جستجوی مقالات مرتبط با کلیدواژه « آمیلاز » در نشریات گروه « کشاورزی »

Microbial enzymes isolated from marine environments have found special applications in various industries, due to their unique properties. The Persian Gulf is a pristine place for the isolation of bacterial strains with the potential to produce new enzymes due to its rich biodiversity. Protease, lipase, and amylase are among the most widely used enzymes in various industries and due to the increasing importance and demand for microbial-marine enzymes in industry, this study aims to optimize and partial purify these enzymes from new strains isolated in port. Choubdeh (north of the Persian Gulf) was performed for the first time. Sampling was performed in November 2019 from 10 different stations (water and sediment samples). A new strain, Aeromonas taiwanensis - Persiangulf ST16 (accession number: OM189448) capable of producing protease, lipase, and amylase were identified by phylogenetic analysis of 16 SrRNA sequences. Optimal conditions for the growth of this bacterium included temperature of 30-37 ° C, pH 6, and salt concentration of 2.5%. The highest enzyme activity was observed for all three enzymes on the second day of incubation. The highest production of protease was reported at 37 ° C, pH 7, with the presence of maltose as a source of carbon and casein as a source of nitrogen, and the lowest was observed in the presence of dextrose and Beaf extract. The optimal conditions for lipase production at 37 ° C were 6-7 pH, and in the presence of olive oil and tryptone. The use of tween 20 and casein produced the lowest amount of enzyme. Optimal amylase production was observed at 35 ° C, pH 7, and the use of starch and yeast extract, but sorbitol and ammonium sulfate-induced the lowest production. During the purification steps, the specific activity of all three enzymes increased so that in the last stage of purification, protease, lipase, and amylase enzymes were purified by 16.23, 2.69, and 2.43 times respectively compared to the crude enzyme. Optimization of production of all three enzymes with significant activity by Aeromonas taiwanensis-Persiangulf ST16 showed that this bacterium could be a good candidate for further studies and use in industry.

Amylase improves the texture and sensory properties of bulky bread by degrading starch and producing dextrin in order to faster metabolism by bakery yeast. This study investigates the effect of thermostable α-Amylase 0, 1.9, 2.9 (U/ml), extracted from Bacillus safensis, and fermentation time at 35, 40 and 45 minutes on the quality of bulky bread baked in oven at 210°C for 20 min. The results of our study showed that adding filtered soup containing   1.9 (U/ml) and fermentation for 40 minutes  was more acceptable than other samples in terms of volume, hardness, cohesiveness and overall acceptance, but adding more amounts of amylase enzyme at 2.9 (U/ml) level did not yield good results in terms of texture and sensory properties of bulky bread.

Fusarium dry rot is one of potatoes' most significant postharvest fungal diseases, reducing crop yield and seed tuber quality. Utilizing certified seed tubers treated with chemical fungicides is the simplest and most cost-effective method for preventing dry rot disease damage to potatoes. Monitoring for diseases transmitted by tubers enhances the quality of seed tubers produced and reduces the risk of disease establishment and soil contamination. This study aimed to identify the causal fungal agents of potato seed tubers dry rot, determine the susceptibility of seed samples from potato seed farms to Fusarium dry rot agents, as well as to evaluate some of the effective factors in disease severity, particularly the levels of extracellular enzyme activity and fusaric acid production on the disease index and dry rot volume of potato tubers.

To identify Fusarium species responsible for dry rot disease in the seed tubers of Agria, Banba, Jelly, Challenger, Ramus, Sagitta, Sante, Sifra, Fabula, and Colomba cultivars of potato grown in Ardabil (Ardabil), Chaharmahal & Bakhtiari (Borujen), Razavi Khorasan (Fariman and Torbat-e Heydarieh), Zanjan (Khodabandeh), Fars (Abadeh and Eqlid), Lorestan (Khorramabad), Markazi (Arak) and Hamedan (Razan, Kabudarahang, and Bahar) provinces were sampled according to the standard guidelines of the National Seedling Health and Propagation Materials Laboratory. The pathogenicity test was carried out on artificially inoculated potato tubers tubers cv. Agria for determining the volume of dry rot caused by Fusarium isolates. Furthermore, spectrophotometry and high-performance liquid chromatography (HPLC) methods were used to evaluate in vitro activities of amylase and cellulase, as well as fusaric acid production.

