Isolation and characterization of bacterial strains that have high ability to degrade 1,4-dioxane as a sole carbon and energy source

Biodegradation (2013) 24:665674 DOI 10.1007/s10532-012-9614-1

ORIGINAL PAPER

Isolation and characterization of bacterial strains that have high ability to degrade 1,4-dioxane as a sole carbonand energy source

Kazunari Sei Keiko Miyagaki

Takashi Kakinoki Kunihiro Fukugasako

Daisuke Inoue Michihiko Ike

Received: 17 October 2012 / Accepted: 4 December 2012 / Published online: 13 December 2012 Springer Science+Business Media Dordrecht 2012

Abstract Four novel metabolic 1,4-dioxane degrading bacteria possessing high ability to degrade 1,4-dioxane (designated strains D1, D6, D11 and D17) were isolated from soil in the drainage area of a chemical factory. Strains D6, D11 and D17 were allocated to Gram-positive actinomycetes, similar to previously reported metabolic 1,4-dioxane degrading bacteria, whereas strain D1 was allocated to Gram-negative Apia sp. The isolated strains could utilize a variety of carbon sources, including cyclic ethers, especially those with carbons at position 2 that were modied with methyl- or carbonyl-groups. The cell yields on 1,4-dioxane were relatively low(0.1790.223 mg-protein (mg-1,4-dioxane)-1), which was likely due to requiring energy for CO bond ssion. The isolated strains showed 2.613 times higher specic 1,4-dioxane degradation rates

(0.0520.263 mg-1,4-dioxane (mg-protein)-1 h-1)

and 2.37.8 fold lower half saturation constants(20.669.8 mg L-1) than the most effective 1,4-dioxane degrading bacterium reported to date, Pseudonocardia dioxanivorans CB1190, suggesting high activity and afnity toward 1,4-dioxane degradation. Strains D1 and D6 possessed inducible 1,4-dioxane degrading enzymes, whereas strains D11 and D17 possessed constitutive ones. 1,4-Dioxane degradation (100 mg L-1) by Apia sp. D1 was not affected by the co-existence of up to 3,000 mg L-1 of ethylene glycol. The effects of initial pH, incubation temperature and NaCl concentration on 1,4-dioxane degradation by the four strains revealed that they could degrade 1,4-dioxane under a relatively wide range of conditions, suggesting that they have a certain adaptability and applicability for industrial wastewater treatment.

Keywords 1,4-dioxane Metabolic 1,4-dioxane

degrading bacteria Isolation and characterization

Wastewater treatment

Introduction

1,4-Dioxane is a cyclic ether that is widely used as a solvent in paints, lacquers, cosmetics, deodorants, fumigants and detergents, as well as a stabilizer for chlorinated solvents such as 1,1,1-trichloroethane. In addition, 1,4-dioxane is formed as an undesired by-product in many industrial processes, especially

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