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AMB Express. 2018 Feb 16;8(1):23. doi: 10.1186/s13568-018-0556-9.

Effects of feedstock and co-culture of Lactobacillus fermentum and wild Saccharomyces cerevisiae strain during fuel ethanol fermentation by the industrial yeast strain PE-2.

AMB Express

Vanda R Reis, Ana Paula G Bassi, Bianca C Cerri, Amanda R Almeida, Isis G B Carvalho, Reinaldo G Bastos, Sandra R Ceccato-Antonini

Affiliations

  1. Dept Tecnologia Agroindustrial e Socio-Economia Rural, Universidade Federal de São Carlos-Centro de Ciencias Agrarias, Via Anhanguera, km 174, Araras, SP, 13600-970, Brazil.
  2. Dept Tecnologia Agroindustrial e Socio-Economia Rural, Universidade Federal de São Carlos-Centro de Ciencias Agrarias, Via Anhanguera, km 174, Araras, SP, 13600-970, Brazil. [email protected].

PMID: 29453625 PMCID: PMC5815976 DOI: 10.1186/s13568-018-0556-9

Abstract

Even though contamination by bacteria and wild yeasts are frequently observed during fuel ethanol fermentation, our knowledge regarding the effects of both contaminants together is very limited, especially considering that the must composition can vary from exclusively sugarcane juice to a mixture of molasses and juice, affecting the microbial development. Here we studied the effects of the feedstock (sugarcane juice and molasses) and the co-culture of Lactobacillus fermentum and a wild Saccharomyces cerevisiae strain (rough colony and pseudohyphae) in single and multiple-batch fermentation trials with an industrial strain of S. cerevisiae (PE-2) as starter yeast. The results indicate that in multiple-cycle batch system, the feedstock had a minor impact on the fermentation than in single-cycle batch system, however the rough yeast contamination was more harmful than the bacterial contamination in multiple-cycle batch fermentation. The inoculation of both contaminants did not potentiate the detrimental effect in any substrate. The residual sugar concentration in the fermented broth had a higher concentration of fructose than glucose for all fermentations, but in the presence of the rough yeast, the discrepancy between fructose and glucose concentrations were markedly higher, especially in molasses. The biggest problem associated with incomplete fermentation seemed to be the lower consumption rate of sugar and the reduced fructose preference of the rough yeast rather than the lower invertase activity. Lower ethanol production, acetate production and higher residual sugar concentration are characteristics strongly associated with the rough yeast strain and they were not potentiated with the inoculation of L. fermentum.

Keywords: Bacterium; Ethanol; Feedstock; Fermentation; Sugars; Wild yeasts

References

  1. J Ind Microbiol Biotechnol. 2012 Nov;39(11):1645-50 - PubMed
  2. Appl Environ Microbiol. 2007 Jul;73(13):4354-6 - PubMed
  3. Antonie Van Leeuwenhoek. 2014 Mar;105(3):481-9 - PubMed
  4. Int J Food Microbiol. 2009 Sep 15;134(3):237-43 - PubMed
  5. Microb Cell Fact. 2015 Jan 30;14:13 - PubMed
  6. Lett Appl Microbiol. 2018 Jan;66(1):77-85 - PubMed
  7. Braz J Microbiol. 2014 Mar 10;44(4):1121-31 - PubMed
  8. Nat Commun. 2015 Jan 20;6:6102 - PubMed
  9. FEMS Yeast Res. 2004 May;4(7):683-9 - PubMed
  10. Cell. 1982 Jan;28(1):145-54 - PubMed
  11. J Appl Microbiol. 2007 Feb;102(2):538-47 - PubMed
  12. Braz J Microbiol. 2016 Dec;47 Suppl 1:64-76 - PubMed
  13. Appl Environ Microbiol. 1999 Jan;65(1):143-9 - PubMed
  14. J Appl Microbiol. 2011 Jan;110(1):1-18 - PubMed
  15. Antonie Van Leeuwenhoek. 1983 Sep;49(3):209-24 - PubMed
  16. Yeast. 2013 Aug;30(8):295-305 - PubMed
  17. FEMS Yeast Res. 2008 Nov;8(7):1155-63 - PubMed
  18. J Biosci Bioeng. 2013 Jan;115(1):43-9 - PubMed
  19. Antonie Van Leeuwenhoek. 2014 Jan;105(1):169-77 - PubMed
  20. Anal Biochem. 1996 Jun 15;238(1):26-8 - PubMed
  21. Antonie Van Leeuwenhoek. 2012 Mar;101(3):529-39 - PubMed
  22. Biotechnol Appl Biochem. 2014 Jan-Feb;61(1):40-4 - PubMed
  23. BMC Microbiol. 2010 Nov 23;10:298 - PubMed

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