Application of simultaneous saccharification and fermentation (SSF) from viscosity reducing of raw sweet potato for bioethanol production at laboratory, pilot and industrial scales

The aim of this work was to research a bioprocess for bioethanol production from raw sweet potato by Saccharomyces cerevisiae at laboratory, pilot and industrial scales. The fermentation mode, inoculum size and pressure from different gases were determined in laboratory. The maximum ethanol concentration, average ethanol productivity rate and yield of ethanol after fermentation in laboratory scale (128.51 g/L, 4.76 g/L/h and 91.4%) were satisfactory with small decrease at pilot scale (109.06 g/L, 4.89 g/L/h and 91.24%) and industrial scale (97.94 g/L, 4.19 g/L/h and 91.27%). When scaled up, the viscosity caused resistance to fermentation parameters, 1.56 AUG/g (sweet potato mash) of xylanase decreased the viscosity from approximately 30000 to 500 cp. Overall, sweet potato is a attractive feedstock for be bioethanol production from both the economic standpoints and environmentally friendly.     

Simplified modeling of fed-batch alcoholic fermentation of sugarcane blackstrap molasses

Simplified modeling based on material balances for biomass, ethanol and substrate was used to describe the kinetics of fed-batch alcohol fermentation of sugarcane blackstrap molasses. Maintenance requirements were previously shown to be of particular significance in this system, owing to the use of massive inoculum to minimize inhibitions; therefore, they were taken into consideration for kinetic modeling. Average values of biomass and ethanol yields, productivities, and substrate consumption rates, calculated at the end of runs performed either at constant or exponentially varying flow rates, demonstrated that all of these parameters were influenced by the initial sugar-feeding rate, F(o)S(o). Under conditions of substrate shortage (F(o)S(o) 相似文献   

Batch fermentation kinetics of sugar beet molasses by Zymomonas mobilis

A new osmotolerant mutant strain of Zymomonas mobilis was successfully used for ethanol production from beet molasses. Addition of magnesium sulfate to hydrolyzed molasses allowed repeated growth without the need of yeast extract addition. The kinetics and yields parameters of fermentation on media with different molasses concentrations were calculated. The anabolic parameters (specific growth rate, mu, and biomass yield, Y(X/S)) were inhibited at elevated molasses concentrations while the catabolic parameters (specific ethanol productivity, q(p), and ethanol yield, Y(p/s)) were not significantly affected. In addition to ethanol and substrate inhibition, osmotic pressure effects can explain the observed results.     

Application of the biorefinery concept to produce L-lactic acid from the soybean vinasse at laboratory and pilot scale

Lactic acid is a product that finds several applications in food, cosmetic, pharmaceutical and chemical industries. The main objective of this work was the development of a bioprocess to produce L(+)-lactic acid using soybean vinasse as substrate. Among ten strains, Lactobacillus agilis LPB 56 was selected for fermentation, due to its ability to metabolize the complex oligosaccharides. Fermentation was conducted without need for supplementary inorganic nitrogen sources or yeast extract. Kinetic and yield parameters determined at laboratory scale were 0.864 and 0.0162 for YP/S and YX/S, 0.0145 g/L h (rx), 1.32 g/L h (rs) and 1.13 g/L h (rp). The use of vinasse enriched with soybean molasses provided higher lactic acid concentration (138 g/L), the best proportion of inoculum being 25% (v/v). After scale-up to a pilot plant, kinetic and yield parameters were 0.849 and 0.0353 for YP/S and YX/S, 0.0278 g/L h (rx), 0.915 g/L h (rs) and 0.863 g/L h (rp).     

Pilot-scale production of fuel ethanol from concentrated food waste hydrolysates using Saccharomyces cerevisiae H058

The aim of this study was to develop a bioprocess to produce ethanol from food waste at laboratory, semipilot and pilot scales. Laboratory tests demonstrated that ethanol fermentation with reducing sugar concentration of 200 g/L, inoculum size of 2 % (Initial cell number was 2 × 10⁶ CFU/mL) and addition of YEP (3 g/L of yeast extract and 5 g/L of peptone) was the best choice. The maximum ethanol concentration in laboratory scale (93.86 ± 1.15 g/L) was in satisfactory with semipilot scale (93.79 ± 1.11 g/L), but lower than that (96.46 ± 1.12 g/L) of pilot-scale. Similar ethanol yield and volumetric ethanol productivity of 0.47 ± 0.02 g/g, 1.56 ± 0.03 g/L/h and 0.47 ± 0.03 g/g, 1.56 ± 0.03 g/L/h after 60 h of fermentation in laboratory and semipilot fermentors, respectively, however, both were lower than that (0.48 ± 0.02 g/g, 1.79 ± 0.03 g/L/h) of pilot reactor. In addition, simple models were developed to predict the fermentation kinetics during the scale-up process and they were successfully applied to simulate experimental results.     

