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1.
Jamal Mouslim Lucien David Gilles Pétel Michel Gendraud 《Applied microbiology and biotechnology》1993,39(4-5):585-588
Addition of methyl oleate to a Streptomyces hygroscopicus NRRL B-1865 culture modified the metabolic properties of this strain. This addition decreased the pH of the medium, increased the valine uptake of the cells and reduced their consumption of glucose until the beginning of antibiotic biosynthesis, which was delayed. At the same time, an increase in growth (× 1.8) and a marked improvement in antibiotic production (× 20) could be observed. The use of labelled methyl oleate showed that methyl oleate was not a precursor of antibiotics produced by S. hygroscopicus NRRL B-1865. It is suggested that methyl oleate addition may cause some alteration in membrane permeability, inducing an increase in H+ extrusion and stimulating the accumulation of branched amino acids, known to be direct precursors of polyether antibiotics.
Correspondence to: L. David 相似文献
2.
Enzymatic labeling of nucleic acids is a fundamental tool in molecular biology with virtually every aspect of nucleic acid
hybridization technique involving the use of labeled probes. Different methods for enzymatic labeling of DNA, RNA and oligonucleotide
probes are available today. In this review, we will describe both radioactive and nonradioactive labeling methods, yet the
choice of system for labeling the probe depends on the application under study. 相似文献
3.
Aline Frville Bndicte Gnangnon Annie Z. Tremp Caroline De Witte Katia Cailliau Alain Martoriati El Moukthar Aliouat Priyanka Fernandes Cerina Chhuon Olivier Silvie Sabrina Marion Ida Chiara Guerrera Johannes T. Dessens Christine Pierrot Jamal Khalife 《Open biology》2022,12(8)
Protein phosphatase 1 (PP1) is a key enzyme for Plasmodium development. However, the detailed mechanisms underlying its regulation remain to be deciphered. Here, we report the functional characterization of the Plasmodium berghei leucine-rich repeat protein 1 (PbLRR1), an orthologue of SDS22, one of the most ancient and conserved PP1 interactors. Our study shows that PbLRR1 is expressed during intra-erythrocytic development of the parasite, and up to the zygote stage in mosquitoes. PbLRR1 can be found in complex with PbPP1 in both asexual and sexual stages and inhibits its phosphatase activity. Genetic analysis demonstrates that PbLRR1 depletion adversely affects the development of oocysts. PbLRR1 interactome analysis associated with phospho-proteomics studies identifies several novel putative PbLRR1/PbPP1 partners. Some of these partners have previously been characterized as essential for the parasite sexual development. Interestingly, and for the first time, Inhibitor 3 (I3), a well-known and direct interactant of Plasmodium PP1, was found to be drastically hypophosphorylated in PbLRR1-depleted parasites. These data, along with the detection of I3 with PP1 in the LRR1 interactome, strongly suggest that the phosphorylation status of PbI3 is under the control of the PP1–LRR1 complex and could contribute (in)directly to oocyst development. This study provides new insights into previously unrecognized PbPP1 fine regulation of Plasmodium oocyst development through its interaction with PbLRR1. 相似文献
4.
We conducted a prospective study to evaluate the prevalence and epidemiology of CDI in Kuwait government hospitals over a 3-year period, January 2003 to December 2005, to determine the ribotypes responsible for CDI and to estimate the prevalence of ribotype 027. We also conducted a case-control study to identify the risk factors in our patient population. A total of 697 stool samples from patients with suspected CDI were obtained and sent to Anaerobe Reference Laboratory, Faculty of Medicine, Kuwait University for Clostridium difficile toxin detection, culture and PCR ribotyping. During the period, 73 (10.5%) out of 697 patients met the case definition of CDI. Of these, 56 (76.7%) were hospital-acquired and 17 (23.3%) were from outpatient clinics. Thus, the prevalence of hospital-acquired CDI amongst patients with diarrhoea was 8% over the study period; the prevalence in 2003, 2004 and 2005 was 9.7%, 7.8% and 7.2%, respectively. Our data showed that 42.9% of the CDI patients were above 60 years, of which >79% were aged 71 years and above. Patients with CDI were more likely than the controls to have been exposed to immunosuppressive drugs and feeding via nasogastric tube. The most common ribotypes isolated during this study were 002, 001, 126 and 140 and they represent 55.1% of all isolates. PCR ribotype 027 was not isolated. 相似文献
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6.
Analysis of the relative amount and distribution pattern of phloem sclerenchyma in some 29 tropical trees of India was carried out with systematic considerations. Both the features exhibited considerable diversity among the species analyzed. The extent of area occupied by sclerenchyma in transections of the bark of these species varied from zero to 35% and 3 to 49% in the conducting and non-conducting phloem zones respectively, the overall amount constituting about 3 to 45% of the secondary phloem as a whole. The sclerenchyma cells differentiated either as isolated elements or in the form of bands or fascicles of diverse shape and size showing various distribution patterns. 相似文献
7.
The isolation of bergenin, 2-hydroxy-4-benzyloxyacetophenone and the related dimer and stilbene from Gnetum ula is reported. 相似文献
8.
9.
Yasir Iftikhar Mazhar Abbas Mustansar Mubeen Muhammad Zafar-ul-Hye Faheema Bakhtawar Sonum Bashir Ashara Sajid Muhammad Asif Shabbir 《Phyton》2021,90(4):1063-1074
Tristeza is a devastating viral disease in all the citrus growing countries throughout the world and has killed millions of citrus trees in severely affected orchards. The citrus species grafted on sour orange rootstock are affected
by this disease. Predominantly, the sweet orange, grapefruit and lime trees grafted on sour orange exhibit severe
symptoms like quick decline, vein clearing, pin holing, bark scaling and degeneration leading to variable symptoms. Symptomatic expression of Citrus tristeza virus (CTV) in different hosts has been attributed to virus isolates
which are from severe to mild. Different serological and molecular assays have been deployed to differentiate the
strains of CTV. Citrus tristeza virus is diversified towards its strains on the basis of biological, serological and
molecular characterization. Phenotypic expression is due to genetic alteration and different molecular basis have
now been adopted for strain differentiation. This review will give a brief idea about the different CTV isolates,
their characterization based on nucleic acid and serological assays. Different methods along with salient features
for strain characterization has also been reviewed. This review will also open the new aspects towards formulation
of management strategies through different detection techniques. 相似文献
10.
Che Mat Mohd Firdaus Mohamad Hanif Ezanee Azlina Abdul Murad Nor Azian Ibrahim Kamariah Harun Roslan Jamal Rahman 《Molecular biology reports》2021,48(2):1493-1503
Molecular Biology Reports - Despite the advancements in primary brain tumour diagnoses and treatments, the mortality rate remains high, particularly in glioblastoma (GBM). Chemoresistance,... 相似文献