Isolation and characterization of Sphingomonas sp. Y2 capable of high-efficiency degradation of nonylphenol polyethoxylates in wastewater

Abstract

Nonylphenol polyethoxylates (NPEOs), although banned for decades, are still widely used in manufactories and thus affect human lives. In this study, a highly efficient NPEO-degrading bacterium, Sphingomonas sp. Y2, was isolated from sewage sludge by enrichment culture. Strain Y2 ensured the complete removal of NPEO in 48 h and degraded 99.2 % NPEO (1,000 mg L(-1)) within 30 h at a specific growth rate of 0.73 h(-1) in minimum salt medium. To date, this degradation efficiency is the highest reported for NPEO metabolism by a pure bacterium under this condition. Furthermore, the application of this bacterium to wastewater treatment demonstrated that it metabolized 98.5 % NPEO (1,000 mg L(-1)) within 5 days with a specific growth rate of 2.03 day(-1). The degradation intermediates, identified as nonylphenol, short-chain NPEOs and short-chain nonylphenol polyethoxycarboxylates by high-performance liquid chromatography and gas chromatography-mass spectrometry, indicated the sequential exo-cleavage of the EO chain. Additionally, the enzymes involved in the biodegradation were inducible rather than constitutive. Considering that strain Y2 exhibits prominent biodegradation advantages in industrial wastewater treatment, it might serve as a promising potential candidate for in situ bioremediation of contamination by NPEOs and other structurally similar compounds.

Complete genome sequencing and analysis of endophytic Sphingomonas sp. LK11 and its potential in plant growth

“…Recent studies have also demonstrated the role of Sphingomonas spp. in the degradation of organic chemical compounds, such as bisphenol (Fujiwara et al 2016 ), phenol (Gong et al 2016 ), triclocarban (Mulla et al 2016 ), phenanthrene (Liu et al 2016 ), chlorogenic acid (Ma et al 2016 ), nonylphenol polyethoxylates (Bai et al 2016 ), astaxanthin (Ma et al 2016 ), dioxin (Miller et al 2010 ), γ-hexachlorocyclohexane (Tabata et al 2013 ), nicotine (Zhu et al 2016 ), plasticizers (Kera et al 2016 ), and hexachlorocyclohexane isomers (Kumari et al 2002 ) among others. In addition to these degradation abilities, the Sphingomonas genus can also produce bioactive metabolites, such as indole acetic acid, gibberellins, sphingan (Li et al 2016 ), and gellan gum (Gai et al 2011b ).…”

Demulsification of crude oil-in-water emulsions by means of fungal spores

“…This kind of compound can be efficiently degraded by Aspergillus sp . [ 14 ]. The Petri dishes were incubated at 35°C for 4 days and the resulting colonies were isolated and subsequently tested for their ability to destabilize O/W emulsions formulated with medium crude oil.…”

Enzyme Recovery from Biological Wastewater Treatment

“…Similarly, Sphingomonas sp. Y2, isolated by Bai et al [129] from sewage sludge, produced inducible enzymes and degraded 99.2% of the surfactant, nonylphenol polyethoxylate, which is an environmentally active anthropogenic compound with oestrogenic and mutagenic properties.…”