Presentation Title

Biosynthesis and Structure of Pulcherrimin Pigment and its Intermediate in Yeast Species Kluyveromyces lactis.

Faculty Mentor

Linda Silveira

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

CREVELING 55

Session

POSTER 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

The yeast species Kluyveromyces lactis is known to produce a red pigment when grown under specific conditions. This pigment behaves similarly to pulcherrimin, an iron-binding cyclo-leucine-leucine derivative made by Metschnikowia pulcherrima and Bacillus subtilis. The amino acid scaffold of pulcherrimin in K. lactis was studied through proton nuclear magnetic resonance (H1NMR) of the wildtype strain and the pulcherrimin over-producing mutant. Results showed strong similarities between pulcherrimin and leucine spectra, indicating that the pigment is produced from cyclization of this amino acid.

A strain of K. lactis discovered through random mutagenesis over-produces pulcherrimin in a larger range of conditions than the wildtype, indicating possible overexpression of the genes involved in this biological pathway. Thus, the two overexpressed genes involved in making pulcherrimin were identified. The gene believed to encode a novel cyclic dipeptide synthase (CDPS) enzyme was inserted into yeast species Saccharomyces cerevisiae to create a cyclo-leucine-leucine producing engineered strain. An engineered control was then created through insertion of only a vector, so the only difference between these two engineered strains is the presence or absence of the putative CDPS-encoding gene.

The function of an enzyme involved in cyclizing dipeptides with a sequence distinct from other CDPSs is being studied through two strains of Saccharomyces cerevisiae engineered to synthesize the putative CDPS in the K. lactis mutant. Results have not yet been determined due to inconclusive HPLC results, but the presence of cyclic dipeptides in the engineered S. cerevisiae are expected to be lacking in the vector-only control.

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

Biosynthesis and Structure of Pulcherrimin Pigment and its Intermediate in Yeast Species Kluyveromyces lactis.

CREVELING 55

The yeast species Kluyveromyces lactis is known to produce a red pigment when grown under specific conditions. This pigment behaves similarly to pulcherrimin, an iron-binding cyclo-leucine-leucine derivative made by Metschnikowia pulcherrima and Bacillus subtilis. The amino acid scaffold of pulcherrimin in K. lactis was studied through proton nuclear magnetic resonance (H1NMR) of the wildtype strain and the pulcherrimin over-producing mutant. Results showed strong similarities between pulcherrimin and leucine spectra, indicating that the pigment is produced from cyclization of this amino acid.

A strain of K. lactis discovered through random mutagenesis over-produces pulcherrimin in a larger range of conditions than the wildtype, indicating possible overexpression of the genes involved in this biological pathway. Thus, the two overexpressed genes involved in making pulcherrimin were identified. The gene believed to encode a novel cyclic dipeptide synthase (CDPS) enzyme was inserted into yeast species Saccharomyces cerevisiae to create a cyclo-leucine-leucine producing engineered strain. An engineered control was then created through insertion of only a vector, so the only difference between these two engineered strains is the presence or absence of the putative CDPS-encoding gene.

The function of an enzyme involved in cyclizing dipeptides with a sequence distinct from other CDPSs is being studied through two strains of Saccharomyces cerevisiae engineered to synthesize the putative CDPS in the K. lactis mutant. Results have not yet been determined due to inconclusive HPLC results, but the presence of cyclic dipeptides in the engineered S. cerevisiae are expected to be lacking in the vector-only control.