Production of inulinase from Rhizopusoryzae by solid state fermentation

Qays M Issa,Muna H Al-Joburi,Abdul-Kareem J Hashim

doi:10.24126/jobrc.2014.8.4.382

Abstract

Fifty Rhizopus spp. isolates were obtained from local natural habitat. The ability of inulinase production by these isolates was screened. The isolate RC-2 which isolated from composite plants was the highest inulinase producer on modified Czapek-Dox agar in primary screening. Secondary screening revealed that the same isolate was the highest production on Nakamura broth medium. Isolate was identified as Rhizopusoryzae. Measurements of reducing sugars in crude filtrate which represent the products of enzyme revealed that Rhizopusoryzae RC-2 produced inulinaseextracellular. The optimum culture conditions for inulinase production by solid state fermentation included a mixture of Jerusalem artichoke Helianthus tuberosus tuber with sugarcane Saccharum sp. bagasse with a ratio (1:1) as carbon source, 2.5% of corn steep liquor as nitrogen source, moisturizing ratio (3:1) (v:w) with tap water, the best inoculums rate was 2.5×105 spore/ml and incubation at (30)ºC for 4 days.

Highlights

Microbial inulinases belong to an important class of industrial enzymes that have gained increasing attention in the recent years [1]
Effect of different inulin-containing plants and agro-waste as carbon sources on inulinase production: All the substrates which have been used as carbon source able to support the growth and stimulate the production of inulinase by Rhizopusoryzaestrain RC-2
In current study high level of inulinase production occurs in Jerusalem artichoke tuber in combination with sugar cane bagasse at ratio 1:1 (W/W) with specific activity (18.89 U/mg), while low level of inulinase production has been recovered in Banana peel (2.76 U/mg)

Summary

Introduction

Microbial inulinases belong to an important class of industrial enzymes that have gained increasing attention in the recent years [1]. A number of filamentous fungi, yeast and bacterial strains have been reported for the production of inulinase, which were usually inducible and extracellular [3]. Few studies on the production of inulinase by solid state fermentation (SSF) have been recently reported [5]. This system offers numerous advantages over submerged fermentation system, including production of bulk chemicals and enzymes, high volumetric productivity, relatively higher concentration of products, etc. The ability of fungi to produce inulinase has not been locally studied yet in sufficient manner, so this study aimed to produce of inulinase at high level from local isolates of fungi

Objectives

Methods

Results