Lipopeptide biodiversity in antifungal Bacillus strains isolated from Algeria.

Several Bacillus strains have been well studied for their ability to control soil-borne plant diseases. This property is linked to the production of several families of lipopeptides. Depending of their structure, these compounds show antifungal and/or plant systemic resistance inducing activities.

Multiresistant opportunistic pathogenic bacteria isolated from polluted rivers and first detection of nontuberculous mycobacteria in the Algerian aquatic environment.

Opportunistic infections constitute a major challenge for modern medicine mainly because the involved bacteria are usually multiresistant to antibiotics. Most of these bacteria possess remarkable ability to adapt to various ecosystems, including those exposed to anthropogenic activities. This study isolated and identified 21 multiresistant opportunistic bacteria from two polluted rivers, located in Algiers.

Synthesisand Biological Evaluationof New Substituted Hantzsch Thiazole Derivatives from Environmentally Benign One-Pot Synthesis Using Silica Supported Tungstosilisic Acid as Reusable Catalyst.

An efficient and green method has been developed for the synthesis of new substituted Hantzsch thiazole derivatives in 79%-90% yield, via the one-pot multi-component procedure, by the reaction of 3-(bromoacetyl)-4-hydroxy-6-methyl-2-pyran-2-one, thiourea and substituted benzaldehydes in the presence of silica supported tungstosilisic acid, as a reusable catalyst, under conventional heating or under ultrasonic irradiation. The catalyst is recoverable by a simple filtration and can be reused in the subsequent reactions. Most of the thiazoles exhibited significant antibacterial activity compared toamoxicillin and ciprofloxacin as positive controls.

Virgibacillus ainsalahensis sp. nov., a Moderately Halophilic Bacterium Isolated from Sediment of a Saline Lake in South of Algeria.

A Gram-positive, moderately halophilic, endospore-forming bacterium, designated MerV, was isolated from a sediment sample of a saline lake located in Ain Salah, south of Algeria. The cells were rod shaped and motile. Isolate MerV grew at salinity interval of 0.

Structure, biosynthesis, and properties of kurstakins, nonribosomal lipopeptides from Bacillus spp.

A new family of lipopeptides produced by Bacillus thuringiensis, the kurstakins, was discovered in 2000 and considered as a biomarker of this species. Kurstakins are lipoheptapeptides displaying antifungal activities against Stachybotrys charatum. Recently, the biosynthesis mechanism, the regulation of this biosynthesis and the potential new properties of kurstakins were described in the literature.

Bioinformatics and molecular approaches to detect NRPS genes involved in the biosynthesis of kurstakin from Bacillus thuringiensis.

Degenerated primers designed for the detection by polymerase chain reaction of nonribosomal peptide synthetases (NRPS) genes involved in the biosynthesis of lipopeptides were used on genomic DNA from a new isolate of Bacillus thuringiensis CIP 110220. Primers dedicated to surfactin and bacillomycin detection amplified sequences corresponding respectively to the surfactin synthetase operon and to a gene belonging to a new NRPS operon identified in the genome of B. thuringiensis serovar pondicheriensis BSCG 4BA1.