sedigheh mehrabian

Some bacteria commonly found on plants can catalyze the freezing of water at a higher temperature than others, at or near 0 °C. The freezing point of pure water is about -40 °C and is initiated by creating ice nucleations. However, when ice nucleation proteins (INPs) are present, ice nucleations form at temperatures close to or above 0 °C. INPs are often attached to the outer membrane by a phosphatidylinositol anchor and are sometimes secreted extracellularly. The monomers of INPs in Pseudomonas syringae are 120 to 180 kDa. INP has three domains, and the central domain is highly repetitive. The central domain consists of the consensus sequence of eight amino acid repeats. Eight amino acid repeats create a 16-residue fragment, and three 16-residue fragments form the 48-residue fragment. Studies have shown that INPs may have a β-helical fold and interact with water through the repetitive motif. Most ice nucleation bacteria are gram-negative, including P. syringae, Pseudomonas viridiflava, Pseudomonas fluorescens, Xanthomonas compestris, Erwinia ananas, and Erwinia herbicola. For optimum protein activity, the presence of the complete bacterial cell is essential. INPs are influential in different aspects, including snowmaking, agriculture, freeze-concentration in the food industry, signal transduction, atmospheric applications as cloud condensation nuclei, and surface display (expression of a foreign protein on the cell surface for biotechnological purposes). This study provides a brief overview of ice nucleation proteins and their applications since ice nucleation is an important phenomenon that affects various aspects, from climate to biological systems.

Several isolated species from symptomatic frozen leaves and soil produce ice nucleation proteins and have been exploited for their Ice Nucleation Activity (INA). Ice nucleation proteins can be employed as promising substances for biotechnological applications such as artificial snow-making, cryopreservation of tissues, and the condensation of ice nuclei in clouds. Considering INA has a direct relationship with bacterial growth, optimization of the culture medium seems indispensable. In this study, the INA of a newly isolated Pseudomonas sp. IRL.INP1 was evaluated. Plackett–Burman was applied for screening several cost-effective carbon and nitrogen sources affecting bacterial growth and INA. The response surface method was employed for medium optimization. Moreover, biomass, whole-cell protein, specific growth rate, and INA were estimated. Rice bran, ammonium sulfate, temperature, and olive oil had significant effects on the INA of Pseudomonas sp. IRL.INP1. Results demonstrated that 5% rice bran, 31 °C, 1.0% olive oil, and 6 g/L ammonium sulfate led to the best INA. The final optical density at 600 nm was 2.3. Also, 1.94 g/L biomass, 1.75 µg/µl whole-cell protein, and 0.26 specific growth rate (day-1) were obtained, and INA was observed after 5 sec at -5 °C. The present research is the first study using agricultural waste for INA optimization. Since rice bran is a cost-effective agro-waste and a qualified replacement for glucose, it can be utilized as a promising substrate for bacterial growth and INA.

Gene expression is regulated with miRNAs, that are non-coding small RNA molecules and genetic variations such as miRNA genes SNPs, which are molecular biomarkers in the prediction of cancers risk. One of miRNAs that is associated with BRCA1 / BRCA2 genes, is miR146a and related with many cancers, including breast cancer. This research aim was association study between prevalence of rs2910164 SNP in miR146a gene with breast cancer in Iranian female population.

This study was performed on 50 patient and 50 control blood samples. DNA was extracted of samples. Then for genotyping was used Tetra Aarms PCR and results was statistically analyzed.Results- Frequency of genotypes for GG, GC and CC in control groups were 30%, 66% and 4%, and for patient groups was 46% , 52% and 2%, respectively. No significant difference was observed between frequency of dominant and recessive allels in control and patients gorups (P > 0.05).

In this study results, there was not significant difference between G and C alleles in the control and case groups. Therefore, could be indicated that there was not association between of miR146a gene rs2910164 polymorphism and breast cancer in the studied Iranian females population. So, further studies with larger sample size are required to support finding of this research.

