Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  amylase production
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
|
|
nr 3
269-273
EN
Fungi are well known for their ability to excrete enzymes into the environment. The fungal isolate FSS60 was the best amylase producer among one hundred and thirty-six isolates obtained from Syrian soils and tested for amylase production. According to the sequence of the internal transcribed spacer (ITS) rDNA gene, the isolate was identified as Aspergillus flavus. Optimal initial pH for amylase production was found to be 9.0. The enzyme was optimally active at 50°C and pH 5.0.
EN
Five fungal isolates were screened for the production of α-amylase using both solid-state and submerged fermentations. The best amylase producer among them, Aspergillus niger JGI 24, was selected for enzyme production by solid-state fermentation (SSF) on wheat bran. Different carbon and nitrogen supplements were used to enhance enzyme production and maximum amount of enzyme was obtained when SSF was carried out with soluble starch and beef extract (1 % each) as supplements. Further attempts to enhance enzyme production by UV induced mutagenesis were carried out. Survival rate decreased with increase in duration of UV exposure. Partial purification of the enzyme using ammonium sulphate fractionation resulted in 1.49 fold increase in the enzyme activity. The enzyme showed a molecular weight of 43 kDa by SDS-PAGE. Metal ions Ca²⁺ and Co²⁺ increased the enzyme activity. The enzyme was optimally active at 30°C and pH 9.5.
EN
Studies of α-amylase production by Bacillus subtilis (CM3) isolated earlier from cow dung microflora, were carried out. The optimum temperature, pH and incubation period for amylase production were 50-70°C, 5.0-9.0 and 36 h, respectively. Enzyme secretion was very similar in the presence of any of the carbon sources tested (soluble starch, potato starch, cassava starch, wheat flour, glucose, fructose, etc.). Yeast extract and ammonium acetate (1%) as nitrogen sources gave higher yield compared to other nitrogen sources (peptone, malt extract, casein, asparagine, glycine, beef extract), whereas ammonium chloride, ammonium sulphate and urea inhibited the enzyme activity. Addition of Ca⁺² (10-40 mM) to the culture medium did not result in further improvement of enzyme production, whereas the addition of surfactants (Tween 20, Tween 40, Tween 80, and sodium lauryl sulphate) at 0.02% resulted in 2-15% increase in enzyme production. There were no significant variations in enzyme yield between shaked-flask and laboratory fermentor cultures. The purified enzyme is in two forms with molecular mass of 18.0 ± 1 and 43.0 ± 1 kDa in native SDS-PAGE.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.