L-leucine, may affect the production of the drug by assuming one or more roles such as precursor, inducer and/or developmental regulator. Some amino acids are believed to act as inducers that must be added in the exponential growth phase in order to enhance secondary-metabolite produc- tion by directing cell development towards the transcription of the genes concerned, a process that occurs during vegetative cell growth. Previ- ous studies have reported that the addition of L- valine and L-leucine could obviously promote the biosynthesis of cyclosporin A (Lee and Agathos 1989). However, our studies indicated that L-leu- cine had no distinct positive effect on cyclosporin A production as a precursor (data not shown). In this study it was found that the cyclosporin A titer continued to increase after cell growth ceased and exogenous L-valine was depleted, which was con- sistant with the earlier findings (Balakrishnan and Pandey 1996). Therefore, the feed of L-valine was
Abstract – An autonomous sugarcane bioethanol plant was simulated in EMSO software, an equation oriented process simulator. Three types of fermentation units were simulated: a six parallel fed-batch reactor system, a set of four CSTR in steady state and one consisting of a single stoichiometric reactor. Stoichiometric models are less accurate than kinetic-based fermentation models used for fed-batch and continuous fermenter simulations, since they do not account for inhibition effects and depend on a known conversion rate of reactant to be specified instead. On the other hand, stoichiometric models are faster and simpler to converge. In this study it was found that the conversion rates of sugar for the fermentation systems analyzed were predictable from information on the composition of the juice stream.Those rates were used in the stoichiometric model, which accurately reproduced the results from both the fed-batch and the continuous fermenter system.
From the ongoing study it can be concluded that the isolated strain of Aureobasidium pullulans was able to produce higher amount of pullulan by utilizing lesser amount of sugar (3%) at 42 o C. This is a novel and an important finding because in industry temperature goes up during fermentation and cooling devices are needed to lower the temperature involving higher cost. Therefore, this strain of A. pullulans can effectively be used for pullulan production in industry to cut down the cost of pullulan. Further, this strain is being improved through mutagenesis, and also through specialized continuousfermentation system using immobilized cells of A. pullulans on suitable matrix by manipulating other fermentation conditions. A significant increase of pullulan has also been reported in the above aspects.
The PE-2 strain was introduced into the process on 04/04/2013. This commercial strain was not able to establish dominance in the presence of more adapted indigenous yeasts found in this bioethanol plant, being easily replaced, as observed in the diverging banding patterns (Figure 1 and 2). It is evident throughout the sampling period, from May to October, that none of the yeast strains identified had the banding pattern compatible to PE-2, but both indigenous strains were able to carry out the fermentationprocess without damages and presence of obvious signs of contamination.
One of the big challenges of the white biotechnology is to find cheap processes and renewable resources to reduce the overall cost of final products, turning them highly competitive to chemical-based products. A natural pathway for the production of 1,3-PD is from glycerol which takes place in a few bacteria species (e.g., Clostridium butyricum, Clostridium pasteurianum, Citrobacter freundii, Klebsiella pneumoniae, Lactobacillus brevis, Lactobacillus buchneri, Bacillus welchii, and Enterobacter agglomerans) (Barbirato et al. 1995; Biebl et al. 1992, 1999; Boenigk et al. 1993; Dabrock et al. 1992; Daniel et al. 1995; Forsberg 1987; Homann et al. 1990; Schutz and Radler 1984). With the expansion of biofuel production, glycerol, which represents a secondary product, may become an abundant and cheap source for the biological production of 1,3-PD. Papanikolaou et al. (2000) showed that equivalent growth characteristics were obtained for batch cultures of C. butyricum F2b on pure or raw glycerol, from the biodiesel production process. A 1,3-PD yield of around 0.55 g g −1 of glycerol was observed for batch and chemostat cultures on raw glycerol; 48 g l −1 of 1,3-PD were produced from 90 g l −1 of raw glycerol, at a dilution rate of 0.02 h −1 , and a volumetric productivity of 5.5 g l −1 h −1 was obtained for a dilution rate of 0.21 h −1 . In order to reach simultaneously high volumetric productivity and product concentration, a two-stage continuousfermentation may be used, where the first reactor operates with a high dilution rate to achieve a high productivity and a low dilution rate is applied to the second reactor to increase product concentration. This strategy led to a 1,3-PD production of 41–46 g l −1 by C. butyricum F2b, growing on raw
Recently, the fermentative performance of selected strains isolated from honey and wine [2,21] and commercial yeasts starter cultures has been studied . However, to date, yeasts isolated from honey have not shown advantages over easily obtained commercial strains, despite the identified resistance to ethanol, sulphurous oxide and high concentrations of sugars . As such, due to the advantages related to yeast stability and the easier access for the mead-makers, the inoculation of the honey-must with commercial yeasts used in the production of white wines is recommended . According to Pereira et al., the most appropriate yeast strain is D47 ICV because it shows a high fermentation rate and a low production of volatile acidity and acetaldehyde . Acetaldehyde is a reactive, flavor active compound, which has been suspected to cause long-term adverse effects in consumers .
