The ability of Aspergillus japonicus'
extracellular lipase to work on sesame, peanut, and sunflower oil substrates
was examined. The enzyme was significantly active between pH 6 and 8 and
between 300 and 400 °C, whereas in sunflower oil, the activity peaked at 500
°C. Only Mg2+ (2 mM) out of the eleven metal ions examined improved enzyme
activity, whilst the others inhibited. The enzyme activity was considerably (P
0.05) increased by EDTA, indicating that metal ions generally do not impact the
lipase isolated from A. japonicus. Higher concentrations of the organic
solvents and acids examined significantly (P 0.05) increased the lipase
activity, perhaps as a result of their effect on the interfacial region.
Lineweaver Burk and Eadie-Hofstee were used to calculate the partial lipase's
Km and Vmax values. Additional research involved looking for thermo-tolerant
lipases with stability across a wide pH range and temperature, suitable for
industrial applications, in fungal infestations of groundnut seeds. Aspergillus
niger GN1 was classified in this investigation based on DNA sequencing results
that showed 99 percent similarity between the isolate and Aspergillus niger in
the ITS 1, 5.8S, and ITS 2 regions. The pellet made from culture extract was
suspended in Tris-buffer and tested for lipase activity after being treated to
a 65 percent ammonium sulphate precipitation. At pH 4 and pH 9, respectively,
two lipase fractions (1 and 2) could be isolated from the solution. LC-MS/MS
spectroscopic analysis was used to characterise the lipase 1 and 2 fractions.
In the 60–80 0C temperature range, the relative and residual activity of the
enzyme fractions were high.
Author(s) Details:
Kota Sobha,
Department of Chemical Engineering, RVR and JC College of Engineering,
Chowdavaram, Guntur 522 019, Andhra Pradesh, India.
Please see the link here:
https://stm.bookpi.org/CTCB-V4/article/view/7816
