فهرست مطالب محسن مبینی دهکردی

Alpha-amylase is one of the most widely-used amylase types in the industry. Bacterial amylase production is less expensive and easier. Also, solid-state fermentation is an efficient method for the production of industrial amylase due to its advantages such as significant cost reduction and recycling of nutrient-rich wastes. Agricultural residues containing nutrients such as wheat bran are more economical substrates for solid-state fermentation. The aim of the present study was to optimize the production of alpha-amylase from Bacillus subtilis using wheat bran under solid-fermentation and partial purification of this enzyme.

In this study, alpha-amylase production by Bacillus subtilis PTCC 1720 in solid-state fermentation (SSF) was investigated and optimized. The produced alpha-amylase in solid-state fermentation was precipitated, separated, concentrated, and dialyzed with 75% ammonium sulfate. Alpha-amylase activity was measured by the DNS method. The protein content after dialysis was estimated by the Bradford method and the purity of the enzyme was calculated. The molecular weight and partial purity of the enzyme were determined by polyacrylamide-sodium dodecyl sulfate gel electrophoresis (SDS-PAGE).

The results of the study showed optimal enzyme production was achieved when 10 gr of wheat bran mixed with 10 ml tap water and inoculated with 3 ml of bacterial inoculum with OD=1.0 (109 CFU/mL) and incubated at 37 °C for 72 h. The alpha-amylase activity after precipitation with 75% ammonium sulfate solutions was 3.563 U/mL.  As a result, the purity of alpha-amylase precipitated with 75% saturated ammonium sulfate was estimated to be 26.8% and its molecular weight was 63 KDa

Based on the results of the study, solid-state fermentation is a new and valuable way for amylase production using Bacillus subtilis.

Salinity is one of the most serious abiotic stresses, causing instability in germination and seed emergence due to low osmotic potential and ionic toxicity. Development of simple and low-cost biologic methods is essential for short-term management of salt stress. The use of plant growth-promoting rhizobacteria increases the rate and uniformity of germination. This research aimed to investigate the effect of bacterial growth-promoting bacteria on the germination and seedling growth indices of alfalfa c.v. Hamedani in different salinity levels.

A CRD factorial experiment with four replications was conducted in Seed Science and Technology Laboratory of Shahrekord University in 2016. The first factor consisted of 6 salinity levels 0, 2.5, 5, 7.5, 10 and 12.5 dS/m created with sodium chloride, and the second was four levels of bacterial pre-treatment: no inoculation with bacteria and biopriming, inoculation of alfalfa seeds with Acinetrobacter calcoaceticus PTCC 1318, Bacillus megaterium PTCC 1250 and Enterobacter aerogenes PTCC 1221. The seeds were treated with bacteria and placed at a 20 °C growth chamber. They were then irrigated with desired solutions depending on the salinity treatment. Germinated seeds were counted daily and the parameters of germination percentage and rate, seedling length, seedling dry weight, vigour index I, II and allometric coefficient were calculated after 10 days.

Salinity levels higher than 10 dS/m reduced germination indices and seedling growth of alfalfa. The highest reductions were obtained for 12.5 ds/m salinity level versus control for germination percentage (10.81%), germination rate (49.48%), plumule and radicle length (13.30% and 28.88% respectively) and vigor index I and II, which were 30.27% and 6.28%, respectively. The seed treated with A. calcoaceticus was able to tolerate salinity stresses more than others. For example, the reduction for the seed treated with A. calcoaceticus was only 4%, compared with non-stressed control. In salinity conditions 2.5 and 5 dS/m, the highest rate of germination was obtained, using A. calcoaceticus bacteria. In addition, the seeds treated with E. aerogenes showed higher stability at different levels of salinity for seedling length traits. The highest vigour index related to the use of A. calcoaceticus in salinity was 7.5 ds/m.

A. calcoaceticus had a significant role in reducing the negative effects of salinity on germination percentage and rate, vigour index I and II and allometric coefficient while E. aerogenes bacteria were more effective in reducing negative effects of salinity on seedling length and dry weight.

Poosti cheese is an artisanal cheese produced mainly from ewe’s milk in southwest Iran. The objective of this study was to identify lactobacilli isolated from Poosti cheese and to investigate their potential probiotic and antioxidative properties. Materials and methods 101 Gram-positive bacilli with catalase-negative reaction were isolated from Poosti cheese. Twenty isolates were selected based on their highest acid and bile salt tolerability. Using genus-specific primers, 10 isolates out of these were identified as Lactobacillus, and they were subsequently identified at species level using 16S rRNA gene sequencing. In vitro tests were used to assess their probiotic properties or antioxidative activities.

