STRESS TOLERANCE YEAST STRAIN FROM PAPAYA WASTES FOR BIOETHANOL PRODUCTION

Authors

  • Gemilang Lara Utama
  • Tyagita
  • Ita Krissanti
  • Dwi Wahyudha Wira
  • Roostita L. Balia

Keywords:

Ethanol, Stress tolerance, Papaya wastes, Yeasts

Abstract

Papaya wastes is naturally fermented and potentially overgrown by microorganisms such yeasts.
The research aims to determine the presence of ethanol-fermenting yeasts on papaya wastes which has the
ability to tolerate high glucose and ethanol contents. Yeasts isolated from papaya wastes with using Potato
Dextrose Agar/PDA which modified with 3% yeast extract/YE and 10 ppm Amoxicillin, then incubated for
48h at room temperature. The isolates were identified macroscopic and microscopically then the yeast-like
isolates cultured on Nutrient Broth/NB with the addition of 3% YE, 10 ppm Amoxicillin and 30% glucose or
alcohol to be tested for the tolerance ability towards high glucose and alcohol. Yeasts presence on high glucose
and alcohol media was determine by UV-Vis spectrophotometer by measuring optical density (OD) for UV
absorbance at λ=600nm. The isolate with highest OD at glucose and alcohol media grown at papaya wastes
for 72h and the ethanol contents measured by chromium dichromate oxidation methods every 24h. Species
identification performed using sequence analysis of the rRNA gene internal transcribed spacer (ITS) region
with using primers ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-
TCCTCCGCTTATTGATATGC-3′), the sequences compared with the GenBank database using Basic Local
Alignment Search Tools/BLAST algorithm. The results showed that three yeast-like isolates found from
papaya wastes, with Y1 isolate identified as best isolate with the OD of 0.4699 at 30% glucose media and OD
of 0.0960 at 30% alcohol media, with the highest ethanol fermented at 48h was 4.34%. The rate of isolate
identification by sequence analysis resulted 96.20% (531/552) identical with Pichia sp. strain AQGWD 7.

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Published

2018-12-30

How to Cite

Gemilang Lara Utama, Tyagita, Ita Krissanti, Dwi Wahyudha Wira, & Roostita L. Balia. (2018). STRESS TOLERANCE YEAST STRAIN FROM PAPAYA WASTES FOR BIOETHANOL PRODUCTION. GEOMATE Journal, 17(61), 97–103. Retrieved from https://geomatejournal.com/geomate/article/view/2134