Screening and degrading characteristics of high efficiency phenol degrading bacteria under low temperature conditions

Two kinds of highly effective bacteria strains using to degrade phenol have been obtained from different bacteria sources under low temperature of 18℃ after enrichment,acclimatization and screening,which have been numbered as A4 and B14.When the phenol's initial concentration is 300mg·L-1,their degrading rates are 90.43% and 99.02% respectively while their decomposition rate can remain more than 98% in neutral condition.After morphological characteristics observation and physiological/biochemical experiment,A4 is identified as Micrococus Cohn and B14 is Pseudomonodaceae Cohn.The experimental results show that the optimum pH of two strains is 6～9,A4 has a more comprehensive range of pH than B14.The decomposition effect increases with the increases of biomass,the degrading rate is nearly 100% when the biomass is more than 5mL·100 mL-1.At the same time,the degrading effect in aerobic condition is superior to that in anaerobic condition.According to comparative study on experiments,A4 is more resistant to the change of the environment than B14,but the latter's growth rate is higher than the former.