فصلنامه تازه های بیوتکنولوژی سلولی مولکولی
پیاپی 49 (زمستان 1401)

Kombucha is a tea with a slightly sweet and sour taste. This drink is rich in acetic, gluconic and glucuronic acids and has a lower concentration of citric acid as well as a limited amount of ethanol and CO2. This article discusses the beneficial effects of kombucha, its chemical composition and metabolites from the fermentation process, as well as the properties of kombucha in particular as a natural probiotic compound. The purpose of this article is to introduce a natural food composition rich in organic matter and essential to increase human health.

This drink is prepared by fermenting Sweet tea with Scooby Carrier of microes. Kombucha is based on a variety of teas such as black tea, green tea or oolong. Usually a piece of polysaccharide containing microbes including Saccharomyces cerevisiae and Acetobacter xylinum is brewed in 150 g of tea with 5 to 15% sucrose and placed in the dark for 7 to 10 days. Next, the polysaccharide layer microbial colony is removed and the kombucha is ready to eat. The final product contains organic acids, vitamins, minerals and antimicrobial and antioxidant compounds. Lowering cholesterol and blood pressure, preventing cancer, improving liver function, immune system and gastrointestinal tract are some of the potentially beneficial effects of kombucha drink. Acetobacter, Glucobacter and Saccharomyces cerevisiae are the most important natural probiotics in this drink, which help protect human health by producing organic acids.

Nowadays, by diversifying the production of kombucha, the amounts of its useful metabolites such as vitamins, organic acids and antimicrobial and antioxidant compounds  can be optimized and used as a natural medicinal supplement.

HCQ is one of the auxiliary drugs for the treatment of malaria, some cancerous tumors and viruses. Targeted drug delivery systems can be used to deliver the drug to the target site, controlling the dose and reducing cell damage. In this project, a magnetic nanocomposite for drug transfer was produced and investigated.

PVA/GT /Fe3O4 nanocomposite was produced for HCQ drug delivery and the drug release rate of this nanocomposite was evaluated at pH 7.4 and at different times. In order to optimize the nanocomposite, the effect of Fe3O4 and maleic anhydride nanoparticles on the swelling of the nanocomposite and drug release was investigated.

Drug release is highly dependent on the amount of Fe3O4 and crosslinker, which can be controlled by changing the dose of nanocomposite. The highest cumulative drug release belonged to nanocomposites containing 4% wt Fe3O4 during 6 hours (13.92%).

PVA/GT /Fe3O4 nanocomposites can control the release of a certain dose of HCQ drug and reduce its side effects, so it can be considered as a drug carrier for the treatment of related diseases that require clinical studies.

Rhamnolipids are one of the most important bio surfactants of glycolipids produced by Pseudomonas aeruginosa. In this study, the expression of bio surfactant producing proteins of Pseudomonas aeruginosa in the presence of sodium dodecyl sulfate coated iron nanostructure (Fe/SDS) were evaluated.

The expression of Surfactant Protein A enzyme was investigated by SDS-PAGE and Western blot. The enzyme rhamnosyl transferase was analyzed on SDS-PAGE gel and confirmed by Western blotting. The presence of nanoparticles on the surface of bacteria and the morphology of nanoparticles were investigated by TEM and SEM.

According to SEM, nanoparticles with a size of 20 nm and a spherical shape were seen. Binding of Fe / SDS nanoparticles to bio surfactant was confirmed by TEM. The enzyme rhamnosyl transferase with a molecular weight of 40 kDa was expressed in the test sample. The results of protein expression showed that the confirmed of rhamnosyl transferase enzyme increased significantly under the influence of Fe/SDS nanoparticles and showed the confirmed compared to other nanoparticles and the control sample. While SDS and Fe nanoparticles alone are not effective in confirmed this protein and are almost identical to the control sample. Western blotting results of SDS-PAGE confirmed the expression of rhamnolipid transferase under the influence of Fe/SDS nanoparticles.

The results of the present study indicate the importance of Fe/SDS nanoparticles in increasing the expression of rhamnolipid transferase enzyme in the production of bio surfactants from Pseudomonas aeruginosa.

Ginger with the scientific name of Zingiber officinale contains the active ingredient Gingerol and many antioxidant and antimicrobial compounds. The aim of this study was to investigate the antimicrobial properties of aqueous and hydro–alcoholic extracts of ginger and to investigate the anti-Alzheimer's effect of its hydro–alcoholic extract by inhibiting the production of amyloid nanofibers.

After milling, aqueous and hydro–alcoholic extract of ginger was prepared by soaking method and its antimicrobial effects on Escherichia coli and Staphylococcus aureus were investigated using agar diffusion method and determination of MIC and MBC. Visible spectroscopy was used to determine the inhibitory effect of hydro–alcoholic extract on the production of amyloid filaments.

The results showed that the diameter of the growth inhibition zone due to hydro–alcoholic extract of ginger in the well method was 15 mm for Staphylococcus aureus and 10 mm for Escherichia coli. The MIC and MBC levels for both bacteria were 50 and 100 mg / ml, respectively, and the aqueous extract of ginger had no effect on Escherichia coli. Increasing the concentration of ginger extract in the sample reduced the production of amyloid fibrils, which was associated with decreased absorption and redshift in the visible absorption spectrum of the Congored. The presence of the active ingredient gingerol was confirmed by GC–Mass method up to 34.7%.

Ginger extract with the presence of antimicrobial compounds such as gingerol, with good performance and lower side effects and cost, can be introduced as an effective medicinal plant for reducing the effects of inflammatory and Alzheimer's disease.

