جستجوی مقالات مرتبط با کلیدواژه "microorganisms" در نشریات گروه "زیست شناسی"

Nepeta binaludensis jamzad, as a medicinal plant, which is at risk of extinction due to irregular harvesting and damage of its habitat. Four treatments including: 1- inoculation with Azotobacter chooroccum, 2- inoculation with Bacillus cereus and Pseudomonas putida, 3- inoculation with a mix of three bacteria (A. chooroccum + B. cereus + P. putida) and 4 controls (without inoculation), in the form of a completely randomized design with 3 replications in two vegetative growth stages (ten and twenty weeks after sowing). Plant growth-promoting bacteria (PGPB) improved all the evaluated morphological characteristics, including the length and dry weight of the aerial part, total leaf area and root length compared to the control. Also, the results of biochemical investigations showed that in 10 and 20 weeks old plants, the application of PGPB could increase the phenolic and flavonoid compounds and also antioxidant activity. The contain of some elements such as calcium, potassium, phosphorus, iron and magnesium also increased as a result of inoculation with PGPB. Since the PGPB improved the growth and also increased the effective compounds of N. binaludensis plants, they can be introduced as useful bio fertilizers and considered as a good alternative to chemical fertilizers.

Every year, more than 600,000 tons of rice husk are produced in rice mills in Iran, which are left in nature without proper use or burned. But, with biotechnological methods, it is possible to convert these agricultural wastes into compost with high content of nitrogen and minerals. Accelerating the production of high quality organic fertilizer and reducing the process time requires determining and studying the factors affecting the composting process. In this research, rotten wood waste in the presence of whey was used as an inoculum and the process was studied for one hundred days. The results showed that the process of rice husk composting decreased the ratio of carbon to nitrogen from 161.2 to 21.1 and also increased the nitrogen content from 0.28 to 1.33 percent. By studying temperature changes during the process, it was determined that the degradation of easily biodegradable compounds at the beginning of the process caused an increase in the population of microorganisms and an increase in temperature, and as the process continued, the temperature of the composting environment gradually decreased. On the other hand, the results indicated that the addition of tree bark fertilizer does not affect the quality of the compost content, but it changed the color of the product. The results of the evaluation of the produced compost showed that adding 10 percent by weight of compost to the soil had a significant effect on the length and weight of cowpea.

Sarcoidosis is a disease with an unknown cause and the onset of the disease is often gradual. The disease may be asymptomatic or chronic. Examining the presence of factors such as micro RNAs may lead to better diagnoses of sarcoidosis and help to better understand the mechanism of sarcoidosis.This is a case-witness study that after obtaining permission from the ethics committee, 40 tissue samples from the lymph nodes of patients with sarcoidosis and 40 control samples were collected with the opinion of an expert doctor, and then RNA was extracted from the lymph nodes. Realtime PCR was done for miR-192 marker.miR-192 biomarker was positive in the lymph node samples of sarcoidosis patients in 28 out of 40 people. The positive rate of this biomarker in healthy people was 17 out of 40 people. miR-192 biomarker showed increased expression in sarcoidosis patients compared to healthy samples.According to the results of this study, miR-192 may be used as a molecular marker for sarcoidosis. It also has significant potential for diagnosis, prognosis and even treatment of sarcoidosis.

