Purple Non-Sulfur Bacteria Biomass as a Chromophoric Particulate System for Textile Printing: A Material-Driven Review Toward Sustainable Printing

Abstract

The textile industry remains one of the most resource-intensive manufacturing sectors, and textile printing still relies heavily on synthetic colorants, auxiliary chemicals, and solvent- or energyintensive processing. Purple non-sulfur bacteria (PNSB) have attracted interest as a bio-based platform for sustainable biomanufacturing because they can convert light and low-value organic substrates into pigment-rich biomass. This review examines a concept that has received little attention in textile research: the use of intact PNSB biomass, rather than extracted pigments, as a chromophoric particulate phase for textile printing. From a materials-oriented perspective, the review considers how the micrometer-scale dimensions of PNSB cells, the intracellular organization of carotenoids and bacteriochlorophylls, and the resulting optical response may support pigment-style surface coloration. Key issues relevant to translation into printing systems are discussed, including biomass production and preparation, dispersion stability, matrix and binder interactions, rheological requirements, fixation pathways, and expected durability. The potential sustainability advantages of this concept include avoidance of extraction-intensive pigment processing, reduced chemical complexity, and compatibility with waste-derived cultivation routes. At the same time, important challenges remain, particularly biomass standardization, batch-to-batch optical variability, preservation of pigment–protein organization during downstream processing, and validation of print performance. Overall, the review reframes intact PNSB biomass as a candidate particulate color phase for textile printing and identifies the main research questions that must be addressed before this concept can be evaluated experimentally and technologically.