Factors affecting the ethanol productivity of yeast in molasses

The ethanol production by a laboratory yeast strain, X2180-1B, was less than half that by an alcohol yeast, YOY655, in a molasses medium containing 30% sugars, although X2180-1B produced approximately the same amount of ethanol as YOY655 in a nutrition medium with the same sugar content. The weak productivity of X2180-1B in the molasses was ascribed to the limitation of sucrose hydrolysis in the molasses. The invertase activity of X2180-1B was 0.019 (mmol sucrose/min/mg protein) in the nutrition medium, but substantially zero in the molasses, while that of YOY655 was 1.75 in the nutrition medium and 1.15 even under the inhibitory conditions in molasses. External addition of invertase greatly enhanced the ethanol productivity of only X2180-1B. The inhibitory factors of invertase in molasses were heat-stable and dialyzable substances.     

Continuous ethanol fermentation using immobilized yeast cells

Growing cells of Saccharomyces cerevisiae immobilized in calcium alginate gel beads were employed in fluidizedbed reactors for continuous ethanol fermentation from cane molasses and other sugar sources. Some improvements were made in order to avoid microbial contamination and keep cell viability for stable long run operations. Notably, entrapment of sterol and unsaturated fatty acid into immobilized gel beads enhanced ethanol productivity more than 50 g ethanol/L gel h and prolonged life stability for more than one-half year. Cell concentration in the carrier was estimated over 250 g dry cell/L gel. A pilot plant with a total column volume of 4 kL was constructed and has been operated since 1982. As a result, it was confirmed that 8-10%(v/v)ethanol-containing broth was continuously produced from nonsterilized diluted cane molasses for over one-half year. The productivity of ethanol was calculated as 0.6 kL ethanol/kL reactor volume day with a 95% conversion yield versus the maximum theoretical yield for the case of 8.5% (v/v) ethanol broth.     

Production of fructose and ethanol from sugar beet molasses using Saccharomyces cerevisiae ATCC 36858

The production of enriched fructose syrups and ethanol from beet molasses using Saccharomyces cerevisiae ATCC 36858 was studied. In batch experiments with a total sugar concentration between 94.9 and 312.4 g/L, the fructose yield was above 93% of the theoretical value. The ethanol yield and volumetric productivity in the beet molasses media with sugar concentration below 276.2 g/L were in the range of 59-76% of theoretical value and between 0.48 and 2.97 g of ethanol/(L x h), respectively. The fructose fraction in the carbohydrates content of the produced syrups was more than 95% when the total initial sugar concentration in the medium was below 242.0 g/L. Some oligosaccharides and glycerol were also produced in all tested media. Raffinose and the produced oligosaccharides were completely consumed by the end of the fermentation process when the total initial sugar concentration was below 190.1 g/L. The glycerol concentration was below 16.1 g/L. The results could be useful for a potential industrial production of ethanol and high-fructose syrup from sugar beet molasses.     

Supercritical carbon dioxide extraction of marigold at high pressures: comparison of analytical and pilot-scale extraction

The effects of pressure and co-solvent on the extraction of anti-inflammatory faradiol esters in marigold (Calendula officinalis L.) were investigated by supercritical fluid extraction at laboratory and pilot scales. Pressures higher than 300 bar and modifier (ethanol) concentrations ranging from 0 to 20% (v/v) were used at an extraction temperature of 50 degrees C. With an analytical extractor, exhaustive extraction of the drug and highest concentrations in the extracts were achieved with 0.5% ethanol at the maximum pressure of 689 bar. Increased modifier concentrations improved the extractability at lower pressure, but the higher amount of total extractables led to a lower concentration of faradiol esters in the extracts. The HPLC fingerprints of the extracts, the yields of total extract and the concentration of faradiol esters obtained with analytical and pilot scale extractors under the same conditions were comparable.     

