scholarly journals Bioreactors for lignocellulose conversion into fermentable sugars for production of high added value products

2015 ◽  
Vol 100 (2) ◽  
pp. 597-611 ◽  
Author(s):  
Rossana Liguori ◽  
Valeria Ventorino ◽  
Olimpia Pepe ◽  
Vincenza Faraco
Author(s):  
Natalia Kordala ◽  
Małgorzata Lewandowska ◽  
Włodzimierz Bednarski

AbstractThe pretreatment of lignocellulosic material performed to improve substrate’s susceptibility to enzymatic hydrolysis is usually accompanied by reactions leading to the synthesis of compounds that inhibit the metabolic activity of microorganisms. Their toxicity is the main obstacle to the successful bioconversion of lignocellulosic hydrolysates. The identification of these inhibitors and the choice of the optimal detoxication method are crucial for the improving the efficiency of fermentation processes. Material rinsing with water after processing is a common detoxication practice. However, it generates material losses, thus affecting contents of saccharides in the fermentation medium, which may in turn trigger higher costs of lignocellulose conversion to ethanol and other products with a higher added value. A study was undertaken to determine the effect of selected methods for the detoxication of an enzymatic hydrolysate from Miscanthus giganteus on the fermentation efficiency of saccharide derivatives. The experiment conducted with Mucor rouxii DSM 1191 demonstrated the usability of the detoxication method based on the activated carbon. After 96-h fermentation of Miscanthus hydrolysates, the alcohol content in the post-reaction medium was higher by 14% than in the control experiment wherein the material was rinsed with water after pretreatment. The experiment carried out with Saccharomyces cerevisiae 7, NRRL 978 showed no positive impact of the alternative detoxication methods replacing material rinsing on the efficiency of ethanol synthesis. The highest concentration of this metabolite (2.04% (v/v)) was obtained in the experimental variant in which the mentioned operation was coupled with detoxication of hydrolysates using calcium hydroxide.


2021 ◽  
Vol 29 ◽  
pp. 381-388
Author(s):  
Petrúcia Karine Santos de Brito Bezerra ◽  
Beatriz Meneghetti Costa de Araújo ◽  
Otávio Lima da Silva ◽  
Beatriz de Azevedo ◽  
Stephanie Caroline Bivar Matias ◽  
...  

The improvement of biotechnological processes capable of transforming agro-industrial waste into products with high added value has stood out in the area of renewable energies, promoting positive impacts to the environment. Thus, the present work evaluated the influence of nickel on the conversion of fermentable sugars, present in the green coconut shell hydrolyzate (GCSH), into butanol and other products. Fermentation assays were performed at 37 °C, starting with 19.4 g.L-1 of sugars and 1.0 g.L-1 of inoculum (C. beijerinckii). The GCSH was supplemented with tryptone, yeast extract, ammonium acetate, minerals and phosphate buffer. Two conditions were tested: with and without addition of nickel. Concentrations of sugars (glucose and xylose), intermediate products (organic acids), acetone, butanol, and ethanol were determined by high performance liquid chromatography (HPLC). The results show that the butanol production was higher from GCSH without addition of nickel, reaching a concentration of 2.14 g.L-1 of butanol. Therefore, the presence of nickel in the hydrolyzate was not favorable in the production of butanol under the studied process conditions.


2010 ◽  
Vol 101 (19) ◽  
pp. 7432-7438 ◽  
Author(s):  
Tam-Anh D. Nguyen ◽  
Kyoung-Rok Kim ◽  
Se Jong Han ◽  
Hwa Young Cho ◽  
Jin Woo Kim ◽  
...  

