Plasmid-mediated bioaugmentation of sequencing batch reactors for enhancement of 2,4-dichlorophenoxyacetic acid removal in wastewater using plasmid pJP4

Abstract

Plasmid-mediated bioaugmentation was demonstrated using sequencing batch reactors (SBRs) for enhancing 2,4-dichlorophenoxyacetic acid (2,4-D) removal by introducing Cupriavidus necator JMP134 and Escherichia coli HB101 harboring 2,4-D-degrading plasmid pJP4. C. necator JMP134(pJP4) can mineralize and grow on 2,4-D, while E. coli HB101(pJP4) cannot assimilate 2,4-D because it lacks the chromosomal genes to degrade the intermediates. The SBR with C. necator JMP134(pJP4) showed 100 % removal against 200 mg/l of 2,4-D just after its introduction, after which 2,4-D removal dropped to 0 % on day 7 with the decline in viability of the introduced strain. The SBR with E. coli HB101(pJP4) showed low 2,4-D removal, i.e., below 10 %, until day 7. Transconjugant strains of Pseudomonas and Achromobacter isolated on day 7 could not grow on 2,4-D. Both SBRs started removing 2,4-D at 100 % after day 16 with the appearance of 2,4-D-degrading transconjugants belonging to Achromobacter, Burkholderia, Cupriavidus, and Pandoraea. After the influent 2,4-D concentration was increased to 500 mg/l on day 65, the SBR with E. coli HB101(pJP4) maintained stable 2,4-D removal of more than 95 %. Although the SBR with C. necator JMP134(pJP4) showed a temporal depression of 2,4-D removal of 65 % on day 76, almost 100 % removal was achieved thereafter. During this period, transconjugants isolated from both SBRs were mainly Achromobacter with high 2,4-D-degrading capability. In conclusion, plasmid-mediated bioaugmentation can enhance the degradation capability of activated sludge regardless of the survival of introduced strains and their 2,4-D degradation capacity.

Plasmid-Mediated Bioaugmentation for the Bioremediation of Contaminated Soils

“… Inoue et al (2012) concluded that genetic bioaugmentation with P. putida and E. coli cells harboring plasmid pJP4 can stimulate the degradation of 2,4-D in soil without a substantial impact on the soil microbial community, as reflected by the values of parameters which provide information on carbon source utilization (through the use of the well-known Biolog TM plates) and nitrogen transformations (nitrate reduction assay, quantification of amoA gene of ammonia-oxidizing bacteria, quantification of nirK and nirS genes of denitrifying bacteria). In sequencing batch reactors, Tsutsui et al (2013) achieved a complete degradation of 2,4-D by plasmid (pJP4)-mediated bioaugmentation with Cupriavidus necator JMP134 and E . coli HB101 as donor strains.…”

Effects of Inoculum Amount, Initial pH, and Nicotine Load on the Set-Up of Bioaugmented System withPseudomonasSp. HF-1 to Treat Tobacco Wastewater

“…It implied that pH also played an important role in its set-up. Besides, the initial pollutant concentration is also an important factor for the set-up of bioaugmentation system that concerned by various researchers [19][20][21][22]. Based on the analysis of its mechanisms, both inoculum and pH and pollutant load should be optimized for its application in engineering [23,24].…”

Conjugative transfer of plasmid pJP4 in defined biofilms and catabolic activity of transconjugant cells

“…Many plasmid mediation bioaugmentation (genetic bioaugmentation) studies have been focused on the herbicide 2,4-D(Bathe et al, 2004b, Aspray et al, 2005, Quan et al, 2011, Newby et al, 2002, Tsutsui et al, 2013.Tstusui et al (2013) observed enhanced plasmid pJP4 mediated bioaugmentation using sequencing batch reactors for the removal of 2,4-D. Cupriavidus necator JMP134 and E. coli HB101 were used as plasmid donor strains. Complete removal of 2,4-D was achieved in the reactor with C. necator JMP134.…”