Identificarion of contaminant bacteria in cachaça yeast by 16s rDNA gene sequencing

Abstract

Cachaça is a typical Brazilian liquor produced from the distillation of fermented sugarcane juice mainly by Saccharomyces cerevisiae. Most of the domestic production is artisanal, and producers usually are not concerned regarding microbiological control of the fermentation. This study aimed to characterize the contaminant bacterial community of the yeast used in the production of cachaça in an artisanal still. Four samples were collected, of which one (NA) was used for comparison purposes and was collected one year earlier. The remaining samples were collected at three different periods: at the end of the first day of fermentation (NP), after fifteen days (NS), and thirty days after the same yeast was used (NT). Five hundred and eighty-seven sequences were analyzed from the partial sequencing of the 16S rDNA gene. Sequence analyses revealed the presence of 170 operational taxonomic units (OTUs). Of these, only one was shared among three samples and seventeen were shared between two samples. The remaining 152 OTUs were identified only once in distinct samples indicating that the contaminant bacterial population is highly dynamic along the fermentation process. Statistical analyses revealed differences in bacterial composition among samples. Undescribed species in the literature on yeasts of cachaça were found, such as Weissella cibaria, Leuconostoc citreum, and some species of Lactobacillus, in addition to some unknown bacteria. The community of bacteria in the fermentation process is much more complex than it was previously considered. No previous report is known regarding the use of this technique to determine bacterial contaminants in yeast for the production of cachaça. Key words: aguardente, alcoholic fermentation, genetic characterization, pé-de-cuba IDENTIFICAÇÃO DE BACTÉRIAS CONTAMINANTES DE FERMENTO DE CACHAÇA POR SEQÜENCIAMENTO DO GENE 16S RDNARESUMO: A cachaça é uma bebida típica brasileira produzida a partir da destilação do caldo de cana-de-açúcar fermentado principalmente por Saccharomyces cerevisiae. Grande parte da produção nacional é artesanal, e não há uma preocupação por parte dos produtores quanto ao controle microbiológico da fermentação. Este trabalho objetivou caracterizar a comunidade bacteriana contaminante do fermento utilizado na produção de cachaça em um alambique artesanal. Foram coletadas quatro amostras, sendo uma (NA) utilizada como efeito comparativo e coletada um ano anterior às demais. As restantes foram coletadas em três diferentes períodos: ao final do primeiro dia de fermentação (NP), após quinze dias (NS) e trinta dias após a utilização do mesmo fermento (NT). Foram analisadas, a partir do seqüenciamento parcial do gene 16S rDNA, 587 seqüências. As análises das seqüências revelaram a presença de 170 unidades taxonômicas operacionais. Destas, 152 foram identificadas uma única vez em diferentes amostras, dezessete foram comuns em pelo menos duas amostras e somente uma foi identificada em três amostras, evidenciando uma grande dinâmica populacional bacteriana durante ...

Bacteriophages as antimicrobial agents against bacterial contaminants in yeast fermentation processes

“…Undoubtedly, more research is needed to address these points fully, but a few insights can be considered currently. 1) Although the variety of contaminants in ethanol fermentation is extensive, it is important to note that the investigations conducted on the identification of these bacteria had a significant number of species in common [10][11][12][13][14]. Moreover, the majority of these contaminants are LAB, hence it can be expected that a single cocktail of phages developed against several LAB species would be effective in a variety of industries in different locations.…”

“…The majority of contaminants found in industrial plants are lactic acid bacteria (LAB) [10][11][12][13][14]. These are aero-tolerant anaerobic, Gram-positive bacteria that can be further divided into two groups -homofermenters and heterofermenters -depending on their products of glucose metabolism [15][16][17].…”

Effect of Co‐Inoculation of Saccharomyces cerevisiae and Lactobacillus fermentum on the Quality of the Distilled Sugar Cane Beverage Cachaça

“…In some beverages, such as wine (Ribéreau‐Gayon and others 2006) and sorghum beers (Sawadogo‐Lingani and others 2008), bacteria are used to improve sensory qualities because these microorganisms produce secondary compounds that influence the flavor of the beverage. Among the bacteria found in the fermentation mixture during cachaça production, the genus Lactobacillus is the most common throughout fermentation (Carvalho‐Netto and others 2008; Gomes and others 2010). The obligatory heterofermentative Lactobacillus fermentum (Klein and others 1998) is a lactic acid bacterium that is found in the sugar cane juice fermentation medium for cachaça (Gomes and others 2010) and bioethanol production (Oliveira‐Freguglia and Horii 1998).…”

Caracterização bioquímica e molecular de linhagens de Saccharomyces cerevisiae isoladas de fermentações artesanais de caldo de cana e melado para a produção de cachaça em Florianópolis-SC

“…A presença de bactérias durante o processo de fermentação para a produção de cachaça já foi mostrada por outros autores (SChwAN et al, 2001;CARVALhO-NETTO et al, 2008). É importante mencionar que altas concentrações de leveduras não-Saccharomyces e de bactérias, como encontrado na amostra A (Figura 2), podem prejudicar o andamento da fermentação e ocasionar a formação de compostos indesejáveis, que alteram o sabor da cachaça.…”