Study of antimicrobial effects of aqueous and methanolic extracts of vegetative and reproductive structures of A. Chamaecistus and A. austro-iranica on several fungi and bacteria

Aquatic and methanolic extracts prepared from Ajuga Chamaecistus, A. austro-iranica were tested for antibacterial activity against gram positive (Satphyloccocus aureous and Streptococus pyogenes) and gram negative (Pseudomonas aeroginosa and Proteus vulgaris) bacteria and Aspergillus niger and fusarium solani. The vegetative and generative shoots of plants were powdered, sterilized, and extracted at 4°C with methanol and water. The concentrations of 50, 100 and 200 mgml-1 of methanolic and aquatic extracts were used to detect the minimum inhibitory concentration (MIC). All experiments were tested three times. The antibacterial effects were evaluated using the cup-plate and antifugal activity using cup-plate and pour plate

The antibacterial effect of aqueous extracts showed that only the leaf extract (vegetative extract) of A. chamaecistus is effective on S. aureus showing that in gram-negative bacteria, the presence of a lipopolysaccharide wall causes greater resistance. Methanolic extracts of both species were more active than aqueous extracts and had antimicrobial effects on all tested bacteria as well as A. niger. In both species, the extracts of the generative parts showed a stronger antifungal effect. In different species of this genus, the presence of phenolic compounds, tannins and terpenoids that have antimicrobial properties confirms the antimicrobial properties of this species. However, the amount of their effect depends on plant and microbe species, the tested parts (plant organs), the extracts concentration, the sampling season, the sample age and soil type.

virulence genes in Salmonella are a combination of plasmid and chromosomal factors and a single genetic position would not be responsible for all biological manifestations in Salmonella. Considering the difference in the serotypes of Salmonella in terms of serious genes, the aim of this study was to compare the presence of plasmid and chromosomal virulence genes (int, inv, spv (vir)) Salmonella typhimurium and Infantis in clinical cases in children and adults by Multiplex PCR.

In this study, 676 stool specimens were collected from patients referring to Imam Khomeini and Milad hospitals and 60 isolates were identified as Salmonella. After serotyping, 30 isolates were recognized as Salmonella infants and 30 isolates as salmonella typhimurium. By using the Multiplex PCR technique, the prevalence of spvC, invA and Int genes was studied.

All investigated serotypes had invA and Int genes. 93.3% of typhimurium serotypes and 6/7% of infantis serotypes infants had SpvC gene. In 93/3% of typhimurium serotypes and 6/7% of infantis serotypes all three genes were present simultaneously.

virulence genes increase the pathogenicity of typhimurium and Infantis strains. Therefore, the genetic and molecular genetic isolation of these genes can help to identify the bacterial enzymes and to make effective drugs for the treatment of related diseases.

Probiotics are living dietary supplements that exert their health benefits by improving the intestinal microbial balance in the host. lactic acid bacteria are the most common type of bacteria that have been identified as probiotics. This study isolated lactic acid bacteria from the traditional yogurt, dooghd and, curd of Mazandaran Province in Iran and investigated their probiotic potency and antimicrobial effect on Pseudomonas aeruginosa. lactic acid bacteria were isolated by phenotypic and biochemical tests of acid resistance and bile salt tolerance tests, and their primary probiotic index was evaluated. Tube dilution and turbidimetry were used to determine the minimum inhibitory concentration of antimicrobial substances. The inhibitory effect of the isolated bacteria on P. aeruginosa was investigated by the disk-diffusion agar method. The non-growth halo diameter was measured around the disk. In order to reduce errors, each test was repeated at least three times, and the mean non-growth halo diameter was measured on Mueller-Hinton agar and its antagonistic effect was investigated. The findings showed that adding a lactobacillus dose increases its inhibitory effects. The Lactobacillus plantarum were identified using specific primer pairs of the 16S rRNA gene, the established specific band, and PCR product sequencing. Rec A gene PCR was performed for differentiating the members of this group using specific primers and five L. plantarum strains were identified. According to the results of this study, lactobacilli were well able to inhibit the growth of pathogenetic strains. In this study, L. plantarum had an inhibitory effect on

Infertility is one of the serious problems in gynecology and one of the most important issues of concern in couples. Meanwhile, a significant rise in infertility is recently reported in Iran due to the infections and harsh environmental conditions.

The current study aimed to detect Chlamydia trachomatis and Listeria monocytogenes in males with infertility using PCR, and to evaluate bacteriospermia effects of the studied bacteria on semen parameters.

