فصلنامه ایمنی زیستی
سال دوازدهم شماره 3 (پاییز 1398)

Halophilic microorganisms cope with environmental stresses by producing and accumulating compatible solutes. Ectoine is one of the most important members of compatible solutes which have extra protective properties compared to other compatible solutes. Ectoine attracts several scientific and commercial attention because of their multiple industrial applications. This brief review presents applications of ectoine as protectants of proteins that can be explained by the preferential exclusion model. Also, other application of ectoine as an enzyme stabilizer and drug for various diseases have also been reviewed. Further, the role of ectoine in stabilizing macromolecules and even whole cells against UV radiation, freezing, drying and high temperatures is briefly described. The ectoine biosynthesis genes are located in cluster ectABC. This paper also briefly described the regulation of these genes under environmental conditions. There are currently two technologies for producing ectoine called bacterial bio-milking and leaky mutant. Several tons of ectoine are produced each year using these methods. Finally, the limitations of the methods are mentioned.

Fluorescent pseudomonads are an effective source of biological control that have high adaptive power and able to produce a wonderful source of secondary metabolites. Antibiotics such as phenazines, diacetylphloroglucinol, and hydrogen cyanide are produced by certain taxonomic groups of the genus Pseudomonas and appear to be ancestral. These compounds often play a physiological role in producing strain, independent of their antibiotic activity. Other secondary metabolites including rhizoxins, promysalin, L- Furanomycin, insect toxins, and biosurfactants (rhamnolipids and cyclic lipopeptides) are only found in certain Pseudomonas isolates. Recent advances in genome sequencing have led to the discovery of a large number of cryptic biosynthetic gene clusters. Genome mining has led to the discovery of many antimicrobial compounds that have the biocontrol role in the plant-pathogenic fungi, oomycetes and bacteria. In addition, some biocontrol strains of Pseudomonas can produce anti-insect compounds. The ability of Pseudomonas biocontrol agents continues to surprise. This paper tries to investigate the latest studies about biocontrol mechanisms of fluorescent pseudomonads.

Production of recombinant proteins has been the most important achievements of biotechnology and genetic engineering in recent years. Therefore, there is a great demand to the production of recombinant proteins for treatment and diagnosis. Researchers are trying to develop different transgenic models for the production of these drugs today. Since it can be expressed a foreign gene in different host systems, therefore finding a system with high yield and safety is necessary. Among the systems developed for the production of recombinant proteins it can be referred to bacteria, yeast, plants and animals. Choosing the type of expression system for the production of each recombinant protein is important. There are several methods for gene transfer and production of transgenic products, but all the methods are not efficient genetically engineered crops. Today, one of the most effective and widely used tools for gene transfer is virus-derived vectors. Virus-derived vectors have been an interest to researchers because of their ability to integrate genes into host cells. The deletion of some basic and structural protein-coding genes from viruses was separately improved by helper vectors. For packing the virus particle, it was used of the packing cells, enhancing the safety of these vectors. Among virus-derived vectors, lentiviral-derived vectors are one of the most powerful and widely used vectors available. So far, three generations of lentiviral-derived vectors were designed, so that each generation is containing the higher bio-safety compared to the previous generation.

Antimicrobial peptides are part of the plant defense system. They are present in all plant organs and in a wide range of plant species and their antimicrobial effects have been proven against phytopathogens as well as human pathogens, viruses, bacteria, fungi, and protozoa , parasites and cancer cell lines. Thus these peptides are promising antibiotic compounds with important applications in pharmaceutical biotechnology. Antimicrobial peptides of plants are grouped in several families based on general characteristics such as positive charge and presence of disulfide bands. Most naturally antimicrobial peptides are between 10 and 50 amino acids long, range in size from 2 to 9 kDa, positively charged, contain highly hydrophobic amino acids, and often have helical structures. The set of antimicrobial peptides synthesized by plants is homologous to the amino acid sequence of defensins, thionins, lipid transfer proteins, cyclotides, snakins, and hevein-like proteins. Antimicrobial peptides of plants have a high potential in health and agricultural care as a natural antibiotic and are an alternative to chemicals to protect humans, plants or animals from disease.

Since the advent of genetic engineering in the 1970s, concerns arose about risks of this technology that led to enforce labeling of transgenic crops. Therefore, it seems, it is necessary to use valid methods to identify transgenic crops to reduce or minimize relative potential errors. The validity of such methods depends on the sampling and the uniformity of distribution of transgenic crop under study. In most cases, the sampling is a source of error. Therefore, some software such as SISSI is designed to reduce sampling errors. This software which works based on Jackknife method is a new tool to determine optimum sample size for the experimental data set. The method estimates the population variance when there is little information about the population. The software graphically displays results as also changes in the mean and standard deviation of the population. Moreover, it has the option to determine the sample size automatically. One of its applications of this is to determine optimal sample size for transgenic shipments that are not uniform. The detection of transgenic material in commercial samples with high sensitivity in the international trade is another instance of its applications.

The prevalence of food allergies in Iranian society is increasing. Knowledge of hazardous allergic reactions is essential in the development and promotion of lifestyle. The aim of this study was to evaluate general knowledge about allergies, to improve and enhance the self-efficacy of lifestyle among students of Kermanshah province high education centers as part of Iranian scientific community.

The two main focus groups of N =1000 including students in both sexes in undergraduate and postgraduate courses in higher education centers of Kermanshah province were evaluated based on a comparative-descriptive questionnaire of ISAAC model to identify the essential points of food allergy knowledge and related diseases. Data were analyzed by SPSS software version 18 using two-way t-test with significance level less than 0.001.

Information level of postgraduate women was significantly higher than other groups and it was in men significantly higher than other groups (P <0.01). The mean of knowledge based on two-way t-test with a significance level of 99% showed a significant difference from higher level of information in bio science students than non- bio science students (P <0.001).

Knowledge of allergies and related diseases can affect the quality of life of people with allergies and their families and the health of the community, however, the results showed a significant difference in information of students in other fields and sections.