Author(s):  
B. Lencova ◽  
G. Wisselink

Recent progress in computer technology enables the calculation of lens fields and focal properties on commonly available computers such as IBM ATs. If we add to this the use of graphics, we greatly increase the applicability of design programs for electron lenses. Most programs for field computation are based on the finite element method (FEM). They are written in Fortran 77, so that they are easily transferred from PCs to larger machines.The design process has recently been made significantly more user friendly by adding input programs written in Turbo Pascal, which allows a flexible implementation of computer graphics. The input programs have not only menu driven input and modification of numerical data, but also graphics editing of the data. The input programs create files which are subsequently read by the Fortran programs. From the main menu of our magnetic lens design program, further options are chosen by using function keys or numbers. Some options (lens initialization and setting, fine mesh, current densities, etc.) open other menus where computation parameters can be set or numerical data can be entered with the help of a simple line editor. The "draw lens" option enables graphical editing of the mesh - see fig. I. The geometry of the electron lens is specified in terms of coordinates and indices of a coarse quadrilateral mesh. In this mesh, the fine mesh with smoothly changing step size is calculated by an automeshing procedure. The options shown in fig. 1 allow modification of the number of coarse mesh lines, change of coordinates of mesh points or lines, and specification of lens parts. Interactive and graphical modification of the fine mesh can be called from the fine mesh menu. Finally, the lens computation can be called. Our FEM program allows up to 8000 mesh points on an AT computer. Another menu allows the display of computed results stored in output files and graphical display of axial flux density, flux density in magnetic parts, and the flux lines in magnetic lenses - see fig. 2. A series of several lens excitations with user specified or default magnetization curves can be calculated and displayed in one session.


2015 ◽  
Vol 25 (1) ◽  
pp. 50-60
Author(s):  
Anu Subramanian

ASHA's focus on evidence-based practice (EBP) includes the family/stakeholder perspective as an important tenet in clinical decision making. The common factors model for treatment effectiveness postulates that clinician-client alliance positively impacts therapeutic outcomes and may be the most important factor for success. One strategy to improve alliance between a client and clinician is the use of outcome questionnaires. In the current study, eight parents of toddlers who attended therapy sessions at a university clinic responded to a session outcome questionnaire that included both rating scale and descriptive questions. Six graduate students completed a survey that included a question about the utility of the questionnaire. Results indicated that the descriptive questions added value and information compared to using only the rating scale. The students were varied in their responses regarding the effectiveness of the questionnaire to increase their comfort with parents. Information gathered from the questionnaire allowed for specific feedback to graduate students to change behaviors and created opportunities for general discussions regarding effective therapy techniques. In addition, the responses generated conversations between the client and clinician focused on clients' concerns. Involving the stakeholder in identifying both effective and ineffective aspects of therapy has advantages for clinical practice and education.


2011 ◽  
pp. 39-50
Author(s):  
V. Lushin

The author analyzes factors that led to a deeper fall in output and profitability in the real sector of the Russian economy in comparison with other segments during the acute phase of the financial crisis. It is argued that some contradictions in the government anti-recession policy, activities of the financial sector and natural monopolies lead to pumping out added value created in manufacturing and agriculture, increase symptoms of the «Dutch disease», etc. It is shown that it may threaten the balanced development of the Russian economy, and a set of measures is suggested to minimize these tendencies and create a basis for the state modernization policy.


2019 ◽  
Vol 10 (1) ◽  
pp. 1-27
Author(s):  
Aniek Wijayanti

Business Process Analysis can be used to eliminate or reduce a waste cost caused by non value added activities that exist in a process. This research aims at evaluating activities carried out in the natural material procurement process in the PT XYZ, calculating the effectiveness of the process cycle, finding a way to improve the process management, and calculating the cost reduction that can achieved by activity management. A case study was the approach of this research. The researcher obtained research data throughout deep interviews with the staff who directly involved in the process, observation, and documentation of natural material procurement. The result of this study show that the effectiveness of the process cycle of natural material procurement in the factory reached as much as 87,1% for the sand material and 72% for the crushed stone. This indicates that the process still carry activities with no added value and still contain ineffective costs. Through the Business Process Mechanism, these non value added activities can be managed so that the process cycle becomes more efficient and cost effectiveness is achieved. The result of the effective cycle calculation after the management activities implementation is 100%. This means that the cost of natural material procurement process has become effective. The result of calculation of the estimated cost reduction as a result of management activity is as much as Rp249.026.635,90 per year.


Sign in / Sign up

Export Citation Format

Share Document