فصلنامه ایمنی زیستی
سال سیزدهم شماره 3 (پاییز 1399)

The Islamic Republic of Iran has a rich agricultural background; agriculture accounts for 10% of the GDP and provides livelihood to about 30% of the population. Efforts to increase farm productivity resulted in importing pesticides with about 3000 tons annually between 2012 and 2014; therefore, there is urgent need for using alternatives such as application of biofertilizers and biopesticides in integrated pest management (IPM) systems. With the rapid development in biotechnology techniques, many scientists in Iran hope to solve the country’s food problems more efficiently. The number of companies engaged in the production of biofertilizers and biopesticides in Iran is far from the number of fingers. Fortunately, public health issue and the need for environmental protection are mentioned in the 20-year plan of the government which indicates that main authorities concern on the production of healthy products. The bright side of market development for biofertilizers and biopesticides in the world, the benefits of using them to provide community health and growing awareness of the people of Iran, provide the legal framework and accompaniment of high-level officials in the field of development in this industry. Moreover, the young population of Iran and raising interests in biofertilizers and biopesticides research and commercialization at research institutes and universities can be considered as promising perspective.

Nanoparticles (NPs) are of great importance in the science of nanobiotechnology, which are particles within the size of 1 to 100 nanometers. The most important and widely used substances are metal nanoparticles. Over the last several years, various physical and chemical methods have been used for the synthesis of metal nanoparticles. Despite the merits of these chemical methods, most of them impose severe environmental problems and biological risks, therefore the present study reports a biological route for the synthesis of metal nanoparticles. Biological methods for nanoparticle synthesis using microorganisms have been suggested as a potential alternative to chemical and physical methods. Compared to the chemical methods, the biological methods are clean, non-toxic, safe, low cost, and environmentally acceptable. The goal of these developments is to allow the use of less toxic chemical substances and reduce energy consumption by using simple, fast and safe routes. In this way, not only the size of the nanoparticles but also their shape is controlled and the NPs are collected as an element in the wall (outside or inside) of the microorganismchr('39')s cell. Natural microorganisms include bacteria, fungi, yeasts, algae, protozoa, and viruses but the importance of bacteria, fungi, yeasts, and algae in the biosynthesis of nanoparticles is greater than that of other microorganisms and in this research, we will talk about it.

Oxidation of fatty acids reduces the quality of sausage over time. The use of natural antioxidants in sausage formulations is a good way to reduce the oxidation of fatty acids. In this study, changes in the microbial count, physicochemical properties, sensorial and textural characteristics were measured in the fermented sausage after the replacement of canola oil with pomegranate seed oil "PSO", omega-3 oil "O-3O" and a combination of PSO and O-3O during ripening. A significant decrease in water activity up to 89% was detected in PSO, O-3O, and their combinations 30 days after ripening, which indicated better conditions for compatibility of beneficial microorganisms in the new formulations. The increase in the lactic acid bacteria in these conditions confirmed this and a significant increase (P<0.05) in the bacterial count, 6.5 Log CFU/g and 6.6 Log CFU/g respectively in PSO and O-3O, compared to control (6.4 Log CFU/g) was observed. The abundance of unsaturated fatty acids was observed at a higher level in PSO, and the fatty acid profile of sausage improved in terms of nutrition. PSO treatment contained high levels of PUFA such as punicic acid (29.03%) and to a lesser extent oleic acid (25.59%) and linoleic acid (16.05%) compared to control. Also, the reduction of lipid oxidation (24.35 % less MDA content) in PSO treatment caused an increase in product acceptance score compared to O-3O. The addition of PSO did not make a difference in the quality of sausages compared to control and prevented the reduction of its quality in samples containing O-3O. These results showed that PSO has the potential to be used in fermented sausage to produce healthier products.

In the fisheries industry, compared to other food industries, a large volume of by-products such as bone, skin, and viscera are produced, which are costly to treat and dispose of in the environment. The rapid growth of tilapia and its marketability have also been considered. The value of proteins as the main source of amino acids in human health has been proven. In addition to their nutritional value, proteins have biological functions. These proteins show their functions through bioactive peptides. Production methods of bio peptides affect their biological activity. The articles showed that the use of enzymatic hydrolysis method for therapeutic applications makes them more stable than fermentation and solvent extraction methods and is a safer method than the other two methods. Bioactive peptides have physiological effects such as antihypertensive, antioxidant, antimicrobial, anti-cancer, anti-diabetic, etc. and have many applications in the food, pharmaceutical and cosmetic industries and can be added to the food industry. The purpose of this article is to review the extraction of bioactive peptides from fish waste.

Environmental pollution of heavy metals and plastics has been a great challenge of the last century. E-wastes increase heavy metals and plastics concentration in the environment. These toxic substances are a threat to organisms. So their removal from the environment seems necessary. There are different disposal methods like landfilling and incineration, which cause a great deal of damage to the environment. On the other hand, the need for precious metals recovery like gold and silver from e-waste makes recycling necessary. Nevertheless, these methods are generally expensive. So applying a new alternative is required. The purpose of this paper is to introduce bioleaching as an alternative to conventional disposal and recycling methods. This method is used to remove the heavy and toxic metals in order to produce metallic nanoparticles. Then the application of nanoparticles in wastewater treatment and microplastics degradation is mentioned. The conversion of insoluble metals to soluble ones by microorganisms is called bioleaching. Bacteria like Chromobacterium violaceum, Pseudomonas species, Sulfobacillus thermosulfidooxidans, and Acidiphilium acidophilum bioleach gold, silver, nickel, and copper of electronic wastes. There are different fungi like Aspergillus niger, Penicillium simplicissimum, Aspergillus fumigatus, and Aspergillus flavus that generate organic acid to leach out copper, lead, nickel, and aluminum. Morganella produces copper nanoparticles from wastes. Factors like microorganisms, particle sizes, temperature, and pH affect the bioleaching process. Bioleaching is a substitution for recycling methods of electronic wastes. Wastewater treatment and photocatalytic degradation of microplastics are two critical applications of produced nanoparticles.

In this research, preparation, characterization, and evaluation of TiO2 encapsulated into zeolitic imidazolate framework (TiO2@ZIF-8) nanophotocatalyst was investigated as an efficient photo-degradation of paraquat (PQ) herbicide from aqueous samples. This study was performed using a ZIF-8-based nanophotocatalyst and a reactor consisting of an ultraviolet (UV) source and a reaction chamber. The effects of various parameters including contaminant concentration, amount of nanophotocatalyst, and pH reaction time were investigated on the removal efficiency of contaminant by the TiO2@ZIF-8 nanophotocatalyst. The results showed by increasing the amount of the TiO2@ZIF-8 nanophotocatalyst and pH, the removal of paraquat showed an increase. The optimal condition was found as nanophotocatalyst concentration (0.05 g.L-1), pH (7) at room temperature for 15 min for removal of 99.8% paraquat. According to the results, TiO2@ZIF-8 emerged as an efficient, robust, and recyclable nanophotocatalyst, which is a potential and environmentally friendly process for the removal of toxic chemical herbicide as hazardous organic contaminants from aqueous samples. The facile fabrication approach and the enhanced photocatalytic activity of TiO2@ZIF-8 were highlighted and notably showed good reusability in 8 consecutive cycles.