BioChem - DOS

Saccharomyces cerevisiae transcriptional reprograming due to bacterial contamination during industrial scale bioethanol production

Microbial cell factories

Carvalho-Netto, Osmar V; Carazzolle, Marcelo F; Mofatto, Luciana S; Teixeira, Paulo JPL; Noronha, Melline F; Calderó n, Luige AL; Mieczkowski, Piotr A; Argueso, Juan Lucas; Pereira, Gonç alo AG

<P><B>Background</B></P><P>The bioethanol production system used in Brazil is based on the fermentation of sucrose from sugarcane feedstock by highly adapted strains of the yeast <I>Saccharomyces cerevisiae</I>. Bacterial contaminants present in the distillery environment often produce yeast-bacteria cellular co-aggregation particles that resemble yeast-yeast cell adhesion (flocculation). The formation of such particles is undesirable because it slows the fermentation kinetics and reduces the overall bioethanol yield.</P><P><B>Results</B></P><P>In this study, we investigated the molecular physiology of one of the main <I>S. cerevisiae</I> strains used in Brazilian bioethanol production, PE-2, under two contrasting conditions: typical fermentation, when most yeast cells are in suspension, and co-aggregated fermentation. The transcriptional profile of PE-2 was assessed by RNA-seq during industrial scale fed-batch fermentation. Comparative analysis between the two conditions revealed transcriptional profiles that were differentiated primarily by a deep gene repression in the co-aggregated samples. The data also indicated that <I>Lactobacillus fermentum</I> was likely the main bacterial species responsible for cellular co-aggregation and for the high levels of organic acids detected in the samples.</P><P><B>Conclusions</B></P><P>Here, we report the high-resolution gene expression profiling of strain PE-2 during industrial-scale fermentations and the transcriptional reprograming observed under co-aggregation conditions. This dataset constitutes an important resource that can provide support for further development of this key yeast biocatalyst.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s12934-015-0196-6) contains supplementary material, which is available to authorized users.</P>

2015

BioMed Central

cc-by

1475-2859

14

pp.13

10.1186/s12934-015-0196-6

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART74015853

https://microbialcellfactories.biomedcentral.com/counter/pdf/10.1186/s12934-015-0196-6

Saccharomyces cerevisiae; Bioethanol; Co-aggregation; Transcriptome; RNA-seq