19 research outputs found
Synergistic degradation of diazo dye Direct Red 5B by Portulaca grandiflora and Pseudomonas putida
Plants and bacterial consortium of Portulaca grandiflora and
Pseudomonas putida showed complete decolorization of a sulfonated
diazo dye Direct Red 5B within 72 h, while in vitro cultures of P.
grandiflora and P. putida independently showed 92 and 81 %
decolorization within 96 h, respectively. A significant induction in
the activities of lignin peroxidase, tyrosinase, 2,6-dichlorophenol
indophenol reductase and riboflavin reductase was observed in the roots
of P. grandiflora during dye decolorization; whereas, the activities of
laccase, veratryl alcohol oxidase and 2,6-dichlorophenol indophenol
reductase were induced in the cells of P. putida. Plant and bacterial
enzymes in the consortium gave an enhanced decolorization of Direct Red
5B synergistically. The metabolites formed after dye degradation
analyzed by UV-Vis spectroscopy, Fourier transformed infrared
spectroscopy and high performance liquid chromatography confirmed the
biotransformation of Direct Red 5B. Differential fate of metabolism of
Direct Red 5B by P. grandiflora, P. putida and their consortium were
proposed with the help of gas chromatography-mass spectroscopy
analysis. P. grandiflora metabolized the dye to give
1-(4-diazenylphenyl)-2-phenyldiazene, 7-(benzylamino)
naphthalene-2-sulfonic acid, 7-aminonaphthalene-2-sulfonic acid and
methylbenzene. P. putida gave 4-hydroxybenzenesulfonic acid and
4-hydroxynaphthalene-2-sulfonic acid and benzamide. Consortium showed
the formation of benzenesulfonic acid, 4-diazenylphenol,
6-aminonaphthalen-1-ol, methylbenzene and naphthalen-1-ol. Consortium
achieved an enhanced and efficient degradation of Direct Red 5B.
Phytotoxicity study revealed the nontoxic nature of metabolites formed
after parent dye degradation. Use of such combinatorial systems of
plant and bacteria could prove to be an effective and efficient
strategy for the removal of textile dyes from soil and waterways
Single-Cell Raman Spectral Profiles of Pseudomonas fluorescens SBW25 Reflects in vitro and in planta Metabolic History
Single-cell Raman microspectroscopy has the potential to report on the whole-cell chemical composition of bacteria, reflecting metabolic status as well as growth history. This potential has been demonstrated through the discriminant functional analysis of Raman spectral profiles (RSP) obtained from the soil and plant-associated bacterium Pseudomonas fluorescens SBW25, grown in vitro using defined media, and in planta using 3-month-old sugar beets (Beta vulgaris var. Roberta). SBW25 in vitro RSP data showed significant variation between those cells grown on different amino acids, sugars, TCA cycle intermediates, rich King's B, and culture media derived from the sugar beet phytosphere. Raman analysis was also able to follow the transition of SBW25 starved of carbon over a period of days, and SBW25 in planta RSP data also showed variation with significant differences between bacteria recovered from soil and the rhizosphere. SBW25 whole-cell chemical composition, and therefore growth and metabolic history, could be interpreted by coanalyzing in vitro and in planta RSP data. SBW25 recovered from the phytosphere was found to be more similar to SBW25 grown in vitro on Fru or Asp, rather than on Glc or Arg, and quite dissimilar to that resulting from carbon starvation. This suggests that SBW25 growth in the phytosphere is generally neither carbon-catabolite-repressed nor carbon-limited. These findings demonstrate that the analysis of single-cell RSP can differentiate between isogenic populations of bacteria with different metabolic histories or after recovery from different parts of their natural environment. In addition, Raman analysis is also capable of providing biologically relevant biochemical inferences, which might then be tested to uncover the mechanistic basis (biochemical–metabolic–genetic) differentiating bacteria growing in complex environments and exposed to different conditions