Six species were Lactobacillus plantarum, and the rest was Lactobacillus paracasei, Lactobacillus acidophilus, Lactobacillus brevis, and Lactobacillus buchneri. The acid and bile tolerances were quantitatively close to the reference probiotic strain. L. plantarum S32E showed the highest survival under simulated gastric or intestinal conditions. Cholesterol reduction ability of L. plantarum S12E and L. acidophilus S37A was significantly higher than that of the reference strain. L. acidophilus S37A and L. plantarum S12E were more susceptible against common antibiotics. It was found that the highest antimicrobial activity was detected in the case of Listeria monocytogenes, and the extent of the activity was species- and strain-dependent. The best result of DPPH radical scavenging activity and hydroxyl radical scavenging activity was achieved by intact cells of L. paracasei S5D and by intracellular cell-free extracts of L. plantarum S8D, respectively. The results indicated that the superoxide dismutase activity of Lactobacillus could not be regarded as an appropriate predictor of antioxidative traits. The highest glutathione content belonged to L. acidophilus S37A and L. parcasei S5D. Discussion and

Overall, some of Lactobacillus strains of Poosti cheese could be considered as potential probiotic candidates; it should, however, be confirmed by further in vivo evaluation.

In order to comparison the effects of growth promoting bacteria on germination of hamadani alfalfa seeds, a randomized complete block design was conducted with 4 replications and 8 levels of bacterial inoculation (include non-inoculation, application of Acinetrobacter calcoaceticus PTCC 1318, Bacillus megaterium PTCC 1250, Enterobacter aerogenes PTCC 1221 lonely and their pairwise and triple combination of them(. Another CRD factorial experiment was also conducted with 3 replications in greenhouse conditions. Mentioned bacterial treatments were as the first factor and injection of bacteria into the soil of pots as the second factor. The results showed that application of bacteria increased the vigor index of seedling, percentage and germination rate, but did not affect other alfalfa traits in the laboratory. Inoculation of seeds with bacteria in the pots had positive effects on alfalfa growth, percentage and rate of emergence, dry weight, root volume and length, chlorophyll a, b and total chlorophyll content. Injection of bacteria to the soil also affected some traits, which could be due to better placement and/or a larger population of bacteria in the rhizosphere. Application of bacteria lonely had better results than their combinations. It may be due to antagonistic effects of bacteria on each other, which may reduce positive effects.

In order to evaluation the effect of plant growth promoting rhizobacteria on germination and primary growth of Darcocephalum  moldavica L. an experiment in completely randomized design was conducted in the laboratory of agronomy science of Shahrekord University. Treatments were included control (no bacterial inoculation), inoculated with Rhodococcus sp., Corynebacterium sp., Mycobacterium sp., Bacillus sp., Azotobacter sp., Pseudomonas putida and Pseudomonas fluorescens bacteria and inoculated with a mixture of all bacteria. Results showed that a significantly effect of bacterial treatments on germination percentage, germination rate, mean germination time, germination rate index, half maximal activation level (T50), length and radical weight, shoot and seedling, vigor index and Allometric coecifficient at 1% probability level. Bacillus sp. bacterial inoculation treatment had the most influence on mean germination time, germination rate index, half maximal activation level (T50), length and radical weight, shoot and seedling, and vigor index traits. Bacteria incubation treatment of Rhodococcus sp. and Pseudomonasfluorescence hadthe most effect on germination speed and germination percentage, respectively. The results showed that bacterial inoculation treatments as biopriming can improve the germination and primary growth indices of D. moldavica herb.

