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Effect of temperature, concentration of alcohols and time on baker’s yeast permeabilization process

Trawczyńska I., Miłek J., Kwiatkowska-Marks S.

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2018

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nr 21(3)

195--206

EN

Baker’s yeast beyond the traditional use in the food industry may be used to carry out biotransformations. The effectiveness of yeast as biocatalysts is based on the presence of large amounts of intracellular enzymes, whose efficiency can be repeatedly increased by permeabilization. It is the process of increasing the permeability of cell walls and membranes in order to facilitate reagents access to the intracellular enzyme. Alcohols permeabilization process allows for approx. 50-fold increase in catalase activity of baker’s yeast. In this paper, the influence of physical and chemical parameters on the effectiveness of permeabilization of baker’s yeast cells using alcohols was analyzed. Research has shown that with increasing temperature of permeabilization process better results are achieved using a lower alcohol concentration. Based on presented response surface graphs, we can also indicate a negligible impact of duration time on the process efficiency.

2

Permeabilizacja komórek drożdży piekarskich – skuteczność procesu w warunkach ustalonych

Trawczyńska I., Wójcik M., Grubecki I.

Inżynieria i Aparatura Chemiczna

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2015

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Nr 3

128--129

PL

Komórki drożdży piekarskich ze względu na dużą zawartość enzymów wewnątrzkomórkowych stosowane są jako biologiczne katalizatory reakcji chemicznych. Proces permeabilizacji z użyciem alkoholi pozwala znacząco zwiększyć ich skuteczność. W oparciu o odpowiednie modele matematyczne przeprowadzono symulację skuteczności permeabilizacji komórek drożdży piekarskich dla ustalonych wartości temperatury procesu. Rezultaty obliczeń analitycznych umożliwiają łatwe prognozowanie aktywności wewnątrzkomórkowej katalazy dla narzuconych temperatur.

EN

Baker's yeast cells due to the high content of intracellular enzymes are used as biological catalysts of chemical reactions. Permeabilization process with the use of alcohol can significantly increase their effectiveness. On the basis of the corresponding mathematical models the simulation of effectiveness of permeabilized baker's yeast cells for predefined temperatures was performed. The results of analytical calculations allows for easy prediction of intracellular catalase activity for the imposed temperatures.

3

Application of Response Surface Methodology for Optimization of Permeabilization Process of Baker’s Yeast

Trawczyńska I., Wójcik M.

Polish Journal of Chemical Technology

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2014

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Vol. 16, nr 2

31--35

EN

Permeabilization was used for the purpose of transforming the cells of microorganisms into biocatalysts with an enhanced enzyme activity. Baker’s yeast cells were permeabilized with various organic solvents. A high degree of catalase activity was observed upon permeabilization with acetone, chloroform, isopropyl alcohol and ethyl acetate. Response surface methodology was used to model the effect of concentration of isopropyl alcohol, temperature and treatment time on the permeabilization of baker’s yeast cells to maximize the decomposition of H2O2. The optimum operating conditions for permeabilization were observed at 53.7% concentration of isopropyl alcohol, treatment time of 40 min and temperature of 15.6oC. A maximum value of catalase activity was found to be 6.188 U/g wet wt. and was ca. 60 times higher than the catalytic activity of yeast not treated by the permeabilization process.

4

Optymalizacja procesu permeabilizacji komórek drożdży Saccharomyces cerevisiae metanolem

Olczak I., Grubecki I., Wójcik M.

Inżynieria i Aparatura Chemiczna

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2010

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Nr 3

89-90

PL

Metodę odpowiedzi powierzchniowej zastosowano do optymalizacji procesu pcrmeabilizacji komórek Sacchromyces cerevisiae metanolem. Badano wpływ stężenia metanolu, temperatury i czasu permeabilizacji na aktywność wewnątrzkomórkowej katalazy. Wykonano 20 doświadczeń dla trzech niezależnych czynników przy pięciu poziomach. Optymalne warunki procesu permeabilizacji uzyskano dla stężenia metanolu 40,6% mas., temperatury 19,2°C ill5 min wytrząsania.

EN

The response surface methodology was used to optimize permeabilization of Saccharomyces cerevisiae cells by methanol. The effect of methanol concentration, temperature, and treatment time on activity of intracellular ca-talase was studied. Three independent factors were studied at five different levels and a set of 20 experiments was carried out. The following optimum operating conditions for permeabilization process were found: 40.6% (w/w) methanol concentration, 19.2°C temperature and 115 min treatment time.

5

Fungal Cells Permeabilization as a Convenient Tool of Bioreduction Enantioselectivity Control

Brzezińska-Rodak M., Żymańczyk-Duda E., Klimek-Ochab M., Lejczak B.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2113-2118

EN

The application of nonionic detergents: Triton X100 and Tween 80, as permeabilizing agents was an effective tool allowing to control the asymmetric hydrogen transfer in the biocatalyzed, enantioselective reduction of acetophenone to the desired optical isomer of 1-phenylethanol. Depending on the permeabilization procedure, the application of Geotrichum candidum, after the Triton X100 was applied, resulted in the formation of the R-enantiomer (79 percent of chemical yield and 72 percent of e.e), whereas bioreduction following the use of Tween 80 led to the S-form of 1-phenylethanol (51 percent of yield and 93 percent of e.e).