Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Microbiology Department, Faculty of Science, Ain Shams University, Abbassia, Cairo, Egypt.
Arch Microbiol. 2024 Nov 22;207(1):2. doi: 10.1007/s00203-024-04195-x.
Azurin, a secondary metabolite from Pseudomonas aeruginosa, has attracted much attention owing to its valuable therapeutic and biological applications. This work aimed to study and chartly maximize the azurin production process using different doses of gamma irradiation (5-400 Gy) in P. aeruginosa isolates. Seventy-six P. aeruginosa isolates were sourced from 135 environmental samples and 35 clinical bacterial isolates with the following descending order: 35 isolates (46%) from clinical samples, 26 isolates (34%) from water samples, and 15 isolates (20%) from soil samples. The disc diffusion technique was used for antimicrobial susceptibility testing, revealing that the multidrug-resistant (MDR) rate among all collected isolates according to the criteria determined by Clinical and Laboratory Standards Institute (CLSI) was 54 (71%). The genomic experimental results revealed that only 37 MDR isolates tested positive for the azurin gene, as detected by the PCR product at 446 bp. These findings were further supported by FTIR analysis, which revealed peaks around 1636.96 cm, indicating a prominent α-helix secondary structure of azurin in these isolates. Related to their pathogenicity and antibiotic resistance, isolates from clinical origin exhibited the higher azurin gene expression level. Besides, this study confirmed the potency of gamma radiation exposure at 50 and 100 Gy significantly increased the azurin expression levels in three tested clinical isolates (P ≤ 0.05), with a maximum fold expression level of 63.55 compared to the non-irradiated samples. In conclusion, low doses of gamma irradiation effectively enhanced expression level of a secondary metabolite azurin, providing a considerable benefit for subsequent purification processes in both biological and medical applications.
铜绿假单胞菌的次生代谢产物天青蛋白因其有价值的治疗和生物应用而受到广泛关注。本工作旨在研究并最大限度地优化铜绿假单胞菌分离株中天青蛋白的生产工艺，使用不同剂量的γ射线（5-400Gy）处理。从 135 个环境样本和 35 个临床细菌分离株中获得了 76 个铜绿假单胞菌分离株，其顺序如下：35 个（46%）来自临床样本，26 个（34%）来自水样，15 个（20%）来自土壤样本。采用圆盘扩散技术进行抗菌药敏试验，根据临床和实验室标准协会（CLSI）确定的标准，所有分离株的多药耐药（MDR）率为 54（71%）。基因组实验结果表明，只有 37 个 MDR 分离株的 PCR 产物在 446bp 处检测到天青蛋白基因呈阳性。这些发现进一步得到傅里叶变换红外光谱（FTIR）分析的支持，该分析显示在 1636.96cm 左右有峰，表明这些分离株中天青蛋白具有明显的α-螺旋二级结构。与它们的致病性和抗生素耐药性有关，来自临床的分离株表现出更高的天青蛋白基因表达水平。此外，本研究证实，在 50 和 100Gy 时，γ 射线照射的强度显著增加了 3 个测试的临床分离株中天青蛋白的表达水平（P≤0.05），与未辐照的样品相比，最大表达水平增加了 63.55 倍。总之，低剂量的γ射线能有效地提高次生代谢产物天青蛋白的表达水平，为其在生物和医学应用中的后续纯化过程提供了相当大的益处。