With the rapid developments in nanotechnology, ZnO-NPs are increasingly being used in various aspects of our lives and their toxicity on body is escalating. This study aimed to investigate the histo-pathological effect of orally and intraperitoneal administrations of toxic ZnO nanoparticles (ZnO-NPs) on kidney function in laboratory male mice Mus musculus.
In this experimental study, a group of 75 BALB/c male mice of about 6 weeks were randomly divided into three groups (n=25). Each of mice in both orally- and intraperitoneal treated groups received the same concentration of ZnO-NPs (0.05 g/ml). On days 1, 7 and 14 of the experiment blood was taken directly from the heart to get serum. The data were analyzed by one-way ANOVA using SPSS. A significant difference was considered to be P In both intraperitoneal and oral treatment groups of mice, a significant increase in the serum level of BUN and Cr at day 7 was found with symptoms of vascular distension and infiltration of blood cells into the vessels, interstitial renal tubules and vacuolation of parietal cells of proximal tubules (necrosis). The observed tissue damage intensity in the orally administered group was less as compared with the intraperitoneal one.
A toxic concentration of ZnO-NPs causes serious physiological and pathological damages including congestion, necrosis in some cells, hydration of proximal tubules and kidney swelling in the oral group. However, the observed damages in the intraperitoneal group were lower as compared with the oral one.

The amylase enzyme hydrolyze starch and break glycosidic internal bonds of this polysaccharides. Amylases are important industrial enzymes for a wide range of applications including starch conversion to sugar syrup, dextrin production, and use in the pharmaceutical and medical industries.
In this study, thermophilic bacterium was isolated and purified from the Qynarcheh hot spring in Ardabil. Desired strain suspension in nutrient broth medium was placed in front of UV rays with a wavelength of 254 nm at a distance of 1 meter for 45 seconds in the laminar air flow. The mutant strains were compared to wild type in temperature and salinity tolerance, amylase production content and different antibiotics resistance.
In this study, two interesting mutant strains were isolated and named B.L.2.M.1 and B.L.2.M.2. Mutations caused many changes in bacteria such as cell growth speed and enzyme production content. Differences in cell growth, production of amylase and other characters were significant at 0.05 level (PvalueDiscussion and According to random mutations, the mutated bacterium-B.L.2.M.1- showed new phenotype with increment of enzyme production, increased cell growth rate and increased resistance to higher temperatures, and salinity. According to the unique features created in the mutant, the groundwork for additional studies is provided in order to produce and optimize the thermophilic amylase enzyme.

Following this study, the effect of zinc oxide nanoparticles on the liver histopathological features and TGF-β and LDH enzyme activity was studied. Ninety male mice were randomly allocated into three groups each whit three repeat in each groups. Group 1and 2 received Zn oxide nanoparticles orally and intra-peritoneal respectively at dose of 2.5 mg/kg for 14 consecutive days; group 3 served as the control. The value of TGF-β and level of LDH enzyme were determined on 14 day and liver samples were collected at supplementation intervals, 14 day. Results showed that TGF-β value in groups 1 and 2 were higher on day 14 compared to the controls, but this increase was no significant (P>0.05). It was also found that on day 14, the activity of LDH enzyme in both treated groups were significantly higher than those of the controls (P0.05). The histopathological results showed that the alterations in the hepatocytes were mainly nuclear enlargement, as nucleus was observed in large and small sizes. Some of the Kupffer cells into hepatic sinusoids included a large nucleus. Hyperemia in central veins was evident and RBCs had infiltrated into matrix. In intra-peritoneal group cytoplasm of hepatocytes showed vacuolization. According to the results it can be concluded that zinc oxide nanoparticles cause changes in the structure of the liver and liver enzymes.

Plant defensins are a family of cationic antimicrobial peptides, small and cysteine rich that have a broad range of antibacterial effects. The aim of this study was designed, synthesis, cloning, expression of wheat defensin (Triticum aestivum) gene and evaluation of the antibacterial effect of recombinant protein. The defensin gene was fused to sumo gene for more expression and solubility and then was optimized by some software and was synthesized and cloned in pGH vector. Then sumo_defensin sequence was sub cloned into pET-32a() vector and transformed into bacterial cells (E.coli origami). Gene expression was induced by 1mM IPTG in 30°C and proteins were analyzed by SDS-PAGE and Western blotting.The fusion protein with a molecular weight of approximately 38 kDa was analyzed on SDS-PAGE gel and confirmed by western blotting. After digestion of protein by Sumo protease, the antibacterial effect of the recombinant wheat defensin was evaluated on the plant pathogenic Gram-negative bacteria Xanthomonase axonopodis, Pseudomonas syringae and some human pathogenic Gram-negative and Gram-positive bacteria such as E.coli and Klebsiella pneumoniae , Staphylococcus aureus and Bacillus cereus. In the end, recombinant wheat defensin had an antibacterial effect against Xanthomonase axonopodis, Staphylococcus aureus and Bacillus cereus. Based on the antimicrobial characteristics of wheat defensin, this study can be effective to introduce a new antimicrobial agent.

