Nigericin and grisorixin methyl ester from the Algerian soil-living Streptomyces youssoufiensis SF10 strain: a computational study on their epimeric structures and evaluation of glioblastoma stem cells growth inhibition.

The present work describes the metabolites produced by a strain identified as Streptomyces youssoufiensis, whose secondary metabolites profile has not been studied so far. The crude ethyl acetate extract was analyzed by high performance liquid chromatography-electrospray ionization mass spectrometry, leading to the detection of the ionophoric polyethers nigericin, epinigericin, abierixin and the newly isolated grisorixin methyl ester. The presence of epimeric forms of nigericin/epinigericin and grisorixin/epigrisorixin has spurred density functional theory computational calculations.

Effect of sulfonylurea tribenuron methyl herbicide on soil Actinobacteria growth and characterization of resistant strains.

Repeated application of pesticides disturbs microbial communities and cause dysfunctions on soil biological processes. Granstar 75 DF is one of the most used sulfonylurea herbicides on cereal crops; it contains 75% of tribenuron-methyl. Assessing the changes on soil microbiota, particularly on the most abundant bacterial groups, will be a useful approach to determine the impact of Granstar herbicide.

High-quality draft genome sequence of Enterobacter sp. Bisph2, a glyphosate-degrading bacterium isolated from a sandy soil of Biskra, Algeria.

Enterobacter sp. strain Bisph2 was isolated from a sandy soil from Biskra, Algeria and exhibits glyphosate-degrading activity. Multilocus sequence analysis of the 16S rRNA, rpoB, hsp60, gyrB and dnaJ genes demonstrated that Bisph2 might be a member of a new species of the genus Enterobacter.

Effects of a sulfonylurea herbicide on the soil bacterial community.

Sulfonylurea herbicides are widely used on a wide range of crops to control weeds. Chevalier® OnePass herbicide is a sulfonylurea herbicide intensively used on cereal crops in Algeria. No information is yet available about the biodegradation of this herbicide or about its effect on the bacterial community of the soil.

Draft genome sequence of Tsukamurella sp. strain 1534.

A draft genome sequence of Tsukamurella sp., an aerobic bacterium isolated from a human sputum specimen, is described here. A new virus or provirus, TPA4, was characterized.

[Antibacterial activity of rare Streptomyces species against clinical resistant bacteria].

In the search for new antibiotics from Steptomyces, investigating extremes habitats enhances the probability of isolating novel producers. In this context, the antibacterial activity of four Streptomyces strains isolated from Ezzmoul saltpans was studied. Two of them showed antibacterial activity against antibiotic's resistant bacteria (Bacillus cereus: β-lactamines and sulfamides resistant, Streptococcus faecalis: penicillin, tetracycline and cotrimoxazole resistant, and Staphylococcus aureus Mu 50: vancomycine resistant).

Halomicrobium katesii sp. nov., an extremely halophilic archaeon.

Two extremely halophilic archaea, strains Al-5(T) and K-1, were isolated from Lake Tebenquiche (Atacama Saltern, Chile) and Ezzemoul sabkha (Algeria), respectively. Cells of the two strains were short-rod-shaped and Gram-negative; colonies were orange-pigmented. They grew optimally at 37-40 degrees C and pH 7.

Halomonas sabkhae sp. nov., a moderately halophilic bacterium isolated from an Algerian sabkha.

A novel moderately halophilic bacterium belonging to the genus Halomonas was isolated from brine samples collected from Ezzemoul sabkha in north-eastern Algeria. The cells of strain 5-3(T) were Gram-negative, rod-shaped and non-motile. The strain was catalase- and oxidase-positive and produced an exopolysaccharide.

Theoretical study of Escherichia coli peptide deformylase inhibition by several drugs.

Because peptide deformylase (PDF) is essential for the initiation of translation in eubacteria but not in eukaryotes, it is a potentially interesting target for antibiotics. Computer simulation using docking software can be used to model protein-ligand interactions, and in this brief report we describe its use in optimizing the design in PDF-directed inhibitors. PDF was used as target for a set of five inhibitors with substantial structural differences.

[Polygalacturonase enzyme production from bacterial isolated from raw milk and green and black olives].

Forty microbial strains isolated from raw milk samples and black and green olives were grown in MP5 (mineral pectin 5) medium containing 0.5% lemon pectin. All strains synthesized an extracellular polygalacturonase.

Halorubrum ezzemoulense sp. nov., a halophilic archaeon isolated from Ezzemoul sabkha, Algeria.

A novel extremely halophilic archaeon was isolated from Ezzemoul sabkha, Algeria. The strain, designated 5.1(T), was neutrophilic, motile and Gram-negative.

Establishment of Eubacterium cellulosolvens in the digestive tract of axenic and meroxenic mice: influence of feed cellulose content.

The cellulolytic bacterial species present in the caecum and colon contents of conventionally reared mature mice did not become established in the digestive tract when inoculated to axenic mice, whatever the size of the inoculum or the cellulose content of the diet. The cellulolytic bacterium Eubacterium cellulosolvens SC 10 isolated from mouse digestive flora was unable to become established in the digestive tract of axenic mice whatever the cellulose content of the diet; it requires a feed rich in cellulose and a highly diversified microflora.

Establishment of cellulolytic bacteria in the digestive tract of conventionally reared young mice: effect of the dietary cellulose content in the adult.

Cellulolytic bacteria became established 12 days after birth in the caecum and colon of conventionally-reared mice fed a diet containing 5 p. 100 crude cellulose (Weende). Their population reached a level between 10(6) and 10(7) bacteria per gram of digestive contents in 25-day-old animals.