Indigenous isolate Bacillus subtilis strain mp1 mediated degradation of di -(2-ethyl hexyl) phthalate and analysis of the degradation intermediates by lc-ms.

Tanuja^a, Madhavi Rashmi^b* & Shivanand Singh^c
aUniversity Department of Botany, Patliputra University, Patna, Bihar, India
^bDepartment of Biotechnology, Magadh University, Bodh Gaya, Bihar, India
^cDepartment of Zoology, B.R.A Bihar University, Muzaffarpur, Bihar, India
Received : 11th January, 2021 ; Revised : 12th February, 2021

Abstract– DEHP (di-ethyl hexyl phthalate) is an endocrine disrupting chemical that is commonly used as a plasticizer worldwide and is reported to adversely affect humans as well as wildlife. In the present study, strain MP1, an indigenous isolate from landfill soil has been selected which was able to grow and metabolize DEHP as sole carbon and energy sources in the MSM liquid media and showed DEHP degrading potential . It was capable of sustaining a wide range of environmental conditions with the optimum pH for bacterial growth 7.0, temperature 28^oC and tolerance upto salinity 5%. The analysis of morphological and biochemical characteristics along with gram staining technique followed by 16s rRNA sequencing, identified it as Bacillus subtilis (Genbank Accession no. KP241787.1). LC-MS) analysis was done for the determination of metabolic intermediates. There are four main peaks identified having different RT values and mass. These are 301.15 at RT value 9.02, 413.29 at RT value 10.14, 441.32 at RT value 10.33 and 757.68 at RT value 11.27. These peaks are degradation intermediates identified as Sodium isooctyl phthalate (mass 300.13), 2-(Dodec-1-yn-1-yl)-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane (mass 412.28), bis[4-(oxolan-2-yl) butan-2-yl] nonanedioate (mass440.31),n-(2-hydroxyethyl)-n,n-dimethyl-2,3- bis(octadecanoyloxy)propan-1-aminium) acetate (mass 755.66). These findings can provide some information in the bioremediation of DEHP from contaminated soil.

Download pdf