Isolation of a novel high erythritol-producing <Emphasis Type="Italic">Pseudozyma tsukubaensis</Emphasis> and scale-up of erythritol fermentation to industrial level

This study isolated a novel erythritol-producing yeast strain, which is capable of growth at high osmolarity. Characteristics of the strain include asexual reproduction by multilateral budding, absence of extracellular starch-like compounds, and a negative Diazonium blue B color reaction. Phylogenetic analysis based on the 26S rDNA sequence and physiological analysis indicated that the strain belongs to the species Pseudozyma tsukubaensis and has been named P. tsukubaensis KN75. When P. tsukubaensis KN75 was cultured aerobically in a fed-batch culture with glucose as a carbon source, it produced 245 g/L of erythritol, corresponding to 2.86 g/L/h productivity and 61% yield, the highest erythritol yield ever reported by an erythritol-producing microorganism. Erythritol production was scaled up from a laboratory scale (7 L fermenter) to pilot (300 L) and plant (50,000 L) scales using the dissolved oxygen as a scale-up parameter. Erythritol production at the pilot and plant scales was similar to that at the laboratory scale, indicating that the production of erythritol by P. tsukubaensis KN75 holds commercial potential.     

Influence of cultivation conditions on xylose-to-xylitol bioconversion by a new isolate of Debaryomyces hansenii

About 270 yeast isolates were screened for xylitol production using xylose as the sole carbon source. The best isolate, Debaryomyces hansenii UFV-170, released 5.84 g L(-1) xylitol from 10 g L(-1) xylose after 24 h, corresponding to a yield of xylitol on consumed substrate (Y(P/S)) of 0.54 g g(-1). This strain was cultivated batch-wise at variable starting concentrations of xylose (S(o)) and biomass (X(o)) and agitation intensity, in order to improve xylitol production and to evaluate, through simple carbon balances, the influence of these conditions on xylose metabolism. Under the best microaerobic conditions (S(o) = 53 g L(-1), X(o) = 1.4 g L(-1), 200 rpm), xylitol production reached 37.0 g L(-1), corresponding to xylitol volumetric productivity of 1.0 g L(-1)h(-1), specific productivity of 0.22 g g(-1)h(-1) and Y(P/S) = 0.76 g g(-1). Almost 83% of xylose was consumed for xylitol production, the rest being consumed for growth, while respiration was negligible. The new isolate appeared to be a promising alternative for industrial xylitol bioproduction.     

Isolation of thermotolerant ethanologenic yeasts and use of selected strains in industrial scale fermentation in an Egyptian distillery

An enrichment and isolation program for new ethanol-producing thermotolerant yeasts as well as a screening program of some known thermotolerant strains resulted in the selection of several strains capable of growth at 40-43 degrees C. Among these strains four grew and fermented sugar cane molasses at 43 degrees C under batch conditions with sugar-conversion efficiencies >94% and ethanol concentrations 6.8-8.0% (w/v). The two best-performing strains, a Saccharomyces cerevisiae F111 and a Kluyveromyces marxianus WR12 were used in eight 87.5 m(3) fermentation runs (four using each strain) for industrial ethanol production in an Egyptian distillery using sugar cane molasses. Mean ethanol production was 7.7% and 7.4% (w/v), respectively, with an added advantage of cooling elimination during fermentation and higher ethanol yields compared to the distillery's S. cerevisiae SIIC (ATCC 24855) strain in use. The isolate S. cerevisiae F111 was subsequently adopted by the distillery for regular production with significant economical gains and water conservation.     

Activated carbon from olive kernels in a two-stage process: industrial improvement

Activated carbons have been prepared from olive kernels and their adsorptive characteristics were investigated. A two stage process of pyrolysis-activation has been tested in two scales: (a) laboratory scale pyrolysis and chemical activation with KOH and (b) pilot/bench scale pyrolysis and physical activation with H(2)O-CO(2). In the second case, olive kernels were first pyrolysed at 800 degrees C, during 45 min under an inert atmosphere in an industrial pyrolyser with a throughput of 1t/h (Compact Power Ltd., Bristol, UK). The resulting chars were subsequently activated with steam and carbon dioxide mixtures at 970 degrees C in a batch pilot monohearth reactor at NESA facility (Louvain-la Neuve, Belgium). The active carbons obtained from both scales were characterized by N(2) adsorption at 77 K, methyl-blue adsorption (MB adsorption) at room temperature and SEM analysis. Surface area and MB adsorption were found to increase with the degree of burn-off. The maximum BET surface area was found to be around 1000-1200 m(2)/g for active carbons produced at industrial scale with physical activation, and 3049 m(2)/g for active carbons produced at laboratory with KOH activation. The pores of the produced carbons were composed of micropores at the early stages of activation and both micropores and mesopores at the late stages. Methylene blue removal capacity appeared to be comparable to that of commercial carbons and even higher at high degrees of activation.     

