فصلنامه ایمنی زیستی
سال پانزدهم شماره 2 (تابستان 1401)

Lead and cadmium are among the most important heavy metals which have entered the life cycle of the earth as a result of human activities.  In this study, in order to evaluate the ability of Indian mustard to uptake heavy metals (cadmium and lead), a survey was performed as randomized complete block design in which each metal was added  to the plant in four concentrations zero (a control), 50, 100 and 200 mg/kg soil. The results showed that the highest concentration of lead in the root and shoot (aerial parts) of Indian mustard was 278.4 and 61.8 mg/kg, respectively, in the 200 mg/kg treatment, while the highest amount of cadmium in these two organs was 14.5, and 10.9 mg/kg respectively in the treatment of 100 mg/kg soil. Also, with the increase of lead concentration in the soil, the amount of this element in Indian mustard increased linearly with a high correlation coefficient, and the bio-concentration coefficient of lead in the plant roots was greater than one in all studied treatments. Finally, it was found that Indian mustard can be used as a bio-indicator of lead and stabilized it in its root, but it is not able to stabilize or extract significant amounts of cadmium from soil.

Global warming is an important phenomenon with many effects on the environment, which is associated with an increase in greenhouse gases such as carbon dioxide, methane and other gases. Accumulation of greenhouse gases, increase or decrease in temperature, and change in rainfall all affect the distribution of plant pathogens and the incidence of disease. On the other hand, by affecting the carriers of pathogens, climate change can cause them to disperse in a wide area or cause pathogens to enter new areas. On the other hand, the effect of global warming on plants is different and diverse depending on the plant species and its pathogens and according to different environmental conditions. These effects can be harmful, positive or neutral. However, according to the pathogenicity triangle, one of the central mainstays of the disease rate is environmental conditions; therefore, plant diseases are strongly affected by the environment; if a sensitive host is placed in unfavorable conditions, it will not be infected by an invasive pathogen. Based on the conducted research, temperature changes in the environment cause the emergence of new diseases and the spread or limitation of diseases. This article discusses the essential effects of global warming on the occurrence and spread of plant diseases in new areas.

Lactic acid bacteria (LAB) are essential microorganisms in the formulation of several starters in the food industry. One of the main problems in food fermentation is the widespread presence of malignant bacteriophages, which can change the quality of fermented products or delay production processes. The anti-phage ability of lactic acid bacteria is a potential feature that has been considered to solve their problem against bacteriophages. During evolution, lactic acid bacteria have used several mechanisms to escape and fight against bacteriophages, including adsorption inhibition, injection blocking, restriction modification (R/M), abortive infection (Abi) and CRISPR/Cas system. In this article, these mechanisms are explained and discussed in detail. Also, common phages that target these bacteria were presented and discussed. This article provides important information about the phages related to lactic acid bacteria and the mechanisms to deal with them and it can be a comprehensive guide for future studies.

Today, pesticides are widely used to control plant pests and are one of the most important factors affecting soil, water and environment pollution. Pesticides and theirenvironmentaltion products may remain in the environment and affect the ecosystem and biodiversity of plants, animals and aquatic organisms. In addition, the degradation of pesticides can lead to the production of harmful metabolites. One of the pesticides widely used to kill plant pathogenic fungi is propamocarb. This chemical poison is a systemic fungicide. Propamocarb in large amounts can reduce the mitotic index in mice, cause behavioral disorders and accelerate the formation of atherosclerosis. Using large amounts of this poison in plants causes yellow spots on the leaves and also reduces the antioxidant capacity of the plant. In aquatic animals, including zebrafish, it can cause liver disorders and intestinal microbiota dysbiosis. In this article, we first introduce propamocarb as one of the widely used fungicides. Then we will examine its effect on mammals and aquatic animals, as well as its durability on different parts of the plant. Although this chemical fungicide is one of the poisons approved by the regulatory organizations of different countries, including Iran, but with the use of new technologies such as nanomaterials, it may be possible to reduce its consumption.

The encapsulation of bioactive compounds not only causes the slow and targeted release of these substances, but also increases the shelf life, improves the taste and aroma of fruits. In the current study, the microcapsules containing effective compounds of savory essential oil and calcium propionate as core, and shell of Hi-Cap 100 and maltodextrin, were prepared by spray-drying method, and compared with commercial formulation to evaluate their effects on the physical and chemical characteristics of pear fruit. The results of GC/MS analysis showed that O-cymene (25 %) and terpinolene (18.5 %) were the most important compounds in savory essential oil. The zeta potential value of the produced microcapsules was -35.23. The encapsulation efficiency was found to be 93.02%. The efficiency of this formulation with three different concentrations (1 g/L (T1), 2 g/L (T2), and 3 g/l (T3) were compared and contrasted with copper oxychloride on the pear fruit in the form of a randomized complete block design with three replications. The results of coliremetre evaluation using Image processing techniques showed that the effect of copper oxychloride treatment on any of the L*a*b* color parameters was not significant, while the effect of all three concentrations of the encapsulated powder were significant (p<0.05) on color parameters of pear fruits in T3 treatment compared to T1 and T2 treatments. Moreover, T3 had the greatest effect on fruit skin color, fruit texture color, quality and flavor index of fruit. It seemed that the prepared microcapsules not only prevented the spoilage of fruit in storage or cold storage, but also maintained the quality of the fruit and improved the taste and aroma of the fruit.

Today, with the expansion of aquaculture activities, the risk of the spread of pathogens is also lurking in this economic sector, which can have many negative consequences. Therefore, maintaining biosecurity in the aquaculture industry is a prerequisite for the sustainable development of this sector. Considering the importance of biosecurity principles in aquaculture and also the role of this issue in the health of human society, the present study was conducted to investigate the principles of biosecurity in aquaculture systems. In this research, we attempt to refer to different aspects of management in farming systems such as fish population management, environmental conditions management, pathogen management, equipment and staff management. The information provided can be used to improve the basics of biosecurity in the country's aquaculture systems as well as farmers' awareness.