---

The use of genetic engineering tools to produce industrial strains, especially from non-model microorganisms such as cyanobacteria, is always subject to limitations. In this research, a system-oriented method was used to design a culture medium instead of strain designing and its ability to increase ethanol production by Synechocystis sp. PCC 6803 was experimentally evaluated. In this method, compounds are added to the medium to regulate the activity of target enzymes not for the purpose of being consumed by the cells, and thus, the designed culture medium eliminates the intracellular constraints on the production. A metabolic model was used to determine the minimum level of ethanol production and to identify genes that increase or decrease of their expression increase this minimum level. Then, regulators of the enzyme expressed by the target genes were extracted from the Brenda database and their effect on the production was evaluated experimentally and design of experiment was performed to optimize the concentration of the selected compounds. Among the compounds identified, two inhibitors (salicylic acid and mercuric chloride) and one activator (pyruvate) were selected to be added to the medium and their concentration was optimized using the central composite design method. The proposed regulatory medium increased the production of ethanol from 352 to 1116 mg/l, indicating the effectiveness of the added regulatory compounds on the cyanobacteria metabolism. The proposed system-oriented method can be used to design medium culture for other important bio-products such as recombinant proteins.

---

Poly-γ-glutamic acid (γ-PGA) is a beneficial, biocompatible, and biodegradable biopolymer. These properties have been led to the development of the use of this compound in various industries such as bio-medicine, biopharmaceutical, biotechnology, and tissue engineering. The limitation of the industrial development of γ-PGA is the high cost of its production. To reduce γ-PGA production costs, various strategies are used, such as culture medium optimization using inexpensive compounds, the development of efficient cultivation processes of batch and fed-batch. In this research, first, an efficient batch culture medium was developed to produce γ-PGA of Bacillus licheniformis ATCC 9945^a. Then, the γ-PGA production increased by the pulsed feeding method and its optimization. By optimal culture medium development, the production of this product in batch culture was increased from 11 g/L to 47 g/L. Then, using the optimized pulsed feeding strategy of citrate (γ-PGA precursor), γ-PGA production was increased to 59.5 g/L, which is one of the highest production values reported with this strain. To optimize two-pulse feeding, the effect of feeding times, stock citrate solution concentration, and time of calcium and manganese solutions addition on γ-PGA production were investigated and optimized. Finally, FTIR confirmed the chemical structure of poly gamma glutamic acid, and the study of γ-PGA morphological properties with SEM showed a nanostructure ideal for biological applications.

---

This study investigated the impact of different nitrogen (sodium nitrate, urea, ammonium chloride, and ammonium nitrate) and carbon (sodium bicarbonate, sodium carbonate, and glucose) sources on the growth characteristics, biomass production, pigments, and polysaccharide content of the halophilic cyanobacterium Cyanothece sp. Growth trends were determined by cell density counting, and biomass was assessed by dry weight measurement. Pigment extraction and quantification were performed using spectrophotometry. Polysaccharide extraction was conducted using a hot water bath method at 80 °C. Based on the results, different nitrogen and carbon sources had no significant effect on the growth trend and biomass production of Cyanothece sp. However, the pigment profile and polysaccharide content of Cyanothece sp. biomass were significantly influenced by the different nitrogen and carbon sources in the culture medium. Among the tested treatments, the highest content of chlorophyll a and phycocyanin was obtained in the presence of sodium nitrate and potassium bicarbonate. The highest production of carotenoids and beta-carotene was observed in culture media containing urea or ammonium nitrate along with potassium carbonate. Comparison of the polysaccharide content in Cyanothece sp. biomass among different treatments showed that the culture medium containing sodium nitrate and potassium bicarbonate significantly increased biomass polysaccharide synthesis. Based on the results of this study, for producing Cyanothece sp. biomass rich in phycocyanin pigment with high polysaccharide content, it is recommended to use sodium nitrate and potassium bicarbonate as nitrogen and carbon sources, respectively.

---

The major objective of seedless grape breeding program is production of grapes with high quality. Breeding of seedless grapes is difficult because the embryos are aborted after fertilization. Embryo rescue technique is utilized to obtain plants from crosses between seedless cultivars. In the present study, the effect of paternal genotypes and different IAA concentrations in presence of BA applications were investigated on embryo rescue in Askari cultivar in randomized complete block design with three replications. Sprays with BA were performed two times at 18 E-L and 27 E-L stages. Hybrid embryos were produced from the cross between Askari cultivar as a female parent and Ruby Seedless, Bidane Sefid, and Bidane Ghermez as male parents. Forty days after pollination (at 29 E-L stage), ovules were cultured on NN medium with three different concentrations of IAA (1, 1.75, 3 mg L^-1). The results showed that male genotypes and different concentrations of IAA on the media had a significant effect on embryo germination. BA treatment did not affect the embryo germination solely. But, the effect of BA and different concentrations of IAA was significant on embryo germination. The best concentration of IAA with BA treatment was 1 mg L^-1 and without BA was 3 mg L^-1. The highest embryo germination rate was observed in 'Askari×Ruby Seedless' cross that was pretreated with BA and cultured on medium with 1 mg L^-1 IAA concentration.

---

Non-ionizing ultraviolet (UV) radiation is a kind of electromagnetic radiation that has been shown to be harmful to microorganisms such as bacteria, viruses, and fungus. The goal of this study is to evaluate the effective and hazardous features of this type of radiation in three regions (UVA, UVB, and UVC), using the approach of biological properties and applications in disinfection and sterilizing. In this research study, in order to be effective on microorganisms in the ultraviolet spectrum and its surroundings near the visible area, two test samples with commercial UVC and blue-LED lamps were used. In this study, the effect of ultraviolet C radiation on pathogenic microorganisms of Staphylococcus aureus and Pseudomonas aeruginosa in liquid environment and solid surface culture, the effect of ultraviolet C radiation on the total count (total count) of microorganisms on paper and mobile surfaces, and finally to The effect of UV LED on the total number of oral microbes attached to the toothbrush after brushing was investigated. In two tests performed with radiation in the ultraviolet region and near it in the visible region, the lethal effect on bacteria and microorganisms was concluded with more than 90% effectiveness and destruction of bacteria. Which indicates the effectiveness of such radiation in disinfecting, disinfecting and sterilizing equipment. Spectroscopic investigations of UV commercial lamps, as well as their efficacy on microbes, demonstrate the use of this sort of radiation, in addition to its biological hazards, which necessitate careful consideration of how it is utilized. In comparison to alternative sterilizing methods, the use of UV radiation in business and medicine is a cool, dry, easy, effective, and economical technique that produces no ionized radiation.