Showing 11 results for Activity
Nayyer Mohammadkhani, Naser Abbaspour,
Volume 2, Issue 1 (6-2015)
Abstract
Salinity is one of the important environmental factors that limit plant growth and product. Grapes are classified as salt sensitive plants. This paper attempts to evaluate the salinity effects on membrane lipid peroxidation, antioxidant components and antioxidative enzymes activity in four grape genotypes (Vitis vinifera L., Gharashani, LaaleBidaneh, Sachagh and Shahroodi) that commonly grow in the regions around Urmia Salt Lake. We came to the conclusion that malondialdehyde content and antioxidative enzymes activity increased significantly (P<0.05) in roots and leaves of all these genotypes. Gharashani and LaaleBidaneh genotypes showed higher antioxidative enzymes activity and lower membrane lipid peroxidation. Also, salinity had a significant effect on the accumulation of total phenolics content and phenylalanine ammonia lyase activity in all genotypes. Gharashani genotype showed the highest total phenols and PAL activity. There was a significant positive correlation among antioxidant enzymes activity, total phenolics content and PAL activity in leaves of all genotypes. It seems that Gharashani and LaaleBidaneh genotypes have a better antioxidant system compared with others and show higher efficiency for salinity tolerance.
Ensieh Salehghamari, Mohammad Ali Amoozegar,
Volume 3, Issue 4 (3-2017)
Abstract
Lipase is one of the most important hydrolytic enzymes widely used in various commercial activities such as food, dairy, pharmaceutical and detergent inducteries. In this experiment, Taguchi method was attempted as a powerful method to optimize the factors affecting enzyme production and to investigate the interactions among these factors and their optimum combination in Salinivibrio sp. SA2. The optimum conditions for pH, temperature, shaker's rpm, olive oil concentration and salt type turned out to be 8, 35 °C, 100 rpm, 2% and sodium chloride 1 M, respectively. Significant factors influencing on the lipase production proved to be pH, agitation and Salt type. The maximum lipase activity in optimum condition and at the 5% significance level (p< 0.05) was 120.4 U/mg.
Nasrin Parvaresh, Mojtaba Mortazavi, Masoud Torkzadeh-Mahani,
Volume 4, Issue 1 (6-2017)
Abstract
Cutinase belongs to the family of serine hydrolases which are capable of hydrolysis of esters and small polyester such as cutin. The cutin of plants is composed of hydroxy and epoxy fatty acids and is substantially imperm-eable to water and only the plant pathogenic bacteria are capable of degrading it. Initially, in order to identify the extent of cutin in cucumber (Cucumis sativus' C. sativus'), golden apples (Golden Delicious apple 'Malus domestica'), red ap-ples (Red Delicious apple 'Malus domestica'') and tomatoes (Solanum lycopersicum Mill. Commun ' S. lycopersicum'), their fruits were obtained. Cutin was extracted from the fruit skin of each studied specimen and compared by chloro-form-methanol method. Then, isolation of enzyme-producing strains was performed by the use of the specific medium containing cutin and enzyme activity assay. DNA of the specimens was extracted, and PCR were performed with univ-ersal primers for 16s DNA. The remainder was devoted to bioinformatic analysis, identification and registration of samples in the gene bank. The results showed that the percentage of extracted cutin in red apple was more than other samples and as a result, red apple are expected to be more resistant against diseases and pests. Also, six cutinase-prod-ucer strains of Klebsiella and Enterobacter were isolated with the help of enzyme activity and special culture medium containing cutin, and their 16s DNA region coding sequences were recorded in the GenBank.
Sarah Khavari-Nejad,
Volume 5, Issue 4 (3-2019)
Abstract
Plant peroxidase (EC: 1.11.1.7) a heme-containing protein which is widely used in plants, microorganisms and animals. This two - substrate enzyme, catalyze the hydrogen peroxide into water with oxidation of many organic and inorganic substrates that all of them can be used to measure enzyme activity. Although it’s specific substrate is hydrogen peroxide. Calcium and at least four disulfide bonds in the protein structure lead the formation and strength of three-dimensional structure of the molecule. Plant peroxidase has several roles including, involvement in lignin biosynthesis, auxin metabolism, cell growth, cell wall cross linking and respond to environmental stress. So peroxidase, considered as a good point to pursue the cell deal with stress factors such as oxidative stress. These days according to produce the pure samples of this molecule, peroxidase also used in ligand-protein studies in pharmaceutical research. So in this brief overview, in addition to introducing plant peroxidase we have had a brief look to measure the enzyme activity, the number of isoenzymes in a cell and the ensuing conformational changes of peroxidase.
