Aerobic nonylphenol degradation and nitro-nonylphenol formation by microbial cultures from sediments

Nonylphenol (NP) is an estrogenic pollutant which is widely present in the aquatic environment. Biodegradation of NP can reduce the toxicological risk. In this study, aerobic biodegradation of NP in river sediment was investigated. The sediment used for the microcosm experiments was aged polluted with NP. The biodegradation of NP in the sediment occurred within 8 days with a lag phase of 2 days at 30°C. During the biodegradation, nitro-nonylphenol metabolites were formed, which were further degraded to unknown compounds. The attached nitro-group originated from the ammonium in the medium. Five subsequent transfers were performed from original sediment and yielded a final stable population. In this NP-degrading culture, the microorganisms possibly involved in the biotransformation of NP to nitro-nonylphenol were related to ammonium-oxidizing bacteria. Besides the degradation of NP via nitro-nonylphenol, bacteria related to phenol-degrading species, which degrade phenol via ring cleavage, are abundantly present

Complete genome sequence of Achromobacter denitrificans PR1

Achromobacter denitrificans strain PR1 was isolated from an enrichment culture able to use sulfamethoxazole as an energy source. Here, we describe the complete genome of this strain sequenced by Illumina MiSeq and Oxford Nanopore MinION. © 2017 Reis et al

Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp strain CDT

Soil contamination with tetrabromobisphenol A (TBBPA) has caused great concerns; however, the presence of heavy metals and soil organic matter on the biodegradation of TBBPA is still unclear. We isolated Pseudomonas sp. strain CDT, a TBBPA-degrading bacterium, from activated sludge and incubated it with C-14-labeled TBBPA for 87 days in the absence and presence of Cu2+ and humic acids (HA). TBBPA was degraded to organic-solvent extractable (59.4% +/- 2.2%) and non-extractable (25.1% +/- 1.3%) metabolites, mineralized to CO2 (4.8% +/- 0.8%), and assimilated into cells (10.6% +/- 0.9%) at the end of incubation. When Cu2+ was present, the transformation of extractable metabolites into non-extractable metabolites and mineralization were inhibited, possibly due to the toxicity of Cu2+ to cells. HA significantly inhibited both dissipation and mineralization of TBBPA and altered the fate of TBBPA in the culture by formation of HA-bound residues that amounted to 22.1% +/- 3.7% of the transformed TBBPA. The inhibition from HA was attributed to adsorption of TBBPA and formation of bound residues with HA via reaction of reactive metabolites with HA molecules, which decreased bioavailability of TBBPA and metabolites in the culture. When Cu2+ and HA were both present, Cu2+ significantly promoted the HA inhibition on TBBPA dissipation but not on metabolite degradation. The results provide insights into individual and interactive effects of Cu2+ and soil organic matter on the biotransformation of TBBPA and indicate that soil organic matter plays an essential role in determining the fate of organic pollutants in soil and mitigating heavy metal toxicity. (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V