Chrysin is a natural and active biological component which is extracted from plants, honey and propolis. Chrysin has anti-inflammatory, anticancer and antioxidant propertis. This study was done to evaluate the effect of chrysin on AGS human gastric cancer cell line. In this descriptive - analytic study, chrysin was dissolved in dimethyl sulfoxide (DMSO) and the cytotoxic effects of concentrations of 10, 15, 20, 30, 40, 50, 60, 70, 80, and 100 µM/ml of chrysin on AGS cells was evaluated. Viability of the cells was determined with MTT assay after 24, 48 and 72 hours and compared to controls. Chrysin inhibited the growth and proliferation of human gastric cancer AGS cell line. The antiproliferative effect of chrysin was dose and time dependent. The IC50 values were determined for 60, 30 and 20 µM, in incubation time of 24, 48 and 72 hour, respectively (P<0.05). Chrysin proved to have antiproliferative activity on human gastric cancer cells in culture medium.

Presently, silver and its compounds are being used as an appropriate solution to treat burns, open and chronic wound infections. This study is, therefore aimed to evaluate the effects of silver nanoparticles on wound healing and some biochemical parameters of blood and kidney tissues in mice (Mus musculus). In this experimental study, 50 female BALB/c mice of (weighting 24.2±3.0 g) about 4 weeks were randomly divided into two groups: Ag-NPs and control. After making a wound in all groups, a volume of 50 microliters from the nanosilver solution (10ppm) was applied to the wound bed in the Ag-NPs group while in the control group no nanosilver solution was used but the wound area was washed by distilled water every day. Samplings were performed on days 2, 7, 14 and 21 of the experiment and the wound's surface area measured on succeeding days. The results of the present study show that the percentage of the wound healed in the treated group was significantly greater than in the control group so that the time required to heal in the former was 14 ± 0.82 days and in the latter 20.75 ± 1.03 (P<0.05). There were significant changes in potassium and blood urea nitrogen (BUN) among all groups studies (P<0.05). This study suggests that recovery with a 10 ppm solution of silver nanoparticles, while accelerates the process of wound healing, will notoriously influence on some biochemical parameters of blood. So, although solution of silver nanoparticles is beneficial for healing, it should be cautious in consuming it.

With the industrialization of the nanotechnology, public exposure to nanoparticles will increase in the near future. So, health impacts of nanoparticles have rarely been studied. The main aim of this study was to assess acute toxicity of ZnO nanoparticles (ZnO-NPs) on serum biochemical function of liver in mice (Mus musculus). In this experimental study, a group of 18 BALB/c mice was randomly divided into three groups: two ZnO-NPs mice groups and one control group. The first day of the experiment, ZnO-NPs were received orally in acute doses of 0.05 g/ml and 0.1g/ml in the experimental groups, while in the untreated (control) group, no ZnO-NPs were used and they received distilled water 1 g/ml. The experiment lasted for 14 days. The serum was obtained by centrifugation of the whole blood at 3000 rpm for 15 min. Serum concentration of lactate dehydrogenase (LDH), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) was assayed using auto analyzer system. The present study showed that both doses of Zno-NPs increased significantly ALP, ALT, and AST enzymes compared with the control (P=0.01). However, LDH elevated in mice treated just with ZnO-NPs with a dose of 0.1g/ml. This showed that ZnO-NPs at acute doses could induce a severe liver damage (P=0.01). The current study results show that acute levels of ZnO-NPs are toxic and have harmful effects on liver function as indicated by increased levels of biochemical serum parameters of liver. Therefore, it is necessary to be cautious in the use of these nanoparticles

Defensins are one of the largest and most studied families of antimicrobial peptides. Defensins are a family of small، variably cationic proteins which are highly abundant in the granules of mammalian phagocytes. The members of this family are variably arginine-rich and all share 6 conserved cysteine residues that participate in intramolecular disulfide bonds. The peptides were first detected in rabbit and guinea-pig neutrophils. Some defensins are broadly antimicrobial، antiviral، and cytotoxic، while others are chemotactic، opsonic، or may modulate hormonal responses. Alpha- and beta-defensins have a similar three-dimensional structure and antimicrobial activity but they differ markedly in the location of the intra-molecular disulphide bridges، structure of their precursors and sites of expression. Due to their activity against bacteria، viruses، and fungi، antimicrobial peptides are important factors in the innate resistance system of humans and animals. They are called “new generation antibiotics” for their potential use in preventive and therapeutic medicine.

