scholarly journals Comparative Study of Ethanol Production from Cassava Pulp by a Mixed Culture of Amylomyces Rouxii with Zygosaccharomyces Pseudorouxii and Zymomonas Mobilis

2019 ◽  
Vol 12 (1) ◽  
pp. 199-210
Author(s):  
Thalisa Yuwa-Amornpitak ◽  
Pa-Nga Yeunyaw
Keyword(s):  
Comparative Study ◽  
Ethanol Production ◽  
Mixed Culture ◽  
Zymomonas Mobilis ◽  
Ethanol Concentration ◽  
Polynomial Equation ◽  
Cassava Pulp ◽  
Optimum Parameters ◽  
Reduced Viscosity ◽  
Order Polynomial

In order to develop a procedure for production bioethanol from cassava pulp, mixed culture of Amylomyces rouxii TISTR 3667 with Zygosaccharomyces pseudorouxii TISTR 5966 or Zymomonas mobilis TISTR 550 and cellulase were evaluated. The parameters such as pH, cellulase, and cassava pulp concentration that influence on the amount of fermentable sugar were optimized by response surface methodology (RSM). Ethanol production was observed and compared to the predicted value that was calculated from the models. The models were fitted to a second-order polynomial equation. They were used to predict ethanol concentration from the use of the mixed culture of A. rouxii TISTR 3667 and Z. mobilis TISTR 550 (G2) that was higher than the amount produced using the mixed culture of A. rouxii TISTR 3667 and Zygosaccharomyces pseudorouxii TISTR 5966 (G1). The following optimum parameters were obtained: pH 6, 20% cassava pulp, and 1% cellulase for G2; and pH 4, 20% cassava pulp, and 0.55% cellulase for G1. The effect of cellulase on ethanol production, a comparative study was conducted in the fermenter by using mixed culture of A. rouxii TISTR 3667 and Z. mobilis TISTR 550. It was showed that more 15% ethanol was gained from 10% cassava pulp with 0.5% cellulase (25 g/l ethanol) compared to the system without cellulase (20 g/l). Mathematically model (equation 4) predicted the ethanol in this system near the actual value of 26.87 g/l. This study indicated that RSM is a powerful tool for optimization fermentation process by using mixed culture including cellulase. Besides these cellulase also reduced viscosity of the cassava medium and enhanced ethanol production. However this process should be more continue to study.

Ethanol production by a mixed culture of flocculent strains of Zymomonas mobilis and Saccharomyces sp.

1996 ◽  
Vol 45 (5) ◽  
pp. 580-583 ◽  
Author(s):  
C. Abate ◽  
D. Callieri ◽  
Emilio Rodríguez ◽  
Oscar Garro
Keyword(s):  
Ethanol Production ◽  
Mixed Culture ◽  
Zymomonas Mobilis

scholarly journals Batch and Fed-Batch Ethanol Fermentation of Cheese-Whey Powder with Mixed Cultures of Different Yeasts

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4495 ◽  
Author(s):  
Csilla Farkas ◽  
Judit M. Rezessy-Szabó ◽  
Vijai Kumar Gupta ◽  
Erika Bujna ◽  
Tuan M. Pham ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Mixed Culture ◽  
Cheese Whey ◽  
Ethanol Concentration ◽  
Fed Batch ◽  
Batch Mode ◽  
Whey Powder ◽  
Cell Counts ◽  
Yeast Strains ◽  
Lactose Conversion

Eight yeast strains of Lachancea thermotolerans, Kluyveromyces marxianus, and Kluyveromyces waltii have been tested for their ability to ferment lactose into ethanol in mashes containing 10% (w/v) cheese whey powder (CWP). The K. marxianus NCAIM Y00963 achieved 3.5% (v/v) ethanol concentration at 96–120 h of fermentation. The ethanol production by the selected lactose-positive strains and the well-known ethanologenic Saccharomyces cerevisiae (Levuline Fb) in mixed culture was also investigated at different CWP concentrations and inoculation techniques in batch mode. The mixed culture in an equal ratio (1:1) of cell counts of K. marxianus and S. serevisiae showed an increase in lactose conversion rate. The two yeast strains in a ratio of 3:1 (three-quarters of K. marxianus and a quarter of S. cerevisiae in a total of 4.5 × 1010 cells) resulted in 72.33% efficiency of lactose bioconversion and 7.6% (v/v) ethanol production at 17.5% (w/v) of CWP concentration. In the repeated inoculation process, with the addition of three-quarter part of 3:1 ratio of mixed culture (3.3 × 1010 cells of K. marxianus) into 150 mL CWP mash at initiation and the rest quarter part (1.2 × 1010 cells of S. cerevisiae) at 24 h, 8.86% (v/v) ethanol content with 87.5% efficiency of lactose conversion was reached. Both the ethanol concentration and efficiency of bioconversion were increased to 10.34% (v/v) and 92%, respectively, by combination with fed-batch fermentation technology. Our results can serve a very good basis for the development of industrial technology for the utilization of cheese whey.

