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Production of inulinase from Kluyveromyces marxianus using Dahlia tuber extractDOI: 10.1590/S1517-83822012000100007 Keywords: inulinase, dahlia, fructose, kluyveromyces marxianus. Abstract: various carbon sources were evaluated for production of inulinase by yeast, kluyveromyces marxianus mtcc 3995. highest inulinase activity was observed with dahlia extract (25.3 nkat ml-1) as carbon source. the enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat ml-1). the yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°c and 120 rpm. lowest inulinase yield (4.8 nkat ml-1) was seen in the medium containing glucose as c-source. although varied inulinase levels were noticed on different c- sources, inulinase: sucrase (i/s) ratios were noticed to be similar. among various protein sources tested, yeast extract was found to be the best source followed by beef extract (17.9 nkat ml-1) and peptone (13.8 nkat ml-1). the enzyme was optimally active at ph (4.0) and 50°c. tlc analysis of end product revealed that inulinase hydrolyzed inulin exclusively into fructose. results suggest that the dahlia extract induced exoinulinase synthesis in kluyveromyces marxianus and can be utilized as a potential substrate for inulinase production.
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