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


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 Fe(2+) or 10(-2) mM Cu(2+), and was strongly inhibited by Mg(2+) and EDTA. In the presence of Ca(2+) and Mg(2+), 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.


CONCLUSIONS
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.
Laboratoire de Génétique, Biodiversité et Valorisation des Bio ressources (UR 03ES09), Institut Supérieur de Biotechnologie, Monastir, Tunisia. ibrahimhoudarf@yahoo.fr
Houda Lazreg
HL
Aref
Habib
H
Mosbah
Hanen
H
Louati
Khaled
K
Said
Boulbaba
B
Selmi
D000681:Amylases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003902:Detergents / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D030681:Ficus / Q000201:enzymology*; D005638:Fruit; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007477:Ions; D007700:Kinetics; D007840:Latex / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D010946:Plants, Medicinal; D013213:Starch / Q000378:metabolism; D013696:Temperature; D014416:Tunisia
D003902:Detergents; D004791:Enzyme Inhibitors; D007477:Ions; D007840:Latex; D008670:Metals; D010940:Plant Proteins; D013213:Starch; D000681:Amylases