Biodegradation of 3.4-Di Chlorobenzoic acid by Edwardsiella tarda: Effect of some growth condition
- Details
- Category: Biological Sciences
- Published: Thursday, 10 May 2012 03:00
- Written by Waleed H. AL-Ja'afreh
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Abstract
Biodegradation of 3,4-DiChlorobenzoic acid by Edwardsiella tarda: Effect of some growth condition
Waleed H. AL-Ja'afreh
Mu’tah University, 2011
The biodegradation of 3,4-DiChlorobenzoic acid was investigated by using Edwardsiella tarda and it used 3,4-DCBA as sole carbon and energy source.
Has been used several concentrations of 3,4-D CBAs ( 1mM , 2mM , 3mM ,4mM and 5mM ). The highest rate of degradation of 3,4-D CBAs was obtained at a concentration(2mM) .The experiments were included substrate concentration, temperature, pH, starvation, adaptation, carbon and nitrogen sources . The degradation ability was monitored through the release of chloride disappearance of the substrate and finally the growth of bacterial cells on that substrate.
The optimal temperature and pH for the bacteria were 42ºC and 7.5, respectively. Adaptation of the cells on 3,4-DCBA for 48 hours and cells starvation for 24 hours and 48 hours increasing the initial degradation rate. The carbon sources( mannitol, maltose, frctuose , sucinnic acid ,sucrose). The carbon sources affected the 3,4 –DCBA degradation differently from that on chloride and cell mass production Mannitol .frctuose repression in 3,4-DCBA degradation.
Nitrogen sources supplied (yeast extract, L-prolin, casein , NH4, K-Nitrate, arginine, urea and glycine ).
urea and casine caused a repression in 3,4-DCBA degradation . Catechol 1,2 dioxygenase activity was found to be present in cell free extracts suggesting that 3,4-DCBA is catabolized by ortho-ring cleavage pathway.