Strategic planning becomes a prominent tool in the mid-1960s as it starts to be seen as an effective process to implement strategies to enhance competitiveness and company value. The first complete book on strategy and planning is George Steiner’s reference title Top Management Planning (1969) which was the first to provide a comprehensive view on the subject. Even though such a tool presented positive results, it did not avoid criticism, namely from Henry Mintzberg in The Rise and Fall of Strategic Planning (1994) where he states that strategic planning is flawed as it achieved in planning and executing, but not in creating and formulating good organizational strategies. One year earlier, Peter Lorange 7 offers an interesting view on the process saying that strategy formulation should be made with different scopes at different organizational levels. He highlights corporate strategy at the top level, business planning and strategy at an intermediate level, and finally, planning and strategy of departments to select objectives for each functional area and to develop a “set of feasible action programs to implement division strategy”.
The control of an industrial process is the background for our presented anal- ysis of the decision-making model. The oxidizing roasting process of sulphide zinc concentrates is chosen as an exemplary industrial process. This industrial process is one of a group that consists of processes being diﬃcult to control with known com- putational techniques. The nature of the chosen process prevents us from obtaining proper values of parameters by computing from determined dependences in the form of mathematical equations. Proper rules of its control are also diﬃcult to formalize, which handicaps the building of a knowledge base, and as a consequence, is diﬃcult at constructing an expert system. Presented in , the proposition of our solution uses a neural net in order to predict results of hypothetical control. This neural net takes, as input, values of all parameters of production without taking into account the big diﬀerence of frequency of parameters measuring (once a second versus once a batch – a day period). Such an approach leads to adding missing data with the use of interpolation techniques, which can be a source of faults and errors in the case of processes with nonuniform frequency of signal measuring. The oxidizing roasting process of sulphide zinc concentrates is an example of a production that is orga- nized into batches. But every batch is continuously controlled, so it is one of the semi-continuous (or semi-batch) processes . Interpolation of parameters, which are measured at the time of diﬀerent production batches, leads to adding nonexistent and perhaps distorted values of parameters, which is the main disadvantage of the solutions presented in .
For continuous production, understanding the dynamics of how a material flows through the process is critical to traceability of the material. This understanding of process dynamics can be obtained by characterizing the residence time distribution (RTD) (6). RTD is a probability distribution that describes the amount of time that a mass or fluid element remains in a unitary operation, throughout a process (6) (20). This (RTD) can be easily obtained for all unit operations in a continuous line with a monitoring response test performed for each unit operation separately and also for the mechanically integrated line. The RTD curve can be used to predict the propagation of material or disturbances through the system (6). It is also useful to characterize the axial mixing, to predict how fluctuations in a feeder and mixer dissipate and what their impact on the uniformity of the mixture and the contents. It can also be used to track materials through the process and potentially isolate materials when specifications are not achieved (21). The distribution of residence time depends on several factors, such as operating conditions, equipment parameters and design, and physicochemical properties of materials (22) (6). Thus, knowledge of RTD is a key aspect of a control strategy for continuous production processes as it has the ability to adequately isolate and reject non-specification materials.
describe changes in the liquid medium during the conduction of fermentation bioprocess in which, sugars in aqueous solution are decomposed into alcohol and carbon dioxide by the action of yeast cells. Recently, most research has been fo- cused on the characterization of fermentation liquid mixtures in bioreactors from alcohol concentration measurements, cal- culating conventionally the propagation velocity by the time of flight of ultrasonic waves , . In this sense, few studies have been addressed to characterize liquid mixtures being fermented from time evolution analysis of its continuous and dispersed phases during the gradual fermentation stages. Therefore, this study shows a quantitative characterization in the interest region (RoI) of the fermentation fluid where are identified and differentiated acoustic reflections associated to groups of solid particles (called dispersed phase) and acoustic reflections from the liquid solution of fermentation fluid (called continuous phase). Classification procedures between the continuous and dispersed phases were made from acoustic parameter calculations on ultrasound vectors collected experimentally during the fermentationprocess. The results of the experimental measurements of pH, density and percentage of solid mass were correlated with values obtained of acoustic parameters and detection rate of solid particles (calculated from ultrasonic backscattering signals by the classification algorithm K-means). Thereby, these estimates allowed describe the local behavior of the main stages of the fermentationprocess, such as cellular adaptation (lag phase), tumultuous phase (given by rapid growth of yeast cells) and stationary phase given by fermentation slowdown and depletion of carbohydrates.