The issue of soil contamination by waste chemicals has raised concerns about the environment. Among them, heavy metals are also known to be important in low concentrations due to their non-degradability and physiological effects on living organisms. In addition to natural processes, heavy metals can be used by human resources such as mining activities, landfilling of various wastes and wastes, use of sewage sludge in agricultural lands, waste leachate, excessive use of chemical fertilizers, fossil fuels and the like cause soil pollution. Heavy metals do not decompose in the environment, so they need to be removed from the environment. On the other hand, the exorbitant costs of physical and chemical methods have led to efforts to achieve cheaper methods. The use of conventional physical and chemical treatment methods is not economical and cost-effective in cases where the concentration of heavy metals is low, and may even lead to the production of secondary effluents, which in turn will lead to more treatment problems. Therefore, researchers have developed a new method using the potential of plants to eliminate soil pollution and preserve this national capital. Some plants, by developing special mechanisms, can accumulate heavy metals in high concentrations, which are called hyperaccumulation plants. The most characteristic disadvantages of this method are limited to sites with medium and low pollution, low biomass production, shallow roots, low biological access of metals in the soil, especially calcareous and young soils in arid and semi-arid regions, time consuming. These unavoidable constraints are forcing researchers to refine traditional approaches and apply new phytoremediation techniques to minimize the constraints and ensure widespread use of phytoremediation.Selecting suitable species for phytoremediation of heavy metals is one of the critical stages of phytoremediation. Another solution to overcome the problems mentioned in phytoremediation is to use heavy metal-resistant bacteria and plant growth stimulants to strengthen the root system, produce more biomass and increase the bioavailability of metals by plants. Therefore, the use of microbial inoculation will help plant species to effectively filter heavy metals from the soil.The application of phytoremediation technique has been less in our country so far and only in laboratories and experimentally and due to the ignorance and negligence of officials has never been used as an effective method in refining heavy metals in contaminated soils. Therefore, it is necessary to introduce and replace plants and apply new strategies based on the study of cooperation between plants - microbial communities, to be able to expand and localize modern phytoremediation, to reduce soil health risk and increase food security effectively and economically.To achieve the above goals, the following suggestions can be considered:1- Introducing suitable crops to replace cultivation in soils contaminated with heavy metals: Contamination of agricultural lands with heavy elements is a serious risk for the production of healthy crops in Iran and the world. Therefore, it is necessary to reduce the contaminants in the soil by accumulating them in the roots of plants or depositing them in the root zone and transferring them to the food chain by using the bio-stabilization technique. Unlike other phytoremediation techniques, plant stabilization does not remove metal from the soil, but by stabilizing them by adsorption or deposition in the root zone, it reduces their risks to human health and the environment. Plants with high bio-concentration factor (BCF, the ratio of metal concentration in the root of the plant to its concentration in the soil) and low transfer factor (TF ratio of metal concentration in the stem to its concentration in the root) are suitable for plant stabilization. The absence of high concentrations of metals in the stem eliminates the need to discard harvested plants. In this project, sorghum, millet and flax species are proposed for cultivation in agricultural lands to reduce the burden of contamination in crops and food health for study.2- Introduction of herbaceous plants (forage) for stabilization of heavy metals in contaminated soilsConsumption of infected forage plants by livestock and domestic animals can be examined from two perspectives. First, the use of contaminated forage causes disturbances in livestock and domestic animals, such as reduced milk production and growth rate, reduced resistance to binaries and infections, and impaired reproduction. Second, by consuming animal products, pollutants will enter the human food cycle. Also, due to the multiplicity of pollution industries and ways of its transmission, currently the best way to reduce these risks is to take seriously how to feed and control the diet of livestock. Therefore, the use of specific plant species to immobilize contaminants in the soil, through surface adsorption and accumulation by the root, intra-root adsorption or deposition in the root zone and physical stabilization of soils or in other words plant stabilization is also necessary. Plant stabilization reduces the mobility of pollutants and prevents their transfer to groundwater and the atmosphere. Therefore, in this study, several types of forage plants that have economic aspects and good yield, including sainfoin (Onobrychis aucheri Boiss), Timothy (Phleum pratense), Lolium perenne, Lemon Grass Tall fescue, Dactylis glomerata, Agropyron desertorum, Agropyron desertorum in order to produce healthy forage and restore vegetation in pastures and animal health are recommended for research.3- Introducing ornamental overgrowth plants for refining soils contaminated with heavy metalsIn recent years, plant-based environmental treatment technology, or phytoremediation, has been widely pursued as an in-situ cost-effective strategy to clean metals from contaminated sites. In this project, plant extraction means using polluting plants to remove metals or organic pollutants from the soil by accumulating them in harvestable areas. Plant extraction involves planting the plant several times in contaminated soil to bring the metal concentration to an acceptable level. The following species are recommended for review: Parsley (Tagetes patula / erecta), Margaret (Chrysantemum maximum) Marigold (Calendula officinalis / alata), Chrysanthemum (Chrysanthemum indicum), Gladiolus grandiflorus, Pelargonium graveos ).4- Investigation of bacteria resistant to heavy metals with plant growth stimulant properties with the aim of increasing the growth and production of plant biomass under conditions of metal stressUsing bacteria can be a simple and effective strategy to increase growth as well as bioremediation activity. Bacteria have different mechanisms for decontamination of contaminated environments through biosorption, bioaccumulation, sales, bio-mineralization and biotransformation. On the other hand, plant growth-promoting bacteria typically improve plant growth under stress. Some rhizosphere bacteria that directly and indirectly have beneficial effects on plants are called growth-promoting rhizosphere bacteria. These beneficial bacteria (PGPR) are also called product-enhancing bacteria. Growth-promoting rhizosphere bacteria can play a direct role in increasing plant growth and yield by using various mechanisms. Increased dissolution of insoluble nutrients such as phosphorus, production of ACC-deaminase, production of plant growth hormones such as auxin, nitrogen fixation and production of siderophore (from the point of view of increasing iron absorption) are the most important direct mechanisms. Indirectly, growth-promoting rhizosphere bacteria neutralize or modify the harmful effects of plant pathogens by using various antagonistic mechanisms, thereby increasing plant growth. Competition to absorb substances and occupy suitable sites for the activity of pathogens, production of antibiotics, production of siderophores (from the perspective of removing elements from the pathogens), lytic enzymes and production of hydrogen cyanide are the most important mechanisms used in this method.5- Study of bacteria capable of producing chelating compounds with the aim of increasing the efficiency of plant extraction by increasing the dissolution and absorption of metalsThe efficiency of plant extraction of metals from soils depends on the availability of metals to plants. The magnitude distribution of metals and the intensity of their bonding in the soil are influenced by metal species, age and soil properties. If the availability of metals for plant uptake is low, microorganisms can add chelating or acidifying agents to increase the availability of metals to the soil.6- Feasibility study of using bacteria to reduce the accumulation of heavy metals in crops grown in soils contaminated with heavy metals with the aim of reducing health risk and increasing food qualityRhizospheric and endophytic bacteria (with greater potency) in addition to modulating the harmful effects of biological and non-biological stresses (due to heavy metals, salinity, etc.) to the plant can reduce the absorption and accumulation of metals through various mechanisms They are also heavy in the plant (or in the aerial parts). In addition to reducing the destructive effects of heavy metal stresses on plants, heavy metal-resistant bacteria can reduce the availability of heavy metals to plants through various mechanisms in the soil. One of these mechanisms is the adsorption or bioaccumulation of heavy metals inside bacterial cells. At present, heavy metal bioabsorption techniques are recommended for the removal of heavy metals because they are more efficient, less costly, and more environmentally friendly. Root endophytic bacteria prevent their transfer to plant shoots (organs that can be harvested by humans or animals) by adsorption of heavy metals (adsorption of heavy metals on the bacterial cell wall), accumulation, complex formation, reduction and oxidation, etc. Finally, with this method in agricultural lands, the risks of these elements for human and animal health can be reduced.