Ethanol fermentation in a magnetically fluidized bed reactor with immobilized Saccharomyces cerevisiae in magnetic particles

Ethanol fermentation by immobilized Saccharomyces cerevisiae cells in magnetic particles was successfully carried out in a magnetically stabilized fluidized bed reactor (MSFBR). These immobilized magnetic particles solidified in a 2 % CaCl(2) solution were stable and had high ethanol fermentation activity. The performance of ethanol fermentation of glucose in the MSFBR was affected by initial particle loading rate, feed sugar concentration and dilution rate. The ethanol theoretical yield, productivity and concentration reached 95.3%, 26.7 g/L h and 66 g/L, respectively, at a particle loading rate of 41% and a feed dilution rate of 0.4 h(-1) with a glucose concentration of 150 g/L when the magnetic field intensity was kept in the range of 85-120 Oe. In order to use this developed MSFBR system for ethanol production from cheap raw materials, cane molasses was used as the main fermentation substrate for continuous ethanol fermentation with the immobilized S. cerevisiae cells in the reactor system. Molasses gave comparative ethanol productivity in comparison with glucose in the MSFBR, and the higher ethanol production was observed in the MSFBR than in a fluidized bed reactor (FBR) without a magnetic field.     

Kefir yeast technology: scale-up in SCP production using milk whey

A three-step process to scale-up kefir biomass production at a semi-industrial scale employing whey is reported. Aerobic fermentations were initially performed at laboratory scales, in 1.5- and 4-L bioreactors, yielding 79 g/L final kefir biomass (0.89 g/g of lactose utilized), in 7 h of fermentation time. The use of whey as carbon source even in solid cultures led to the formation of a granular biomass. These results encouraged scale-up at a semi-industrial-scale pilot plant employing 100- and 3,000-L bioreactors, leading to the development of a process for granular kefir biomass production. The results validated the laboratory-scale experiments and the avoidance of centrifugal separators due to granular biomass formation. Pilot-plant operations showed kefir to be highly resistant to contamination under actual industrial conditions and no serious problems in handling of raw materials and equipment were observed. Economic analysis showed a 20% higher cost of the market price of products, with added value of up to 15.9 x 10(9) within the European Union.     

Co-fermentation of cassava waste pulp hydrolysate with molasses to ethanol for economic optimization

Cassava waste pulp (CWP)–enzymatic hydrolysate was co-fermented with molasses (CWP-EH/molasses mixture) with the aim to optimize ethanol production by Saccharomyces cerevisiae TISTR 5606 (SC 90). The optimal fermentation conditions for ethanol production using this mixture were 245 g/L initial total sugar supplemented with KH₂PO₄ (8 g/L), at 30 °C for 48 h of fermentation under an oxygen-limited condition with agitation at 100 rpm, producing an ethanol concentration of 70.60 g/L (0.31 g ethanol/g total sugar). The addition of cassava tuber fiber (solid residue of CWP after enzymatic hydrolysis) at 30 g/L dry weight to the CWP-EH/molasses mixture increased ethanol production to 74.36 g/L (0.32 g ethanol/g total sugar). Co-fermentation of CWP-EH with molasses had the advantage of not requiring any supplementation of the fermentation mixture with reduced nitrogen.     

Optimization of culture conditions and scale-up to plant scales for teicoplanin production by <Emphasis Type="Italic">Actinoplanes teichomyceticus</Emphasis>

This report describes the optimization of culture conditions for teicoplanin production by Actinoplanes teichomyceticus KCCM-10601, an identified high-teicoplanin-producing strain (US 2006/0134757 A1). Among the conditions tested, temperature, pH, and the dissolved oxygen tension (DOT) were key factors affecting teicoplanin production. When the temperature, pH, and DOT were controlled at 34 degrees C, 7.0 and 20-30%, respectively, a dry-cell weight of 42.8 g l(-1) and a teicoplanin production of 2.9 g l(-1) were obtained after 120 h of batch culture, corresponding to a specific teicoplanin content of 67.8 mg g-DCW(-1). Teicoplanin production was scaled-up from a laboratory scale (7-l fermenter) to a pilot scale (300 l) and a plant scale (5,000 l) using the impeller tip velocity (V tip) as a scale-up parameter. Teicoplanin production at the laboratory scale was similar to those at the pilot and plant scales. This is the highest report of pilot- and plant-scale production of teicoplanin.     

