Showing 8 results for Spore
Volume 2, Issue 1 (1-2000)
Abstract
The percentage of urediniospore germination of two isolates of yellow rust {Puccinia
striiformis f. sp. tritici) namely, WYR 69/10 |Race 104E 137(1)] and isolate WYR 79/4
|Race 41E 139 (4)], was studied at various temperatues between 5-20°C on agar and
the adaxial surface of detached leaves on a layer of benzimidazole agar. Four
replicates for five temperature treatments were arranged as a preliminary
investigation to find the most appropriate temperature for the subsequent comparison
of spore germination on the host material under investigation. Mean percentage
values were analysed separately and the levels of urediniospore germination at
different temperatures were compared using analysis of variance and Student-
Newman-Keuls techniques. Spore germination of both isolates was high over the
temperature range 5-10°C, but dropped significantly at 15-20°C . At the cooler
temperatures 5° , 7.5° and 10°C , isolate WYR 69/10 consistently germinated at a
higher level than isolate WYR 79/4 , whereas at 20°C, the latter isolate gave the
highest figures. This observation indicates that both isolates germinated most
effectively at 10°C on agar and detached leaves.
Volume 2, Issue 4 (12-2014)
Abstract
To identify arbuscular mycorrhiza fungi (AMF) associated with Crataegus pontica C. Koch, 54 soil samples were collected from the rhizosphere of this plant in Ilam Province, western Iran. Isolation of mycorrhizal spores was conducted by wet sieving followed by centrifuge. AMF were identified based on morphological characteristics of spores. In this study, 13 species of AMF belonging to five genera (i.e. Acaulospora, Entrophospora, Glomus, Funneliformis and Claroideo glomus) were identified. The result showed that Acaulospora was the most dominant (30.77%) isolated from the rhizosphere of C. pontica. The Glomus caesaris andClaroideoglomus etunicatum had the highest (17%) and G. pansihalos had the lowest (3.7%) frequency in this study. Results indicated that AMF spores had high variation in the rhizosphere of C. pontica.
Volume 4, Issue 3 (9-2015)
Abstract
Effects of three nutritional levels of beet root molasses, cheese permeate, wheat bran extract, rice bran extract and Sabouraud,s Dextrose Broth (SDB) were evaluated for blastospore production by two isolates of Beauveria bassiana sensu lato. at an interval of 24 h for seven days. Depending on the isolate, maximum blastospore production was obtained in 12% rice bran extract and 20% cheese permeates on the 7th day. Both isolates produced the fewest blastospores in 4% cheese permeate. Virulence of blastospores, produced in liquid media containing beet root molasses, permeate, wheat bran extract and SDB (as control), on third instar larvae of brown tail moth Euproctis chrysorrhoea indicated that there were no significant differences among these nutritional media for either one of the isolates. Considering blastospore quantity and quality in terms of virulence and local accessibility, cheese permeate was found to be the best medium for mass production of B. bassiana blastospores.
F. Jaberi Ansari, H. Jalili ,
Volume 9, Issue 4 (12-2018)
Abstract
Aims: One of the ways to reduce cholesterol is to use statins that prevent cholesterol synthesis. The statins are similar to mevalonate and act as a competitive inhibitor of HMG-CoA reductase enzyme. Lovastatin is the eminent derivate of the statins group, which is produced by many microorganisms. At commercial scale lovastatin is produced in submerged culture by Aspergillus terreus. The industrial production of this metabolite is carried out by Aspergillus turosus in liquid culture. The main aim of this research was to investigate the effect of spore age on lovastatin production at the inoculation stage; also, the impact of adding olive oil and tetracycline as inducers for lovastatin production were examined.
Materials and Methods: In the present experimental research, different suspensions from varying ages of spore were prepared and added to the medium of Aspergillus terreus ATCC 20542; lovastatin concentration also was measured by High Performance Liquid Chromatography (HPLC).
Findings: The utmost lovastatin was observed in inoculum with 85 days spore age and equal to 60 mg/l, which was approximately twice higher compared to when inoculated with 10 days spore age. The best concentration of spore inoculation was 0.5×107 spores/ml. Lovastatin production significantly increased when tetracycline and olive oil were used as inducers.
Conclusion: As the inoculated spore age increases, lovastatin and biomass production is increased. The lovastatin production is increases by more than 1.5 times while adding tetracycline and olive oil compared to date syrup alone.
