sedigheh asad

In the last month of 2019, an unknown virus appeared in Wuhan, China. Sequencing studies have shown that the virus is a new member of the coronavirus family, which mostly causes a respiratory disease with pneumonia-like symptoms. The new coronavirus consists of 25 proteins, including 4 important structural proteins and 15 non-structural proteins. Spike protein is one of the most important structural proteins on the surface of the virus; It is highly glycosylated and plays a key role in the virus binding to the host cells. The binding of glycans to proteins affects their structure and function in two ways; They lead to proper protein folding, and can play an important role in protein interactions, and also, by covering the surface of the protein, it causes the virus to escape from the immune system. So it is obvious that the study of glycan structures becomes more important when either a vaccine is going to be designed or glycan structures have important roles in the folding, activity, and interaction of a protein. Therefore, since the spike protein is a non-functional structural protein, the study of glycan structures is important for two goals of vaccine design and investigating the role of glycans in protein interactions. In this article, we are going to review the most important findings on spike protein glycosylation and compare the amount of glycosylation in different viruses, indicating the importance of glycan structures in designing an effective vaccine.

Phenols are organic and highly toxic compounds commonly found in the effluents of various industries due to their wide range of applications. The inhibitory effect of phenol at high concentrations, as well as the high salinity of industrial effluents, poses a serious challenge for treatment by microorganisms. One of the most common approaches to overcome this problem is the immobilization of phenol-degrading microorganisms. The aim of this study was to study the immobilization effect on the phenol removal efficiency of native Janibacter halotolerant bacterium. For this purpose, mica was used as a carrier for bacterial immobilization and the protein concentration assay was applied to determine the immobilization efficiency. The phenol removal by free and immobilized cells was studied as well as the effect of different parameters on phenol removal efficiency. The immobilization efficacy on mica was %68.75, based on protein concentration measurements. The removal time of 100 mg/L phenol by suspended cells was 88 h, while the immobilized cells degraded it in 40 h. Immobilized cells, unlike free cells, were able to remove phenol at lowered temperatures up to 16℃ , salt concentrations greater than 7/5%, and pH levels below 7/5 and above 8/5. Similar results regarding the superior performance of immobilized cells have been obtained in other studies. As a result, the immobilization process considerably improves the efficiency of phenol removal and makes the cells resistant to harsh environmental conditions by protecting the cells from the toxic effects of phenol.

The treatment of prostate cancer patients usually starts with androgen ablation and followed by chemotherapy; however, in some cases the tumor develops resistant phenotype. Combination therapy is currently regarded as a cornerstone in cancer therapy to overcome the drug resistance. Herein, we investigated the combinatory effect of Docetaxel and Trastuzumab with a novel nanomedicine, BCc1. Also, we knocked down the expression of Heat shock factor-1, HSF1, in resistant Prostate Cancer cell line 3, PC3, using RNA interference, RNAi, to sensitize the cancer cells to the drug treatment. We observed down-regulation of Erb-B2 Receptor Tyrosine Kinase 3, ERBB3, B-Cell Leukemia/Lymphoma 2, BCL2, and Heat Shock Protein 90, HSP90, in HSF1 knockdown PC3 cells.  Knockdown of HSF1 made PC3 cells more susceptible to Docetaxel treatment. Additionally, BCc1 nanomedicine was tested on prostate cancer cell line PC3 for the first time. It resulted in reduced metabolic activity in these cells.  We propose that a combination of the gene therapy and the chemotherapy gives more favorable results in the treatment of refractory prostate cancer.

Azo dyes are the most widely used synthetic colorants in the textile, food, pharmaceutical, cosmetic, and other industries, accounting for nearly 70% of all dyestuffs consumed. Recently, much research attention has been paid to efficient monitoring of these hazardous chemicals and their related metabolites because of their potentially harmful effect on environmental issues. In contrast to the complex and expensive instrumental procedures, the detection system based on the quantum dots (QDs) with the superior optochemical properties provides a new era in the pollution sensing and prevention.

We have developed a QD-enzyme hybrid system to probe methyl red (MR) in aqueous solutions using a fluorescence quenching procedure.

The azoreductase enzyme catalyzed the reduction of azo group in MR, which can efficiently decrease the Förster resonance energy transfer between the QDs and MR molecules. The correlation between the QDs photoluminescence recovery and MR enzymatic decolorization at the neutral phosphate buffer permitted the creation of a fluorescence quenching-based sensor. The synthesized biosensor can be used for the accurate detection of MR in a linear calibration over MR concentrations of 5-84 μM, with the limit of detection of 0.5 μM in response time of three minutes.

