Enhancing Chlorobenzene Biodegradation by Delftia tsuruhatensis Using a Water-Silicone Oil Biphasic System

Abstract

In this study, a water–silicone oil biphasic system was developed to enhance the biodegradation of monochlorobenzene (CB) by Delftia tsuruhatensis LW26. Compared to the single phase, the biphasic system with a suitable silicone oil fraction (v/v) of 20% allowed a 2.5-fold increase in the maximum tolerated CB concentration. The CB inhibition on D. tsuruhatensis LW26 was reduced in the presence of silicone oil, and the electron transport system activity was maintained at high levels even under high CB stress. Adhesion of cells to the water–oil interface at the water side was observed using confocal laser scanning microscopy. Nearly 75% of cells accumulated on the interface, implying that another interfacial substrate uptake pathway prevailed besides that initiated by cells in the aqueous phase. The 8-fold increase in cell surface hydrophobicity upon the addition of 20% (v/v) silicone oil showed that silicone oil modified the surface characteristics of D. tsuruhatensis LW26. The protein/polysaccharide ratio of extracellular polymeric substances (EPS) from D. tsuruhatensis LW26 presented a 3-fold enhancement. These results suggested that silicone oil induced the increase in the protein content of EPS and rendered cells hydrophobic. The resulting hydrophobic cells could adhere on the water–oil interface, improving the mass transfer by direct CB uptake from silicone oil.

Plasma Applications in Microalgal Biotechnology

“…Biological processes involve several steps such as absorption, diffusion and biodegradation. The efficiency of the process requires the involvement of resistant microorganisms as well as a good mass transfer between the different steps, a transfer that can be difficult when less-water-soluble CleVOCs are considered (Ye et al, 2019). Non-thermal plasma (NTP), eventually coupled to another method, has been proposed as a pretreatment step to facilitate the mass transfer because it could convert less-water-soluble CleVOCs to more soluble intermediates (Schiavon et al, 2017).…”

Reduction characteristic of chlorobenzene by a newly isolated Paenarthrobacter ureafaciens LY from a pharmaceutical wastewater treatment plant

“…During this exposure, certain gene clusters undergo linkage and hybridization, leading to the emergence of genes capable of degrading CB. These genetic adaptations have gradually equipped these microorganisms to thrive in CB‐contaminated environments 21 . Consequently, researchers are actively involved in the isolation and screening of adaptive strains.…”

“…These genetic adaptations have gradually equipped these microorganisms to thrive in CB-contaminated environments. 21 Consequently, researchers are actively involved in the isolation and screening of adaptive strains.…”

Novel therapeutic targets identification of Delftia tsuruhatensis strain TR1180 employing subtractive genomics approach

“…Studies on these species are focused on environmental applications. For instance, this bacteria can biodegrade organic contaminants, including phenolic compounds and chlorobenzene (Jimenez et al, 2012, Ye et al, 2019. Delftibactin, a non-ribosomal peptide produced by D. tsuruhatensis showed effective antimicrobial activity against methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii and vancomycin-resistant Enterococcus(Tejman-Yarden et al, 2019).…”