Semen specimens of 100 infertile men were collected. Then, each specimen was divided into two parts: the first part was tested by semen analysis according to the WHO guidelines and the second was tested using the PCR method. The PCR intended to identify C. trachomatis and L. monocytogenes.

Out of 100 semen samples, 20% were positive for C. trachomatis, 3% were positive for L. monocytogenes, and 3% were positive for both bacteria (co-infection). The leukocyte count was higher than the normal range (0 - 1 Mil/mL) in all semen specimens. The prevalence of C. trachomatis in azoospermic patients was significantly higher than that of nonazoospermic (P < 0.05). However, there was no significant difference between the two groups in terms of the detection of L. monocytogenes (P > 0.05). Detection of C. trachomatis and L. monocytogenes had no significant association with abnormal semen parameters in asymptomatic patients (P > 0.05).

The results indicated that precise analysis of semen parameters and diagnosis of leukocytospermia in patients using the PCR can be considered as a rapid and accurate technique to detect bacteria such as C. trachomatis and L. monocytogenes in semen specimens. Therefore, the utilization of this technique in the screening programs for asymptomatic infertile couples can be helpful for early treatment.

Klebsiella pneumoniae is a Gram-negative, non-motile, encapsulated, lactose-fermenting, facultatively anaerobic, rod-shaped bacterium.It has traditionally been considered an opportunistic pathogen and is a common cause of nosocomial infections. The pks gene cluster encodes enzymes responsible for the synthesis of colibactin. Colibactin is a genotoxin that has been shown to induce DNA damage and contribute to increased virulence. Colibactin is also strongly suspected of being involved in the development of colorectal cancer. The present study investigated the prevalence of pks, clbN, and clbB genes in Klebsiella pneumoniae isolates. In this study, 220 samples were obtained from raw milk. Then, all samples were cultured in the violet red bile agar and then cultured in blood agar, MacConkey agar, and chocolate agar for bacterial isolation. Biochemical and microbiological tests were performed for confirmation of the bacteria. DNA was extracted from all isolates using a genomic DNA extraction kit. Then multiplex polymerase chain reaction (M-PCR) method was performed using specific primers. It was found that 60 K. pneumonia isolates out of 220 samples (27.27%) were confirmed by standard phenotypic tests. The PCR test indicated that 6 (10%) strains carried clbN and clbB genes. The pks positive K. pneumoniae was more prevalent in our samples. Owing to its pleiotropic effects, colibactin profoundly influences cellular physiology, inducing DNA breaks that lead to senescence or apoptosis. It seems that the identification of the pks positive K. pneumoniae in milk is essential to prevent colorectal cancer.

Candida albicans has numerous virulence factors such as the agglutinin-like sequence(ALS) genes which code the large glycoprotein family that has a role in the adherence of Candida. The present study was to observe the synergistic effect of ketoconazole and probiotic composition of Bifidobacterium bifidum on expression of C. albicans als gene biofilm isolated from oral samples.

In this cross-sectional study, 12 clinical isolates of C. albicans were collected from oral periodontal infection in patients referred to dental clinic in Kerman. The MIC and FIC values for each treatment(keto and probiotic alone and keto-probiotic composition) were obtained using micro broth dilution method. Finally, a real-time PCR test was performed to evaluate the level of ASL gene expression in the strains and the results were analyzed using the 2 -ΔΔct method.

The results showed that the combination of ketoconazole and bifidobacterium bifidum had synergistic effects. The results of this study showed that the effect of Ketoconazole(keto), B. bifidum(probiotic) alone and the effects of ketoconazole+Bifidobacterium(keto+pro) were 1.47, 1.61 and 1.29 times, reduced the als gene, respectively.

The results of this study showed that synergistic effects between ketoconazole and probiotic B. bifidum have been shown to reduce als gene expression(biofilm production). Therefore, it is recommended to administer probiotic supplementation with ketoconazole in the treatment of candidal infections.

Probiotic bacteria is  potential hazards should also be considered and used at concentrations that have not mutagenic or carcinogenic effects. This study aimed to assess Investigation about the Mutagenic and Carcinogenic Effects of Probiotice Bacteria with Using Salmonella typhimurium TA100 and Rat Liver Microsomes(S9).
 

