Bio-ethanol production by an autochthonous Saccharomyces cerevisiae immobilized in alginate-chitosan complex carrier under furfural tension

Subject Areas : Industrial Microbiology

Mahroo Ahooy Simin ¹ , Azadeh Tofighi ² , Mohammad Hosein-Arash Asadirad ³

1 - M.Sc., Department of Microbiology, Biology Research Center, Zanjan branch, Islamic Azad University, Zanjan, Iran.
2 - Assistant Professor, Department of Microbiology, Biology Research Center, Zanjan branch, Islamic Azad University, Zanjan, Iran.
3 - Assistant Professor, Department of Microbiology, Biology Research Center, Zanjan branch, Islamic Azad University, Zanjan, Iran.

Received: 2017-03-31 Accepted : 2017-06-17 Published : 2017-08-23

Keywords: Chitosan, Alginate, Immobilization, Bio-ethanol, Furfural,

Abstract :

Background & Objectives: One of the major problems in bio-ethanol production is formation of toxic compounds such as furfural and hydroxymethyl furfural from acidic hydrolysis of lignocellulosic materials. Cells immobilization is a useful method for protecting microorganisms against direct physicochemical tensions and reusing them. This study was conducted to assess the effect of alginate-chitosan complex carrier on immobilizing Saccharomyces cerevisiae in order to enhance the yield of ethanol production in the presence of furfural. Methods & Materials: In this study, S. cerevisiae AT-1350 were immobilized in alginate-chitosan complex carrier. Then, 3 g/L of furfural was added to the fermentation medium as the stressor. Glucose consumption was determined using glucose sensing kit. High performance liquid chromatography was used to measure the amount of ethanol production. Results: The results showed that the ethanol yield was decreased 21% by non-immobilized autochthonous yeast, in the medium containing 3 g/L furfural as compared to the control (furfural-free medium). On the other hand, in the presence of furfural, using yeast immobilized in alginate-chitosan complex increased the ethanol yield 6.9% and 14.4% in comparison with yeasts immobilized in alginate and non-immobilized yeasts, respectively. Conclusion: The alginate-chitosan complex can be used as a suitable carrier to immobilize and protect yeast cells against tensions and thusto enhance the ethanol yield obtained from lignocellulosic wastes.