فصلنامه ایمنی زیستی
سال پانزدهم شماره 1 (بهار 1401)

Micrografting is a grafting technique that involves the placement of a small meristem or section of shoot-tip onto a decapitated rootstock that has been grown aseptically from in vitro seedlings. In vitro micrografting provides many benefits to producers in agriculture and natural resources. The success rate in micrografting can be affected by different factors such as cultivar or genotype, scion length and rootstock development stage and adaptation of a micrografted seedling in greenhouse conditions. In this review, various applications of micrografting techniques such as early detection of viral, viroid and phytoplasma infections, obtaining of grafted disease-free plants free from virus and virus-like disease, overcoming ecological limits, providing an alternative production technique, rejuvenation of mature tissue, bypassing the juvenile phase in fruit trees, recovery of cryopreserved shoot tips, allowing a quick supply of  safe germplasm exchange, facilitating the early diagnosis of grafting incompatibilities, saving rootless shoots and deficient embryos, testing long-distance signalling in plants, productions of polyploidy plants are discussed.

Today, water pollution is a global challenge that, in addition to developing countries, is also present in developed countries. This global challenge is linked to economic growth, environmental health, and the health of billions of people. Water can be consumed by living organisms directly or indirectly by entering agricultural products, and the quantity and quality of life of living organisms, especially plants and humans, will suffer from serious problems. Today, agriculture is still recognized as the most important source of water pollution in the world and industrial activities are an important complement to this pollution. Various factors can cause water pollution, the most important of which are microbial, chemical, and heavy metal pollution. Heavy metals generally reduce the growth and yield of plants, and their effects on humans can lead to a variety of diseases, including cancer. Although prevention is the most important way to control water and heavy metal contaminants, there are several ways to remove them from the environment, one of the most important of which is phytoremediation. Phytoremediation is a type of bioremediation in which the plant is used to reduce the concentration or toxic effects of pollutants in the environment. This article reviews the types of heavy metals and their sources, the effects of heavy metals on humans and plants, and methods for repairing soils contaminated with heavy metals.

Knowledge and awareness related to the risks of contracting diseases caused by contaminated food is essential in the development and improvement of lifestyle. Students are an important element in the healthy population of the country. The aim of this study was to evaluate the general knowledge about food health and safety, improve and enhance the self-efficacy of lifestyle of students in educational centers of Kermanshah province as part of the target population of Iran. Using a descriptive-analytical questionnaire of questions in three sections, to assess the level of knowledge, attitude and practice of students in Kermanshah educational centers in two different genders and fields of study (N= 400), about food health and safety as an essential biosafety approach was investigated. The level of information of biological science students with 76.7%, 83.9% and 80.3% respectively compared to non- biological science with 58.25%, 74.4% and 76.25% and in women with 71.1%, 82.8% and 80.6% compared to men with 63.85%, 75.5% and 75.95% had a significant difference in knowledge, attitude and practice, respectively (P<0.05). Therefore, holding training workshops and determining courses in this field can be useful.

Since an effective drug against Covid-19 was not approved, researchers worldwide are trying to develop an effective vaccine against the disease to prevent related morbidity and mortality. According to the latest report of the World Health Organization, August 5, 2022, there are about 170 vaccine candidates for SARS-coronavirus-2 in the clinical and 198 vaccine candidates in the pre-clinical stage. In this review article, emphasis is placed on only 7 vaccines that have passed clinical phase IV. The mechanism of action of most of the proposed vaccines is the induction of a neutralizing antibody against the spike protein (glycoprotein S). These antibodies prevent the virus from entering the host cell by blocking the virus from attaching to its cell receptor (ACE-2). In this review, the role of SARS-coronavirus-2 proteins in the viral replication cycle and its pathogenic mechanism, and also the variants of SARS-coronavirus-2 are discussed to have an overview of the goals of designed vaccines. Then, the technology of producing various types of vaccines and the effectiveness of these vaccines against the virus variants are discussed.

Nanoparticles are used as a pharmaceutical tool for infections against microbes and in the near future, there is an urgent need to replace antibiotics with new substances with antibacterial properties. One of the most efficient methods of nanoparticle synthesis is the method of green synthesis of nanoparticles by plants. In this study, an environmentally friendly extracellular biosynthesis method, namely reducing agents of Mentha piperita L. extract, was used to produce gold nanoparticles. The gold nanoparticles were characterized by color changes, the XRD method and the UV-visible spectroscopy and the antibacterial activity of nanoparticles against four species of bacteria (Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Bacillus cereus) investigated through bacteria disc fusion assays. Results showed that due to the reduction of gold ions and the production of nanoparticles, the color of the samples changed from yellow to brown, which indicates the production of a colloidal suspension of gold nanoparticles. The gold nanoparticles have the maximum absorbance at 550 nm, spherical shape and their average size was 2-10 nm. Further investigation revealed that synthesized nanoparticles have relatively antibacterial activity on Escherichia coli, Salmonella typhimurium but have no effect on Bacillus cereus and Staphylococcus aureus. In general, based on the observations of this study, it can be concluded that the aqueous extract of Mentha piperita L. due to its secondary components and antioxidant activity, has high potential in the reduction of gold metal ions as well as synthesis and stabilization of gold nanoparticles. Also, the synthesized gold nanoparticles show relatively good antibacterial activity against some bacteria.

Microalgae-based products are an emerging class in food and nutrients. Due to population growth and modernization of lifestyle, consumption of high-calorie foods has become common, which causes the problems such as obesity, heart disease and diabetes, which require the use of healthy foods containing vitamins, minerals, PUFA. For this reason, there has recently been a great deal of interest in separating new compounds from marine resources because of their health benefits. Among marine resources, algae are valuable resources with diverse structures of bioactive substances. Algae are important sources of phytochemicals with antioxidant properties that are directly and indirectly involved in the food industry. Many compounds such as carotenoids, phycobilin, unsaturated fatty acids, polysaccharides, vitamins and biologically active molecules that are important for use in human health have been identified in algae. Long-chain unsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid are very important for the body's metabolism in humans. Chorophylll and bryophyte algae are used to extract these essential fatty acids. Macro and microalgae have a wide range of genetic and biodiversity sources that increase their importance due to their high nutritional value, trace minerals, high protein content and unsaturated fatty acids have been used in human, animal and aquatic nutrition. Therefore, in the present study, the properties, that potential and application of algae for the preparation of beneficial foods are discussed.