Newly Isolated Ligninolytic Bacteria and Its Applications for Multiple Dye Degradation

Abstract

The textile industry is expanding globally and is considered the backbone of the world’s largest source of foreign exchange. The development of the textile industry has caused environmental contamination due to its dye waste, which is complex and very difficult to resolve with chemical and physical treatments. Azo dye is one of the most widely used dyes in textile and other industries. It is one of the significantly toxic dyes, and when released in water bodies, it causes a serious threat to the environment. A bacterial strain having the potential to degrade a variety of azo dyes such as Congo red (CR), methylene blue (MB), Alizarin Red S (AR), and Remazol Brilliant Blue R (RBBR) was isolated from soil samples in the wood weathering area and further identified and characterized. Ligninolytic microorganisms produce laccase enzymes, lignin peroxidase, manganese peroxidase, and other enzymes that can decolorize dye waste from the textile industry. The research phase was qualitative and quantitative tests of ligninolytic bacteria in the decolorization process using several selected synthetic dyes, antagonism tests, and identification of potential bacteria based on 16S rDNA gene sequences. The L11 isolate showed high performance on CR dye of 82.79%, L1 isolate on dye AR of 40.51%, L7 isolate on dye MB of 38.69%, and L8 isolate on RBBR dye of 30.34%. The L11 isolate with the highest potency was identified as Bacillus paramycoides K7.2 with a similarity of 99.71%. After 7 days of incubation, the quantitative test findings are the same as the qualitative test results, with isolate L11 having the largest clear zone on CR, AR, and RBBR dyes.