Characterization of Aerobic Bacteria Involved in Degrading Polyethylene Glycol (PEG)-3400 Obtained by Plating and Enrichment Culture Techniques |
| |
Authors: | Li Pan Ji-Dong Gu |
| |
Institution: | (1) Laboratory of Environmental Microbiology and Toxicology, Department of Ecology and Biodiversity, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, P.R. China;(2) The Swire Institute of Marine Science, The University of Hong Kong, Cape d’Aguilar, Shek O, Hong Kong SAR, P.R. China |
| |
Abstract: | Polyethylene glycol (PEG) 3400-degrading aerobic bacteria were isolated from tap water and wetland sediments and then characterized.
Only one Sphingomonas strain was obtained in enrichment cultures from each inoculum source whereas a total of 15 bacterial strains were isolated
on agar plates. Nine of the 15 isolates were confirmed as PEG 3400 degraders. Three of the 9 PEG 3400 degraders were Gram-negative
bacteria belonging to the genus Pseudomonas and genus Sphingomonas. The remaining six isolates were Gram-positive bacteria belonging to genera Rhodococcus, Williamsia, Mycobacterium and Bacillus. PEG 3400 was quantified at 194 nm spectrophotometrically and, at the same time, the growth of two Gram-negative (isolates
P1 and P7) and five Gram-positive (isolates P2, P3, P4, P5 and P6) PEG 3400-degrading bacteria were assayed in liquid media
and on agar plates amended with PEG 3400, and also on Nutrient Agar plates and pure agar plates without PEG 3400 addition.
No growth was observed on the pure agar plates for all the tested strains for a period of 31 days. All tested PEG 3400 degraders
showed much lower viability in liquid culture than on the corresponding agar plates in the presence of PEG 3400. Two Gram-negative
isolates P1 and P7 did not show significant growth advantage over the Gram-positive isolates both on the agar plates and in
the liquid medium amended with PEG 3400. Our results suggest that diversity of PEG degrading bacteria is high in the environments
and culturing techniques affect the successful isolation of the bacteria responsible for degradation. |
| |
Keywords: | Aerobic degradation Culturability Polyethylene glycol Gram-positive bacteria |
本文献已被 SpringerLink 等数据库收录! |
|