Screening and partial purification of amylase from Aspergillus Niger isolated from deteriorated tomato ( Lycopersicon Esculentum mill.) fruits

Amylases (EC 3.2.1.1) are cellwall degrading enzymes associated with the pathogenicity of microorganisms in the spoilage of tomato fruits. The use of amylase in many industries has made it very important to optimize production process to achieve maximum yields. Screening and partial purification of Amylase from Aspergillus niger isolated from tomato ( Lycopersicon esculentum Mill.) fruits was studied. Amylase producing fungi were isolated from fresh tomatoes kept at ambient temperature (28±1˚C). Isolates were characterized on the basis of their morphological and cultural techniques. Partial purification of amylase was carried out by ammonium sulphate precipitation. The enzyme activity was determined and optimum conditions were obtained. The molecular weights of the crude and partially purified Amylase were determined by SDS PAGE method. A total of five isolates were obtained using basic screening technique for amylase activity, one of the isolates (Isolate code F2) exhibited maximum amylase activity. The fungi isolate code F2 was identified as Aspergillus niger . Optimum conditions for Amylase AMY F2 were ascertained at pH 6.0; temperature 30°C; substrate concentration of 0.3mg/ml, and time of heating of less than 10min. The molecular weights  f the crude and partially purified Amylase AMY F2 were found to be 55kDa and 35kDa respectively by SDS PAGE method. Microorganisms had been an encouraging means of economical production of enzymes in large scale for the food and drug industry.  Keywords: Amylase, Partial Purification, Enzyme, Tomato Fruits Rendement et purification partielle de l'amylase de A spergillus Niger isole a partir de tomate deteriore ( L ycopersicon Esculentum mill.) fruits Les amylases (EC 3.2.1.1) sont des enzymes degradant les parois cellulaires associees a la pathogenicite des microorganismes dans la deterioration des fruits a la tomate. L'utilisation de l'amylase dans de nombreuses industries a rendu tres important d'optimiser le processus de production pour obtenir des rendements maximaux. Le depistage et la purification partielle de l'amylase d'Aspergillus niger isoles a partir des fruits a la tomate ( Lycopersicon esculentum Mill.) Ont ete etudies. Les champignons producteurs d'amylase ont ete isoles a partir de tomates fraiches conservees a temperature ambiante (28 ± 1 ° C). Les isolats ont ete caracterises en fonction de leurs techniques morphologiques et culturelles. La purification partielle de l'amylase a ete realisee par precipitation au sulfate d'ammonium. L'activite enzymatique a ete determinee et des conditions optimales ont ete obtenues. Les poids moleculaires de l'Amylase brut et partiellement purifiee ont ete determines par un procede SDS PAGE. Au total, cinq isolats ont ete obtenus en utilisant une technique de depistage basique pour l'activite amylase, l'un des isolats (code isole F2) presentait une activite amylase maximale. Le code isolant F2 des Fusions a ete identifie comme Aspergillus niger . Les conditions optimales pour Amylase AMY F2 ont ete determinees a pH 6,0; temperature 30 ° C; concentration de substrat de 0,3 mg / ml et temps de chauffage de moins de 10 min. On a trouve que les poids moleculaires de l'amylase brute et partiellement purifiee etaient respectivement de 55 kDa et 35 kDa par le procede SDS PAGE. Les microorganismes ont ete un moyen encourageant de production economique d'enzymes a grande echelle pour l'industrie alimentaire et pharmaceutique. Mots-cles: Amylase, Purification partielle, Enzyme, Fruits tomates