&lt;b&gt;Agave syrup as a substrate for inulinase production by &lt;i&gt;Kluyveromyces marxianus&lt;/i&gt; NRRL Y-7571

Luana Paula De Azevedo De Oliveira,Tiago Felipe Oliveira,Márcia Luciana Cazetta,Jonas Contiero

doi:10.4025/actascibiolsci.v38i3.31489

<b>Agave syrup as a substrate for inulinase production by <i>Kluyveromyces marxianus</i> NRRL Y-7571

Luana Paula De Azevedo De Oliveira, Tiago Felipe Oliveira + Show 2 more

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https://doi.org/10.4025/actascibiolsci.v38i3.31489

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Abstract

The factorial planning was used to plan and optimize inulinase production by the yeast Kluyveromyces marxianus NRRL Y-7571. The experiments were conducted using a Central Composite Design (CCD) 22, at different concentrations of agave syrup (3.6 to 6.4%) and yeast extract (2.2 to 3.0%). After 96 hours of fermentation, the best condition for the inulinase production was 5% agave syrup and 2.5% yeast extract, which yielded an average of 129.21 U mL-1 of inulinase. Partial characterization of the crude enzyme showed that the optimal pH and temperature were 4.0 and 60°C, respectively. The enzyme showed thermal stability at 55°C for 4 hours.

Highlights

Inulinases are 2,1-β-D-fructanfructanohydrolases (EC 3.2.1.7), which act on the 2,1-β-D-fructosidic linkages of inulin
The yeast culture was transferred to a test tube containing 5 mL of pre-inoculum medium composed of the basal medium (%): sucrose, 1.0; MgSO4, 0.07; KH2PO4, 0.5; KCl, 0.12; NH4Cl, 0.15; yeast extract, 0.5; and peptone, 1.0
The results showed that the maximum enzyme production was achieved in run 2, with 5.0% agave syrup and 1.5% yeast extract, after 96 h of fermentation, resulting in a productivity of 118.62 U mL-1

Summary

Introduction

Inulinases are 2,1-β-D-fructanfructanohydrolases (EC 3.2.1.7), which act on the 2,1-β-D-fructosidic linkages of inulin. The application of inulinases in high-fructose syrup production has been investigated for decades (Vandamme & Derycke, 1983; Parekh & Margaritis, 1985; Etallibi & Baratti, 2001). These enzymes have many other applications, such as in the production of fructooligosaccharides, which are fermentable sugars that enhance alcoholic beverages production, such as tequila, and biofuels production from inulin-rich substrates (Chi et al, 2011; Lim et al, 2011; Waleckx et al, 2011; Flores-Gallegos, Morlett-Chávez, Aguilar, & Rodríguez-Herrera, 2012). Besides being considered as GRAS (Generally Recognized as Safe), those yeasts have been described as some of the best producers of inulinase in several fermentative processes (submerged and solid fermentation) with a wide range of substrates (Selvakumar & Pandey, 1999; Silva-Santisteban & Maugeri, 2005; Xiong, Jinhua, & Dongsheng, 2007; Treichel, Mazutti, Maugeri, & Rodrigues, 2009; Neagu & Bahrim, 2011)

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