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Received: 1 December 2014
Received in revised form: 15 January 2015
Accepted: 23 January 2015
Keywords
Pullulanase
Bacillus
Pullulan
Optimization
Abstract
The objective of this study was to isolate, identification the highest pullulanase that produced by Syrian bacteria from different environmental sources such as baking wastes, soil, and food wastes samples, then optimization production of pullulanase. 17 isolates was positive for pullulanase production, The isolate P8 demonstrated the highest extracellular pullulanase activity, it was identified as Bacillus cereus based on Morphological and biochemical experiments. Culture conditions parameters for production enzyme were optimized partial characterization of extracellular pullulanase from Bacillus cereus. The results showed maximum pullulanase production occurred after 48 h, 107 colony frame unit (cfu), at pH 7.5. The optimum temperature for pullulanase production was found to be 37°C in the presence of 1% soluble pullulan as a carbon source and 0.5% tryptone. The activity of pullulanse at this optimal conditions was (1.18 U/ml) which is 2.14 fold higher than before optimization. By characterization of pullulanase, highest activity observed at pH 6.0 and 50°C.
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Introduction
In the recent years the world tends toward using renewable, cheap and readily available materials such as the biomass to produce or convert these materials into useful substances. Utilize the microorganisms by their enzymes are widely used to convert the biomass into target products (Sweeney and Xu, 2012). However many of these processes require high temperature therefore enzymes which are operationally stable at high temperature is essential to complete the task (Vieille and Zeikus, 2001). Thermostable enzymes can be used in different application such as technical enzymes, food enzymes, and animal feed enzymes (Adrio and Demain, 2014). The largest section is technical enzymes where enzymes used for detergents and pulp and paper processing (Li et al., 2012).
One of the candidate of the industrial enzymes is Pullulanase; an important debranching enzyme that has been widely used to hydrolyse the α-1,6 glucosidic in starch, amylopectin, pullulan, and related oligosaccharides (Hii et al., 2012). Several amylolytic enzymes, such as α-amylase, β-amylase and glucoamylase, with different specificities can contribute to starch degradation (Martin and stefan, 2007). These enzymes, all of which hydrolyze α-1,4-glucosidic bonds, are capable of amylose degradation, yielding glucose, maltose, maltotriose, and other oligosaccharides....