Effect of the cultivation mode on red pigments production from Monascus ruber

Abstract

Summary In submerged cultures performed in chemically defined fermentation medium containing glucose and glutamate, the growth and production of water‐soluble red pigments and citrinin by the filamentous fungus Monascus ruber were studied under various carbon/nitrogen (C/N) ratios. The specific production of the red pigments was optimal at a glucose/glutamate ratio of about 10 and then steadily decreased at higher C/N ratio. In contrast, the production of the mycotoxin increased with increased C/N with an optimum in the range of 30–45. In a fed‐batch mode, it was also found that the production of pigments was not favoured in fed‐batch mode by feeding the medium with glucose while keeping the C/N ratio lower than 10. This low production likely resulted from concurrent high accumulation of L‐malic acid that was reported to inhibit this production. In contrast, this mode of cultivation was rather favourable for the production of the mycotoxin.

Production of Melanin Pigment by Fungi and Its Biotechnological Applications

“…Several studies have shown that the composition of the growth medium, nature and concentration of carbon and nitrogen sources, minerals, vitamins, temperature, pH, the presence of Melanin 50 oxygen and aeration, light, stress, and irradiation, among others, affect the growth and pigment production in fungi and that the manipulation of the culture conditions can result in enhanced pigment production [41][42][43][44][45][46][47].…”

“…These nutrients may regulate the expression of genes of interest and activate important metabolic pathways for the production of pigments [45,58,59]. In general, glucose, an excellent carbon source for growth, interferes with the formation of many secondary metabolites, including pigments.…”

“…However, M. purpureus was not able to grow in media containing peptone, and a maximum yield of the pigment was achieved when the media were supplemented with yeast extract (1%) and monosodium glutamate (5%) as nitrogen source [41]. In M. ruber, the use of glutamic acid as a nitrogen source showed promising results, either as stimulating the accumulation of extracellular pigments or contributing to increase the efficiency of the pigment production process [45]. The production of high amounts of extracellular melanin by the fungus Gliocephalotrichum simplex was obtained in cultures supplemented with tyrosine (2.5%) and peptone (1%) [64].…”

Screening and evaluation of Monascus purpureusFJMR24 for enhancing the raw material utilization rate in rice wine brewing

“…All flasks were incubated in a thermostatic shaker at 30 °C for 6 days. After incubation, the mycelia and the fermentation broth were separated through ultrafiltration, and the weight of the mycelia was determined by gravimetric analysis 17 . The fermentation broth was used to determine the activities of amylase and glucoamylase according to the methods described by Liu et al .…”

“…Similarly, the seed medium was adjusted to pH 2–8 or supplemented with 8–18% ethanol and inoculated with 10% spore suspension, and then incubated at 30 °C for 6 days. The weight of the mycelia obtained from each treatment was determined by gravimetric analysis 17 …”