Microorganisms make a significant portion of biodiversity, and the growth of inventions related to microorganisms shows their importance for various industries, including biotechnology. Maintenance of microorganisms can be studied from two points of view in the framework of “conservation of genetic resources and “patent requirements”. When an invention relates to a microorganism, in some countries, such as the United States, the written description is not necessarily sufficient to disclose the invention, and a sample of the microorganism needs to be submitted to a specialized center. In fact, the deposit of microorganisms for the purposes of patent procedures has also been recognized internationally by the Budapest Treaty. In the present article, based on the documentary and library research method, while delimitation of the scope of the term “microorganism” in the Budapest Treaty, the technical and legal rules for the conservation of microorganisms and biological materials in international depository authorities have been examinated according to the Budapest Treaty. By examining the challenge of Iranian cultivation collections for acceding to the Budapest Treaty, it has been concluded that an appropriate legal protection system and completion of specialized infrastructures are the important missing links in the field of conservation of Iran's genetic resources and patenting of microorganisms.

The vast expanse of the oceans and high biodiversity of such ecosystem, especially in microorganismchr('39')s community has been known as a huge source of marine natural products. Marine natural products are natural compounds derived from the marine organisms which are used in diverse fields of industries, food industries, pharmaceuticals, beauty products, health products and etc. Due to natural source of such compounds, they are environmental friendly and have fewer side effects compare to synthetic compounds. Today, there is an especial look for these great sources in many countries and also several researches have been conducted to study the extraction of these compounds and their diverse effects. Marine microorganisms are a huge part of marine bio-richness, and for this reason they make a suitable source for extraction of marine natural products. In present study, there is a brief introduction to marine natural products whit emphasis on the compounds extracted from marine microorganisms.