Neshat Saffarzadeh, Hamid Moghimi,
Volume 6, Issue 1 (5-2019)
Abstract
Impranil DLN is a class of plastics belonging to the polyurethane family with high application in textile industries. The aim of this study was to evaluate the potential of native strain to degrade impranil DLN. In this study, yeast strains were isolated from different areas and purified in minimal medium containing 1% impranil. Isolate NS-10 was selected as the superior strain capable of degrading impranil and identified through PCR and ITS gene. Esterase, urease and protease assays were carried out for the superior strain. Finally, the biodegradation of impranil was investigated. In total, 40 yeast strains were isolated and isolate NS-10 was selected as a superior strain based on impranil removal assay. NS-10 strain was identified as Sarocladium kiliense with 100% homology. Enzymatic assays showed that the S.kiliense could produce esterase, urease and protease. In addition, it could produce significant clear zones on impranil plates. Degradation rate for impranil was 100% for 10 g/l within 14 days. Finally, S.kiliense was taken to medium containing pure polyurethane film and the capacity of degradation was investigated by the scanning electron microscopy. Our results indicated that S.kiliense is capable of degrading impranil. These results could contribute to a better insight into the mechanism of plastic biodegradation.
Rezvan Mohammadi, Parto Roshandel, ,
Volume 6, Issue 1 (5-2019)
Abstract
In order to study the effects of magnetopriming on the physiological and phytochemical characteristics of Hyssopus officinalis plants, this research was conducted as a factorial experiment in a completely randomized design. Results showed that magnetopriming (particularly at 200mT/5 min) increased the level of shoot dry weight (82.6 percent), root dry weight (86.5 percent), total chlorophyll (32.8 percent), carotenoids concentration (32.4 percent) and polyphenols content (2 folds) in 60-day-old Hyssopus officinalis. Also, electrolyte leakage and lipid peroxidation decreased by 27.6 and 45 percent, respectively. In addition, reducing power, DPPH and superoxide anion scavenging activities significantly augmented. However, higher activities of superoxide dismutase (76 percent), catalase (4.2 folds), ascorbate peroxidase (2.4 folds) and guaiacol peroxidase (48 percent) were found at 90 mT. Results suggested that the application of magnetopriming promoted growth in H. officinalis through augmentation of cellular membrane integrity as well as biomass and photosynthetic pigments content. Furthermore, it was found to enhance the antioxidative system. Magnetopriming might apparently improve the medicinal properties via increasing the level of polyphenols and antioxidant capacity in H. officinalis.
Mahnaz Nasre Taheri, Gholamhossein Ebrahimipour, Hossein Sadeghi,
Volume 6, Issue 3 (10-2019)
Abstract
Proteases are important industrial enzymes used in different areas of industry, mainly detergent, food and leather industries. In this study, novel alkaline protease-producing bacterium was isolated from Geinarje hot spring and examined for maximum protease activity to be utilized in washing-powder. The isolated bacterium was cultured in mineral salt medium including 2% Skim Milk. Proteolytic activity of supernatant was measured by caseinolytic method. The effects of pH, temperature, SDS, Tween 80 and EDTA on protease stability and activity were investigated. The detergent compatibility of protease was assayed. On the basis of phylogenetic analysis and morphological as well as biochemical tests, the isolate was identified as a new strain of Brevibacillus borstelensis capable of generating extracellular alkaline protease. The generated protease was determined as alkaline metallo-protease having high activity at 60 oC and pH 9. Moreover, the alkaline protease was stable in the presence of SDS, Tween 80 and H2O2. It is compatible with commercial detergents. Finding proteases capable of degrading proteins in extreme environment (i.e. alkaline pH, high temperature and presence of surfactants) is valuable in biotechnological and industrial practices. Therefore, it can be utilized in detergent formulation in the future.
Elaheh Zadeh-Hosseingholi, Nader Chaparzadeh, Samira Mahmudi Aghdam,
Volume 6, Issue 4 (1-2020)
Abstract
Some rhizobacteria have positive effects on plants growth. Syrian bean-caper (Zygophyllum fabago) is a weed plant with medicinal value. This study was conducted to isolate and identify bacteria from Syrian bean-caper rhizosphere. Characteristics associated with plant growth stimulation, such as phosphate and zinc dissolution, production of Indole acetic acid and antifungal activity, were investigated. The isolates were separately inoculated to the plant and after plant root establishment was ensured, their effectiveness in increasing plant growth in greenhouse conditions was measured. Biochemical and molecular identification results showed that five isolates belonged to the genera Bacillus, Pseudomonas, Pantoea, and Brevibacterium. All five isolates showed some degree of plant growth promotion capabilities. Among the isolates, only the genus Bacillus increased the dry weights of plants significantly. The amount of phosphate solubilization for this isolate was 440 μg ml-1 and its acid production in the culture medium was higher than that in other isolates. The isolate had zinc solubilisation capability and produced 3.89 mg ml-1 indole acetic acid. However, this isolate did not show antifungal activity against two fungal pathogens of Aspergillus niger and Botrytis cinerea.
