ABSTRACT
Since 1970's , lots of studies on biodegradation of chloroanilines (CAS) have been done, especially, in these aspects: spieces and capability of the microbes; metabolic pathway; gene cloning, expression of degradation plas-mid and pivotal metabolic emzymes. It is necessary for us to review the study on biodegradation of chloroanilines in order to summarize some useful results and the problems in this study.
ABSTRACT
A bacterial strain Eml isolated from contaminated soil of Shengli oil field was identified as Rhodococcus ruber according to its phenotype, physiological and chemical properties, and its 16S rRNA gene sequence. This strain could degrade various polycyclic aromatic hydrocarbons as well as alkanes in petroleum, and produce bioemulsifier. The results indicated that strain Eml could produce bioemulsifier efficiently when n-hexadecane was used as sole carbon source. The optimal conditions for the synthesis of bioemulsifier were as followed: 10g/L of n-hexadecane, 1g/L of yeast extract, media initial pH 7, and cultivation was carried out at 30℃ on a rotary shaker at 200 rpm. Under these conditions the surface tension of culture decreased to the lowest value, around 30 mN/m, after 1 day, and the emulsifying capacity was 100% . The concentration of bioemulsifier reached to the highest value, around 68 times of CMC , after 5 days' cultivation. The results also showed that the bioemulsifier produced by this strain should be lipid.