Production of fructose syrup by selective removal of glucose from hydrolyzed Jerusalem artichoke juice

Summary The study shows that the yeastSaccharomyces cerevisiae ATCC 36859 can be successfully used for the production of fructose syrup from glucose-fructose mixtures or from Jerusalem artichoke juice by the conversion of glucose to ethanol. During these processes fructose concentration was unchanged.Ethanol yield (Y_P/S), based on glucose consumed in Jerusalem artichoke juice, and ethanol concentration were 0.428 g/g and 1.7% (w/v) respectively. When the juice was supplemented with glucose higher ethanol concentrations were attained but with lower ethanol yields.     

Continuous production of fructose syrup and ethanol from hydrolysed Jerusalem artichoke juice

Summary The results from this study showed that Jerusalem artichoke juice can be used for the production of very enriched fructose syrup by selective conversion of glucose to ethanol in a continuous process using immobilized cells ofSaccharomyces cerevisiae ATCC 36859. The product contained up to 99% of the total carbohydrates as fructose compared to 76% in the feed. Using Jerusalem artichoke juice supplemented with some glucose a product was obtained with 7.5% w/v ethanol which made ethanol recovery economically favourable. It was found that some fructose was consumed in these continuous processes; the glucose/fructose conversion rate ratio was regulated by the glucose concentration in the product stream.     

发酵菊芋汁生产果糖糖浆研究

分析了来自不同地区的菊芋成分,干物质含量在23％～26％,菊粉多糖含量为17％～18％（鲜重）。制备菊芋汁中的主要固形物成分是菊粉多糖,游离的还原糖和可溶性蛋白质含量很低,菊芋用于果糖或果糖糖浆生产具有较高的经济价值;通过摇瓶发酵试验确定了利用菊芋汁生产果糖糖浆的工艺,用自动模拟发酵罐进行了生产模拟实验。产品总糖含量为61％,其中果糖95％,葡萄糖5％,通过发酵法生产果糖糖浆总糖得率为90％。     

Optimization of simultaneously enzymatic fructo- and inulo-oligosaccharide production using co-substrates of sucrose and inulin from Jerusalem artichoke

Prebiotic substances are extracted from various plant materials or enzymatic hydrolysis of different substrates. The production of fructo-oligosaccharide (FOS) and inulo-oligosaccharide (IOS) was performed by applying two substrates, sucrose and inulin; oligosaccharide yields were maximized using central composite design to evaluate the parameters influencing oligosaccharide production. Inulin from Jerusalem artichoke (5–15% w/v), sucrose (50–70% w/v), and inulinase from Aspergillus niger (2–7 U/g) were used as variable parameters for optimization. Based on our results, the application of sucrose and inulin as co-substrates for oligosaccharide production through inulinase hydrolysis and synthesis is viable in comparative to a method using a single substrate. Maximum yields (674.82?mg/g substrate) were obtained with 5.95% of inulin, 59.87% of sucrose, and 5.68 U/g of inulinase, with an incubation period of 9?hr. The use of sucrose and inulin as co-substrates in the reaction simultaneously produced FOS and IOS from sucrose and inulin. Total conversion yield was approximately 67%. Our results support the high value-added production of oligosaccharides using Jerusalem artichoke, which is generally used as a substrate in prebiotics and/or bioethanol production.     

Ethanol fermentation with Kluyveromyces marxianus from Jerusalem artichoke grown in salina and irrigated with a mixture of seawater and freshwater