Ali Bahrami, Bita Jenabzadeh, Hamid Mosmeri, Mohammad Davoud Ghafari,
Volume 7, Issue 1 (4-2020)
Abstract
Phenazine 1-corboxylic acid (PCA) is an antibiotic, which inhibits the growth of a vast number of micro-organisms. PCA has has been applied in fields such as pharmaceutical, agricultural, marine and chemical industries. In this study, the antibiotic properties of PCA (produced by pseudomonas aeruginosa MUT.3, which is kept at the Microbial Collection of Malek Ashtar University of Technology) was studied. The impacts of temperature and light conditions on the activity of PCA was investigated within a 230-day period. To investigate the rate of PCA destruction in the experiment, high performance liquid chromatography (HPLC) was utilized. Moreover, the antibacterial activity of PCA under various conditions was studied by minimum inhibitory (MIC) and minimum biocidal concentration (MBC) methods against E. coli DH5α. The results showed that PCA could be active up to 210 days in darkness (at 25oC). Meanwhile, the antibacterial activity of PCA was reduced to 100 and 50 days by increasing the temperature to 35 and 45oC, respectively. In addition, PCA could be active up to 120 and 10 days in visible and ultraviolet light condition, respectively. The MIC and MBC data were consistent with the HPLC results. Detailed data on the activity and stability of phenazine 1-corboxylic acid under various environmental conditions, as presented in this study, could be helpful in industries and healthcare services.
Sogol Tavanaeian, Javad Hamedi, Setareh Haghighat,
Volume 7, Issue 1 (4-2020)
Abstract
Exopolymers (EPS) are high-molecular-weight polymers secreted by some micro-organisms and have several applications in food, pharmaceutical, packaging and agricultural industries, as well as medicine. Actinobacteria are valuable bacteria in biotechnology and many commercial drugs such as antibiotics, antioxidants and immune-suppressant agents are derived from Actinobacteria. Recently, their other capabilities such as exopolymer production have been taken into consideration. Due to the high potential of actinobacteria in producing various compounds and increased prevalence of infections by antibiotic-resistant pathogens, the aim of the present study was to evaluate the potential of isolated Actinobacteria from various locations of Iran to produce EPS with antimicrobial activity. Appropriate dilutions of the samples were, therefore, cultured in ISP2 medium after treatment. The isolates were primarily identified by morphological tests. Then, their ability to produce EPS was investigated in BHI medium with 5% sucrose. The exopolymers of the most efficient strain were analyzed by UV-visible spectroscopy and FT-IR. Finally, the most efficient isolate was molecularly identified. Of the 120 isolates, 38 were able to produce EPS, and six had significant capability of producing EPS (10-14 g/L) and showed antibiotic activity against Staphylococcus aureus, Bacillus subtilis and Aspergillus niger. The EPS of the strain So49 had high absorbance in 190-230 nm, but did not have absorbance in 260-280 nm. Therefore, it does not have any protein impurity. The EPS has hydroxyl and carboxyl functional groups, according to FT-IR analysis. 16S rRNA gene analysis showed that the most efficient isolate had 99.68% similarity to Promicromonospora xylanilytica.
Bahare Asgari, Dr Ali Mohammadi, Dr Bahare Attaran,
Volume 11, Issue 1 (6-2024)
Abstract
The aim of the present work was to produce a stable nanoemulsion containing clove (Syzygium aromaticum) essential oil (PCLO) and evaluate its antimicrobial activity. The effect of the preparation technique, the type of surfactant and the ratio of surfactant to oil was evaluated to optimize the preparation formula of oil-in-water nanoemulsion. The optimized formula prepared by low energy production method containing 4% w/w PCLO and 12% w/w mixed surfactant (SDS + Tween 80) produced a clear and stable nanoemulsion for 90 days with an average particle diameter below 150 nm. The antibacterial activity of pure PCLO and its nanoemulsions (NCLO) was investigated by disk diffusion, agar well, and broth methods in 3 indicator bacteria of gastrointestinal infections, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. Minimum inhibitory concentration (MIC) and bacteriocidal concentration (MBC) as well as dynamic killing time were determined in the tested bacteria. Strong antibacterial activity of PCLO and NCLO was revealed in the concentration range of 1000-2000 ppm. The killing kinetics study showed that during the first 15 minutes of exposure to NCLO at the MIC concentration, there was a rapid and extensive reduction in the amount of viable microorganisms. The presented data, considering the optimal performance of antimicrobial substances in food, cosmetics and chemical industries, can help in the rational design of nanoemulsion-based essential oil delivery systems.