TY - JOUR AU - Hargono, Hargono AU - Kumoro, Andri Cahyo AU - Jos, Bakti PY - 2019/01/01 Y2 - 2024/03/29 TI - Inhibitory Effects of Cyanide on the Activity of Granular Starch Hydrolyzing Enzyme (GSHE) during Hydrolysis of Cassava (Manihot Esculenta Crantz) Starch JF - Periodica Polytechnica Chemical Engineering JA - Period. Polytech. Chem. Eng. VL - 63 IS - 1 SE - DO - 10.3311/PPch.12006 UR - https://pp.bme.hu/ch/article/view/12006 SP - 11-17 AB - <p>The kinetics and inhibitory effects of cyanide on the granular starch hydrolyzing enzyme (GSHE) activity during hydrolysis of cassava (Manihot esculenta Crantz) starch at low temperature were studied. The substrates included native cassava starch at various concentrations (100-400 g/L) and native cassava starches with added cyanide at various concentrations (50-150 mg/kg), while the concentration of enzyme was5% (w/w). A decrease in reducing sugar concentration during hydrolysis of cassava starch indicated that the cyanide reduced the enzyme activity. Lineweaver-Burk plot of Michaelis-Menten equation was used to study the inhibition kinetics. The maximum velocity (<em>V</em><sub>max</sub>) value was higher for native cassava starch than that of native cassava starch with added cyanides. The presence of cyanide was found to reduce the <em>V</em><sub>max</sub> values. No significant different of the saturation constant (<em>K<sub>m</sub></em>) value between native cassava starch and native cassava starch with added cyanides was observed. Based on the inhibition type analysis, the effect of cyanide in the cassava starch can be classified as a noncompetitive inhibition, with the <em>K<sub>i</sub></em> value of 0.33 mg/L.</p> ER -