The unique physicochemical properties of nano-metals compared with those of non-nanomaterials have led to many investigations in recent decades. Nano-titanium dioxide has been chiefly applied in novel implant forms. Also, the structures of selenium-containing compounds play a critical role in the biological activity of these elements. According to recent studies, nano-selenium is not only less toxic, but also has a higher biological activity than selenium ions such as selenium (IV) (Se⁴⁺) and selenium (VI) (Se⁶⁺). Researchers have turned to green nanostructure synthesis due to the drawbacks of chemical techniques. This paper presents a literature review on recent advances in microbial synthesis methods for producing nano-selenium and nano-titanium dioxide. Despite numerous research articles on green nanoparticle production, little information has been provided on the microbial formation of titanium and selenium nanoparticles. This review paper focuses on the possible mechanism of nano-selenium production by selenium respiration. Although there are reports of microbial synthesis of these particles, their production by probiotic bacteria is of great value. Considering the compatibility of probiotic bacteria with the immune system and their tremendous applications in medicine, it is suggested to use them in combination with nano-titanium dioxide and nano-selenium for various ends such as implant scaffolds and food additives, respectively.

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纳米硒和纳米二氧化钛的微生物合成：亚硒酸盐呼吸的机制

近几十年来，与非纳米材料相比，纳米金属具有独特的物理化学性质，引发了许多研究。纳米二氧化钛主要应用于新型植入物形式。此外，含硒化合物的结构在这些元素的生物活性中起着至关重要的作用。根据最近的研究，纳米硒不仅毒性更小，而且比硒（IV）（Se ⁴⁺）和硒（VI）（Se ^{6+ ）等硒离子具有更高的生物活性}). 由于化学技术的缺点，研究人员已转向绿色纳米结构合成。本文综述了微生物合成法生产纳米硒和纳米二氧化钛的最新进展。尽管有许多关于绿色纳米粒子生产的研究文章，但关于钛和硒纳米粒子的微生物形成的信息却很少。这篇综述论文着重于硒呼吸作用产生纳米硒的可能机制。尽管有关于这些颗粒的微生物合成的报道，但益生菌生产它们具有很大的价值。考虑到益生菌与免疫系统的相容性及其在医学上的巨大应用，