Isolation, Identification of a Halotolerant Acid Red B Degrading Strain and its Decolorization Performance

One salt-tolerant strain (named P-1) which can efficiently degrade azo dye acid red B was isolated and screened from activated sludge of a wastewater treatment unit of a dye plant. On the basis of morphological observation, physiological and biochemical test, 26S rDNA gene sequence and phylogeny analysis, the strain P-1 was identified as Pichia kudriavzevii strain. The effect of salinity, initial concentration of acid red B solutions, temperature and pH on decolorization performance was investigated to optimize decolorization conditions. The results showed that, the optimal conditions for degradation of acid red B by strain P-1 were: salinity, 10%; initial concentration of acid red B solutions, 100 mg/L; temperature, 33^oC; pH, 5.0. Under the optimal conditions, the degradation rate of acid red B reached 94.29%.