The Microbial Degradation of Cotton and Silk dyed with Natural Dye: A Laboratory Investigation

ABSTRACT: In the present work the microbial degradation of cotton and silk fabrics dyed with natural dyes was studied in laboratory conditions. 100 % cotton and tussar silk was used as the fabric material for dyeing with Carrisa carandas Linn (leaves) extract as a dye source and alum as a mordant. Under laboratory conditions on the 20th day, growth of microorganisms on dyed cotton and silk fabric was observed. Cultivation of microorganisms on PDA (Potato dextrose medium) showed the presence of fungi belonging to families Mucoraceae, Aspergillaceae, Mycosphaerellaceae. Where as cultivation of microorganisms on nutrient agar medium showed the presence of gram positive bacillus on cotton and well as gram negative bacilli on silk fabric. It was noted that microbial growth played a role in drastic discoloration of fabric, which changed clearly from red brown colour to pink brown colour. Growth of microorganisms were found to deteriorate the tensile and tearing strength of cotton & silk fabric