Iidentifications of Bacillus species is very important Because of dispersion in the environment and their application in biotechnology. In the present text, sporulation stage genes were studied which are unique to Bacillus. 17spoIIPgene sequences of Bacillus anthracis obtained from the NCBI website were studied using software CLC Main Workbench 5-6-1 - Limited Mode. The RFLP patterns were obtained by cutting the gene sequences with the 15 restriction enzymes and then compared together. Since the patterns of cutting of Bacillus anthracis were different from other bacilli, it was possible to design the specific primers for initiation and end of the genes and then amplified the sequence specifically. Finally, based on the restriction enzymes patterns, identification of bacteria were done in species and subspecies levels.

Although nanosilver (Ag-NPs) has long been used to treat wounds، little attention has been paid to the toxicity of nanosilver wound dressing. This study aimed to examine the effect of nanosilver used for wound healing on some hematological parameters. In this experimental study، 50 BALB/c mice were randomly allocated into the treatment and control groups (n=25). After creating similar wound on the back of all animals، the wound bed in the treatment and control groups was treated with a volume of 50 microliters nanosilver solution (10ppm)، and distilled water. Afterwards، the mean percentage reduction in wound area was determined at the end of each week by measuring the wound area at 0، 7 and 14 days post-wounding. MCV، distribution range of RBC، hematocrit and the number of blood cells were measured for both groups. By the end of the second week، a significant reduction was observed in the mean wound area in the treatment group. In treatment group، the number of white blood cells was increased; however، no significant changes in the number of RBCs and other blood parameters were observed. Application of nanosilver wound dressing not only can accelerate healing process، but also can stimulate the immune system with no adverse effect on some hematological parameters.

Defensins are one of the largest families of antimicrobial peptides and, because of their activity against bacteria, fungi, and many coated and uncoated viruses are very profitable as new antibiotics. This study was done to evaluate the optimization of expression, purification and handling antibacterial features of BNBD2 protein.

In this experimental laboratory study, E. coli BNBD2 (DE3) carrying pET-32a(+) vector in which BNBD2 was homogenized was used. BNBD2 expression was evaluated through changes in cell density, growth temperature, the duration of induction using vertical electrophoresis (SDS-PAGE) and Bradford test both qualitatively and quantitatively. The purification of recombinant protein was done by chemical method of fission in the position of formic acid and passing Centricon, and anti-bacterial effect of the purified protein on some gram negative and gram positive bacteria was examined

By induction start in optical absorption of 0.8 in wave length of 600 nm and inducing IPTG in concentration of 1 milimolar, growth temperature of 300C, and duration of 4h after induction, the highest expression was obtained in Luria-Bertani culture medium. The recombinant protein was purified by fission in formic acid and passing centricon. Western blot test results indicated that the recombinant protein was specifically connected to mouse anti-(His) 6 peroxidase antibody. The formation of inhibition zone in culture media of Hinton agar containing culture swab of the studied bacteria indicated this protein’s antibacterial property.

BNBD2 protein has antibacterial effects and can be expressed in E. coli and this protein has antibacterial effects.

Silver nanoparticles (Ag-NPs) have long been used to treat acute and chronic wounds. Very little attention has been paid to the toxicity of this nanoparticle. In this study، the possible toxicological effects of nanosilver particles، was assessed by determining the enzyme levels of liver along with hemoglobin over the period of skin wound healing in mice. A group of 50 Balb/c mice of about 8 weeks (weighting 24. 2±3. 0 g) were randomly divided into two groups: Ag-NPs and control groups، each with 25 mice. After creating the equal wound on the back of all animals، the wound bed was treated in the Ag-NPs group with a volume of 50 microliters from the nanosilver solution (10ppm)، and in the control group with the same amount of distilled water. The experiment lasted for 21 days. On days 2، 7، 14 and 21 of the experiment the serum concentrations of alanine aminotransferase (ALT)، aspartate aminotransferase (AST) and hemoglobin were measured. Statistical analysis was performed using independent t-test. Results showed that AST، ALT and hemoglobin levels were not significantly different between Ag-NPs and the control groups. The study suggests that treatment of wounds with silver nanoparticles may not produce toxicological effects on hemoglobin and liver function in mice (Mus musculus) as indicated by measurment of serum levels of AST and ALT enzymes.

