Characterization of a Polyphenol-Oxidase and Lipase Produced by
Microorganisms Isolated from Palm Oil Sludge.
Abstract
In the current study, the waste-to-wealth concept has been applied. We
were focused on using waste palm oil sludge to isolate and characterize
various microorganisms that produce various industrial significant
enzymes, such as polyphenol oxidases. We were able to isolate several
bacteria that were discovered to be tyrosinase producers: Bacillus
cereus, Acinobacter seifertii, Klebsiella variicola, and Pseudomonas
stutzeri. Laccase producers Trametes polyzona, Bacillus subtilis,
Bacillus pumilus, and Staphylococcus condimenti, as well as lipase
producers. After they were grown for 18 hours at 35°C, pH 6.0, with
substrates of 0.1% casein and 2.0% glucose, it was confirmed that they
produce industrially important enzymes. Further, we focused specifically
on B. cereus because it was evident that it produces tyrosinase. Lipase
is another targeted enzyme, and S. condimenti was discovered to be a
hyperproducer. The production conditions included are 24-hour incubation
period at 40°C and pH 6.0, while typical substrates like starch and
coconut oil were employed. 43 kDa-identified lipase that was found to be
active at pH 7.0 and 40°C. Salts like NaCl, different detergents like
Triton X-100, and Tween-80, and many metal ions all enhanced the
activity, making the enzyme unique in its biological function. Only 40%
inhibition has been seen, even with EDTA (2.5 mM), which does not
completely block its function. Very few organic solvents such as
butanol, acetone, and DMF are involved in inhibiting its activity.