Abstract The objective of this study was to optimize the composition of the fermentation medium through a Central Composite Rotational Design (CCRD) for the production of L (+)- latic acid (LA) using Lactobacillus rhamnosus ATCC 9595 and potato, corn steep liquor (CSL) and calcium carbonate as raw materials. A CCRD with three independent variables (potato flour (PF), CSL and CaCO3 concentrations) was performed for a total of 17 treatments. Kinetic studies were conducted, and samples were taken at time intervals of 0 to 72 h. Cell count, pH, reducing sugars and LA concentrations were determined. LA productivity and yield, sugar consumption and cell growth factor were calculated. The highest concentration of LA was 183.8 g/L, with 2.553 g/L.h productivity, 94.2% yield and 96.1 % sugar consumption.

The objective of the present study was to analyze the use of vinasse from cachaça as an ingredient of the fermentation medium for the spirit production. The fermentations were conducted out in three successive batches using a Saccharomyces cerevisiae isolate. In the first batch, the sugarcane broth was only diluted with distilled water. In the second and third batches, the fermentations were carried out using the cane broth diluted with vinasse from the distillation of the sugarcane wines of the first and second batches, respectively at a concentration of 10% (v/v). The spirits were submitted to the physicochemical and sensorial analyses. The results showed that vinasse addition did not affect the fermentation, distillation and chemical-sensorial quality of the beverage. Therefore, the vinasse addition could be an alternative use for that residue.

Foram isoladas leveduras prevalescentes de dois alambiques, em Betim e Rio Manso/MG, por meio de plaqueamento (WLN) e caracterizadas segundo a macromorfologia de colônias, após 8 dias de incubação a 32ºC. A amostra de Rio Manso apresentou 4 linhagens dominantes, com concentrações entre 2,0 x 10(7) e 4,0 x 10(5) UFC/mL. No alambique de Betim foram isoladas três linhagens dominantes, com contagens entre 1,3 x 10(8) e 2,0 x 10(4) UFC/mL. Foram determinados a velocidade específica máxima de crescimento (µmax) e o fator de conversão de substrato em biomassa (Yx/s) para dois isolados. Os valores de μmax foram 0,24 e 0,4 h-1, sendo que a linhagem RM01 apresentou maior valor. Para Yx/s, os resultados obtidos pelas linhagens RM01 e CV01 foram 0,179 e 0,185 g.g-1, respectivamente. Verificou-se uma semelhança nos resultados entre as linhagens RM01 e CV01. Concluiu-se que, do ponto de vista de μmax e de Yx/s, a melhor linhagem para produção de cachaça é a RM01.

Predominant yeasts of two cachaça distilleries were isolated in the cities of Betim and Rio Manso, in the State of Minas Gerais and characterized using WLN agar, according to colony morphology, after 8 days of imcubation at 32ºC. The sample from Rio Manso presented 4 dominant yeasts with concentrations between 2.0 x 10(7) and 4.0 x 10(5) CFU/mL. At Betim distillery, three dominant yeasts were isolated with cell density between 1.3 x 10(8) and 2.0 x 10(4) CFU/mL. The values of the maximum specific velocity for growth (µmax) and the conversion factor for substrate into cells (Yx/s) were determined for two isolates. The μmax values were 0.24 and 0.4 h-1, being RM01 strain the one with the highest value. Regarding to Yx/s, the results obtained by strains RM01 and CV01 were 0.179 and 0.185 g.g-1, respectively. Resemblances of results were observed between strains RM01 and CV01. It was concluded that, as far as μmax and Yx/s are concerned, the best strain to produce cachaça is RM01.