Enhanced biotransformation of mononitrophenols by Stenotrophomonas maltophilia KB2 in the presence of aromatic compounds of plant origin

Abstract

Stenotrophomonas maltophilia KB2 used in this study is known to metabolise broad range of aromatic compounds including phenol, some chloro and methylphenols, benzoic acids, catochols and others. To study the applicability of the strain for degradation of mononitrophenols in monosubstrate as well as cometabolic systems its degradation potential in the presence of mononitrophenols or different aromatic compounds of plant origin was tested. Stenotrophomonas maltophilia KB2 strain was not able to degrade any of mononitrophenols used in the single substrate experiments. Effect of additional carbon source on nitrophenols degradation revealed that presence of benzoate, 4-hydroxybenzoate or 3,4-dixydroxybenzoate stimulate transformation of 2-nitrophenol, 3-nitrophenol as well as 4-nitrophenol. Depending on growth substrate and mononitrophenol used, decrease in cometabolite concentration was from 25 to 45%. Obtained results suggest that Stenotrophomonas maltophilia KB2 strain could be potentially used for cometabolic degradation of nitrophenols in the presence of aromatic acids, for the bioremediation of contaminated sites.

Immobilization of Planococcus sp. S5 Strain on the Loofah Sponge and Its Application in Naproxen Removal

“…Proliferation of S5 cells was carried out in the nutrient broth (BBL) at 30 • C on a rotary shaker at 130 rpm. After 72 h of incubation bacterial cultures were centrifuged (5000 rpm, 15 min), washed twice with mineral salts medium [56] and resuspended in the same medium. Prepared bacterial suspensions were used as an inoculum for immobilization and control non-immobilized cells experiments.…”

“…Naproxen decomposition was conducted in 500 mL Erlenmeyer flask containing 250 mL of the mineral salts medium [56] and 10 pieces of the loofa sponge colonized by bacteria. Each flash was supplement with naproxen (Sigma-Aldrich, USA) to obtain a final concentration of 6, 9, 12 or 15 mg/L and at every 3 days with glucose (0.5 g/L, POCH, Gliwice, Poland) and incubated with shaking (130 rpm) at 30 • C. The control cultures contained non-immobilized cells of Planococcus sp.…”

Dynamics of ibuprofen biodegradation by Bacillus sp. B1(2015b)

“…The bacterial strain was cultured in modifi ed mineral medium (Kojima et al, 1961) Degradation of ibuprofen in a monosubstrate, as well as cometabolic systems, were performed in 500 ml Erlenmeyer fl asks containing 250 ml of the mineral salts medium (Greń et al 2010) inoculated with cells to obtain a dry-mass concentration of 0.426 mg L -1 and 0.053 mg L -1 for mono-and cometabolic systems, respectively. Ibuprofen was added to obtain the fi nal concentration of 1, 3, 5, 7 and 9 mg L -1…”

“…Supplementation of the culture with growth substrates such as glucose, acetate or glutamate is necessary for biomass enhancement, and may activate some non-specifi c enzymes (Greń et al 2010). Nowadays, very few microorganisms have been described as capable of removing ibuprofen in the presence of other carbon sources (Almeida et al 2013, Marco-Urrea et al 2009, Murdoch and Hay 2005.…”

Toxicity of Diclofenac and its Biotransformation by Raoultella sp. DD4

“…Degradation of diclofenac was performed in 500 ml Erlenmeyer flasks containing 250 ml of a mineral salt medium [12] and inoculated with cells to a final optical density of about 1.0 at λ = 600 nm (OD600). Diclofenac was added to obtain a final concentration of 6 mg/L, and all cultures were incubated with shaking at 30ºC for 28 days.…”