The following work is about the creation of two computer programs, one for simulation and one for parameter estimation of fermentation processes from cassava hydrolyzed in a batch system. The first program estimates the biomass, substrate and product concentration at different times during a fermentationprocess. The other program performs adjustments at the mathematical model to provide great kinetics parameters from the comparison among data calculated by the program and data obtained in the literature. Based on comparison of results with literature data, it can be stated that the programs provide a true representation of the fermentationprocess. The structure of the programs developed allows its use for simulating and providing data of different fermentation processes changing only the input data and equations involving the kinetics.
Plant cell-wall components are more methanogenic than the carbohydrate of inner cell contents (Johnson & Johnson, 1995). Therefore, the methane production mechanism may be affected by the amount of fermented organic matter in the rumen and the type of carbohydrate in the diet. Forage intake results in production of ruminal methane, which is increased with addition of digestible organic matter until ruminal pH becomes inhibitory to microbial growth or when the passage rate increases, reducing the fermentation degree of feed in rumen. Giger- Reverdin & Sauvant (2000) observed a quadratic result in methane production with the increase of grain in the diet
Yeast population and dynamics associated to spontaneous fermentation of green table olives Negrinha de Freixo cv. were evaluated. Olives and brine samples were taken at different fermentation times, and yeast were enumerated by standard plate count and identi ﬁed by sequencing of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA (rDNA). Saccharomyces cerevisiae was the most frequent, followed by Candida tropicalis, Pichia membranifaciens and Candida boidini, representing together 94.8% of the total isolates. Galactomyces reessii was also identiﬁed for the ﬁrst time in table olives. The highest species diversity was found between 44 and 54 days of fermentation, both in brine and olive pulp. Furthermore, high similarity was observed between brine and olive pulp microbiotas. In conclusion, these results give valuable information to table olive industrials in order to achieve more knowledge on the fermentationprocess of this important Protected Designation of Origin product.
A total of 358 organisms were isolated, and 31 (9%) were yeasts and 327 (91%) were bacteria (divided into lactic and acetic bacteria’s). The isolates were identiﬁed by MALDI-TOF MS technique ( Fig. 2 ). According to Fig. 2 a, the beginning of fermentation (0 h) showed higher population of Lactobacillus paracasei (10 6 CFU/mL). Saccharomyces cerevisiae, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were found in smaller quantities (10 5 CFU/mL) at the beginning of the alcoholic fermentation. These microorganisms were found throughout the alcoholic and acetic fermentation (10% and 20% keﬁr). According to Fig. 2 b, at the end of 264 h (11 days) of fermentation the population of S. cerevisiae, remained the same initial population of 10 5 CFU/mL. The population of L. paracasei and L. plantarum increased, compared to the initial time reaching 10 8 CFU/mL and 10 7 CFU/mL, respectively. The population of A. pasteurianus and A. syzygii had the highest increase 10 9 CFU/mL at the end of acetic fermentation.
In Latin America, the efforts have been also promising, although to a smaller degree and many years later than in the USA and the United Kingdom (MOYADO-ESTRADA, 2002). For this reason, when exploring the literature in Latin America, only some few specific references to the TQM and process innovation were found (ALBIZU; OLAZARÁN; SIMÓN, 2004; ANDREU; RICART; VALOR, 1996; SUÁREZ- BARRAZA; RAMIS-PUJOL, 2010). The first of them is the reference to Andreu, Ricart and Valor (1996) that indicates that to allow the application of process innovation it is necessary to have a TQM process supported by the Information Technology (IT) efforts, which along with the organizational change are considered as key- catalyzers in the efforts of process innovation. To Albizu, Olazaran and Simón (2004), the TQM projects have been mainly related to the organizational change: organizational structure, and organization and contents of the work. These authors say that on applying a process innovation methodology, the change is not as radical as the one considered in the orthodox model of the Process Reengineering (HAMMER; CHAMPY, 1993), considering that such TQM efforts can exist simultaneously with the methodology of continuous improvement and process innovation. At last, Suárez-Barraza and Ramis-Pujol show an example of TQM application through the continuous improvement to reduce the time of a staff hiring service process in a human resources office of the public administration in Mexico, showing the connection between both focuses.