The results indicated that approximately 18% of the seed tubers samples collected from different fields were infected with Fusarium dry rot disease in the 1 to 3% range. A total of 26 isolates were identified based on morphological and molecular characteristics belonging to F. solani sensu lato (13 isolates, 11%), F. oxysporum (8 isolates, 7%), and F. sambucinum (5 isolates, 5%). Analyzing the activity of extracellular enzymes revealed that all recovered Fusarium isolates were capable of producing amylase and cellulase enzymes but at varying levels. The maximum amount of extracellular enzymes produced by Fusarium spp. isolates ranged from 286 to 675 μg mL-1 for cellulase and from 103.5 to 317 μg mL-1 for amylase. According to the results, cellulase peaked sooner than amylase, but both enzymes contributed to the development of dry rot in potato tubers. The results revealed that approximately 38% of the isolates produced fusaric acid in the 13-32 μg kg-1 range. Moreover, the disease index level and the volume of dry rot caused by different Fusarium species isolates on potato tubers varied.

It appears that the amount of dry rot caused by Fusarium spp. isolates on potato tubers are affected by the production of fusaric acid and the activity levels of cellulose and amylase. This research provides new insights into the health status of potato seed tubers, the predominant Fusarium species causing dry rot disease, and the effect of the level of extracellular enzymes and fusaric acid secreted by fungal isolates on the disease progress in potato tubers, which can be applied to the revision of the national standard for seed tuber health and effective disease management during storage. The dry rot disease and its detrimental impact on tubers significantly threaten the official seed tubers certification system, production, and storage procedures. The current study is the first report on identifying the Fusarium dry rot disease agents from potato seed tubers in Iran and investigating the relationship between the disease severity of isolates and their extracellular enzyme activity, and fusaric acid production.

Honey is a natural product that has long been used for treatment in addition to nutrition. In this regard, the antimicrobial effect of some Iranian kinds of honey against antibiotic-resistant bacterial strains and the relationship between this effect and the enzymatic activity of honey samples were evaluated. In this study, the protein content of 20 honey samples before and after extraction was determined and analyzed by SDS-PAGE technique. Then the activity of glucose oxidase, amylase, invertase, and catalase enzymes of each honey was measured. Inhibition of the tested bacterial strains in the presence of honey was investigated by ager well diffusion method and the relationship between enzymatic activity with antibacterial effect and freshness of honey was evaluated. The protein content of the samples before extraction ranged from 0.4 06 0.06 to 1.0 64 64.19 mg/g honey and after extraction this amount decreased by about 50% or less. In the protein profile of all kinds of honey after electrophoresis, 3 bands related to amylase, invertase, and glucosidase enzymes were visible. The activity of enzymes was assigned to glucose oxidase> invertase> amylase> catalase, respectively. The selected honey samples did not affect Staphylococcus epidermidis and had the least effect on Pseudomonas aeruginosa. After honey inoculation, the inhibitory pattern of Escherichia coli and Enterococcus faecalis were similar, but a different inhibitory pattern was observed from Staphylococcus aureus strain. This study showed that glucose oxidase plays an important role in bacterial inhibition, but this role fluctuates in catalase-positive strains. Also, Amylase and invertase enzymes can be a measure of the freshness of honey.

In order to investigate the effects of priming and aging (controlled deterioration) on germination and amylase activity in rice seeds, a factorial experiment was conducted based on completely randomized design with four replications and 12 treatments including aging (control, 87 and 77 % of control germination) and priming (control, hormone priming with gibberellin (GA3) and salicylic acid (SA) and hydro priming) at the University of Mohaghegh Ardabili in 2016. Results showed that the highest germination percentage (GP) and rate (GR), radicle and plumule length, radicle and plumule fresh and dry weight observed in priming with GA3 and non-aged seeds. GA3 increased GP about 17% in comparison to control (from 71.5 to 83.5%) and this increase for hydro and SA priming was about 9 %. Aging decreased the amylase activity, but priming types increased the activity of enzyme. From the results it is concluded that priming specially with GA3 is a proper method to decrease the germination time and increase the seed vigor of aged rice seeds.