Aims: To study fuel ethanol fermentation with Kluyveromyces marxianus ATCC8554 from Jerusalem artichoke (Helianthus tuberosus) grown in salina and irrigated with a mixture of seawater and freshwater. Methods and Results: The growth and ethanol fermentation of K. marxianus ATCC8554 were studied using inulin as substrate. The activity of inulinase, which attributes to the hydrolysis of inulin, the main carbohydrate in Jerusalem artichoke, was monitored. The optimum temperatures were 38°C for growth and inulinase production, and 35°C for ethanol fermentation. Aeration was not necessary for ethanol fermentation with the K. marxianus from inulin. Then, the fresh Jerusalem artichoke tubers grown in salina and irrigated with 25% and 50% seawater were further examined for ethanol fermentation with the K. marxianus, and a higher ethanol yield was achieved for the Jerusalem artichoke tuber irrigated with 25% seawater. Furthermore, the dry meal of the Jerusalem artichoke tubers irrigated with 25% seawater was examined for ethanol fermentation at three solid concentrations of 200, 225 and 250 g l^?1, and the highest ethanol yield of 0·467, or 91·5% of the theoretical value of 0·511, was achieved for the slurry with a solid concentration of 200 g l^?1. Conclusions: Halophilic Jerusalem artichoke can be used for fuel ethanol production. Significance and Impact of the Study: Halophilic Jerusalem artichoke, not competing with grain crops for arable land, is a sustainable feedstock for fuel ethanol production.     

Effect of Formic Acid on Conversion of Fructose to 5-Hydroxymethylfurfural in Aqueous/Butanol Media

Acid-catalyzed dehydration of carbohydrates into 5-hydroxymethylfurfural (HMF), a valuable biomass-derived intermediate, has received increasing attention. Efficient methods for HMF production are needed for successful commercialization of HMF in the near future. A new process for the dehydration of sugars into 5-hydroxymethylfurfural in aqueous/butanol media enhanced by using formic acid was developed. The effects of formic acid concentration, reaction temperature, and reaction time on the fructose conversion and HMF yield showed the significant influences of these process variables. The optimum conditions were found to be 2.5?mol/L formic acid concentration, 170°C and 70?min. Under such conditions, a fructose conversion of 98.3% with a HMF yield of 69.2% was achieved. The application of the butanol solvent and formic acid led to the conversion of fructose to HMF with high yield. The catalytic system in this study has prospects for commercial application due to its less corrosion and convenient downstream separation.     

Penicillium subrubescens, a new species efficiently producing inulinase

Inulin is a reserve carbohydrate in about 15 % of the flowering plants and is accumulated in underground tubers of e.g. chicory, dahlia and Jerusalem artichoke. This carbohydrate consists of linear chains of β-(2,1)-linked fructose attached to a sucrose molecule. Inulinases hydrolyse inulin into fructose and glucose. To find efficient inulin degrading fungi, 126 fungal strains from the Fungal Biotechnology Culture Collection (FBCC) at University of Helsinki and 74 freshly isolated strains from soil around Jerusalem artichoke tubers were screened in liquid cultures with inulin as a sole source of carbon or ground Jerusalem artichoke tubers, which contains up to 19 % (fresh weight) inulin. Inulinase and invertase activities were assayed by the dinitrosalicylic acid (DNS) method and a freshly isolated Penicillium strain originating from agricultural soil (FBCC 1632) was the most efficient inulinase producer. When it was cultivated at pH 6 and 28 °C in 2 litre bioreactors using inulin and Jerusalem artichoke as a carbon source, inulinase and invertase activities were on day 4 7.7 and 3.1 U mL^?1, respectively. The released sugars analysed by TLC and HPLC showed that considerable amounts of fructose were released while the levels of oligofructans were low, indicating an exoinulinase type of activity. Taxonomic study of the inulinase producing strain showed that this isolate represents a new species belonging in Penicillium section Lanata-divaricata. This new species produces a unique combination of extrolites and is phenotypically and phylogenetically closely related to Penicillium pulvillorum. We propose the name Penicillium subrubescens sp. nov. (CBS 132785^T = FBCC 1632^T) for this new species.     

