Showing 2 results for B. Ali
M. Niknejad Kazempour, E. Kamran, B. Ali,
Volume 11, Issue 40 (summer 2007)
Abstract
Fire blight caused by Erwinia amylovora, is a serious disease of pome fruits in many areas in the world which causes evaluative necrosis. Indeed, E. amylovora can invade the whole tree solely by internal progression through the host tissues. In this research, symptoms of necrotic shoots and exudates production on infected pear trees in different areas of Guilan province (Astaneh Ashrafieh, Lahijan and Kiashahr) were surveyed. Samples were taken from infected tissues of diseased trees. For isolation of bacterial causal agent, the infected tissues were crushed in pepton water, then 100µl of the extracts were cultured on Sucrose Nutrient Agar (SNA) and Luria Berthani (LB) containing Cyclohexamid antibiotic (50 µg / ml). The isolated bacteria were rod-shaped , gram negative and facultatively an-aerobic. The bacteria produced Levan on media including sucrose , but could not produce fluorescent pigments on King’s B medium. All strains made hypersensitive reaction on tobacco leaves. All isolates were oxidase , nitrate, urease and indole negative and were not able to rot potato tuber slices, produce H2S and grow in 36 °C. The isolates could use citrate, acetoin, sorbitol and trehalose and their gelatin test was positive. Based on morphological, biochemical, physiological characteristics and production of a 937 bp with specific primer Ea1 and Ea2 in PCR method, the strains were identified as E. amylovora. This is the first report of the existence of this bacterium on pear fruit trees in Guilan province.
V. Sarvi Moghanloo , M. Chorom, H. Motamedi , B. Alizadeh, Sh. Ostan,
Volume 15, Issue 56 (sumer 2011)
Abstract
Soil enzymes are the catalysts for important metabolic process functions including the decomposition of organic inputs and the detoxification of xenobiotics. The aim of this research was to determine the pattern of variation in the activities of dehydrogenase, urease, lipase and phosphatase enzymes, determining the number of hetrotrophic and degrading bacteria and measuring the soil respiration and yield plants during the bioremediation of oil contaminated soils. To this aim, the soil deliberately contaminated with crude oil at a 1 and 2 wt% rate and in four treatments including: plant multiflorum (T1), plant multiflorum with mycorrhiza inoculation (T2), plant multiflorum with oil degrading bacteria inoculation (T3), plant multiflorum with mycorrhiza and oil degrading bacteria inoculation (T4) was employed for bioremediation of oil contaminated soil. The above parameters were determined in five stages during bioremediation and ultimately for the yield of plants at the end of this period .The results showed that the activity of urease and hydrogenase anzymes were increased or decreased parallel to contaminant increase and decrease. In contrast, the activity of lipase anzyme was decreased with contaminant increase and increased with contaminant decrease. Therfore, it can be a good choice for monitoring of bioremediation of contaminated soils. The results showed that the number of degrading and hetrotrophic microorganisms were increased by increasing the amount of contamination and the number of degrading and heterotrophic bacteria were decreased parallel to contaminant decreasing especially in those samples treated with mycorrhiza inoculation. The plant yield and amount of degradation of oil compounds were highest in mycorrhiza plus degrading bacteria treatment.
