化学
核化学
发酵
黑色素
细菌
DPPH
水溶液
水溶液中的金属离子
有机化学
金属
抗氧化剂
生物化学
生物
遗传学
作者
Chuanchao Wu,Huan Li,Zhongwei Yin,Hongtao Zhang,Minjie Gao,Lan Zhu,Xiaobei Zhan
标识
DOI:10.1016/j.procbio.2022.07.009
摘要
In this study, a novel water-insoluble bacterial melanin was first isolated and purified from the fermentation culture of Gram-negative bacterial Rhizobium radiobacter ATCC 1333 through the thermal acid-alkali treatment. The highest extracellular melanin production was 3.46 ± 0.07 g·L−1 when the initial glutamic acid concentration was 10 g·L−1. The molecular weight of the purified bacterial melanin (TPBM) was 686 g/mol. The molecular formula (C34H30N4O12) and chemical structure were defined based on FT-IR, MALDI-TOF/MS, Py–GC/MS NMR (1H and 13C), and elemental analyses. Furthermore, UV–vis spectroscopy results indicated that TPBM showed maximum absorption at around 222 nm. TPBM was easily soluble in alkaline solutions, but hardly-soluble in aqueous and majority of the organic solvents. In addition, TPBM was stable to temperature, light, reducing agent, and most metal ions. However, TPBM could be bleached when subjected to the action of oxidants and precipitated with FeCl3 and AgNO3. TPBM (50 µg·mL−1) possessed high DPPH free radical (89.74% ± 1.10%) and hydroxyl scavenging properties (84.12% ± 1.31%). Finally, TPBM displayed potential anti-bacterial properties against E. coli, S. aureus, A. baumanii, and M. albican. These results provided a theoretical basis for the later development and utilization of TPBM.
科研通智能强力驱动
Strongly Powered by AbleSci AI