A computational thermal-mechanical simulator using the Element based Finite Volume Method Element based Finite Volume Method (EbFVM) has been elaborated to investigate the solid- ification of continuous casting ingots. The thermal behavior was evaluated using the two- dimensional transient heat conduction equation with phase change in conjunction with a numerical-experimental film coefficients. In addition, the thermal-mechanical approach in- cludes three inelastic representations, which are based in the Ramberg-Osgood plastic and Odqvist’s viscoplastic models. The simulator is validated using several benchmarks tests, along with the analytical solution of the Stefan’s problem. The numerical solution provided by the proposed in-house simulator were compared with a commercial simulator. From the comparisons performed, one can notice that EbFVM makes accurate prediction as the traditional numerical approach commonly employed to obtain the solution of computational mechanical cases. In the context of continuous casting herein were investigated two casting velocities and in order to enhance the cooling stage, in the sprays zone, as well as the crack formation, a new sprays set were proposed for the investigated cases. The thermal-mechanical study provided by EbFVM is able to provide good results for the temperature profile and thermomechanical state that could be used to address problems caused by the cooling process.
O n t h e o t h e r h a n d , t h e L o c a l Administration “B”, “C” and “D” have not used operation standards. Nevertheless, their measurement process was the percentage of progress of the process redesign techniques application to improve the process. For example, in the Local Administration “B”, in its design and construction process of a multi-sports field, the process progress improved 88%; while in the Local Administration “C”, the management process of work construction licenses had a progress of 98%. At last, according to Chart 4, evidences were also found indicating that the PI is directly applied with small adaptations of language and incorporation (development of specific methodologies), in the studied cases. This result confirms what Mayordomo (1990) has highlighted when saying that the management techniques, such as the Operation Guidance, which include the PI, can be applied in a direct manner in the public sector. Another result emerging from this research, which goes beyond what was found in the literature, was that the PI was not only applied in a direct manner, but also the improvements obtained by it could be sustained throughout time.
Brazilian sugar cane spirit (cachaça) production is traditional among rural producers in Santo Antônio da Patrulha-RS-Brazil. In this work, in similar conditions used by the producers, the effect of different °Brix and nutrients concentration on sugar cane juice fermentation time and ethanol yield was tested. Sixteen experiments were executed, predicted in a statistical planning, in order to identify the effect of eight factors. The results indicate that the increase on manganese sulfate concentration and cornmeal amount, and also the zinc sulfate concentration increase in interaction effect with higher °Brix, cause increase in fermentation time. It was also observed that the ethanol yield was higher at lower °Brix and at higher triple superphosphate amount in interaction effect with higher °Brix. Ammonium sulfate and copper sulfate concentrations, and also rice bran amount had no significant influence on the process. The best parameters determined, at local conditions, to obtain the lowest fermentation time and higher ethanol yield are the following: 14°Brix, triple superphosphate 0.5 g/L, zinc sulfate 0.5 g/L, manganese sulfate 0.2 g/L, cornmeal 5 g/L. It is also indicated the maintenance of ammonium sulfate 0.5 g/L and rice bran 5 g/L.
The proper oxygenation of the culture is important for the metabolic functions of organisms are correctly accom- plished. Paradoxically, it was recently shown that hypoxic conditions significantly increased the specific productivity of P. pastoris recombinant (Swartzlander et al., 2010), in- creased cell density, viability remained constant compared to control lines, but decreased the production of endoge- nous proteins (Baumann et al., 2010), indicating that yeast grown in cultures with limited oxygen availability signifi- cantly improve their characteristic to be a host with high ca- pacity for purification of monoclonal antibodies. The results of HIF-1 a showed that the three cultures would be under limited conditions of oxygen (Figure 1A), but only in 3% (v/v) methanol -10 °C and 1% (v/v) methanol -10 °C cultures it would be translocating into the nucleus (Figu- re 2) to dimerize with ARNT (subunit b of HIF-1), bind to DNA and activate the transcription of its target genes (Bra- liou et al., 2006). In contrast, despite the detection of HIF-1a in the 3% (v/v) methanol -30 °C culture, it was lo- calized in the cytoplasm indicating that degradation would be constant due to the presence of oxygen in the culture, which should be considered that this may be related to the cell number because the agitation and aeration was constant and same for all three, so as 3% (v/v) methanol -10 °C and 1% (v/v) methanol -10 °C cultures were those who obtained higher cell density, especially the 1% (v/v) methanol -10 °C culture. Therefore, by decreasing the amount of carbon source for growth to the same initial cell density and con- stant induction time for all these cultures, they must acti- vate another system to survive as is the shift of a respiratory metabolism to a respiratory-fermentation (Baumann et al., 2010; Charoenrat et al., 2005), so that its main function us- ing methanol as an inducer for the production of antibodies may be varying a function of production of ethanol which acts as a repressor generating a negative feedback in the