Enzymatic hydrolysis of inulin to fructose by glutaraldehyde fixed yeast cells

Inulin, a polyfruction, is found as the reserve carbohydrate in the roots and tubers of various plants (i.e. Jerusalem artichoke, chicory, and dahlia tubers). The beta-fructofuranosidase (inulase) from the yeast Kluyveromyces fragilis is of interest because of its industrial potential in fructose syrup and alcohol production from inulin containing plants. We have found that the inulase of K. fragilis can be immobilized in the yeast cells by glutaraldehyde treatment. These cells are resistant to physical and enzymatic destruction. Although the exact nature of the immobilization is not fully understood, the kinetic parameters of the immobilized enzyme are similar to those of the soluble enzyme. No reduction of enzyme activity was observed after glutaraldehyde treatment and glutaraldehyde concentration did not affect enzyme activity. A 96% hydrolysis of dahlia inulin was achieved in 10.5 h with a 9.5% (w/v) fixed enzyme suspension. A Jerusalem artichoke extract containing 16.8%polyfructan was completely hydrolyzed in 3.5 h with a 0.24% (w/v)fixed enzyme suspension. This is a time frame feasible for industrial consideration.     

Molecular properties and prebiotic effect of inulin obtained from artichoke (Cynara scolymus L.)

A high molecular weight inulin has been prepared from artichoke (Cynara scolymus L.) agroindustrial wastes using environmentally benign aqueous extraction procedures. Physico-chemical analysis of the properties of artichoke inulin was carried out. Its average degree of polymerization was 46, which is higher than for Jerusalem artichoke, chicory, and dahlia inulins. GC-MS confirmed that the main constituent monosaccharide in artichoke inulin was fructose and its degradation by inulinase indicated that it contained the expected beta-2,1-fructan bonds. The FT-IR spectrum was identical to that of chicory inulin. These data indicate that artichoke inulin will be suitable for use in a wide range of food applications. The health-promoting prebiotic effects of artichoke inulin were demonstrated in an extensive microbiological study showing a long lasting bifidogenic effect on Bifidobacterium bifidum ATCC 29521 cultures and also in mixed cultures of colonic bacteria.     

菊芋粕菊粉的酶法提取、组成及抗氧化活性研究

本研究拟应用酶法提取技术解决菊芋菊粉工业化生产中的废弃物——菊芋粕再利用程度低的问题,并评价菊芋粕菊粉的抗氧化活性功效。对菊芋粕菊粉的果胶酶酶法提取的最佳条件通过响应面法进行了优化,并对菊芋初次水提菊粉(primary water-extracted inulin,PWI)和二次酶提菊粉(secondary enzymatic-extracted inulin,SEI)的组成成分和抗氧化活性进行了比较分析。响应面法优化确定的菊芋粕菊粉最佳酶法提取条件为:pH4.5、提取温度50 ℃、酶底比7.5 U/g、提取时间2 h,该提取方法所得菊芋粕菊粉的得率为35.30%±0.85%,与传统热水浸提法相比菊粉得率提高38.16%。组成分析结果显示,SEI的总糖和菊粉含量均显著高于PWI( P <0.05)。在菊粉聚合度方面,PWI中蔗果三糖和蔗果四糖含量较高,而SEI中蔗果五糖、蔗果六糖及其以上聚合度菊粉的含量较高。此外,SEI的抗氧化活性优于PWI。因此,果胶酶辅助提取方法有望为菊芋粕菊粉的再利用难题提供新的解决思路。     

Thermotolerant Kluyveromyces marxianus and Saccharomyces cerevisiae strains representing potentials for bioethanol production from Jerusalem artichoke by consolidated bioprocessing

Thermotolerant inulin-utilizing yeast strains are desirable for ethanol production from Jerusalem artichoke tubers by consolidated bioprocessing (CBP). To obtain such strains, 21 naturally occurring yeast strains isolated by using an enrichment method and 65 previously isolated Saccharomyces cerevisiae strains were investigated in inulin utilization, extracellular inulinase activity, and ethanol fermentation from inulin and Jerusalem artichoke tuber flour at 40?°C. The strains Kluyveromyces marxianus PT-1 (CGMCC AS2.4515) and S. cerevisiae JZ1C (CGMCC AS2.3878) presented the highest extracellular inulinase activity and ethanol yield in this study. The highest ethanol concentration in Jerusalem artichoke tuber flour fermentation (200?g?L(-1)) at 40?°C achieved by K. marxianus PT-1 and S. cerevisiae JZ1C was 73.6 and 65.2?g?L(-1), which corresponded to the theoretical ethanol yield of 90.0 and 79.7?%, respectively. In the range of 30 to 40?°C, temperature did not have a significant effect on ethanol production for both strains. This study displayed the distinctive superiority of K. marxianus PT-1 and S. cerevisiae JZ1C in the thermotolerance and utilization of inulin-type oligosaccharides reserved in Jerusalem artichoke tubers. It is proposed that both K. marxianus and S. cerevisiae have considerable potential in ethanol production from Jerusalem artichoke tubers by a high temperature CBP.     

