Biodyes: a new approach in textile dyeing and printing technological processes.
Authors: Carvalho Cristina , Costa Pereira Carla , Montagna Gianni , Manuel Figueiredo Carlos 
Published: June 2023

The textile industry is responsible for the production of more than 2 billion tons of effluents/waste, most of which are discarded into the ecosystem, namely and mostly into water ecosystems, essentially after the dyeing and printing processes. In fact, dyeing is one of the most polluting processes in the textile industry, representing a high source of pollution. According to the World Bank, the textile dyeing industries are responsible for more than 20% of the pollution of all water used at the industrial level.One of the serious problems related to the group of synthetic dyes is the level of chemical compounds used for their production, which has a high level of toxicity. In this context, the group of azo dyes stands out, for example, which predominate in most textile processing applications and have carcinogenic and mutagenic potential. These mentioned problems do not only have an impact in terms of the environment, but also in terms of human health since they can cause irritation to people's skin, eyes, and respiratory tract. Additionally, various health problems such as neurotoxicity, carcinogenicity, reproductive toxicity, and developmental toxicity can arise because of exposure to wastewater pollution.One of the emerging research domains is related to the exploration of obtaining natural dyes from microorganisms, known as Bio colorants. However, the approaches used also limit the yield and performance of the obtained formulations, since the dyeing process occurs directly, through the exposure of the microorganism to the substrate. Additionally, to date, there is no solution applicable to continuous dyeing.This research work has as its main objectives the research and development to obtain dyes for application in textile finishing processes, namely dyeing and printing, resorting to bacterial metabolic processes for the bioproduction of these same dyes. Complementarily, with this project, it is expected to obtain dyeing and printing processes with a reduction in contaminated effluents, because of the high biodegradability of the biodyes to be developed, thus contributing to the reduction of decontamination processes of industrial effluents.This project, therefore, aims to achieve the following research and development milestones:i. New biotechnological approach for obtaining the biodye;ii. High performance and functionalization of the biodye on textile substrates.iii. Reproducibility and uniformity of the process on various types of substrates.A differentiating approach will be investigated, through the metabolic study of the culture conditions of microorganisms, without resorting to genetic modification, and without the use of toxic chemical compounds, allowing, in this way, to generate a unique concept in the sector. As will be duly demonstrated given that, to date, Biodye solutions obtained from microorganisms for continuous dyeing are unknown.At the level of the proposed concept, it is intended to develop formulations of biodye in powder and/or liquid, with performances equivalent to synthetic dyes, to meet the facilities and operational needs of industrial textile dyeing and printing processes, directly responding to industry and market requirements. Effectively, this concept is unique and distinct in the sector, since the discontinuous dyeing solutions of biodyes (from microorganisms) available, occur by direct transfer of the color of the microorganism to the substrate, which entails high constraints in the productive processes in the industries of the sector, which do not have the capacity to adapt their infrastructures. The provision of a powder/and/or liquid formulation makes it possible to respond to this problem and needs.Within the scope of this research process, difficulties may be encountered in obtaining a sufficiently high production yield of biodyes using the different substrates to be tested. Although this is not expected for the production of the red biodye (using the E.coli microbiological strain), it may eventually occur in the production of the yellow and/or blue biodyes. In this case, the consortium team will investigate metabolic pathways of different bacterial and fungal strains to analyze alternatives for obtaining biodye with chromophores of different tones that are an added value for the needs of the sector, through the study and production based on Blakeslea trispora, or in fungi of the genus Penicillium. These strategies will enable the investigation of Biocolorant solutions with yields compatible with industrial needs.This research project also intends to demonstrate and validate the application of the biocolorant to textile ennoblement processes, in the specific case, industrial textile dyeing, and printing processes (batch and continuous) applied to a series of prototypes/pieces of clothing, with different compositions of textile fibers, for which it is intended to demonstrate high levels of intensity, saturation, and colorimetric solidity.