Biotransformation of a crizotinib intermediate using a mutant alcohol dehydrogenase of Lactobacillus kefir coupled with glucose dehydrogenase

Abstract

(S)-1-(2, 6-dichloro-3-fluorophenyl) ethanol, the key chiral intermediate of crizotinib, was prepared from 1-(2, 6-dichloro-3-fluorophenyl) ethanone using the alcohol dehydrogenases from Lactobacillus kefir (ADH-LK) with a tetrad mutant (ADH-LKM, F147L/Y190P/V196L/A202W), coupled with glucose dehydrogenase (GDH). In the present study, ADH-LKM and GDH were successfully heterologous expressed in recombinant Escherichia coli. During the regeneration of NADPH with GDH, 150?g/L substrate was totally transformed into target chiral alcohol with an enantiomeric excess value of 99.9% after 12?h at 30?°C (pH 7.0). Our study demonstrates the potential for industrial green production of the key chiral intermediate of crizotinib.     

Integrating sugarcane molasses into sequential cellulosic biofuel production based on SSF process of high solid loading

Background

Sugarcane bagasse (SCB) is one of the most promising lignocellulosic biomasses for use in the production of biofuels. However, bioethanol production from pure SCB fermentation is still limited by its high process cost and low fermentation efficiency. Sugarcane molasses, as a carbohydrate-rich biomass, can provide fermentable sugars for ethanol production. Herein, to reduce high processing costs, molasses was integrated into lignocellulosic ethanol production in batch modes to improve the fermentation system and to boost the final ethanol concentration and yield.

Results

The co-fermentation of pretreated SCB and molasses at ratios of 3:1 (mixture A) and 1:1 (mixture B) were conducted at solid loadings of 12% to 32%, and the fermentation of pretreated SCB alone at the same solid loading was also compared. At a solid loading of 32%, the ethanol concentrations of 64.10 g/L, 74.69 g/L, and 75.64 g/L were obtained from pure SCB, mixture A, and mixture B, respectively. To further boost the ethanol concentration, the fermentation of mixture B (1:1), with higher solid loading from 36 to 48%, was also implemented. The highest ethanol concentration of 94.20 g/L was generated at a high solid loading of 44%, with an ethanol yield of 72.37%. In addition, after evaporation, the wastewater could be converted to biogas by anaerobic digestion. The final methane production of 312.14 mL/g volatile solids (VS) was obtained, and the final chemical oxygen demand removal and VS degradation efficiency was 85.9% and 95.9%, respectively.

Conclusions

Molasses could provide a good environment for the growth of yeast and inoculum. Integrating sugarcane molasses into sequential cellulosic biofuel production could improve the utilization of biomass resources.

     

Effect of substrate concentration on ethanol production by Zymomonas mobilis on cellulose hydrolysate

Summary A cellulose hydrolysate from Aspen wood, containing mainly glucose, was fermented into ethanol by a thermotolerant strain MSN77 of Zymomonas mobilis. The effect of the hydrolysate concentration on fermentation parameters was investigated. Growth parameters (specific growth rate and biomass yield) were inhibited at high hydrolysate concentrations. Catabolic parameters (specific glucose uptake rate, specific ethanol productivity and ethanol yield) were not affected. These effects could be explained by the increase in medium osmolality. The results are similar to those described for molasses based media. Strain MSN77 could efficiently ferment glucose from Aspen wood up to a concentration of 60 g/l. At higher concentration, growth was inhibited.Nomenclature S glucose concentration (g/l) - X biomass concentration (g/l) - P ethanol concentration (g/l) - C conversion of glucose (%) - t fermentation time (h) - q_S specific glucose uptake rate (g/g.h) - q_p specific ethanol productivity (g/g.h) - YINX/S biomass yield (g/g) - Y_p/S ethanol yield (g/g) - specific growth rate (h^-1)