One bacterial strain capable to degrade and metabolize formaldehyde as a sole carbon source was isolated from soil. Based on the results of standard morphological identification, physiological and biochemical characters, and 16S rDNA sequence analysis, the strain was identified as Pseudomonas putida. After single factor test and orthogonal test, the optimal condition for formaldehyde degradation was determined as the follows: peptone1.2 g/L, KH2PO4 4 g/L, K2HPO4 3 g/L, MgSO4·7H2O 0.2 g/L, trace elements solution 0.1 mL/L, temperature 30℃, pH 8. Under the optimal conditions, the strain tolerance of original formaldehyde concentration was up to 6 g/L and 86% of formaldehyde was consumed after 54 h. It completely consumed 5 g/L formaldehyde after 46 h and degraded 100% of 4 g/L formaldehyde after 35 h. |