title: Isolation and characterization of polyacrylamide-degrading bacteria from dewatered sludge.
abstract: Polyacrylamide (PAM) is a water-soluble polymer that is widely used as a flocculant in sewage treatment. The accumulation of PAM affects the formation of dewatered sludge and potentially produces hazardous monomers. In the present study, the bacterial strain HI47 was isolated from dewatered sludge. This strain could metabolize PAM as its sole nutrient source and was subsequently identified as Pseudomonas putida. The efficiency of PAM degradation was 31.1% in 7 days and exceeded 45% under optimum culture condition (pH 7.2, 39 °C and 100 rpm). The addition of yeast extract and glucose improved the bacterial growth and PAM degradation. The degraded PAM samples were analyzed by gel-filtration chromatography, Fourier transform infrared and high-performance liquid chromatography. The results showed that high-molecular-weight PAM was partly cleaved to small molecular oligomer derivatives and part of the amide groups of PAM had been converted to carboxyl groups. The biodegradation did not accumulate acrylamide monomers. Based on the SDS-PAGE and N-terminal sequencing results, the PAM amide groups were converted into carboxyl groups by a PAM-induced extracellular enzyme from the aliphatic amidase family.
authors.affiliation: College of Life Sciences, Northwest University, Xi'an 710021, China. yufeng_029@163.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.affiliation: College of Life Sciences, Northwest University, Xi'an 710021, China. angelaminmin@163.com.
authors.forename: Ruimin
authors.initials: R
authors.lastname: Fu
authors.affiliation: Test Department, Northwest Maternal and Child Hospital, Xi'an 710061, China. lovenight029@gmail.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xie
authors.affiliation: College of Life Sciences, Northwest University, Xi'an 710021, China. wulingchen1954@163.com.
authors.forename: Wuling
authors.initials: W
authors.lastname: Chen
mesh_terms: D000180:Acrylic Resins / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005427:Flocculation; D005947:Glucose / Q000494:pharmacology; D016958:Pseudomonas putida / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015003:Yeasts; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D005947:Glucose; D012722:Sewage; D014867:Water; D014874:Water Pollutants, Chemical; D000099166:Polyacrylamides