Our findings revealed that this fluorometric sensor has the potential to be successfully applied for monitoring a wide linear range of MR concentration with the relative standard deviation of 4% rather than the other method.

L-asparaginase has an essential role in the treatment of cancers, especially Acute Lymphoblastic Leukemia. The rapid removal of the enzyme from the bloodstream, glutaminase activity, and also inducing an immune response in the body are disadvantages of commercial enzymes, therefore, the identification of new L-asparaginase with desirable properties is essential. Previously, the coding sequence of L-asparaginase isolated from Halomonas elongata had been cloned in E. coli and had shown to have advantageous properties as a chemotherapeutic agent. However, it was mostly expressed as inclusion bodies.

In this study, soluble enzyme expression was examined in two E. coli hosts, BL21 (DE3) and ArcticExpress strains. After selecting the host, the effects of various factors such as culture media, inducer concentration, inoculum size, induction duration, temperature, and also aeration rate were optimized using the one-factor-at-a-time approach.

Based on the results, the highest amount of active L-asparaginase production was related to Escherichia coli host Bl21 (DE3) strain in LB culture medium by adding 1% inoculum size, after 9 h induction with 0.5 mM IPTG at 37 ˚C, and shaking at 150 rpm. In the next step, the effect of various additives on the culture medium was investigated and it was observed that the addition of ethanol 2% (v/v) or arginine (200 mM) has a significant effect on increasing the specific activity of the enzyme.

Finally, the optimization could increase soluble L-asparaginase production from 1000 U/mg in the basal condition up to approximately 3500 U/mg (more than three times).

Azo dyes are the biggest group of colors. One of the special characteristic of this group of dye is the presence of double bonds of Nitrogen (N=N). Several studies reported biodecolorization using microorganisms, so far. However, it is for the first time to our knowledge that decolorization by halophilic archaea have been reported.
Among the 15 strains of archaea isolated from Qeshm saline cave and 7 type strains from Iranian biological resource center, 2 strains showed high ability in decolorization of azo dye. Effects of different factors including pH (5-9), temperature (30-50 °C), various salt concentrations (12.5-30%), different concentrations of dye (400-5000 mg/L), different carbon sources and several nitrogen sources and agitation have been measured after 4 days of incubation in static condition. Moreover, the toxicity tolerance of halo archaeal strains to dye, growth and decolorization rates were studied. Statistical significance was assessed by ANOVA Tukey’s multiple comparison test.
Strain A with 99.1 % similarity to Halogeometricum borinquense and strain B with 99.4 % similarity to Haloferax mediterranei were the best decolorizing strains. Both strains had their highest decolorization rate in the presence of NaCl (15-17.5 %), pH 7, microaerophilic condition and yeast extract as nitrogen source. Halogeometricum borinquense showed higher decolorization rate in the presence of saccharose and glucose as carbon sources at 45 oC temperature and for Haloferax mediterranei temperature of 40 oC and propionic acid as carbon source were best decolorizing conditions. These strains were able to decolorize dyes at 1000 mg/L concentration and tolerate dye concentrations to the highest level of 5000 mg/L.
Discussion and In conclusion, our results indicate that halophilic archaea have very high potential to decolorize azo dyes. Regarding high amounts of salts in textile wastewaters, using such microorganisms which can tolerate the harsh environment in order to decolorize azo dyes, could be a new approach in this field.

Halophilic and halotolerant microorganisms are good candidates for decolorization of azo dyes which are routinely used in the dyeing process in textile industries. In this paper, theoptimization of biological decolorization of synthetic dye solutions containing Remazol Black B by the previously isolated halophilic bacterium Halomonas sp. D2 is investigated. In a primary investigation using a one-factor–at-a-time method, temperature, initial pH of the solution, and concentrations of glucose, yeast extract, and sodium chloride were chosen for optimizing dye removal using the Taguchi method. Based on the statistical analysis of the results, the most significant parameter by far was the yeast extract concentration which accounted for 72.67% of the total effect, followed by pH (11.84%) and the NaCl concentration (8.90%). The optimized conditions for dye removal were predicted to be a temperature of 35°C, an initial pH of 10, glucose concentration of 1% (w/v), yeast extract concentration of 1% (w/v), and sodium chloride of 10% (w/v). Under these conditions, 95% decolorization was achieved in confirming experiments.