In this study, we utilize the Ames test using Salmonella typhimurium TA100. Firstly, the purity of the strains was confirmed in terms of purity of mutagenic properties. In the next phase of this research the rat liver micrsomes was separately added to the minimal glucose agar medium containing the suspected carcinogenic, andprobiotice bacteria negative and positive controls and all back colonies were counted.

The number of revertant colonies the treated plates with S9 is decreased and it means mutagenic and carcinogenic effect of probiotice bacteria with S9 is decreased.

The results of the present study shows that the probiotice bacteria at concentrations examined had no mutagenic and carcinogenic effect.

Background and purpose: Ureaplasma urealyticum is one of the most common causes of Non-Gonococcal Urethritis (NGU). Asymptomatic clinical infection caused by this bacterium can cause malnutrition of the sexual attachment glands and its presence in semen contributes to lower fertility. The aim of this study was to identify Ureaplasma urealyticum in semen of infertile men using PCR method as an accurate diagnostic method. The PCR test was optimized by standard strain to detect Ureaplasma urealyticum and then was studied in terms of specificity and limit of detection (LOD). Semen samples were collected from 100 infertile men and each sample was divided into two parts: the first part was tested by semen analysis and the second part was tested by PCR method. DNA was extracted using phenol-chloroform method and the PCR test was done for detection of Ureaplasma urealyticum. Among the semen samples, 16 cases (16%) were found to be positive for Ureaplasma urealyticum. According to the spermogram test, the leukocyte level was also more than normal level in these samples (0-1 Mil/ml). Screening of infertile couples for Ureaplasma urealyticum infection in those without clinical symptoms, thereby performing timely antibiotic therapy play key roles in treatment of infertility. Hence, PCR method is introduced as a valuable and reliable technique to identify Ureaplasma urealyticum.

Recently, the use of probiotics for the treatment of Urinary Tract Infections has become more popular. The use of probiotics in therapy is useful as only a few side effects such as destruction of resistant bacteria or disturbance of the intestinal microbiota have been reported. The aim of this study was to evaluate the probiotic effects of lactic acid bacteria by co-aggregation of ciprofloxacin-resistant uropathogenic Escherichia coli strains using microbial techniques.
Three strains of Lactobacillus plantarum, Lactobacillus casei and Lactobacillus acidophilus were provided. Twenty isolates of uropathogenic Escherichia coli were collected from Shahid Labbafinejad hospital, Tehran. Eight samples with resistance to ciprofloxacin were selected using the disk diffusion method for the co-aggregation test. PCR was used to evaluate the presence of qnrA and qnrS genes in ciprofloxacin-resistant isolates. To evaluate the antimicrobial activity of complete culture and supernatants of lactobacilli, modified double-layer culture method and well diffusion methods were used, respectively. Co-aggregation of lactobacilli was evaluated by the co-aggregation test and microscopy test.
Results showed that the eight human isolates were resistant to ciprofloxacin among other samples. Only one strain had both qnrA and qnrS genes simultaneously. L. plantarum with the average growth inhibition zone of 42 mm and with 65% of the co-aggregation had the best probiotic effects among all lactobacilli bacteria.
The probiotic lactobacilli had spectacular antimicrobial effects against the ciprofloxacin-resistant uropathogenic Escherichia coli strains. Also, lactobacillus spp. were aggregated with uropathogenic Escherichia coli strains and preventing from their adhesion to specific receptors on the Urethra, thus, the subsequent invasion to the host was prevented.

