African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5090

Full Length Research Paper

Efficient production of second generation ethanol and xylitol by yeasts from Amazonian beetles (Coleoptera) and their galleries

Gisele de Fátima Leite Souza*
  • Gisele de Fátima Leite Souza*
  • Institute of Exact Sciences and Technology (ICET), Federal University of Amazonas (UFAM), Itacoatiara, Amazonas, Brazil.
  • Google Scholar
Luana Tainah Campos Nazare Valentim
  • Luana Tainah Campos Nazare Valentim
  • Institute of Exact Sciences and Technology (ICET), Federal University of Amazonas (UFAM), Itacoatiara, Amazonas, Brazil.
  • Google Scholar
Samila Rayana Pinto Nogueira
  • Samila Rayana Pinto Nogueira
  • Institute of Exact Sciences and Technology (ICET), Federal University of Amazonas (UFAM), Itacoatiara, Amazonas, Brazil.
  • Google Scholar
Maxwel Adriano Abegg
  • Maxwel Adriano Abegg
  • Institute of Exact Sciences and Technology (ICET), Federal University of Amazonas (UFAM), Itacoatiara, Amazonas, Brazil.
  • Google Scholar


  •  Received: 11 March 2017
  •  Accepted: 04 May 2017
  •  Published: 28 May 2017

Abstract

Beetles of the Passalidae family live and feed on decaying wood and their guts are richly colonized by yeasts. The goal of this research was to prospect xylolytic yeasts with potential for the production of second-generation bioethanol. Therefore, 83 specimens of beetles belonging to the Passalidae and the Scarabaeidae families were collected in the Amazonian rainforest in Itacoatiara - AM, Brazil. Morphological differences of the beetles were identified and 25 chosen specimens were dissected. Yeasts from galleries inhabited by beetles and from insect guts were isolated. Isolates were previously selected through tolerance tests for temperature, ethanol and xylose assimilation capacity. Those isolates were then submitted to a panel of conditions related to ethanol production. The ethanol production reached 24.70 g.L-1 and the xylitol production reached 21.66 g.L-1. One of the isolates with a promising profile was identified as Spathaspora roraimanensis and six as Spathaspora passalidarum. Three isolates showed to be more promising and, curiously, all came from the gut of the species Popilius marginatus (Percheron, 1835). In plate testing, however, the isolates obtained from galleries showed a greater capacity to assimilate xylose. As reported in this field of study, no isolate tolerated all conditions tested. Wild isolates with this profile may be used for testing larger-scale ethanol production, genetic engineering, or evolutionary techniques.

Key words: Beetles, bioethanol, Popilius marginatus, xylose.