Effect of fermentation time on antibacterial activity of Mirabilitum Praeparatum and screening of its antibacterial active parts / 中草药

Objective: To investigate the effect of fermentation time on antibacterial activity of Mirabilitum Praeparatum (MP) and screen the antibacterial active parts from MP with the optimal fermentation time. Methods: Using test tube in vitro antibacterial test and flat germicidal test, the pathogenic bacteria activities of MP with different fermentation time (7, 15, 22, 30, 50 d) were studied, and the optimal fermentation time was screened. The methanol extracts from MP with fermentation time of 15 d and its aqueous and 95% ethanol elution parts were prepared. The antibacterial and bactericidal effects of methanol extracts from MP and its aqueous and 95% ethanol elution parts were compared. Results: The 15 d fermentation MP had the strongest antibacterial activity. The 95% ethanol elution parts from MP had the strongest antibacterial activity on nine kinds of common pathogens, especially for the oral and upper respiratory tract pathogens. Conclusion: Fermentation time has obvious effect on antibacterial activity of MP, and 95% ethanol elution parts of macroporous adsorption resin from MP may be active parts.

Isolation and identification of bacteria in fermentation broth of Mirabilitum Praeparatum / 中草药

Objective: In order to provide the standardization of production and quality control method of Mirabilitum Praeparatum, the fungi from fermentation broth of Mirabilitum Praeparatum were isolated and identificated, and the fermentation and processing of Mirabilitum Praeparatum were investigated. Methods: The traditional fermentation conditions of Mirabilitum Praeparatum such as temperature and humidity were imitated, using watermelon as culture media. Separation and purification of fungi in fermentation broth of Mirabilitum Praeparatum were carried out on PDA, CZA, and Sabourand media, using plate streaking method. The fungi isolated from fermentation broth of Mirabilitum Praeparatum were identified by morphological observation, microstructure observation, and comparison on DNA ITS sequences. Results: Six fungi were isolated from the fermentation broth of Mirabilitum Praeparatum and identified as WF-1 (Fusarium); WF-2 (Penicillium), WF-3 (Mucor); WF-4, WF-5, and WF-6 (Alternaria). Conclusion: Mirabilitum Praeparatum is produced by salt-tolerant fungi in fermentation broth of watermelon, rather than the traditional view that it is the small crystallization seeping from the watermelon.