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
AbstractThe 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 oC. The optimum activity of the enzyme secreted in vitro by Aspergillus niger was obtained at a temperature of 25 oC, and at temperature of 25 oC and 30 oC for that secreted in vivo., with a value of 142.9 R. V.U. The least activity of the enzyme was obtained at 20 oC, 40 oC, 45 oC and 50 oC in vitro, and at 20 oC ,45 oC and 50 oC 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.