Preparation of Extracellular and Intracellular Water-Insoluble Monascus Pigments during Submerged Fermentaion
- PDF / 1,249,394 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 104 Downloads / 181 Views
reparation of Extracellular and Intracellular Water-Insoluble Monascus Pigments during Submerged Fermentaion Z. Qiua, J. Zhangb, S. Chena, Y. Liua, Q. Wua, H. Yanga, M. Gaoa, and L. Lia, * a
b
College of Life Science, Yangtze University, Jingzhou, Hubei, 434025 China College of Animal Science, Yangtze University, Jingzhou, Hubei, 434025 China *e-mail: [email protected] Received February 23, 2020; revised June 1, 2020; accepted July 2, 2020
Abstract—Monascus pigments (MPs) are a group of secondary metabolites produced by the filamentous fungus Monascus. In this study, the dominant MPs in the submerged cultures of Monascus ruber M7, rubropunctatin and monascorubrin, were found to be produced both intracellularly in the cell-bound state and extracellularly in the form of free crystals. To prepare and quantify the extracellular and intracellular water-insoluble MPs (wiMPs), separation of the extracellular crystalline MPs (ecMPs) and mycelia from the fermentation broth was carried out by filtration using filter papers (FPs), nylon mesh filters (NMFs), and sand core funnels (SCFs). Subsequently, the collected ecMPs and mycelia were subjected to microscopic observation and MPs quantitative analysis to evaluate the separation efficiency. Results showed that 200 to 300 mesh/inch NMFs were the optimum filters for separating the ecMPs and the mycelia. This study is the first comparative analysis of different filters for the preparation of extracellular and intracellular wiMPs. It would lead further investigations on the production and secretion of wiMPs by Monascus. Keywords: crystal, filtration, submerged fermentation, water-insoluble Monascus pigment DOI: 10.1134/S0003683820060149
Monascus pigments (MPs) are a large group of secondary metabolites that are produced via the polyketide pathway of the filamentous fungus Monascus [1]. MPs have been widely used as natural food colorants for more than two thousand years [2]. The biological properties of MPs, such as antioxidant and anticancer activities, have also been described in recent studies [3–6]. To date, approximately 111 MPs congeners have been identified [2]. Some of these MPs are water-insoluble, such as 6 major MPs, including 2 yellow MPs: monascin and ankaflavin; 2 orange MPs: rubropunctatin and monascorubrin; and 2 red MPs: rubropunctamine and monascorubramine [7], while some MPs are water-soluble, such as red pigments originating from the reaction of amino acids with rubropunctatin or monascorubrin [7–9]. Generally, MPs produced by submerged fermentation (SmF) consist of a large amount of water-insoluble pigments and a small amount of water-soluble pigments [10]. Until the report in 2018 [11], there was a longstanding misconception that the water-insoluble MPs (wiMPs) were mainly produced intracellularly in the cell-bound state, while water-soluble MPs (wsMPs) were mainly produced extracellularly dissolved in the aqueous phase of fermentation broth [7, 12, 13]. In 2018, Lu et al. [11] reported that in Monascus anka, the wiMPs were produced not only intracel
Data Loading...
