Karaj Region Research Articles

Insecticidal Activity and Chemical Composition of Artemisia sieben Besser Essential Oil from Karaj, Iran

Atremisia sieberi Besser is a widely distributed plant that grows in many areas of Iran and has strong insecticidal activity against stored product pests, so an experiment was conducted to investigate fumigant toxicity of the A. sieberi oil collected from Karaj region of Iran. The oil was applied against one to seven day old adults of three major stored product insects including: Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.), and Tribollium castaneum (Herbst). The potency of fumigant toxicity of A. sieberi on C. maculatus was higher (LC 50: 1.64 μL per L) than S. oryzae (LC 50: 4.41 μL per L) and T. castaneum (LC50: 20.31 μ.L per L). The relationships between the time exposure and oil concentration on mortality show that the mortality was increased as oil concentration and exposure time was increased. The concentration of 185 μL per L and exposure time of 24h was enough to obtain 100% kill of the insects. It was also found that the regions where A. sieberi grows affect essential oil components of the plant and can play an important role in properties of fumigant toxicity.

Halobacillus karajensis sp. nov., a novel moderate halophile.

A moderately halophilic, gram-positive, spore-forming bacterium was isolated from surface saline soil of the Karaj region, Iran. The strain, designated MA-2T, was strictly aerobic with rod-shaped cells that occurred singly, in pairs or short chains. It contained L-Om-D-Asp-type peptidoglycan and the major respiratory lipoquinone was MK-7. It was non-motile and had an ellipsoidal endospore located centrally or subterminally. Growth occurred at 10-49 degrees C and in the pH range 6.0-9.6. Strain MA-2T grew at salinities of 1-24% (w/v) NaCl, showing optimal growth at 10% (w/v). The DNA G + C content was 41.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain MA-2T was associated with Bacillus rRNA group 1. The micro-organisms showing the closest phylogenetic relationship to strain MA-2T were Halobacillus litoralis and Halobacillus trueperi. On the basis of phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence analysis and DNA-DNA similarity data, it is proposed that strain MA-2T (= DSM 14948T = LMG 21515T) should be placed in the genus Halobacillus as the type strain of a novel species, Halobacillus karajensis sp. nov.