B-group vitamins have important roles in many aspects of cellular metabolism and humans cannot synthesize them. So, they should be obtained from external resources. This project provides a new insight into assessing the production of vitamins B3, B6 and B9 by Lactobacillus, isolated from traditional yogurt samples from 3 different cities of Iran; Golpayegan, Sanandaj and Tehran (Damavand).
Material and Following 72 h of anaerobic culture of the Lactic acid bacteria at 37°C in 5% CO2, some Lactobacillus species from traditional yogurt samples were isolated and characterized both morphologically and biochemically. Isolates were identified following 16S rRNA PCR-amplification and sequencing. Including Lactobacillus (L.) ozensis strain Gon2-7, L. acidophilus strain KU, L. helveticus strain D76, L. helveticus strain Dpc 4571, L. fermentum strain 1, L. rossiae strain DSM15814T, L. casei strain NCDO, L. delbrueckii strain ATCC 11842, L. crispatus strain MRS 54.4, L. delbrueckii strain SB3 and L. paracasei subsp. tolerans JCM1171 (T). The sequence of L. paracasei subsp. tolerans JCM1171 (T) was submitted to the NCBI. The ability to produce B-group vitamins was evaluated by high performance liquid chromatography. Lactobacillus strains and amount of vitamin B3, B6 and B9 production were analyzed by Analysis of Variance test.
Results and Eleven isolates of Lactobacillus species from traditional yogurt samples were identified. Optimal conditions for Lactobacillus growth were pH 5-6 and temperatures 37-40°C. The isolates produced vitamins B3, B6 and B9. L. paracasei subsp. tolerance JCM 1171 (T) showed the highest amount of produced vitamins (p≤0.01) consist of vitamin B6 (1566.17 µg ml-1) and B9 (1279.72 µg ml-1). L. acidophilus strain KU showed the highest production of vitamin B3 (522.7 µg ml-1). L. fermentum produced the highest amount of vitamin B2. These strains are a natural and cost efficient source of vitamin. The Lactobacillus strains isolated in this research particularly, L. paracasei, could be applied in improving new fermented products, fortified with B-group vitamin that could be applied as substitution for enriching and supplementation with the controversial synthetic vitamins.

Uropathogenic Escherichia coli-induced urinary tract infections are the most common uropathogenic Escherichia coli etiological agent. In addition, most of biofilms created by these bacteria can be regarded as a serious problem in the food industry. Foodborne diseases have always been considered an emerging public health concern throughout the world. Many outbreaks have been found to be associated with biofilms. Thus, the aim of the present study is to investigate the anti-adhesive effects of lactic acid bacteria against strains of Ciprofloxacin-Resistant Uropathogenic Escherichia coli using microbial techniques in pasteurized milk. In this study, strains of Lactobacillus plantarum, Lactobacillus casei and Lactobacillus acidophilus were provided from Pasteur Institute of Iran. Twenty strains of Uropathogenic Escherichia coli-Induced Urinary Tract Infections were isolated from patients with urinary tract infection in Shahid Labbafinejad hospital of Iran. Eight strains with ability of biofilm formation were selected for microbial tests. All of these eight strains were resistant to ciprofloxacin. Disk diffusion method was used to assess the susceptibility of all isolates to the ten common antibiotics. Eight samples of Uropathogenic Escherichia coli were inoculated in pasteurized milk. The microtitre plate 100 method was used to detect anti-adhesive activity of lactobacilli supernatant.Results and Results showed that the eight human isolates were resistant to antibiotics. Isolate of number 4 was the most susceptible strains to antibiofilm effects of lactobacilli in the pasteurized milk. The anti-adhesive effects of lactobacilli on Uropathogenic were confirmed in all microbial tests. In this study, Lactobacillus plantarum revealed the highest inhibitory activity against Uropathogenic Escherichia coli 4 strain with inhibition zones of 42 mm. This strain was reported as a proper probiotic bacterium. According to the results, these lactobacilli have had spectacular effects on biofilm formation and pathogenicity of Uropathogenic strains to prevent the adhesion.

Haussknechtia elymaitica Boiss. belongs to Apiaceae family.Considering the importance of recognizing the developmental stages in the development of biology knowledge Haussknechtia elymaitica Which is a rare and endemic species of Iran, was selected for this research. The samples of vegetative and reproductive organs at different stages of development were gathered and investigated by cell-histology methods. The investigation of the anatomical structure of vegetative organs showed that the secretory cavity are arranged between the parenchymal tissues of the leaf. Section of flower buds revealed that anthers had 4 pollen sacs, the division of pollen mother cell was of the simultaneous type, microspore tetrads were of tetragonal type and the tapetum layer was secretory. The ovary was found to be two chambered and two-carpeled; the ovule to be anatropous and to have one membrane. In embryogenic investigationit was found that the embryos were globular, cordate, cotyledonary and torpedo-shaped and the transition between globular embryos to cordate embryos was found. The vegetative organs were observed to have the general structure of dicotyledons. The development patterns of ovule and embryo sac follow the Polygonum type. Tetrahedral, Tetragonal and Liner microspore tetrads were observed. All stages of embryogenesis were covered in this study.

