An enhancement of red pigment production by submerged culture of Monascus purpureus MTCC 410 employing statistical methodology

Enhancing bioprocessing of red pigment from immobilized culture of gamma rays mutant of the endophytic fungus Monascus ruber SRZ112

Considerable attention has been paid to exploring the biotechnological applications of several Monascus sp. for pigment production. In this study, our focus is on enhancing the bioprocessing of red pigment (RP) derived from the endophytic fungus Monascus ruber SRZ112. To achieve this, we developed a stable mutant strain with improved productivity through gamma irradiation. This mutant was then employed in the immobilization technique using various entrapment carriers. Subsequently, we optimized the culture medium for maximal RP production using the Response Surface Methodology. Finally, these immobilized cultures were successfully utilized for RP production using a semi-continuous mode of fermentation. After eight cycles of fermentation, the highest RP yield by immobilized mycelia reached 309.17 CV mL-1, a significant increase compared to the original titer. Importantly, this study marks the first report on the successful production of Monascus RP in a semi-continuous mode using gamma rays' mutant strain, offering prospects for commercial production.

Ascomycota as a source of natural colorants

In the last few decades, there has been a great demand for natural colorants. Synthetic colorants are known to be easy to produce, are less expensive, and remain stable when subjected to chemical and physical factors. In addition, only small amounts are required to color any material, and unwanted flavors and aromas are not incorporated into the product. Natural colorants present in food, in addition to providing color, also have biological properties and effects that aid in the prevention and cure of many diseases. The main classes of colorants produced by phylum Ascomycota include polyketides and carotenoids. A promising producer of colorants should be able to assimilate a variety of sources of carbon and nitrogen and also exhibit relative stability. The strain should not be pathogenic, and its product should not be toxic. Production processes should also provide the expected color with a good yield through simple extraction methods. Research that seeks new sources of these compounds should continue to seek products of biotechnological origin in order to be competitive with products of synthetic and plant origin. In this review, we will focus on the recent studies on the main producing species, classes, and metabolic pathways of colorants produced by this phylum, historical background, impact of synthetic colorants on human health and the environment, social demand for natural colorants and also an in-depth approach to bioprocesses (influences on production, optimization of bioprocess, extraction, and identification), and limitations and perspectives for the use of fungal-based dyes.

Utilization of Whey for Red Pigment Production by Monascus purpureus in Submerged Fermentation

Various biotechnological approaches have been employed to convert food waste into value-added bioproducts through fermentation processes. Whey, a major waste generated by dairy industries, is considered an important environmental pollutant due to its massive production and high organic content. The purpose of this study is to investigate the effect of different fermentation parameters in simultaneous hydrolysis and fermentation (SHF) of whey for pigment production with Monascus purpureus. The submerged culture fermentation parameters optimized were type and pretreatment of whey, pH, inoculation ratio, substrate concentration and monosodium glutamate (MSG) concentration. Demineralized (DM), deproteinized (DP), and raw whey (W) powders were used as a substrate for pigment production by simultaneous hydrolysis and fermentation (SHF). The maximum red pigment production was obtained as 38.4 UA510 nm (absorbance units) at the optimized condition of SHF. Optimal conditions of SHF were 2% (v/v) inoculation ratio, 75 g/L of lactose as carbon source, 25 g/L of MSG as nitrogen source, and fermentation medium pH of 7.0. The specific growth rate of M. purpureus on whey and the maximum pigment production yield values were 0.023 h−1 and 4.55 UAd−1, respectively. This study is the first in the literature to show that DM whey is a sustainable substrate in the fermentation process of the M. purpureus red pigment.

Natural Red Pigment Production by Monascus Purpureus in Submerged Fermentation Systems Using a Food Industry Waste: Brewer's Spent Grain

This paper studies the production of natural red pigments by Monascus purpureus CMU001 in the submerged fermentation system using a brewery waste hydrolysate, brewer's spent grain (BSG). The chemical, structural and elemental characterization of the BSG was performed with Van-Soest method, Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. The lignocellulosic structure of BSG was hydrolyzed with a dilute sulfuric acid solution (2% (w/v)) followed by detoxification with Ca(OH)2. Maximum red pigment production (22.25 UA500) was achieved with the following conditions: 350 rpm shake speed, 50 mL fermentation volume, initial pH of 6.5, inoculation ratio of 2% (v/v), and monosodium glutamate (MSG) as the most effective nitrogen source. Plackett-Burman design was used to assess the significance of the fermentation medium components, and MSG and ZnSO4·7H2O were found to be the significant medium variables. This study is the first study showing the compatibility of BSG hydrolysate to red pigment production by Monascus purpureus in a submerged fermentation system.

Natural colorants from filamentous fungi

In the last years, there is a trend towards the replacement of synthetic colorants by natural ones, mainly due to the increase of consumer demand for natural products. The natural colorants are used to enhance the appearance of pharmaceutical products, food, and different materials, making them preferable or attractive. This review intends to provide and describe a comprehensive overview of the history of colorants, from prehistory to modern time, of their market and their applications, as well as of the most important aspects of the fermentation process to obtain natural colorants. Focus is given to colorants produced by filamentous fungal species, aiming to demonstrate the importance of these microorganisms and biocompounds, highlighting the production performance to get high yields and the aspects of conclusion that should be taken into consideration in future studies about natural colorants.