Study on the mechanism of azotobacter chrococum MTCC 446 after degradation of phenol and cyanide

Abstract

Cyanide and phenol are emitted generally from various industries in a large scale as toxic pollutants for living organisms. In spite of toxicity, many micro-organisms take these elements as a carbon or nitrogen sources for their metabolic activities and produces other compounds which are less harmful for environment. Biodegradation is one of the safest methods for degradation of such type of carcinogenic pollutants. In this paper, Azotobacter chrococum was used for biodegradation of cyanide and phenol and their mechanism during the degradation has been observed. Azotobacter chrococum degraded cyanide and formed methane as an end product which indicated that it followed reductive pathway among all of five pathways. Gas Chromatography (Model MICHRO-9100) detected methane produced during cyanide degradation at the retention time 0.26 min. On the other hand, during the degradation of phenol, conversion of catechol to 2-hydroxymuconic semialdehyde catalyzed by catechol 2,3-dioxygenase and also absence of cis, cis-muconic acid indicated that Azotobacter chrococum metabolize phenol via meta-pathway.