Isolation, Identification Of Microbial Able To Metabolize High Concentrations Of Formaldehyde And Cloning It's Related Gene

In this study, formaldehyde-resistanced bacterias and fungis were isolated from furniture factory sewage as the experimental material.The results were as follows.1,Isolated and identified the formaldehyde-resistanced bacterias8 strains formaldehyde-resistanced bacterias were isolated on selective media contaning formaldehyde.There are 6 isolated strains named as SG-32,SG-71,SG-87,SG-107,SG-122,SG-135 could grow on medium with 20mmol/L formaldehyde.One isolated strain named as SG-zong could grow on medium with 10mmol/L formaldehyde,and the anther one strain named as SG-ju could grow on medium with 4mmol/L formaldehyde.SG-32,SG-71,SG-87,SG-107,SG-122,SG-135 were identified as Pseudomonas putida by plentiful physiological-biochemical experiments and molecular identification.SG-zong was identified as Pseudomonas fluorescen.SG-ju was identified as Acinetobacter johnsonii.2,Analysis the growth and the ability of formaldehyde-resistanced of bacteriasThe optimal temperature were 30℃for SG-32,SG-71,SG-107 respectively and which were 35℃for SG-135. The optimal pH value were 7 for SG-32,SG-135 respectively and which were 8 for SG-71,SG-107.They all could tolerated 20mmol/L-35mmol/L formaldehyde.3,Isolated and identified the formaldehyde-resistanced fungisFormaldehyde-degrading fungis(SG-huang,SG-hei,SG-qing) were isolated and identified as Aspergillus nomius,Aspergillus versicolor,Penicillium vinaceum by morphological observation and molecular identification.4,Analysis the growth and the ability of formaldehyde-resistanced of fungisThe optimal temperature were 25℃for SG-huang,SG-he,SG-qing respectively.The optimal pH value were 5 for SG-huang,SG-he,SG-qing respectively.After shaking culturing 7 days, formaldehyde degraded from 80, 50, 30mmol/L to almost 0 mmol/L bySG-huang,SG-he,SG-qing respectively.All the isolated strains could grow on medium with formaldehyde as the sole carbon source.5,Cloning of Gfa from the formaldehyde-resistanced bacteria The DNA sequence of Gfa gene from Pseudomonas putida strain SG-32 was determined by PCR.The results of sequence analysis show that the full length of Gfa from Pseudomonas putida strain SG-32 is 393 bp; it encodes 131 amino acids. The gene was logged in GenBank, serial number is HM016790.BLAST search analysis showed that,Gfa gene from Pseudomonas putida strain SG-32 shares homology of 96% in nucleotide acid sequence compared with that of Pseudomonas putida F1.It has four regions, a VWFC domain , a C-terminal cystine knot , a Tubulin subunits alpha, beta and gamma signature and an Anaphylatoxin domain.The cloning of Gfa gene from Pseudomonas putida strain SG-32 provides a fundamentalbasis for further improvement of formaldehyde-resistanced of plants through genetic engineering.