Determination Of In Vitro And In Vivo Production Of Polygalacturonase (pg) By Storage mold Aspergillus Niger V. Tieghem, During Storage Of Rice ( Oryzae Sativa L) Seeds|
Ibiam, O.F.A & Arinze, A.E.
The in vitro and in vivo production of pectic enzyme polygalacturonase (PG) by storage mold
of rice Aspergillus niger and the effect of temperature and pH on the activity of the mold were investigated. The
result of the assay for the production of polygalacturonase (PG) by the mold in vitro and in vivo showed that the
activity of the enzyme when tested viscometrically, using 10% pectin was 142.9 R.V.U (Relative viscometric
units) at 25°C. The optimum activity of the enzyme secreted in vitro by Aspergillus niger was obtained at a
temperature of 25 °C, and at temperature of 25 °C and 30 °C for that secreted in vivo., with a value of 142.9 R.
V.U. The least activity of the enzyme was obtained at 20 °C, 40 °C, 45 °C and 50 °C in vitro, and at 20 °C ,45 °C
and 50 °C with a value of 111.1 R.V.U each. The optimum activity of the enzyme produced in vitro by the
fungus obtained at pH 5 and 6 with a value of 125R.V.U, and at pH 5 with a value of 142.9 R .V. U. in vivo. The
activity of the enzyme was least at pH 2, 3, 4, 7,8, 9 and 10 in vitro, and at pH 2,3,8,9 and 10. in vivo with a value
of 111.1 R. V. U.