การชักนำการหลังเอนไซม์ไนเตรทรีดักเทสและผลต่อกระบวนการผลิตอนุภาคนาโนเงินของเชื้อรา

• Main Author: เมษศิรินทร์ คนแรง
• Other Authors: สริสา ณ ป้อมเพ็ชร์
• Format: Senior Project
• Language: Thai
• Published: จุฬาลงกรณ์มหาวิทยาลัย 2019
• Subjects: อนุภาคนาโน; เงินไนเตรท; เชื้อรา; Nanoparticles; Silver nitrate; Fungi
• Online Access: https://digiverse.chula.ac.th/Info/item/dc:10657
• Institution: Chulalongkorn University

Nitrate reductase has been reported to be involved in the biosynthesis of silver nanoparticles (AgNPs). In this study, we focused on the induction of nitrate reductase in Aspergillus niger that might affect the synthesis of silver nanoparticles. First, the multiple alignment analysis of nitrate reductase gene in A. niger with other microbes showed many conserved sequences among fungi and bacteria. Nitrate reductase of A. niger was the most similar to Fusarium oxysporum, followed by Aspergillus clavatus, Pseudomonas aeruginosa, and Bacillus clausii, respectively. Next, we examined the effect of potassium nitrate (KNO₃) on the induction of nitrate reductase secretion by enzyme assay. The result showed that 25 mM of KNO₃ was the most effective concentration for the induction of nitrate reductase. Then the study of an effect of KNO₃-inducing nitrate reductase on the biosynthesis of silver nanoparticles showed that 20 mM of KNO₃ was the most effective concentration for the biosynthesis of silver nanoparticles. In summary, KNO₃ could induce nitrate reductase secretion and lead to a higher level of silver nanoparticles production than the uninduced condition.