Probiotics have some beneficial effects on health so these microorganisms are added to dairy products and other foods as well. Lactobacillus bacteria are the most commonly used for this purpose. The aim of this study was to find native Lactobacillus bacteria which has the potentiality for using as probiotic. For isolating lactobacilli، gram strain reaction and catalase test were performed on separated bacteria from 40 local yoghurt samples: after isolating، the acid resistance ability of isolates were evaluated by placing isolates in pH=2. 5 for 2 hours and culturing samples on medium and colony counts. Then، among 18 acid resistant bacteria، by gel diffusion method the inhibitory effect of isolates on pathogens bacteria such as E. coli and Pseudomonas aeruginosa were investigated. The results were compared to the results of investigated commercial strains. The results revealed that S4 isolate had the most inhibitory effect، it showed %80 good-inhibitory and %20 strong-inhibitory effect on pathogenic bacteria، which were completely consistent with results for commercial Lactobacillus gasseri strain. Also، the lowest inhibitory effect against pathogens was related to (Y4-Y5-Y11-Y14-Y15) isolates that all of them had weak-inhibitory effect on pathogens. Other strains were classified in good-inhibitor group. Discussion and Considering daily increasing of drug resistance relating to pathogenic bacteria، today، the use of probiotics، especially lactobacilli as an appropriate alternative of antibiotics is important. The investigated bacteria in this study were able to inhibit pathogens’s growth to some extent، but for investigating the results more accurately، some methods with more sensitivity، for instance، two layers method and MIC method can be used as well.

the use of lactic acid bacteria in fermented dairy products due to their effects participation in flavor، texture and most probiotic properties goes back to centuries ago. Optimal amount of lactic starter culture in the production of lactic acid in the production of cheese and yogurt are used. Isolation of Lactobacillus in MRS medium from various samples was performed. Then، The variation of different characteristics in terms of the ability of Lactobacilli to produce CO2 from glucose، the ability to grow at pH 2. 5 to 8. 5، different concentration of NaCl، 1. 5 to 10. 0 (percent w / v) and temperatures of 15 ° c، 45° c، the ability to move، indole and H2S production were also studied. The production of lactic acid was assayed in skim milk by titration with %1 NaOH. L-lactate isomer was investigated using UK Randox kit. In this study، from 30 samples of different indigenous yoghurt and cheese 43 gram-positive، catalase-negative، oxidase negative lactobacilli were isolated. All isolates were resistant to pH 2. 5 and 30 and %69 of the isolated were sensitive to 7. 5 and %10 concentration of salt respectively. Most of lactic acid production with % 1. 8 and L-lactate 6. 8 g/l were consididered for one isolated. This isolated bacillus based on biochemical tests was identified as Lactobacillus acidophilus. Discussion and The amount of lactic acid production at temperature 37°C was found to be higher than the temperature 25°C criteria that were statistically significant at %1 level. The optimal production of lactic acid in the native isolates and tolerance to appropriate pH and salt tolerance، these properties and studies are provided complementary knowledge to be used in the food industry.

L-glutaminase is widely used in pharmaceutical and food industries, such as treatment of leukemia. This study aimed to isolate and identify native L-glutaminase producing bacteria in Iran and to study its quantitative activity in submerged fermentation. The L-glutaminase producer bacteria were isolated from soil and water samples of Zayandehrod and Karoon Rivers and also from the sediments of fishing pools. The isolates were screened using minimal glutamine agar (MGA) medium for producing L-glutaminase enzyme. The samples were grown in a submerged fermentation system using mineral salt glutamine (MSG) medium, and the produced enzyme was assayed quantitatively. The best glutaminase producer bacterium was identified by the gram-staining and biochemical tests. In this study, 11 glutaminase producer strains were isolated. Bacillus subtilis CH3-GLU strain showed maximum enzyme productivity 37.91±0.62 U/ml at temperature 45° C after 96 hours. Based on this study, Bacillus subtilis CH3-GLU showed the highest rate of glutaminase production.

Saccharomyces cerevisiae is the most important industrial yeast for production of biochemical components, recombinant proteins and single-cell protein. We can use various genetic engineering methods for changing of yeast metabolic pathway(s) to increase of substrate source range such as xylose and lactose, increase of production efficiency and facilitate of industrial fermentation process. These modifications are discussed in new phylome of biology named “metabolic engineering”. Here we are going to introduce a brief expression of this scientific field.