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1.
Biologically produced 3-hydroxypropionic acid (3HP) is a potential source for sustainable acrylates and can also find direct use as monomer in the production of biodegradable polymers. For industrial-scale production there is a need for robust cell factories tolerant to high concentration of 3HP, preferably at low pH. Through adaptive laboratory evolution we selected S. cerevisiae strains with improved tolerance to 3HP at pH 3.5. Genome sequencing followed by functional analysis identified the causal mutation in SFA1 gene encoding S-(hydroxymethyl)glutathione dehydrogenase. Based on our findings, we propose that 3HP toxicity is mediated by 3-hydroxypropionic aldehyde (reuterin) and that glutathione-dependent reactions are used for reuterin detoxification. The identified molecular response to 3HP and reuterin may well be a general mechanism for handling resistance to organic acid and aldehydes by living cells. 相似文献
2.
The genus Crepis L. (Asteraceae) comprises more than 200 currently recognized species. Several studies have been conducted on non-volatile phytochemicals of Crepis spp., featuring mainly sesquiterpene lactones and phenolic derivatives. Nevertheless, no report has been made on assessing the volatile constituents of the genus. Therefore, the present study is the first report to the chemical composition of the volatile constituents of two odoriferous Crepis spp., namely C. foetida L. and C. rubra L. Flowers and stems with leaves volatiles were analysed separately by gas chromatography coupled with mass spectrometry. In total, 37 volatile compounds were detected. Salicylaldehyde, carvacrol and aliphatic hydrocarbons are the main components of both C. foetida fractions, however C. rubra flowers are characterized by the abundance of β-sitosterol and eicosanoic acid, while the stems-leaves volatiles revealed to be more complex with hydrocarbons as main constituents.In addition, we investigated the salicylaldehyde rich volatile fraction for its in vitro activity on TNF-α induced ICAM-1 expression. 相似文献
3.
Polysaccharide breakdown by mixed populations of human faecal bacteria 总被引:10,自引:0,他引:10
4.
In order to clarify volatile accumulation patterns along with their adaptability to temperature stress, replicas of two different accessions of Salvia lavandulifolia appointed as chemotypes (A and B) were subjected to increasing temperatures in environmental controlled cabins. Their respective volatile chemical profiles kept their integrity until reaching the growing temperature of 24 °C. Then, remarkable changes were observed. Stressed plants of both accessions showed an increase in the sesquiterpenic fraction and a decrease in the monoterpenic one, although changes in volatile percentages were highly related to the accession. Accession B overexpressed β-caryophyllene, caryophyllene oxide and manool when subjected to the higher temperature tested. On the other hand, accession A mainly showed a remarkable increase of β-bisabolene and viridiflorol. Furthermore, viridiflorol and manool have been confirmed as new chemotaxonomic markers for chemotypes A and B, respectively. The capacity to adjust the production of volatile compounds seems mostly attributed to the genetic background of the plant although more research is needed to understand the stress and its implications for the secondary metabolism. These results contribute remarkably to the chemical phenotyping of this species and may be useful for selection of genotypes. 相似文献
5.
Lennard van der Woude Markus Piotrowski Gruson Klaasse Judith K. Paulus Daniel Krahn Sabrina Ninck Farnusch Kaschani Markus Kaiser Ondřej Novák Karin Ljung Suzanne Bulder Marcel van Verk Basten L. Snoek Martijn Fiers Nathaniel I. Martin Renier A. L. van der Hoorn Stéphanie Robert Sjef Smeekens Martijn van Zanten 《The Plant journal : for cell and molecular biology》2021,106(6):1523-1540
Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2–deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound ‘Heatin’, containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2666-2672
3-Phenylpropionitrile was synthesized from Z-3-phenylpropionaldoxime (0.75 M) in a quantitative yield (98 g/l) by the use of cells of Eschrichia coli JM 109/pOxD-9OF, a transformant harboring a gene for a new enzyme, phenylacetaldoxime dehydratase, from Bacillus sp. strain OxB-1. Other arylalkyl- and alkyl-nitriles were also synthesized in high yields from the corresponding aldoximes. Moreover, 3-phenylpropionitrile was successfully synthesized by the recombinant cells in 70 and 100% yields from 0.1 M unpurified E/Z-3-phenylpropionaldoxime, which is spontaneously formed from 3-phenylpropionaldehyde and hydroxylamine in a butyl acetate/water biphasic system and aqueous phase, respectively. 相似文献
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9.
Antifungal effects of the volatile oils from Allium plants against Trichophyton species and synergism of the oils with ketoconazole 总被引:2,自引:0,他引:2
In an attempt to develop stable and safe antifungal agents from natural products (daily foodstuffs in particular), the activities of essential oils from Allium sativum for. pekinense, A. cepa, and A. fistulosum against three Trichophyton species responsible for severe mycoses in humans were investigated and compared with activity of allicin in this study. The fungistatic activities of Allium oils were evaluated by the broth dilution method and disk diffusion assay. The combined effects of Allium oils with ketoconazole were tested by the checkerboard titer test. Among the tested oils, A. sativum for. pekinense oil exhibited the strongest inhibition of growth of T. rubrum, T. erinacei, and T. soudanense with MICs (minimum inhibiting concentrations) of 64microg/ml, while the activities of A. cepa and A. fistulosum were relatively mild. The inhibiting activities of the oils on Sabouraud agar plates were dose dependent against Trichophyton species. Additionally, these oils showed significant synergistic antifungal activity when combined with ketoconazole in the checkerboard titer test and disk diffusion test. 相似文献
10.
d-Galactose is widely used as an agent to cause aging effects in experimental animals. The present study aims to investigate the effects of hydrogen sulfide (H2S) in human neuroblastoma SH-SY5Y cells exposed to d-galactose. Cells were pretreated with NaHS, an H2S donor, and then exposed to d-galactose (25–400 mM for 48 h). We found that NaHS pretreatment significantly reversed the d-galactose-induced cell death and cellular senescence. MTT assay shows that NaHS significantly increased cell viability from 62.31 ± 1.29% to 72.34 ± 0.46% compared with d-galactose (200 mM) treatment group. The underlying mechanism appeared to involve a reduction by NaHS in the formation of advanced glycation end products (AGEs), which are known to contribute to the progression of age-related diseases. In addition, NaHS decreased the elevation of reactive oxygen species from 151.17 ± 2.07% to 124.8 ± 2.89% and malondialdehyde from 1.72 ± 0.07 to 1.10 ± 0.08 (nmol/mg protein) in SH-SY5Y cells after d-galactose exposure. NaHS also stimulated activities of superoxide dismutase from 0.42 ± 0.05 to 0.73 ± 0.04 (U/mg protein) and glutathione peroxidase from 3.98 ± 0.73 to 14.73 ± 0.77 (nmol/min/mg protein) and upregulated the gene expression levels of copper transport protein ATOX1, glutathione synthetase (GSS) and thioredoxin reductase 1 (TXNRD1) while down-regulated aldehyde oxidase 1 (AOX1). In summary, our data indicate that H2S may have potentially anti-aging effects through the inhibition of AGEs formation and reduction of oxidative stress. 相似文献