Medicinal use of plants dates long back in the history of the human beings and has recently gained a great deal of importance in treating different diseases. Due to the importance of Pseudomonas aeroginosa strains as agents responsible for common secondary infections and their resistance to antibiotics and disinfectants, the present study aimed at investigating the antimicrobial effects of the plant Cyperus rotundus on multiple drug resistant (MDR) Pseudomonas aeruginosa strains.
Ethanolic extracts of Cyperus rotundus tuber were prepared by maceration. The antimicrobial effect of these extracts on Pseudomonas aeruginosa isolates (ie., sensitive to antibiotics and multiple drug resistant strains), isolated from clinical and soil samples, was determined by both disk diffusion and broth microdilution methods..
It was revealed that ethanolic extract concentrations of Cyperus rotundus tuber higher than 0.1 mg/ml suppresses the growth of all antibiotic sensitive and resistant Pseudomonas aeruginosa strains which were used in this study.
It is concluded that Cyperus rotundus possesses antimicrobial properties and thus can be used in treating multidrug resistant Pseudomonas aeruginosa-induced wounds and infections.

Inroduction & Colorectal cancer is the second most common cancer in the world Domain genetic changes in the development of colorectal cancer showed a large. Infection is a particular type of E. coli bacteria in patients with inflammatory bowel disease, particularly ulcerative colitis, and colorectal cancer can begin. Certain types of bacteria Escherichia coli siderophore production of toxins disrupt the cell cycle and begin the development of colorectal cancer, the aim of this study is the relationship between strains of E. coli siderophore and colorectal cancer patients. Biopsy of the large intestine The clinic includes 35samples from colorectal cancer patients and 35samples from healthy individuals and colorectal cancer were intestinal diseases. Smears of E. coli isolated from healthy tissue and cancer tissue, and DNA extraction by Duplex PCR technique for two genes, feoB and fyuA, as a marker genes siderophore was done. The study of 70patients with colorectal cancer and individual health clinic of intestinal biopsy was obtained and E. coli were isolated from cancerous tissue %59.3 gene feoB and %20 of healthy tissue and gene fyuA %14.8 in patients and %8 were observed in healthy individuals. The results of the genetic study published in Iran similar to the results in many European countries show less.

Due to the importance of the metal zinc as an essential biological element with known toxic properties, and considering the widespread secondary infections caused by Pseudomonas aeruginosa strains with resistance to antibiotics and disinfectants, the present study aimed at exploring the antimicrobial properties of the metal zinc in both clinical and environmental multiple drug resistant (MDR) strains of P. aeruginosa. MDR in P. aeruginosa is defined as the resistance to several antibiotics. Bacterial strains were cultured in cetrimide agar medium at 37 ℃ for 48 h. Strains were identified both morphologically and biochemically. MIC values of the metal zinc were reported using the broth microdilution method. A total of 84 strains were isolated and identified. MIC values for sensitive and MDR strains were reported at 20 and 130 ppm, respectively. It was concluded that the metal zinc at concentrations greater than 130 ppm will have an antimicrobial effect on all sensitive and MDR strains of S. aeruginosa.