Plants continuously confronted with unfavorable environmental conditions such as heavy metal stress Cadmium (Cd) is currently one of the most important environmental pollutants. Among heavy metals, cadmium (Cd) is a non-essential and toxic metal rapidly taken up by roots and accumulated in various plant tissues which hamper the crop growth and productivity worldwide. The main symptoms of Cd toxicity to plants are stunting and chlorosis. Plants employ various strategies to counteract the inhibitory effect of Cd, which include cell wall binding, chelation with phytochelatins (PCs), compartmentation of Cd in vacuole and enrichment in leaf trichomes. In spite of its high phytotoxicity, Cd is easily taken up by plant roots and transported to above-ground tissues and enters into the food chain where it may pose serious threats to human health.This review has focused on recent evidevce that identifies potential mechanism that may be involved in the tolerance plant to heavy metal in envierment.

Three types of chitin as α (exoskeleton of crustaceans), β (cuttlebone of cephalopods) and γ (some fungal cell wall) exist in nature. Chitosan is the most important derivative of chitin, which has various biological activities. In this study, α, β and γ-chitosans were extracted from Portunus segnis exoskeleton, Sepia pharonis cuttlebone and Aspergillus niger cell wall, respectively. Samples of crab and sepia from Bandar Abbas coastal waters were gathered in the summer of 2014 and samples of Aspergillus niger (PTCC 5223) were obtained from the Iranian Research Organization for Science and Technology (IROST). The amount of chitosan extracted from the Crab was significantly higher than other samples. Antimicrobial properties of these three types of chitosan were explored against 9 bacterial and 2 fungal strains using disc diffusion method. On average α chitosan and γ chitosan revealed to have highest and lowest antimicrobial activities, respectively. Antibacterial properties of chitosan extracts were more than their antifungal properties. Gram negative bacteria as well as gram positive bacteria were sensitive to three types of chitosan. According to observed results, all three types of chitosans have good antimicrobial activities, and further investigations are suggested.

Colored sewage discharge into rivers and lakes, resulting in decreased water quality and reduce the solubility of gases. highly toxic, carcinogenic and mutagenic can be noted as the problems that dyes created for mammals and aquatic organisms. For the removal of dyes there are two physical and chemical methods. Due to the limitations of this methods we can take biodegradation method which is cheaper and more effective as an alternative for old methods. In biodegradation method, microorganisms such as bacteria, fungi, algae and actioiomycetes are used. Due to the fact that these microorganisms are better and more compatible absorbent Using These microorganisms for decolonization is expanding day by day. In this study, the bacterium Acinetobacter baumannii was used for the biodegradation indegocarmin. After the bacteria resistant to indegocarmin color, the effect of time, initial dye concentration, pH and temperature effects were studied to determine the percentage degredation. The optimum conditions of temperature 55 ° C and pH was about 10, with the requirements of 100 mg /L Indigocarmin of color were analyzed in a period of 66 hours at the rate of 88/98 percent.

Due to high biomass and substantial amount of chitosan in the cell wall, cultivation and production of chitosan from Aspergillus niger was studied. The fungus grown on Potato Dextros Agar (PDA) slants were inoculated in Potato Dextros Broth (PDB) and incubated (25°C, 180 rpm). To evaluate changes in biomass, chitosan and other growth parameters over a period of 21 days and the interval of 3 days these factors were measured. The results showed that maximum of fungal biomass (22.5 g/L), chitosan (7.37%) and other growth parameters in the late exponential growth phase found. The pH of the medium in this stage was the lowest (2.5). After entering the medium to stationary phase, these factors were significantly reduced. Gram positive bacteria were more sensitive to chitosan compared to gram negative bacteria (P≤0.5). But Candida albicans showed the highest sensitivity to chitosan. The antibacterial properties of chitosan were more than their antifungal properties. Due to availability, ease of cultivation and maintenance this strain and acceptable level of chitosan, can be used as an alternative for transitional source (shellfish). Based on the present finding, it could be inferred that the A. niger can be considered as an source of chitosan which have inhibitory activity against some microorganisms that require further study.