Partial characterization of a novel amylase activity isolated from Tunisian Ficus carica latex

Abstract

Context: A large number of plants still need to be investigated through screening of amylases suitable for industry. In the present study, and for the first time, we describe the amylolytic activity of Saint Pedro Ficus carica L. (Moraceae) crude latex of Kahli and Bidhi varieties.

Objective: Effects of temperature, pH, metal ions, and inhibitors and compatibility with some commercial detergents were investigated for amylase activity.

Materials and methods: Amylase activity was screened in crude latex using the DNS method and potato starch as a substrate. Analyses of amylolytic reaction products by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) were performed.

Results: Bidhi and Kahli amylases were active in optimal pH of 6.5 and 7 at 45°C, respectively, displaying a half life of 85 and 60 min, respectively, at 80°C, and they were very stable in a wide range of pH (4–12). Bidhi amylase activity increased to 260% by addition of 10⁻³ mM Fe²⁺ or 10⁻² mM Cu²⁺, and was strongly inhibited by Mg²⁺ and EDTA. In the presence of Ca²⁺ and Mg²⁺, Kahli amylase activity was dramatically enhanced by 220 and 260%, respectively. The compatibility of both amylases with certain commercial detergents was also shown to be good as enzymes retained up to 98% of their activities after 30 min of incubation at 80°C.

Discussion and conclusion: Analysis of amylolytic reaction products by TLC and HPLC suggested that Kahli amylase was an amyloglucosidase and Bidhi amylase was β-fructose, α(1–4) glucose. Bidhi amylase is a good choice for application in starch, food, detergents and medical industries.

Keywords::

• Saccharose
• glucose
• metal ion
• detergents
• HPLC

Acknowledgments

The authors are grateful to Pr. Ben Ouada Hafed (Directeur de l’Institut Supérieur des Sciences Appliquées et de Technologie de Mahdia) and Pr. Abdelwaheb Fekih (Laboratoire de Chimie, 03/UR/1202, Faculté de Médecine Dentaire, 5000 Monastir, Tunisia) for providing facilities for this work.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.