Search results

Sort By:

Limit search:

Bioremediation Of A Spent Metalworking Fluid With Auto- And Allochthonous Bacterial Consortia

100%

Kaszycki P., Petryszak P., Supel P.

Ecological Chemistry and Engineering S

2015

vol. 22

issue 2

285-299

Spent mineral oil-based metalworking fluids are waste products of the machining processes and contribute substantially to the global industrial pollution with petroleum oil products. Wastewaters containing oily emulsions are ecologically hazardous and thus a variety of methods have been implemented to prevent these effluents from affecting the natural environment. Most of these methods rely upon physical-chemical treatment and phase separation; however, none of them proved to be effective enough to meet tightening environmental regulations. Therefore, novel technologies need to be elaborated and there is growing interest in implementing biological treatment methods based on microbial bioremediation. In this study an oil/water emulsion obtained from a waste stream of the metal-processing industry was tested for biodegradability of its organic constituents. This liquid waste was found non-toxic to bacterial consortia and was colonized with indigenous microorganisms (approx. 107 cfu · cm−3). The total load of organic content was determined as a chemical oxygen demand (COD) value of 48 200 mg O2 · dm−3. Emulsion treatment was carried out using a threefold wastewater dilution and employing two variants of biostimulated aerobic bacterial communities: (1) uninoculated emulsion, where bioremediation was carried out by the autochthonous bacteria alone, and (2) wastewater samples inoculated with a ZB-01 microbial consortium which served as a source of specialized bacteria for process bioaugmentation. Biodegradation efficiency achieved in a 14-day test was monitored by measuring both the COD parameter and the concentration of high-boiling organic compounds. Both approaches yielded satisfactory results showing significant reduction of the emulsion organic fraction; however, the resultant decrease of wastewater load tended to be more efficient for the case where the process was bioaugmented with the inoculated consortium. Gas chromatography analyses coupled with mass spectrometric detection (GC-MS) confirmed high degradation yields obtained for both cases studied (58 and 71%, respectively) in a 28-day test. It is concluded that oil-based metalworking emulsions can undergo efficient biological treatment under conditions enabling aerobic bacterial proliferation and that xenobiotic biodegradation kinetics can be accelerated by bioaugmenting the process with allochthonous microbial consortia.

Methylotrophic extremophilic yeast Trichosporon sp.: a soil-derived isolate with potential applications in environmental biotechnology

76%

Kaszycki P., Czechowska K., Petryszak P., Międzobrodzki J., Pawlik B., Kołoczek H.

2006

vol. 53

issue 3

463-473

A yeast isolate revealing unique enzymatic activities and substrate-dependent polymorphism was obtained from autochthonous microflora of soil heavily polluted with oily slurries. By means of standard yeast identification procedures the strain was identified as Trichosporon cutaneum. Further molecular PCR product analyses of ribosomal DNA confirmed the identity of the isolate with the genus Trichosporon. As it grew on methanol as a sole carbon source, the strain appeared to be methylotrophic. Furthermore, it was also able to utilize formaldehyde. A multi-substrate growth potential was shown with several other carbon sources: glucose, glycerol, ethanol as well as petroleum derivatives and phenol. Optimum growth temperature was determined at 25°C, and strong inhibition of growth at 37°C together with the original soil habitat indicated lack of pathogenicity in warm-blooded animals and humans. The unusually high tolerance to xenobiotics such as diesel oil (>30 g/l), methanol (50 g/l), phenol (2 g/l) and formaldehyde (7.5 g/l) proved that the isolate was an extremophilic organism. With high-density cultures, formaldehyde was totally removed at initial concentrations up to 7.5 g/l within 24 h, which is the highest biodegradation capability ever reported. Partial biodegradation of methanol (13 g/l) and diesel fuel (20 g/l) was also observed. Enzymatic studies revealed atypical methylotrophic pathway reactions, lacking alcohol oxidase, as compared with the conventional methylotroph Hansenula polymorpha. However, the activities of glutathione-dependent formaldehyde dehydrogenase, formaldehyde reductase, formate dehydrogenase and unspecific aldehyde dehydrogenase(s) were present. An additional glutathione-dependent aldehyde dehydrogenase activity was also detected. Metabolic and biochemical characteristics of the isolated yeast open up new possibilities for environmental biotechnology. Some potential applications in soil bioremediation and wastewater decontamination are discussed.

Refine search results

1 Acta Biochimica Polonica

1 Ecological Chemistry and Engineering S

1 2015

1 2006

2 Kaszycki P.

2 Petryszak P.

1 Czechowska K.

1 Kołoczek H.

1 Międzobrodzki J.

1 Pawlik B.

1 Supel P.

Search results

Bioremediation Of A Spent Metalworking Fluid With Auto- And Allochthonous Bacterial Consortia

Methylotrophic extremophilic yeast Trichosporon sp.: a soil-derived isolate with potential applications in environmental biotechnology