Publicação
Optimization of fungal pigments production through different types of fermentation
| Resumo: | Pigments are organic or inorganic compounds with the ability to provide color, and therefore, are widely applied in several industrial products. Once public awareness concerning environment preservation and safety, sustainability and health issues have been increasing, industries began to call for different pigments from natural sources, obtained by cleaner processes and with less ecological impact. The production of natural pigments through microbial fermentation is considered a very promising alternative. Fungi are known to naturally synthesize and secrete several classes of pigments. Recently, some Penicillium species have been reported as effective pigment producers. The use of fungi cultures to obtain products of interest is generally performed under two types of fermentation: submerged fermentation (SmF) and/or solid-state fermentation (SSF), with SmF being the most industrially used. For fermentation processes to become economically viable, the extractive fermentation (FE) has been proposed as an emerging option which allows the integration of fermentation and selective separation of the product of interest. In this work, the pigments production using alternative low-cost media containing agroindustrial residues was evaluated under SmF (with and without biomass immobilization), SSF and EF conditions. For that purpose, 6 different culture media composed of cheese whey (CW) and/or corn steep liquor (CSL) in different ratios (culture media B-G) were prepared and compared with a reference synthetic medium (A). Regarding the production under SmF conditions, the results revealed no significant differences between the alternative media D, F and G and the reference synthetic medium A. The immobilization of the fungus on a natural support (corn cob, SmFn) under SmF conditions led to higher amount of pigments obtained than with an inert support (nylon sponge, SmFi). Furthermore, most of the culture media tested under SmFn proved to be a suitable alternative to the reference medium A. On the other hand, better pigments yields were achieved using the inert support under SSF conditions. Overall, the best conditions found for pigments production were media D and G both under SmFn conditions. For all types of fermentation processes considered in this work, pigments mixtures were obtained with yellow, orange and red pigments present. The pigments production was also attempted under EF conditions using a PEG8000-NaCit aqueous two-phase system (ATPS) and their recovery and concentration in top phase was observed. In conclusion, the use of alternative low-cost culture media composed of agroindustrial residues to produce pigments by P. brevicompactum was successfully demonstrated. |
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| Autores principais: | Basto, Bruna Isabel Teixeira |
| Assunto: | Agroindustrial residues Fungal pigments Immobilization supports Penicillium brevicompactum Resíduos agroindustriais Pigmentos fúngicos Imobilização em suportes |
| Ano: | 2019 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Pigments are organic or inorganic compounds with the ability to provide color, and therefore, are widely applied in several industrial products. Once public awareness concerning environment preservation and safety, sustainability and health issues have been increasing, industries began to call for different pigments from natural sources, obtained by cleaner processes and with less ecological impact. The production of natural pigments through microbial fermentation is considered a very promising alternative. Fungi are known to naturally synthesize and secrete several classes of pigments. Recently, some Penicillium species have been reported as effective pigment producers. The use of fungi cultures to obtain products of interest is generally performed under two types of fermentation: submerged fermentation (SmF) and/or solid-state fermentation (SSF), with SmF being the most industrially used. For fermentation processes to become economically viable, the extractive fermentation (FE) has been proposed as an emerging option which allows the integration of fermentation and selective separation of the product of interest. In this work, the pigments production using alternative low-cost media containing agroindustrial residues was evaluated under SmF (with and without biomass immobilization), SSF and EF conditions. For that purpose, 6 different culture media composed of cheese whey (CW) and/or corn steep liquor (CSL) in different ratios (culture media B-G) were prepared and compared with a reference synthetic medium (A). Regarding the production under SmF conditions, the results revealed no significant differences between the alternative media D, F and G and the reference synthetic medium A. The immobilization of the fungus on a natural support (corn cob, SmFn) under SmF conditions led to higher amount of pigments obtained than with an inert support (nylon sponge, SmFi). Furthermore, most of the culture media tested under SmFn proved to be a suitable alternative to the reference medium A. On the other hand, better pigments yields were achieved using the inert support under SSF conditions. Overall, the best conditions found for pigments production were media D and G both under SmFn conditions. For all types of fermentation processes considered in this work, pigments mixtures were obtained with yellow, orange and red pigments present. The pigments production was also attempted under EF conditions using a PEG8000-NaCit aqueous two-phase system (ATPS) and their recovery and concentration in top phase was observed. In conclusion, the use of alternative low-cost culture media composed of agroindustrial residues to produce pigments by P. brevicompactum was successfully demonstrated. |
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