Zaban Mayasar Ibrahim, Azim Nahla Shazli Abdel, Abd El-Aziz Abeer Ramadan Mohamed
Biology Department, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.
Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia.
Pak J Pharm Sci. 2019 Sep;32(5(Special)):2509-2526.
Date palm (Phoenix dactylifera L.) is considered the main crop in deserts and arid areas such as Saudi Arabia. Fifteen species belonging to 7 fungal genera were isolated from date palm rhizosphere soil at Riyadh, Saudi Arabia. Twenty-one isolates of Aspergillus spp. were used in producing silver nanoparticles (SNPs), five of A. flavus, nine of A. niger and seven of A. terreus. Synthesis of SNPs by these fungi is emerging as an important branch of nanotechnology due to it'secofriendly, safe and cost-effective nature. SNPs have been characterized by UV-Visible Spectrophotometer and Transmission Electron Microscope (TEM). In order to increase the yield of biosynthesized SNPs of desired shape and size, it is necessary to control the cultural and physical parameters during the synthesis. We reported the optimum synthesis of SNPs on a liquid medium at 1.5mM of silver nitrate, pH 9 and 26°C after 96 hours. Antifungal activity of SNPs colloids has indicated that the highest inhibition zone was detected with SNPs. In the case of SNPs synthesized by A. terreus PNU37, the highest Inhibition percentage (IP %) 67.6% at the concentration 150 ppm of SNPs. Results have also indicated that the SNPs synthesized by A. flavus PNU05 at a concentration of 150 ppm/100 ml culture medium gave the highest reduction of B1 determined by HPLC, where the percentages of reduction (PR%) was 56.45%.ISSR analysis revealed a high level of genetic diversity in the Aspergillus spp. population and useful for genetic characterization. ISSR markers were not suitable to discriminate between producing and non-producing SNPs isolates. There was no clear-cut relationship between the ISSR markers (genotype of isolates), antifungal and anti-aflatoxigenic properties.
海枣（Phoenix dactylifera L.）被认为是沙特阿拉伯等沙漠和干旱地区的主要作物。从沙特阿拉伯利雅得的海枣根际土壤中分离出了属于7个真菌属的15个物种。21株曲霉属菌株被用于生产银纳米颗粒（SNP），其中5株黄曲霉、9株黑曲霉和7株土曲霉。由于其生态友好、安全且具有成本效益的特性，这些真菌合成SNP正成为纳米技术的一个重要分支。已通过紫外可见分光光度计和透射电子显微镜（TEM）对SNP进行了表征。为了提高生物合成的具有所需形状和尺寸的SNP的产量，在合成过程中控制培养和物理参数是必要的。我们报道了在1.5mM硝酸银、pH 9和26°C的液体培养基中96小时后SNP的最佳合成。SNP胶体的抗真菌活性表明，SNP检测到的抑制圈最大。在土曲霉PNU37合成的SNP的情况下，在150 ppm的SNP浓度下抑制率最高（IP%）为67.6%。结果还表明，黄曲霉PNU05在150 ppm/100 ml培养基浓度下合成的SNP通过HPLC测定对B1的还原率最高，还原率（PR%）为56.45%。ISSR分析揭示了曲霉属种群中的高水平遗传多样性，并且对遗传表征有用。ISSR标记不适用于区分产生和不产生SNP的分离株。ISSR标记（分离株的基因型）与抗真菌和抗黄曲霉毒素特性之间没有明确的关系。
