Decolorization efficiency of Funalia trogii under static condition: Effect of C: N ratios

Abstract

Effects of physical conditions (pH and temperature), carbon and nitrogen source on decolorization of Reactive black 5 (RB5) by Funalia trogii were investigated under the static condition. Optimization of temperature and pH were also examined. Moreover, two different carbon sources (sucrose and starch), four different nitrogen sources and also four different C:N ratios (0.9, 3.0, 6.0, 18.0) were studied. Decolorization was expressed by mg dye / g dry mycelium weight. Optimal pH and temperature were found to be 4.78 and 30ºC, respectively. Decolorization efficiency increased with decreasing C:N ratio in starch-NH₄H₂PO₄, starch-urea, sucrose-NH₄H₂PO₄ and sucrose-urea containing media. Maximum decolorization was found as 9.61 and 7.77 mg dye/g dry mycelium weight in media containing no extra carbon and nitrogen sources. Kinetic studies were also carried out. The Lineweaver-Burk plot gave a Km of 406.66 mg/L and Vmax of 196.07 mg/L day for the diazo dye Reactive Black 5 decolorization by F. trogii under static condition.

Key words: Funalia trogii, decolorization, reactive black 5, static condition.