Textile dye decolourisation of yeast isolated from Tuak starter culture

Abstract

Abstract The textile industry is one of the largest industries in the world and contributes positively to the economic growth of a country. However, the improper disposal of textile dye effluents results in discharging of high concentrations of textile dyes into the environment. Moreover, the inherent stability of textile dyes makes them hard to remove from the environment, which can harm organisms in polluted areas. Biological decolourisation was considered as a strategy to remediate textile dyes. Microbial decolourisation of textile dyes involves using various species of bacteria and fungi from different sources that can degrade or accumulate dye molecules. Although Indonesia is a well–known country with rich biodiversity, research on microbial decolourisation is still limited. Therefore, this study explored the decolourisation potential of microbes from the starter culture of Tuak, a traditional Indonesian alcoholic beverage made from fermented sugar palm or rice. Potential microbes were screened on yeast peptone dextrose solid agar (YPD) supplemented with various textile dyes. Isolates that formed a clear zone around the colony were further examined for decolourisation activity in broth culture media, and the decrease in dye concentration was measured spectrophotometrically. The results showed that two potential yeast isolates could decolourise Congo red and malachite green. Identification of the isolates by observation of colony and cell morphology and biochemical characteristics indicated that the two isolated yeasts belonged to the genera Saccharomyces and(or) Candida.