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Nova Petrópolis, Brazil

Campos C.R.,Federal University of Lavras | Silva C.F.,Federal University of Lavras | Dias D.R.,Unilavras Centro Universitario Of Lavras | Basso L.C.,Escola Superior de Agricultura Luiz de Queiroz | And 2 more authors.
Journal of Applied Microbiology | Year: 2010

Aims: To evaluate the dominance and persistence of strains of Saccharomyces cerevisiae during the process of sugar cane fermentation for the production of cachaça and to analyse the microbial compounds produced in each fermentative process. Methods and Results: Three S. cerevisiae strains were evaluated during seven consecutive 24-h fermentation batches using recycled inocula. The UFLA CA 116 strain had the largest population of viable organisms, and the maximum population was achieved in the fourth batch after 96 h of fermentation. The UFLA CA 1162 and UFLA CA 1183 strains grew more slowly, and the maximum population was reached in the seventh batch. Molecular characterization of isolated yeast cells using PFGE (pulse field gel electrophoresis) revealed that more than 86% of the isolates corresponded to the initially inoculated yeast strain. The concentration of aldehydes, esters, methanol, alcohol and volatile acids in the final-aged beverages were within the legal limits. Conclusions: Cachaça produced by select yeast strains exhibits analytical differences. UFLA CA 1162 and UFLA CA 116 S. cerevisiae isolates can be considered the ideal strains for the artisanal production of cachaça in Brazil. Significance and Impact of the Study: The use of select yeast strains can improve the quality and productivity of cachaça production. Our findings are important for the appropriate monitoring of yeast during sugar cane fermentation. In addition, we demonstrate that UFLA CA 116 and UFLA CA 1162, the ideal yeast strains for cachaça production, are maintained at a high population density. The persistence of these yeast strains in the fermentation of sugar cane juice promotes environmental conditions that prevent or decrease bacterial contamination. Thus, the use of select yeast strains for the production of cachaça is a viable economic alternative to standardize the production of this beverage. © 2009 The Society for Applied Microbiology. Source

Amorim H.V.,Fermentec | Lopes M.L.,Fermentec | De Castro Oliveira J.V.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | Buckeridge M.S.,CTBE - Brazilian Bioethanol Science and Technology Laboratory | And 2 more authors.
Applied Microbiology and Biotechnology | Year: 2011

Bioethanol (fuel alcohol) has been produced by industrial alcoholic fermentation processes in Brazil since the beginning of the twentieth century. Currently, 432 mills and distilleries crush about 625 million tons of sugarcane per crop, producing about 27 billion liters of ethanol and 38.7 million tons of sugar. The production of bioethanol from sugarcane represents a major large-scale technology capable of producing biofuel efficiently and economically, providing viable substitutes to gasoline. The combination of immobilization of CO 2 by sugarcane crops by photosynthesis into biomass together with alcoholic fermentation of this biomass has allowed production of a clean and high-quality liquid fuel that contains 93% of the original energy found in sugar. Over the last 30 years, several innovations have been introduced to Brazilian alcohol distilleries resulting in the improvement of plant efficiency and economic competitiveness. Currently, the main scientific challenges are to develop new technologies for bioethanol production from first and second generation feedstocks that exhibit positive energy balances and appropriately meet environmental sustainability criteria. This review focuses on these aspects and provides special emphasis on the selection of new yeast strains, genetic breeding, and recombinant DNA technology, as applied to bioethanol production processes. © 2011 Springer-Verlag. Source

Basso T.O.,Novozymes AS | Gomes F.S.,University of Sao Paulo | Lopes M.L.,Fermentec | De Amorim H.V.,Fermentec | And 2 more authors.
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2014

Bacterial contamination during industrial yeast fermentation has serious economic consequences for fuel ethanol producers. In addition to deviating carbon away from ethanol formation, bacterial cells and their metabolites often have a detrimental effect on yeast fermentative performance. The bacterial contaminants are commonly lactic acid bacteria (LAB), comprising both homo- and heterofermentative strains. We have studied the effects of these two different types of bacteria upon yeast fermentative performance, particularly in connection with sugarcane-based fuel ethanol fermentation process. Homofermentative Lactobacillus plantarum was found to be more detrimental to an industrial yeast strain (Saccharomyces cerevisiae CAT-1), when compared with heterofermentative Lactobacillus fermentum, in terms of reduced yeast viability and ethanol formation, presumably due to the higher titres of lactic acid in the growth medium. These effects were only noticed when bacteria and yeast were inoculated in equal cell numbers. However, when simulating industrial fuel ethanol conditions, as conducted in Brazil where high yeast cell densities and short fermentation time prevail, the heterofermentative strain was more deleterious than the homofermentative type, causing lower ethanol yield and out competing yeast cells during cell recycle. Yeast overproduction of glycerol was noticed only in the presence of the heterofermentative bacterium. Since the heterofermentative bacterium was shown to be more deleterious to yeast cells than the homofermentative strain, we believe our findings could stimulate the search for more strain-specific antimicrobial agents to treat bacterial contaminations during industrial ethanol fermentation. © 2013 Springer Science+Business Media Dordrecht. Source

Amorim H.V.,Fermentec | Gryschek M.,Brasmetano | Lopes M.L.,Fermentec
ACS Symposium Series | Year: 2010

Currently, Brazil has 410 sugar and ethanol plants that crush about 660 million tons of cane per crop, producing about 28.5 billion liters of ethanol and 38.7 million tons of sugar. New sugarcane varieties launched in the last two years are less demanding in water, have high sugar concentration, and are more adaptable to mechanical harvesting. Regarding the sustainability of ethanol production from sugarcane, it is essential to consider the use of the land, reduction of greenhouse gases (GHG), bioelectricity production from bagasse, energy balance of ethanol produced from sugarcane and reduction of vinasse. No other technology available to date has been able to transform the sun's energy and to reduce carbon emissions as efficiently and economically as the production of ethanol from sugarcane and its use as biofuel. This amazing combination of the sun's energy, fixation of CO2 by sugarcane, and the transformation of sugars into a high quality, clean, liquid fuel has made the ethanol industry in Brazil a success as well as an example of sustainability. Copyright. © 2010 American Chemical Society. Source

Borges E.P.,Fermentec | Lopes M.L.,Fermentec | Amorim H.,Fermentec
International Sugar Journal | Year: 2012

It is well known that sugar cane composition affects clarification, sugar recovery, and quality. However, not so well known are the levels of such variables in clarification and VHP sugar that affect quality. This research was performed in a sugar and ethanol plant in Brazil which crushes 4 million tons of cane per season (25,000 tons per day). Fifty four samples were collected in first extraction juice, limed juice and clarified juice during several weeks and also samples of the VHP sugar, were analyzed. The samples were analyzed for the concentration of sucrose, glucose, fructose, lactic acid, acetic acid, dextran, minerals, insoluble impurities, turbidity and color. Positive correlations were found between phosphorus and clarification efficiency and VHP sugar quality. Lactic and acetic acids, as well as glucose and fructose in juice, correlated negatively with sugar quality (increased color). Iron concentration correlated with color of the clarified juice as it may contribute to the oxidation of polyphenols compounds and catalyzes the alkaline destruction of glucose and fructose. Dextran interfered in clarification and in sugar quality, due to positive correlation with clarified juice and VHP sugar color. Finally, it was observed that the interpretation Honig-Bogstra ratio can be affected by microbial contamination. Having better knowledge about the variables that affect clarification and sugar quality makes it possible to improve the process. Source

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