A Study on Actinorhodin-like Substance Production by Streptomyces IQ45

Production of pH-pigment (actinorhodin – like substance) was ascertained from ten Streptomyses isolates. Streptomyses IQ45 isolate was only isolated which produced pH- sensitive pigment. The production of pH-sensitive pigment was detected by fuming over ammonia. After extraction of this antibiotic, a number of physiocochemical characterizations were carried out which involved (IR, UV, MP, CHN-analysis, and solubility test). Indicated that this antibiotic is an actinorhodin-like substance. TLC of the extracted substance showed a single spot with Rf value equivalent to (0.26) which was close to that of actinorhodin. These antibiotics showed inhibitory activity against Staphylococcus aureus similar to that of actinorhodin produced by Streptomyces coelicolor A3 (2). The productivity of this antibiotics was (45 mg/L) at pH 8.5 and (40 mg/L) at pH 7 from the mycelial mat and (10 mg/L) when extracted from the liquid medium at pH7.