Biotransformation Preparation And In Situ Dyeing Of Plant Indigo

Plant indigo,as a plant-derived natural reducing dye,has a history of more than3,000 years,and plays an important role in China’s dyeing and weaving culture.Today,with the unswerving implementation of the five development concepts of"innovation,coordination,greenness,openness,and sharing",plant indigo,as a sustainable biomass pigment,has positive significance for the preparation of ecological textiles.In order to explore a clean and efficient method for making indigo,referring to the traditional method of preparing plant indigo,introducing modern biotechnology,conducting research on the preparation of plant indigo dye by biotransformation,and exploring an in-situ dyeing method based on plant indigo biotransformation.In this study,a clean and efficient preparation of plant-based indigo based on biotransformation was achieved,and an in-situ dyeing method based on the biotransformation of indole material was established,which provided new ideas for the biological preparation of textile pigments and the dyeing process of biomass pigments..By monitoring the changes of pH value,redox potential,electrical conductivity and indolin content of indigo leaf fermentation broth,the biotransformation process in the preparation of indigo was studied.The results showed that the fermentation broth was acidic during the fermentation of bluegrass and had certain reducing properties.The concentration of indolin in the fermentation broth reached the highest value at 12 h.With the progress of the fermentation,the concentration of indolin started to decrease and eventually stabilized.The higher the concentration of indole glycosides in the fermentation broth,the lower the pH value,redox potential,and electrical conductivity of the fermentation broth,which is more conducive to the production of indigo.By examining the effects of bluegrass growth period,temperature,fermentation time,and the addition of catalysts on the preparation of plant indigo,the biological preparation process of indigo was optimized.The results showed that the content of indole glycosides in bluegrass was the highest in July,and the preparation effect was the best.The addition of saccharifying enzyme can significantly increase the amount of refined indigo,and the initial pH has little effect on the preparation of indigo.When the fermentation temperature is 37℃and the fermentation time is 48 h,the preparation effect is the best.The stronger the alkaline environment,the better the indigo production.With Na OH as the alkali agent and Ca CO₃ as the adsorbent,the yield of plant indigo is the highest.By constructing the bluegrass fermentation broth dyeing system,the in situ dyeing of fabrics by plant indigo was realized,and the dyeing principle was explored.The effects of factors such as dyeing temperature,time and solid-liquid ratio of bluegrass on the dyeing effect were obtained.Optimal dyeing process.Under aerobic conditions,indophenol dyes fibers at a slower rate in an acidic environment.As the dyeing pH increases,the dyeing rate becomes faster,and in an alkaline environment,the dyeing rate is faster.When the solid-liquid ratio is 1:5 and the dyeing temperature is 35℃,the dyeing effect is the best and the dyeing rate is the highest.The addition of endophytic bacteria liquid can promote the staining.The best in-situ dyeing process of plant indigo is:solid-liquid ratio 1:5,dyeing temperature 35℃,dyeing time 3 d,the K/S value of the fabric can reach 6.9,and the fabric’s sun fastness is 4-5.The dry rubbing is 4th grade,the wet rubbing is 3rd grade,and the washing resistance is 3rd grade.At this time,the amount of refined indigo remaining in the fermentation broth is also high.While dyeing fabrics reach the deepest color,the higher recovery rate of refined indigo can also maximize economic benefits.