This study investigated the antimicrobial and antioxidant activity of three Spirulina extracts (methanol, acetone, and hexane) and the biological selenium nanoparticles (SeNPs) fabricated by Bacillus subtilis AL43. The results showed that Spirulina extracts exhibited antimicrobial activity against tested pathogens. Besides, Spirulina extracts significantly scavenged ABTS and DPPH radicals in a dose-dependent manner. The methanolic extract had higher total phenolic content, antimicrobial activity, and antioxidant activity than other extracts. The selenium nanoparticles were synthesized by Bacillus subtilis AL43 under aerobic conditions and were characterized as spherical, crystalline with a size of 65.23 nm and a net negative charge of −22.7. We evidenced that SeNPs possess considerable antimicrobial activity against three gram-positive, three gram-negative bacteria, and three strains from both Candida sp. and Aspergillus sp. Moreover, SeNPs were able to scavenge ABTS and DPPH radicals in a dose-dependent manner. An association was found between the total phenolic content of Spirulina and SeNPs and their biological activities. Our results indicate that Spirulina and SeNPs with significant antimicrobial and antioxidant activities seem to be successful candidates for safe and reliable medical applications.

本研究调查了三种螺旋藻提取物（甲醇、丙酮和己烷）和由枯草芽孢杆菌AL43 制造的生物硒纳米颗粒 (SeNPs) 的抗菌和抗氧化活性。结果表明，螺旋藻提取物对测试的病原体表现出抗菌活性。此外，螺旋藻提取物以剂量依赖性方式显着清除 ABTS 和 DPPH 自由基。甲醇提取物比其他提取物具有更高的总酚含量、抗菌活性和抗氧化活性。硒纳米粒子由枯草芽孢杆菌合成AL43 在有氧条件下被表征为球形，结晶，尺寸为 65.23 nm，净负电荷为 -22.7。我们证明，SeNPs 对三种革兰氏阳性菌、三种革兰氏阴性菌和两种念珠菌属的三种菌株具有相当大的抗菌活性。和曲霉属。此外，SeNPs 能够以剂量依赖的方式清除 ABTS 和 DPPH 自由基。发现螺旋藻和SeNPs的总酚含量与其生物活性之间存在关联。我们的结果表明，具有显着抗菌和抗氧化活性的螺旋藻和 SeNPs 似乎是安全可靠的医疗应用的成功候选者。