In a world of nanotechnology, the first concern is the potential environmental impact of nanoparticles. An efficient way to estimate nanotoxicity is to monitor the responses of bacteria exposed to these particles. The current study explored the antimicrobial properties of nZVI (zero-valent Iron nanoparticles) on the Gram-negative bacterial systems Erwinia amylovora, Xanthomonas oryzae and the Gram-positive bacterial systems Bacillus cereus and Streptomyces spp. The genotoxicity potential of nZVI was also assayed. The toxicity of nZVI was tested by two different Growing bacteria in liquid (broth dilution) and agar media (challenge test) containing different nZVI concentrations for 24-72 hours. The genotoxicity of nZVI was assessed using the preincubation version of the Ames test. The lowest concentrations of nZVI that inhibited the visible growth (MIC) of E. amylovora, X. oryzae, B. cereus and Streptomyces spp. were 625, 550, 1250 and 1280 ppm, respectively. The minimum bactericidal concentration (MBC) for E. amylovora and X. oryzae were 10,000 and 5,000 ppm of nZVI, respectively. MBC was not observed for the Gram positive bacteria. No bacteriostatic and bactericidal effects were observed for oxidized nZVI. Mutant frequency did not increase according to the vehicle control at the concentrations assayed, indicating a lack of mutagenicity associated with nZVI. nZVI nanoparticles are not mutagenic at low concentrations, therefore they can be used without detrimental effects on soil bacteria.

Zinc is an essential micronutrient used in the form of zinc sulfate in fertilizers in the agriculture production system. Nitrogen-fixing microorganisms are also of considerable value in promoting soil fertility. This study aimed to investigate the degree of sensitivity to varying concentrations of zinc, in the form of ZnSO4, in different strains of Azotobacter chroococcum in a laboratory environment. To isolate A. chroococcum strains, soil samples were collected from wheat, corn and asparagus rhizospheres and cultured in media lacking nitrogen at 30˚C for 48 hours. Strains were identified based on morphological and biochemical characteristics. The presence of the nitrogenase enzyme system was confirmed by testing for the presence of the nifH gene using PCR analysis. The minimum inhibitory concentration (MIC) and optimal zinc concentration for the growth of each strain was determined. A total of 12 bacterial strains were isolated from six different soil samples. A. chroococcum strains were morphologically and biochemically characterized. The presence of the nifH gene was confirmed in all the strains. MIC and the optimal zinc concentration for bacterial growth were 50 ppm and 20 ppm, respectively. It was concluded that increasing the concentration of zinc in the agricultural soil is harmful to beneficial microorganisms and reduces the soil fertility. A 20-ppm zinc concentration in soil is suggested to be optimal.

Strawberry (Fragaria vesca L.) is a plant belonging to the Rosaceae family with medicinal properties, including antioxidant activity. The present study aimed at investigating the antioxidant properties of strawberry. To examine the antioxidant effect, fruit extracts at two phonological stages of growth (ripe and unripe strawberry) were prepared. In addition, four different solvents, including 80% ethanol, 80% methanol, acetone and distilled water were used for the preparation of plant extracts. In total, eight different plant extracts were prepared and their properties comparatively studied. To study the antioxidant effect, potassium ferricyanide and reducing power determination method were used. Results indicated that strawberry fruit had antioxidant effects in both of two stages. That is due to the presence of the higher pigments and phenolic compounds in ripe fruit than unripe fruit. The results of present indicated the red fruit had the highest antioxidant activity.

Pseudomonas aeruginosa is a common hospital-acquired bacterium which has ability to produce fluorescent pigment like pyorubin and nonfluorescent pigment like pyocyanine. The aim of this study was exciting of production of pyoverdin pigments as biomarker for quick detection of this bacterium in foods and hygienic products. In this research, different concentrations of cadmium sulfate were used for showing the exciting of pyoverdin pigments. Pigment type was evaluated according to the maximum absorbance and its solubility in water, acetic acid and chloroform. Also, bacterium growth pattern was determined according to pigment production in optimal conditions of agitation, temperature, cultivate media, sources of carbon and nitrogen. Relation between pigment production and number of bacteria was calculated by absorbance and cell accumulation. Bacteria tracking was investigated using pigment production as biomarker in foods (spaghetti and apple juice) and hygienic products (hand and dish washing liquids) and compared to standard method. This study showed maximum absorbance of extracted pigment at 403 nm and its solubility in water and acetic acid. Production of fluorescent pigment in bacterium was observed at concentrations 0.3-0.5 mM of cadmium sulfate. Maximum production of florescent pigments based on cell accumulation was established by agitation in 150 rpm, temperature of 35oC, 0.5 mM solution of cadmium and concentration of 330 mgml-1of 1% sucrose and potassium nitrate. Monitoring of Pseudomonas aeruginosa in contaminated foods and hygienic products based on fluorescent pigments production was reduced from 72 to 20 hours.