scholarly journals The Quorum Sensing Auto-Inducer 2 (AI-2) Stimulates Nitrogen Fixation and Favors Ethanol Production over Biomass Accumulation in Zymomonas mobilis

2021 ◽  
Vol 22 (11) ◽  
pp. 5628
Author(s):  
Valquíria Campos Alencar ◽  
Juliana de Fátima dos Santos Silva ◽  
Renata Ozelami Vilas Boas ◽  
Vinícius Manganaro Farnézio ◽  
Yara N. L. F. de Maria ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Quorum Sensing ◽  
Ethanol Production ◽  
N2 Fixation ◽  
Energy Demand ◽  
Zymomonas Mobilis ◽  
Biomass Accumulation ◽  
High Energy ◽  
Gram Negative ◽  
Expression Of Genes

Autoinducer 2 (or AI-2) is one of the molecules used by bacteria to trigger the Quorum Sensing (QS) response, which activates expression of genes involved in a series of alternative mechanisms, when cells reach high population densities (including bioluminescence, motility, biofilm formation, stress resistance, and production of public goods, or pathogenicity factors, among others). Contrary to most autoinducers, AI-2 can induce QS responses in both Gram-negative and Gram-positive bacteria, and has been suggested to constitute a trans-specific system of bacterial communication, capable of affecting even bacteria that cannot produce this autoinducer. In this work, we demonstrate that the ethanologenic Gram-negative bacterium Zymomonas mobilis (a non-AI-2 producer) responds to exogenous AI-2 by modulating expression of genes involved in mechanisms typically associated with QS in other bacteria, such as motility, DNA repair, and nitrogen fixation. Interestingly, the metabolism of AI-2-induced Z. mobilis cells seems to favor ethanol production over biomass accumulation, probably as an adaptation to the high-energy demand of N2 fixation. This opens the possibility of employing AI-2 during the industrial production of second-generation ethanol, as a way to boost N2 fixation by these bacteria, which could reduce costs associated with the use of nitrogen-based fertilizers, without compromising ethanol production in industrial plants.

scholarly journals Hemicellulosic Bioethanol Production from Fast-Growing Paulownia Biomass

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 173
Author(s):  
Elena Domínguez ◽  
Pablo G. del Río ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
Lucília Domingues
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Xylose Reductase ◽  
Energy Crop ◽  
Scheffersomyces Stipitis ◽  
Fractionation Process ◽  
Renewable Source ◽  
Fast Growing ◽  
Engineered Strain

In order to exploit a fast-growing Paulownia hardwood as an energy crop, a xylose-enriched hydrolysate was obtained in this work to increase the ethanol concentration using the hemicellulosic fraction, besides the already widely studied cellulosic fraction. For that, Paulownia elongata x fortunei was submitted to autohydrolysis treatment (210 °C or S0 of 4.08) for the xylan solubilization, mainly as xylooligosaccharides. Afterwards, sequential stages of acid hydrolysis, concentration, and detoxification were evaluated to obtain fermentable sugars. Thus, detoxified and non-detoxified hydrolysates (diluted or not) were fermented for ethanol production using a natural xylose-consuming yeast, Scheffersomyces stipitis CECT 1922, and an industrial Saccharomyces cerevisiae MEC1133 strain, metabolic engineered strain with the xylose reductase/xylitol dehydrogenase pathway. Results from fermentation assays showed that the engineered S. cerevisiae strain produced up to 14.2 g/L of ethanol (corresponding to 0.33 g/g of ethanol yield) using the non-detoxified hydrolysate. Nevertheless, the yeast S. stipitis reached similar values of ethanol, but only in the detoxified hydrolysate. Hence, the fermentation data prove the suitability and robustness of the engineered strain to ferment non-detoxified liquor, and the appropriateness of detoxification of liquor for the use of less robust yeast. In addition, the success of hemicellulose-to-ethanol production obtained in this work shows the Paulownia biomass as a suitable renewable source for ethanol production following a suitable fractionation process within a biorefinery approach.

scholarly journals Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation, scale-up from 5-L laboratory and 200-L pilot plant to 3000-L industrial fermenters

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Morakot Krajang ◽  
Kwanruthai Malairuang ◽  
Jatuporn Sukna ◽  
Krongchan Rattanapradit ◽  
Saethawat Chamsart
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Consolidated Bioprocessing ◽  
Scale Up ◽  
Cassava Starch ◽  
Single Step ◽  
Starch Hydrolysis ◽  
Yield Coefficient ◽  
Raw Starch ◽  
Raw Starch Hydrolysis

