Double mutation of Saccharomyces cerevisiae for enhanced -D-fructofuranosidase fructohydrolase productivity and application of growth kinetics for parametric significance analysis
Ali, Sikander; Aslam, Aafia; Hayyat, Muhammad Umar.
Braz. J. Microbiol.;
47(1): 136-142, 2016. ilus, tab, graf
Artigo
em Inglês
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| ID: vti-688329
Resumo
The kinetics of an extracellular -D-fructofuranosidase fructohydrolase production by Saccharomyces cerevisiae in a chemically defined medium, i.e., sucrose peptone agar yeast extract at pH 6, was investigated. The wild-type was treated with a chemical mutagen, methyl methane sulfonate. Among the six mutants isolated, methyl methane sulfonate-V was found to be a better enzyme producing strain (52 ± 2.4a U/mL). The maximum production (74 ± 3.1a U/mL) was accomplished after at 48 h (68 ± 2.7a mg/mL protein). The mutants were stabilized at low levels of 5-fluoro-cytocine and the viable ones were further processed for optimization of cultural conditions and nutritional requirements. The sucrose concentration, incubation period and pH were optimized to be 30 g/L, 28 °C, and 6.5, respectively. The methyl methane sulfonate-V exhibited an improvement of over 10 folds in enzyme production when 5 g/L ammonium sulfate was used as a nitrogen source. Thin layer chromatography and high-performance liquid chromatography analysis illustrated the optimal enzyme activity supported by the higher rate of hydrolysis of sucrose into monosaccharides, particularly -D-glucose and -D-fructose. The values for Qp (2 ± 0.12c U/mL/h) and Yp/s (4 ± 1.24b U/g) of the mutant were considerably increased in comparison with other yeast strains (both isolates and viable mutants). The mutant could be exploited for enzyme production over a wider temperature range (2634 °C), with significantly high enzyme activity (LSD 0.048, HS) at the optimal temperature. (AU)
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BR68.1
Localização: BR68.1
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