Probiotics are live microbial feed supplements, which beneficially affect the host by improving its intestinal microbial balance[8].Recently, researches have shown that lactic Acid Bacteria(LAB), especially Bacillus (because of having endospore) remain stable at cooking temperature and retain their probiotic benefits in baked goods [3]. The purposeof this study,was using of Bacillus coagolans, as a resistant probiotic,for enrichment of bread. First, these probiotic bacteria were determined by the tests of salt tolerance, heat resistance, bile tolerance, tolerance of acid and pepcin, resistance of antibiotics, and preventing the growth of pathogenic starins[18].Then a certain number cells of BC were entered in bread dough,before& after baking the number of live bacteria were calculated by colony count in 1g of dough and bread. The number of BC decreased from 108 to 106 units per gram, after baking. Also,the amount of starch decreasd and changed into simple sugers. The pH was estimated about 4.5-5 and TTA (Total Titritable Acidity) was between 6-8. Finally, the enrichment of bread was evaluated by experts and its quality and taste were compared with a control sample. The Results showed this bacterium survives in baked bread and makes good chemical changes on it.

Nowadays, cancer is one of the main causes of death in the world and mutagens cause death in millions of patients. Noticing the side effects of the drugs used to treat cancer, scientists are looking for drugs with fewer side effects and more therapeutic effects. Accordingly, the number of studies in this field is rapidly increasing. This study was done to evaluate the effects of antimutagenesis of aqueous and alcoholic extracts of A. vera leaf gel and latex by Ames test against the mutagenic substance named sodium azid in the presence and absence of microsomal homogenates of rat liver (S9). In this experimental study, after preparing different extracts of A. vera gel and latex, the antimutagenic effect of different extracts was assessed by Ames test, within which a mutant strain was grown on a culture containing mutagen substance (NaN3). Antimutagen (A. vera extract) reduced reversed mutation. The difference between the mean number of revertants per plate in relation to the mutagens was analyzed through one-way ANOVA using SPSS software. The results showed that the ethanol extract of latex and aqueous extract of gel had the maximum (91%) and minimum (56%) percentages of inhibition, respectively. This assessment revealed strong antimutagenicity effect for all of the extracts due to the presence of different kinds of antioxidants substances such as various anthraquinones, flavonoids, and vitamins A, C, and E. The maximum inhibition of mutation was observed in ethanol extract of latex. This observation supports the results obtained from the application of microsome mixture as well as those reported by other researchers.

As can VI ads through the world as well as the country of Iran, the need for medicines with fewer side effects and more efficacy has increasingly become the center of attention of researchers. Aditionally, more than 60 percent of of anti-cancer compounds for treating cancer patients is derived from herbs and micro organisms. Rosemary (Rosemarinus officinalis L.) and lavender (Lavandula angustifolia Mill.) of the mint family (Lamiaceae) posess numerous medical properties such as anti-cancer, anti-tumor and wound and infection healing qualities. Due to the importance of the above mentioned herbs and their increased cultivation in different climatic conditions all around the country of Iran, this study has focused on the anti- mutation and anti-cancer effects of them.

To investigate the anti-mutation and anti-cancer properties of these two herbs, their flowers were collected in summer and fall from southeast of Tehran. The specimens were dried in the room tempature, in the shade. Methanol and ethanol extracts were produced. Following AIMS protocol and through utilizing Salmonella TA100, the anti-mutation effects of the extracts were determined. To investigate the anti-cancer effect, mouse liver microsome (S9) was added to the specimen. Each test was repeated three times simaltanously. Sodium Azide was used for the positive control group and water and organic solvents were used for the negative control group. The anti-mutation and anti-carcinogenic effect was calculated using the ong equation.

Methanol extract of rosemary flowers was most effective in fall in terms of anti-cancer (65.95%) and anti-mutation (63.12%) properties. Ethanol extracts of lavender had minimum anti-cancer (32.80%) and anti-mutation (30.88%) effects in summer.

Extract of rosemary flowers was more effective in comparison to that of lavender. Extract of the specimens collected in the fall was more effective, as well. Methanol extract is more effective in terms of anti-mutation and anti-cancer compared to ethanol extract.