Time filter

Source Type

Piracicaba, Brazil

Lunelli B.H.,Laboratory of Optimization | Andrade R.R.,Laboratory of Optimization | Atala D.I.P.,Sugarcane Technology Center | MacIel M.R.W.,Laboratory of Optimization | And 2 more authors.
Applied Biochemistry and Biotechnology | Year: 2010

Lactic acid is an important product arising from the anaerobic fermentation of sugars. It is used in the pharmaceutical, cosmetic, chemical, and food industries as well as for biodegradable polymer and green solvent production. In this work, several bacterial strains were isolated from industrial ethanol fermentation, and the most efficient strain for lactic acid production was selected. The fermentation was conducted in a batch system under anaerobic conditions for 50 h at a temperature of 34 °C, a pH value of 5.0, and an initial sucrose concentration of 12 g/L using diluted sugarcane molasses. Throughout the process, pulses of molasses were added in order to avoid the cell growth inhibition due to high sugar concentration as well as increased lactic acid concentrations. At the end of the fermentation, about 90% of sucrose was consumed to produce lactic acid and cells. A kinetic model has been developed to simulate the batch lactic acid fermentation results. The data obtained from the fermentation were used for determining the kinetic parameters of the model. The developed model for lactic acid production, growth cell, and sugar consumption simulates the experimental data well. © Humana Press 2009. Source

Junior A.M.,Food Technology Institute ITAL | De A. Vitali A.,Food Technology Institute ITAL | Berteli M.N.,Food Technology Institute ITAL | Berto M.I.,Food Technology Institute ITAL | And 2 more authors.
Microwave and RF Power Applications: Proceeding of the 13th International Conference on Microwave and Radio Frequency Heating, AMPERE 2011 | Year: 2011

Normally the sugarcane must used in fermentation processes carries heavy microbiological loads made up of bacteria and wild yeasts. When harvest season starts, the selected bacteria with excellent fermentation potential are rapidly substituted by the wild yeasts, decreasing process performance. Pasteurizing the must by microwaves before the fermentation process is an efficient alternative, easily adaptable to the present Brazilian ethanol plants. The dimension of the heat treatment depends on lethality parameters (D and Z) of the target microorganism. This study presents preliminary results from the determination of D and Z of a selected lineage of S. cerevisiae which were used to suggest time/temperature of the pasteurization process by using microwave energy, which can be applied to the must in order to achieve a better process performance. Source

Neves P.V.,Federal University of Parana | Pitarelo A.P.,Federal University of Parana | Pitarelo A.P.,Sugarcane Technology Center | Ramos L.P.,Federal University of Parana
Bioresource Technology | Year: 2016

The production of cellulosic ethanol was carried out using samples of native (NCB) and ethanol-extracted (EECB) sugarcane bagasse. Autohydrolysis (AH) exhibited the best glucose recovery from both samples, compared to the use of both H3PO4 and H2SO4 catalysis at the same pretreatment time and temperature. All water-insoluble steam-exploded materials (SEB-WI) resulted in high glucose yields by enzymatic hydrolysis. SHF (separate hydrolysis and fermentation) gave ethanol yields higher than those obtained by SSF (simultaneous hydrolysis and fermentation) and pSSF (pre-hydrolysis followed by SSF). For instance, AH gave 25, 18 and 16 g L-1 of ethanol by SHF, SSF and pSSF, respectively. However, when the total processing time was taken into account, pSSF provided the best overall ethanol volumetric productivity of 0.58 g L-1 h-1. Also, the removal of ethanol-extractable materials from cane bagasse had no influence on the cellulosic ethanol production of SEB-WI, regardless of the fermentation strategy used for conversion. © 2016 Elsevier Ltd. Source

Duarte C.L.,Brazilian Nuclear Energy Research Institute (IPEN) | Ribeiro M.A.,Brazilian Nuclear Energy Research Institute (IPEN) | Oikawa H.,Brazilian Nuclear Energy Research Institute (IPEN) | Mori M.N.,Brazilian Nuclear Energy Research Institute (IPEN) | And 2 more authors.
Radiation Physics and Chemistry | Year: 2012

The use of microbial cellulolytic enzymes is the most efficient process to liberate glucose from cellulose in biomass without the formation of fermentation inhibitors. A combination of pretreatment technologies is an alternative way to increase the access of enzymes to cellulose, and consequently, the conversion yield. In this way, the present study reports on the enzymatic hydrolysis of SCB submitted to three kinds of pretreatment: electron beam processing (EBP), and EBP followed by hydrothermal (TH) and diluted acid (AH) treatment. SCB samples were irradiated using a radiation dynamics electron beam accelerator, and then submitted to thermal and acid (0.1% sulfuric acid) hydrolysis for 40 and 60. min at 180 °C. These samples were submitted to enzymatic hydrolysis (EH) using commercial preparations, including Celluclast 1.5. L and beta-glycosidase. The addition of diluted acid improved TH treatment allowing for a shorter application time. EBP with 50. kGy increased the enzymatic hydrolysis yield of cellulose by 20% after TH and 30% after AH. © 2011 Elsevier Ltd. Source

Marin F.R.,Embrapa Agriculture Informatics | Jones J.W.,University of Florida | Royce F.,University of Florida | Suguitani C.,Sugarcane Technology Center | And 3 more authors.
Agronomy Journal | Year: 2011

The DSSAT/CANEGRO model was parameterized and its predictions evaluated using data from fi ve sugarcane (Saccharum spp.) experiments conducted in southern Brazil. The data used are from two of the most important Brazilian cultivars. Some parameters whose values were either directly measured or considered to be well known were not adjusted. Ten of the 20 parameters were optimized using a Generalized Likelihood Uncertainty Estimation (GLUE) algorithm using the leave-one-out cross-validation technique. Model predictions were evaluated using measured data of leaf area index (LAI), stalk and aerial dry mass, sucrose content, and soil water content, using bias, root mean squared error (RMSE), modeling efficiency (Eff), correlation coefficient, and agreement index. The Decision Support System for Agrotechnology Transfer (DSSAT)/CANEGRO model simulated the sugarcane crop in southern Brazil well, using the parameterization reported here. The soil water content predictions were better for rainfed (mean RMSE = 0.122mm) than for irrigated treatment (mean RMSE = 0.214mm). Predictions were best for aerial dry mass (Eff = 0.850), followed by stalk dry mass (Eff = 0.765) and then sucrose mass (Eff = 0.170). Number of green leaves showed the worst fit (Eff = -2.300).The cross-validation technique permits using multiple datasets that would have limited use if used independently because of the heterogeneity of measures and measurement strategies. © 2011 by the American Society of Agronomy. Source

Discover hidden collaborations