In dentistry, antimicrobial materials are selected due to their antimicrobial effects and tissue-compatibility. In the present study, cell-toxicity of calcium hydroxide and sodium fluoride powders were evaluated in L929 fibroblast cell line. Also in this study, possible effect of calcium hydroxide was evaluated in decreasing cell-toxicity effect of sodium fluoride.

Experimental materials were evaluated in time points of 6, 12, 24, 48 and 72 hrs with concentrations of 0.05, 0.1, 0.25, 0.5, 0.75, 1, 5, 25, 100, 500 and 1000 ppm by MTT test on L929 fibroblast cells and as negative control untreated cells were evaluated.  

Calcium hydroxide alone, showed low cell-toxicity (p<0.05). Sodium fluoride in concentrations of 500 and 1000 ppm showed a meaningful difference versus negative control sample (p<0.05). Combination of calcium hydroxide and sodium fluoride reduced sodium fluoride cell-toxicity meaningfully in concentration of 500 ppm (p<0.05).

Using of new compounds is so useful in dentistry for disinfection. One solution is reducing current compounds cell-toxicity. In the other hand, calcium hydroxide did not show noticeable cell-toxicity but it reduced sodium fluoride cell-toxicity in a combination form.

Caves are less studied oligotrophic and dark environments and can be suitable sources for finding promising strains having biotechnological potentials. Sahoulan Cave has a dolomitic structure and is located 42 km southeast of Mahabad city. The aim of the current research was to study the actinobacterial diversity of this cave and evaluate their antimicrobial activity.

In this project, different samples of soil, water, floor, wall, roof as well as invertebrates of the Sahoulan cave were collected to isolate actinobacteria. To facilitate the isolation, three pretreatments (centrifugation, drying and, microwave) and an antibiotic treatment were performed on the isolates. Then, they were cultured in 10 different isolation media. The isolates were also screened for antimicrobial activity against 10 bacteria and fungi.

From 13 samples obtained from the Sahoulan Cave, 8 actinobacteria were isolated from the genera Streptomyces, Micromonospora, and Lysinibacter. Lysinibacter sp. UTMC 3606 had 99.3% similarity to Lysinibacter cavernae, which was isolated from a cave in China in 2015 as a new species. Of the 8 isolates, 5 isolates had antimicrobial activity, including three Streptomyces and two Micromonospora. Three isolates were active against Staphylococcus aureus and Micrococcus luteus. One isolate was active against Escherichia coli TolC. Antimicrobial activity against Bacillus subtilis UTMC1464 was observed in one strain. Three isolates also showed activity against Candida albicans UTMC5055. The isolated Micromonospora sp. UTMC3322 showed the highest antimicrobial activity against S. aureus, M. luteus, and C. albicans.

Comparison of the obtained results with that of other studies on caves in Iran shows that caves are valuable environments for biodiversity studies and isolation of actinobacteria, however, pristine caves are more preferred. Actinobacterial diversity in the Sahoulan cave was less than Hampoil cave, but the biological activity of the isolates was higher. Study of tourist caves such as the Sahoulan Cave can be a good subject to study the impact of humans and tourism on the biodiversity of caves.

 This study aimed to investigate the effect of microgravity and light spectral composition on the levels of antioxidant enzyme activity, minerals, and  some photosynthetic pigments in Physalis alkekengi.

This study was performed in vitro. Seedlings were exposed to the microgravity treatments under two different light conditions, including white (C) and red+blue (R+B).

 The microgravity treatments were more capable of rapidly influencing growth performance than the light spectrum quality. Red+blue light increased the amount of chlorophyll a and b. Antioxidant enzymes under microgravity stress showed an increase, while changing the quality of the light spectrum did not make a significant difference. An increase in malondialdehyde (MDA) was observed in the microgravity treatment compared to the light spectrum. The amount of Cu+2 and Zn+2 were increased by the R+B+microgravity treatment. However, Mn+2 was increased in the microgravity treatment. The highest uptake of Fe+2 and Ca+2 was recorded under microgravity conditions. R+B+Microgravity treatment increased K+ content compared to white control. The microgravity treatment increased Mg+2 in the root cell.

 In general, microgravity and light spectrum can increase biomass. Microgravity has little effect on photosynthetic pigments, but the R+B light spectrum increased the pigments. Microgravity increased the activity of antioxidant enzymes and the content of MDA. The concentration of some elements in roots and leaves can be modified by the light and microgravity conditions.

Diagnosis of drug-resistant tuberculosis is of high value considering the importance of controlling tuberculosis. Identifying and introducing a rapid and specific diagnostic method for the causative agent of tuberculosis, Mycobacterium tuberculosis, is of great importance. The aim of this study is molecular characterization the presence of drug-resistant Mycobacterium tuberculosis to first- and second-line drugs in suspected tuberculosis patients.

This study was conducted on 2895 patients referred to different laboratory centers who were suspected to tuberculosis. The samples that were positive on the culture medium were examined by the drug resistance evaluation method and also the sequencing was performed on drug resistant genes including katG, rpoB, rrsL and gyrA to identify the corresponding mutations.

During the study period from October 2018 to March 2022, 2895 people, a total of 283 positive samples and 60 resistant samples were isolated, and the relevant mutations in each gene were determined based on nucleotide changes on the relevant genes.

Due to the fact that the diagnosis of tuberculosis, especially in the case of Mycobacterium tuberculosis, is time consuming especially when samples are positive and it takes a long time to perform the resistance evaluation test. So molecular identification and identification of the relevant mutations on the related drug-resistance genes, provides the possibility of accurate diagnosis and timely treatment