Indonesian Journal of Agricultural Science
Vol 18, No 1 (2017): June 2017

INHIBITION OF THE GROWTH OF TOLERANT YEAST Saccharomyces cerevisiae STRAIN I136 BY A MIXTURE OF SYNTHETIC INHIBITORS

Eny Ida Riyanti (Indonesian Centre Agricultural Biotechnology and Genetic Resources Research and Development Jl. TentaraPelajar No. 3A.Bogor 16111, West Java, Indonesia)
Edy Listanto (Indonesian Centre Agricultural Biotechnology and Genetic Resources Research and Development Jl. TentaraPelajar No. 3A.Bogor 16111, West Java, Indonesia)



Article Info

Publish Date
14 Sep 2017

Abstract

Biomass from lignocellulosic wastes is a potential source for biobased products.  However, one of the constraints in utilization of biomass hydrolysate is the presence of inhibitors. Therefore, the use of inhibitor-tolerant microorganisms in the fermentation is required. The study aimed to investigate the effect of a mixture of inhibitors on the growth of Saccharomyces cerevisiae strain I136 grown in medium containing synthetic inhibitors (acetic acid, formic acid, furfural, 5-hydroxymethyl furfural/5-HMF, and levulinic acid) in four different concentrations with a mixture of carbon sources, glucose  (50 g.l-1) and xylose (50 g.l-1) at 30oC. The parameters related to growth and fermentation products were observed. Results showed that the strain was able to grow in media containing natural inhibitors (BSL medium) with µmax of 0.020/h. Higher level of synthetic inhibitors prolonged the lag phase, decreased the cell biomass and ethanol production, and specific growth rate. The strain could detoxify furfural and 5-HMF and produced the highest ethanol (Y(p/s) of 0.32 g.g-1) when grown in BSL. Glucose was utilized as its level decreased in a result of increase in cell biomass, in contrast to xylose which was not consumed. The highest cell biomass was produced in YNB with Y (x/s) value of 0.25 g.g-1. The strain produced acetic acid as a dominant side product and could convert furfural into a less toxic compound, hydroxyl furfural. This robust tolerant strain provides basic information on resistance mechanism and would be useful for bio-based cell factory using lignocellulosic materials. 

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Journal Info

Abbrev

IJAS

Publisher

Subject

Agriculture, Biological Sciences & Forestry

Description

The journal publishes primary research articles from any source if they make a significant original contribution to the experimental or theoretical understanding of some aspect of agricultural science in Indonesia. The definition of agricultural science is kept as wide as possible to allow the ...