Volume 14, Issue 4 (7-2012)
Abstract
The impact of land use intensity on the abundance and diversity of arbuscular mycorrhizal fungi (AMF) was investigated at six land use types viz., natural forest, grassland, acacia plantations, cardamom plantations, coffee plantations and paddy fields in the Niligiri Biosphere of the Western Ghats in South India. There was no significant difference in AMF root colonization in different land use types during pre-monsoon but there was a significant difference in AMF root infection ratings between different land use types during post-monsoon season, where it was higher in natural forests and grasslands. The AMF spore density and infective propagules were significantly higher in grasslands and acacia plantations compared to all other land use types during both seasons. Except for paddy fields, the spore density and number of infective propagules were higher in post-monsoon season compared to pre-monsoon season in other land use types. The numbers of AMF species identified were 56 during pre-monsoon and 67 species during post-monsoon season suggesting seasonal variations in diversity. During both seasons Glomus fasciculatum was recorded in maximum number of sampling points across the landscape followed by G. geosporum during pre-monsoon and G. mosseae during post-monsoon season. The species diversity was highest in natural forests and grasslands as compared to other land use types in both seasons. The species richness index for AMF was highest in natural forests and least in paddy fields during both study periods. The sand content, bulk density, total N, organic C, alkaline and acid phosphatases positively correlated with AMF activity while clay, silt, K, total P and available P were negatively correlated.
Volume 18, Issue 1 (4-2015)
Abstract
Objective: Organophosphorus (OPs) compounds are widely used in many pesticides, insecticides and chemical nerve agents. These compounds are hazardous for humans and the environment. Organophosphate hydrolase (OPH) is a homodimeric protein initially isolated from Pseudomonas diminuta MG and Flavobacterium species. This enzyme is able to degrade a broad spectrum of toxic OPs compounds. Using immobilized OPH commonly presents a variety of advantages versus the free form of the enzyme. Advantages include an increase in stability, cost reduction by simple recovery and reutilization of the enzyme, quick and easy separation of the reactant and product in the reaction medium.
Methods: Plasmid pET-26b (+) was used to generate the OPH protein under the control of the T7lac promoter. E. coli BL21 (DE3) pLysS was used as the host for expression of the OPH enzyme. Recombinant OPH was secreted into the extracellular medium and the purified enzyme was immobilized on the surface of Bacillus subtilis spores by the adsorption method, for the first time.
Results: Approximately 42% to 45% enzymatic activity was determined to be associated with spores. Optimal pH and temperature of the enzyme were not altered by the presence of the spores. Thermo and pH stabilities of the immobilized enzyme was higher than the free form of the enzyme.
Conclusion: Bacillus subtilis spores are safe for humans and the environment. Therefore this system can be considered an environmentally friendly biocatalyst for degradation of OPs.
Volume 19, Issue 2 (3-2017)
Abstract
The aim of the study was the analysis of Lithuanian honeys for the presence of the spores of Clostridium botulinum. The analyses were performed on multifloral, honeydew, nectar-honeydew, rape, buckwheat, heather and linden honey bought in direct sale. Prior to culture on solid media the samples were prepared by supernatant filtration method and cultured in parallel in Cooked Meat Medium (CMM) and Tripticase Peptone Glucose Yeast (TPGY) enrichment broths. Bacteria of typical phenotypic features were obtained by culture method from 48 honey samples. Identification of Clostridium botulinum types A, B, E and F was performed with the use of multiplex-PCR method. The prevalence analysis showed 30 (60%) samples contaminated with Clostrdium botulinum spores. The major serotype detected was type A: 20 (66.6%) positive honey samples; while type B was found in 7 samples (23.3%), type E in 4 samples (13.3%) and type F in 3 (10%) positive honey samples. Contamination with more than one type of C. botulinum spores was observed in 3 honey samples.
Volume 20, Issue 3 (5-2018)
Abstract
In order to investigate the Aflatoxin B1 (AFB1) removal ability of Brevibacillus laterosporus (Bl), 125 male Japanese quails aged 21-day-old were divided into 5 experimental groups with 5 replicates of 5 birds each. The experimental groups were control (basal diet), Bl (basal diet+108 cfu Bl mL-1), AFB1 (basal diet+2.5 mg AFB1 kg-1), AFB1+Bl (basal diet+2.5 mg AFB1 kg-1 and 108 cfu Bl mL-1), and AFB1+Improved Milbond-TX® (basal diet+2.5 mg AFB1 and 2.5 g Improved Milbond-TX® kg-1). The AFB1 decreased hematocrit (P= 0.003), red blood cells (P< 0.001), and white blood cells (P= 0.012) compared to the control while Bl probiotic improved those parameters. The highest relative liver and heart weight and lowest foam production and relative weight of bursa of Fabricius were observed in AFB1 group (P< 0.05). However, the relative weight of bursa of Fabricius and cloacal gland of birds fed Bl were similar to those in the control group. The low oxidation stability of meat samples resulting from the use of AFB1 improved due to use of Bl probiotic (P< 0.001). The ileal population of Escherichia coli increased in AFB1 group while the lactic acid bacteria decreased. This condition was reversed due to administration of Bl probiotic (P< 0.001). This study clearly showed that indigenous Bl probiotic could be effectively used to lessen the negative effects of AFB1 on meat quality and microbial ecosystem of growing quail chicks.
