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Anna Roosdiana
Fakultas MIPA Universitas Brawijaya Jalan Veteran Malang 65145

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Effect of Adding Ions - Metal Ions to Pectinase Activity Isolation from Bacillus Subtilis on Bleaching Paper Mardiana Prasetyani Putri; Anna Roosdiana; Sasangka Prasetyawan; Diah Mardiana
Natural B, Journal of Health and Environmental Sciences Vol 2, No 1 (2013)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (155.888 KB) | DOI: 10.21776/ub.natural-b.2013.002.01.11

Abstract

Pectinase enzyme used as biocatalyst to overhaul pectat compounds or pectin. Pectinase avtivity was affected by metal ions. The purpose of this study is to determine the effect of adding metal ions on pectinase activity and its inhibition type.. Determination of enzyme activity was based on galacturonic acid produced, which was analyzed by spectrophotometric using DNS reagent. Concentration of metal ions used i.e. Zn2+, Cu2+, Fe3+ were 2-10 mM. The result showed that Vm and KM number without ions were 161.29 µmol/mL minutes and 0.55%(w/v), respectively. While the presence of ions Zn2+, Cu2+, Fe3+ were producing Vmapp 147.06; 156.25 and 153.85µg.ml-1min-1, KMapp of 0.56%; 0.63% and 0.65%, and also KI of 333,33; 41,38; 32,9. The inhibition to metal ions are non-competitif inhibition.
Effect of Metal Ions on Pectinase Activity from Aspergillus niger on Purifying Guava Fruit Dian Puspita Anggraini; Anna Roosdiana; Sasangka Prasetyawan; Diah Mardiana
Natural B, Journal of Health and Environmental Sciences Vol 2, No 1 (2013)
Publisher : Natural B, Journal of Health and Environmental Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (83.749 KB) | DOI: 10.21776/ub.natural-b.2013.002.01.10

Abstract

Pectinase can be used on various fruit juices clarification; however, the activities can be affected by their metal ions content. The purpose of this study was to determine the type of metal ions inhibition i.e. Zn2+; Mg2+ and Ca2+ on the pectinase activity of Aspergillus niger, and its potential application in guava juice clarification. Activity assays performed at pH 5, temperature 50°C during 55minutes and each ion concentration were 2-10 mM. Galacturonic acid concentration, as the product of pectin substrate hydrolysis, used as the basis for determining its activity and analyzed by visible spectrophotometry. The results showed that the ions concentration of Zn2+ and Mg2+ more than 4 mM were inhibitor for pectinase activity while Ca2+ ion concentration was 6mM. KI values for the metal ions Zn2+; Mg2+ and Ca2+ at concentrations of 6mM were 176.99; 326.09 and 280.37 mM respectively. Pectinase from Aspergillus niger were able to reduce 18% of pectin of guava juice.