol (2.0–3.8%). Screening of the essential oils showed promising antibacterial activity (7–16 mm inhibition zone) against Streptococcus mutans, Pseudomonas putida, Bacillus subtilis, Klebsiella pneumoniae and antifu…
Über die mikrobiologische Umwandlung N-haltiger Substrate. 4. Mitt.: Über die mikrobiologische Umwandlung von 5-Hydroxyindol durch Claviceps purpurea…
1968
Aus 5-Hydroxyindol wird durch den Claviceps purpurea-Stamm 47 A 5-Hydroxytryptophan und ω-N-Acetyl-5-hydroxy-tryptophan, durch Cordyceps militaris ω-N-Acetyl-5-hydroxytryptophan und ω-N-Acetyl-serotonin, durch Aspergillus oryzae nur ω-N-Acetyl-serotonin in der Schuttelkultur gebildet. 5-Hydroxyindole, added to submerged cultures, is converted into 5-hydroxytryptophan and ω-N-acetyl-5-hydroxytryptophan by Claviceps purpurea strain 47 A; into ω-N-acetyl-5-hydroxytryptophan and ω-N-acetyl-serotonin by Cordiceps militaris; and only into-ω-N-acetyl-serotonin by Aspergillus oryzae.
A search for beta-lactamase in chlamydiae, mycoplasmas, planctomycetes, and cyanelles: bacteria and bacterial descendants at different phylogenetic p…
2000
Bacteria from different phylogenetic positions such as chlamydiae, mycoplasmas, planctomycetes and also endosymbiotic murein-containing cyanelles were investigated for the production of beta-lactamases. No beta-lactamase activity was found in bacteria lacking murein such as Chlamydia pneumoniae, Mycoplasma pneumoniae, Pirellula marina and Planctomyces maris. In the murein-containing cyanelles of Cyanophora paradoxa no beta-lactamase activity could be detected.
ITS region of Pythium canariense sp. nov., its morphology and its interaction with Botrytis cinerea.
2002
A new species Pythium canariense (CI-07), isolated from soil samples taken in the San Nicolas region of the Canary islands (Gran Canaria, Spain), is being described here. This species is characterised by its spherical to pyriform, intercalary to catenulate sporangia, smooth-walled terminal oogonia supplied with monoclinous and diclinous antheridia which at times are branched and wrap around the female gametangia. The fungus has an antagonistic effect on Botrytis cinerea, the grey mould fungus. Morphological features are being given here together with the sequence of the complete internal transcribed spacer region of the nuclear ribosomal DNA of the fungus, its comparison with related specie…
ITS1 region of the rDNA of Pythium megacarpum sp. nov., its taxonomy, and its comparison with related species.
2000
Pythium megacarpum sp. nov., was isolated from a soil sample taken from a wheat field in Lille in northern France. It was mistakenly described as Pythium ostracodes Drechsler [Paul, B (1994) Cryptogam. -Mycol. 15,263-271]. Despite morphological resemblance, the comparison between the internal transcribed spacer (ITS)1 regions of the rDNA of the two fungi, leaves no doubt of their different identities. This species is unique because of its large oogonia and plerotic, thick walled oospores, its monoclinous antheridia with large antheridial cells and its lack of zoospores. The character combination of P. megacarpum and the ITS1 sequence of its rDNA, justifies the creation of a new species with…