My Long Term Project

TITLE OF THE PROJECT

                                            "IN SILICO COMPARISON OF XENOBIOTIC DEGRADATION PATHWAYS AMONG THREE STRAINS OF PURPLE NON SULFUR BACTERIA AND CONFIRMATION OF ANILINE DEGRADATION BY RHODOBACTER SPHAEROIDES DSM 158".

ABSTRACT

                          Anoxygenic phototropic bacteria have the potential to degrade aromatic hydrocarbons but their role in xenobiotic degradation was not known much. The main focus of the study was to know the efficiency of the strains among Rhodopseudomonas palustris DSM 123, Rhodobacter sphaeroides DSM 158, Rhodospirillum rubrum ATCC 11170 to be a potential player in xenobiotic degradation. Due to the lack of gene level reports in xenobiotic degradation for APB, in silico approaches like comparative genomics and mining of metabolic databases was made. These results helped in distinguishing their in built capability for degrading xenobiotics. Rhodopseudomonas palustris CGA 009 was selected for in silico analysis instead of Rhodopseudomonas palustris DSM 123 due to the lack of its whole genome sequences. In silico analysis results revealed the hierarchy of  xenobiotic degrading  capability which falls through Rhodopseudomonas palustris CGA 009, Rhodobacter sphaeroides DSM 158, Rhodospirillum rubrum ATCC 11170.

                                Finally, due to the non availability of the strain Rhodopseudomonas palustris CGA 009, the next efficient strain Rhodobacter sphaeroides DSM 158 was selected and the in vivo studies were done. The substrate Aniline was selected through metabolic databases. Through in vivo studies it was observed that Aniline is not toxic when provided as an additional supplement to the medium, however the growth of the organism is highly affected when Aniline was provided either as carbon or nitrogen source. The complete disappearance of Aniline was observed through HPLC analysis of the culture supernatant. Also to add support to the utilization of Aniline by the strain there were eight metabolites formed. Among them two were identified as Indole 3 aldehyde and Anthranilic acid based on the standards. 

                                This is the first report of studying Xenobiotic degradation carried out by integrating in silico and in vivo approaches for “knowing the capability of three strains to degrade xenobiotics”. The work was carried out in a hierarchy starting from in silico and ended with in vivo which is given below as a flow chart.