Agro-Industrial Residues: Eco-Friendly and Inexpensive Substrates for Microbial Pigments Production

Abstract

Many commodities are abundantly produced around the world, including soybean, corn, rice sugarcane, cassava, coffee, fruits, and many others. These productions are responsible for the generation of enormous amounts of daily residues, such as cassava and sugarcane bagasses, rice husk, and coffee peel. These residues are rich sources for renewable energy and can be used as substrates for industrial interest products. Microorganisms are useful biofactories, capable of producing important primary and secondary metabolites, including alcohol, enzymes, antibiotics, pigments, and many other molecules. The production of pigments was reported in bacteria, filamentous fungi, yeasts, and algae. These natural microbial pigments are very promising because synthetic colorants present a long history of allergies and toxicity. In addition, many natural pigments present other biological activities, such as antioxidant and antimicrobial activities, that are interesting for industrial applications. The use of inexpensive substrates for the production of these metabolites is very attractive, considering that agro-industrial residues are generated in high amounts and usually are a problem to the industry. Therefore, in this article we review the production of microbial pigments using agro-industrial residues during the current decade (2010–2020), considering both submerged and solid state fermentations, wild-type and genetically modified microorganisms, laboratorial to large-scale bioprocesses, and other possible biological activities related to these pigments.

Antimicrobial Food Packaging Based on Prodigiosin-Incorporated Double-Layered Bacterial Cellulose and Chitosan Composites

“…Nonetheless, regarding the microbial bioresources employed, some economic and technological challenges must be surpassed for the double-layer materials' cost-effective production. Over the last years, efforts have been made to reduce production costs, by replacing synthetic media constituents with alternative feedstock, which would be a suitable strategy to obtain cost-effective bioresources, such as BC and PG pigment [48,99]. Moreover, the path for the cost-effective production of bacterial pigments may be the identification of new bacterial sources, such as actinobacteria, able to produce bioactive pigments that might diffuse into the medium, which ultimately facilitates pigment recovery and reduces the overall cost of the downstream process [100].…”

“…Furthermore, the higher efficacy of PG antibacterial properties has also been reported with the synergic combination of prodigiosin with antibiotics and biosurfactants [47]. Moreover, unlike synthetic dyes, natural pigments are biodegradable, non-toxic, non-carcinogenic, and several efforts have been made towards their cost-effective production through the identification of new bacterial sources, utilization of low-cost substrates, and optimization of process parameters [48].…”

Biological Approaches for Extraction of Bioactive Compounds From Agro-industrial By-products: A Review

“…Thus, it is relevant to identify new applications to convert these residues into high-value-added products (Irmak, 2017). In general, agro-industrial residues present considerable concentrations of compounds such as fibers, lipids, carbohydrates, peptides, carotenoids, phenolic compounds, and other compounds, which have multiple functionalities and bioactivities and can be applied as ingredients in other products (Varzakas et al, 2016;Coman et al, 2020;Lopes and Ligabue-Braun, 2021).…”

A new endophyte Monascus ruber SRZ112 as an efficient production platform of natural pigments using agro-industrial wastes

“…Natural pigments consist of several types of bioactive compounds used extensively in several applications of biopigments in different industrial sectors, as food colorants, dietary supplements, pharmaceuticals, cosmetics, aquaculture and poultry feed 1 . Currently, natural pigments in comparison to the synthetic colors have taken a lead in a rapidly changing industry.…”