Legumes are the most important source of plant protein and Mung bean has a high nutritional value for humans, as it produces seeds containing high protein percentage. The major problem of salinity in seed germination of higher plants is due to excessive amounts of sodium chloride, osmotic pressure, disruption of nutrient uptake and transport, and direct effects of ionic toxicity on the membrane and enzymatic systems that in turn reduce germination. External use of methyl jasmonate can modulate the effects of various stresses, such as salinity and drought, by increasing the antioxidant activity of the seed. Therefore, the purpose of this research was to evaluate the effect of methyl jasmonate and salinity stress on germination and enzymatic properties of Mung bean.

This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. The experimental treatments included four methyl jasmonate solution (0, 50, 100 and 150 mM) and four salinity stress levels (0, 2, 4 and 6 dS/m salinity from NaCl). Petri dishes were placed in a germinator at 25 ° C and in full darkness for 14 days. In this experiment, germination rate and percentage, time to reach 50% germination, alpha and beta amylase, catalase and peroxidase were measured.

The results of the experiment showed that the lowest rate of slope and final germination percentage were obtained in 50 and 100 mM solutions of methyl jasmonate. In terms of T50, an increase of 4.7 days was observed per one dS/m increase in salinity stress and the lowest T50 was estimated at a methyl jasmonate solution concentration of 78.68 mM. In terms of the activity of germination enzymes, reduction of 0.031 μmol/ml/min per 1 dS.m increase in salinity stress and the highest amount of α-amylase were estimated 72.6 μmol/ml/min at a methyl jasmonate solution concentration of 73.33 mM. Also, the lowest activity of β-amylase enzyme was 0.79 μmol/ml/min at a concentration of 5.6 dS/m salinity stress and the highest activity of β-amylase enzyme was estimated to be 1.7 μmol/ml/min at a methyl jasmonate solution concentration of 86.67 mM. The highest activity of catalase (25.7 ∆A/mg protein/min) was observed at 14.72 dS/m salinity stress and the lowest activity of catalase enzyme (8.9 ∆A/mg protein/min) was estimated at 5.88 mM methyl jasmonate solution. The highest activity of peroxidase enzyme (22.06 ∆A/mg protein/min) was at 24.3 dS/m salinity stress and the lowest activity of the enzyme peroxidase (2.5 ∆A/ mg protein/min) was determined at a methyl jasmonate solution concentration of 266.66 mM.

In general, pre-treatment of methyl jasmonate can reduce the germination time, increase the rate of germination and reduce the oxidative stress in salt stress conditions by improving the activity of germination enzymes, increasing the activity of enzymes, increasing the activity of hydrolyzing enzymes and increasing the easy availability of seedlings to nutrients during germination. Highlights: 1- Germination rate and percentage and morpho-physiological changes of Mung bean seed as affected by methyl jasmonate were investigated. 2- The role of alpha and beta amylase germination enzymes in accelerating the production of Mungbean seedlings under saline conditions were estimated. 3- Methyl jasmonate- induced catalase and peroxidase enzymes activity in resistance to salinity stress were estimated.

Amylase is one of the important industrial enzymes, which is used in the food industry, detergent production, glucose, textile, and paper making. Bacillus spp. is considered as a major amylase producing microorganisms. The main objective of this study is isolation and phylogenic study of amylase producing thermophile Bacillus spp. from Ghainarjeh hot sprin in East Azarbaijan.

Samples from water of Ghainarjeh hot spring were cultured on recommended mediums. The grown colonies were tested for amylase production and positive colony determined a gram positive Bacillus using morphological and microscopically characteristics. Selected colony was used for total genomic DNA extraction, 16S rRNA fragment amplification and sequencing was done according to standard procedures. The sequence of 16S rRNA was used for phylogenetic investigation using maximum likelihood and maximum parsimony methods.

According to the results from morphological and biochemical investigations, the isolate is a gram positive, spore forming Bacillus with ability for use glucose, fructose and sucrose but not galactose and lactose. This isolate was positive for endol, citrate and VP but negative for catalase and oxidase.

The results of phylogenetic investigation from both method show that the amylase producing isolated Bacillus is a new member of Bacillus Subtilis spp. in this study a new member of Bacillus subtilis spp. with the ability in amylase production was successfully isolated.