Abstract Background A single-step ethanol production is the combination of raw cassava starch hydrolysis and fermentation. For the development of raw starch consolidated bioprocessing technologies, this research was to investigate the optimum conditions and technical procedures for the production of ethanol from raw cassava starch in a single step. It successfully resulted in high yields and productivities of all the experiments from the laboratory, the pilot, through the industrial scales. Yields of ethanol concentration are comparable with those in the commercial industries that use molasses and hydrolyzed starch as the raw materials. Results Before single-step ethanol production, studies of raw cassava starch hydrolysis by a granular starch hydrolyzing enzyme, StargenTM002, were carefully conducted. It successfully converted 80.19% (w/v) of raw cassava starch to glucose at a concentration of 176.41 g/L with a productivity at 2.45 g/L/h when it was pretreated at 60 °C for 1 h with 0.10% (v/w dry starch basis) of Distillase ASP before hydrolysis. The single-step ethanol production at 34 °C in a 5-L fermenter showed that Saccharomyces cerevisiae (Fali, active dry yeast) produced the maximum ethanol concentration, pmax at 81.86 g/L (10.37% v/v) with a yield coefficient, Yp/s of 0.43 g/g, a productivity or production rate, rp at 1.14 g/L/h and an efficiency, Ef of 75.29%. Scale-up experiments of the single-step ethanol production using this method, from the 5-L fermenter to the 200-L fermenter and further to the 3000-L industrial fermenter were successfully achieved with essentially good results. The values of pmax,Yp/s, rp, and Ef of the 200-L scale were at 80.85 g/L (10.25% v/v), 0.42 g/g, 1.12 g/L/h and 74.40%, respectively, and those of the 3000-L scale were at 70.74 g/L (8.97% v/v), 0.38 g/g, 0.98 g/L/h and 67.56%, respectively. Because of using raw starch, major by-products, i.e., glycerol, lactic acid, and acetic acid of all three scales were very low, in ranges of 0.940–1.140, 0.046–0.052, 0.000–0.059 (% w/v), respectively, where are less than those values in the industries. Conclusion The single-step ethanol production using the combination of raw cassava starch hydrolysis and fermentation of three fermentation scales in this study is practicable and feasible for the scale-up of industrial production of ethanol from raw starch.

scholarly journals Methods to extract the exopolymeric matrix from biofilms: a comparative study

1999 ◽  
Vol 39 (7) ◽  
pp. 243-250 ◽  
Author(s):  
Joana Azeredo ◽  
Valentina Lazarova ◽  
Rosário Oliveira
Keyword(s):  
Organic Carbon ◽  
Comparative Study ◽  
Mixed Culture ◽  
Pure Culture ◽  
Cell Walls ◽  
Extraction Method ◽  
Extraction Methods ◽  
Suitable Method ◽  
The Matrix ◽  
Biofilm Matrix

To study the composition of a biofilm a previous extraction method is required to separate cells from the matrix. There are several methods reported in the literature; however they are not efficient or promote leakage of intracellular material. In this work several extraction methods were assayed in mixed culture and pure culture biofilms and their efficiency was evaluated by the amount of organic carbon, proteins and intracellular material extracted. The results showed that the extraction with glutaraldehyde 3% (w/v) was the most suitable method, extracting great amounts of organic carbon without promoting cell lysis or permeabilization. Glutaraldehyde is a bifunctional reagent that binds to cell walls avoiding their permeabilization and the biofilm matrix is solubilized in the solution.

scholarly journals Formulation and Mathematical Optimization of Controlled Release Calcium Alginate Micro Pellets of Frusemide

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Amitava Ghosh ◽  
Prithviraj Chakraborty
Keyword(s):  
Sodium Alginate ◽  
Calcium Alginate ◽  
Mathematical Optimization ◽  
Extended Period ◽  
Cost Effective ◽  
Polynomial Equation ◽  
Chronic Hypertension ◽  
Order Polynomial ◽  
High Degree

Objective. Frusemide loaded calcium alginate micropellets, an oral microparticulate delivery system, was statistically optimized exhibiting prolonged therapeutic action minimizing its adverse effects.Methods. Ionotropic Gelation technique was adopted employing 32Factorial designs and keeping the entire process free from organic solvents. Physicochemical and the release characteristics of the prepared formulations were studied, keeping variations only in sodium alginate (primary polymer) and Acrycoat E30D (copolymer) dispersion.Result. Sodium alginate was predominant over Acrycoat E30D in all batches. Nonadditives or interaction was observed to be insignificant. Multiple regressions produced second-order polynomial equation, and the predictive results obtained were validated with high degree of correlation. Thein vivostudy applauded that optimized calcium alginate micropellets of frusemide can produce a much greater diuretic effect over an extended period of 24 hours.Conclusion. This study reveals that the potential of a single dose of the mathematically optimized micro pellets of frusemide formulation is sufficient in the management of peripheral edema and ascites in congestive heart failure and as well in the treatment of chronic hypertension, leading to better patient compliance, and can be produced with minimum experimentation and time, proving far more cost-effective formulation than the conventional methods of formulating dosage forms.

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