Ethyl methanesulfonate (EMS)- induced mutagenesis and genome shuffling for the improvement of thermotolerance, ethanol tolerance and ethanol productivity of Saccharomyces cerevisiae 2013.

Date

4-2012

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Ivan Marcelo A. Duka

Co-adviser

Jessica F. Simbahan

Restrictions

Restricted: Not available to the general public and to those bound by the confidentiality agreement. Access is available only after consultation with author/thesis adviser.

Abstract

OROSCO, FREDMOORE L. 2012. Ethyl Methanesulfonate (EMS)-lnduced Mutagenesis and Genome Shuffling for the Improvement of Ethanol Tolerance, Thermotolerance and Ethanol Productivity of Saccharomyces cerevisiae 2013. University of the Philippines Los Banos B. S. Biology Major in Cell and Molecular Biology.

Adviser: Prof Ivan Marcelo A. Duka Co-Adviser: Dr. Jessica F. Simbahan ABSTRACT

Ethyl methanesulfonate-induced mutagenesis and genome shuffling was performed to develop superior strains of Saccharomyces cerevisiae 2013 with improved ethanol tolerance, thermotolerance and ethanol productivity. The condition for isolating protoplasts of S. cerevisiae 2013 was optimized. The use of 0.10 mg/mL zymolyase 100T led to 96% yield of protoplasts after 120 minutes of incubation at 37 °C. Media supplied with 0.8 M sorbitol was proven to have higher efficiency in regenerating protoplasts. There were 12 promising strains obtained after mutagenesis and two rounds of genome shuffling. All these mutant and genome-shuffled strains exhibited higher ethanol yield compared to the parental strain at 42 °C. This might be correlated to the presence of heat shock proteins which were detected in all the genome-shuffled strains. All isolates were able to grow at 15% ethanol to 20% ethanol in the medium. This ability might be correlated to increased level of trehalose present among the mutants. lnvertase activity was not correlated to the rate of ethanol yield. It was also found out that cell size has no correlation with the increase in cell area after protoplast fusion. Based on the results of DNA microsatellite fingerprinting, all the genome-shuffled strains exhibited distinct banding patterns of GTG-primed PCR products which proved that the mutants have undergone genome shuffling. The FlD was found to be the most promising isolate with higher ethanol yield by 7.40% at 42 °C compared to the parental strain.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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