Effect of acid or enzymatic hydrolysis on ethanol production by Zymomonas mobilis growing on Jerusalem artichoke juice

Summary Ethanol production from the inulin of Jerusalem artichoke byZ. mobilis was studied in batch and continuous fermentations. Both acid or enzymatic hydrolysis were used. In continuous cultures enzymatic hydrolysis showed better results. Ethanol productivities of 17.7 and 29.0 g/l.h were obtained at output concentrationsca 35 g/l (% of conversion 99 and 83; ethanol yield 0.45 g/g). The hydrolysed juice could be used without any nutrient addition.     

Fructose syrups and ethanol production by selective fermentation of inulin

Jerusalem artichoke is a favorable substrate for inulin or fructose syrup production. The sugar content and the fructose ratio of inulin depend on various factors, particularly on the date of harvest. Incomplete fermentation of extracts by selected yeasts allows the production of inulin with increased fructose content. The yeast strains (Saccharomyces cerevisiae, S. diastaticus...) are chosen for their ability to ferment sucrose and inulin small polymers, but not easily inulin large polymers. A good increase in the fructose ratio and a good yield in residual sugars can be obtained with the better strains. After fermentation and acid or enzymatic hydrolysis, extracts from early and late harvested tubers lead to syrups of good quality containing up to 95% and 90% of fructose respectively. This fermentative enrichment process is competitive with others (for example, chromatographic enrichment), is appropriate to raw extracts, simplifies the purification steps, and also permits the simultaneous benefit of production of by-products in the form of ethanol and yeast (in addition to the pulps). Unhydrolyzed inulin polymers with high fructose content can be recovered by this selective fermentation.     

Construction of a flocculating yeast for fructose production from inulin

Construction of flocculating yeast lacking for fructose utilisation was realised by integration of the FLO1 flocculation gene in the ribosomal DNA of an hexokinase deficient (hxk1, hxk2) Saccharomyces cerevisiae strain (ATCC36859). Simultaneous production of ethanol and fructose was obtained from glucose/fructose mixtures or from hydrolysed Jerusalem artichoke extracts using the transformed yeast in batch fermentations and in a continuous reactor with internal biomass recycle. This allowed the production of 5 g ethanol/L and 48 g sugars/L containing up to 99 % fructose from diluted hydrolysed Jerusalem artichoke extracts containing 60 g sugars/L. © Rapid Science Ltd. 1998     

Enhanced antitumor activity of inulin-capped Se nanoparticles synthesized using Jerusalem artichoke tubers

Glycoconjugate Journal - An inulin polysaccharide with a molecular weight of?~?2600&nbsp;Da was derived from Jerusalem artichoke tubers and referred to as “JAP”....     

Analytical Procedures for Studying the Dehydration of D-Fructose

In order to study the kinetics of the dehydration of D-fructose, procedures for the qnantitation of fructose and its dehydration products, S-hydroxymethyI-2W furaldehyde (HMF), Ievulinic acid, and a “humin”, were developed. For many reaction conditions, these compounds, together with soluble polymers (up to 15%) that are humin precursors, account for at least 98% of the amount of initial D-fructose. Fructose, HMF, and levulinic acid were determined by g.l.c. of their O-trimethylsilyl derivatives. U.v. absorption and titration could also be used for the determination of HMF and levulinic acid. Humin was determined gravimetrically.     

Dehydration of fructose to 5-hydroxymethylfurfural by rare earth metal trifluoromethanesulfonates in organic solvents

The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) was investigated by using various rare earth metal trifluoromethanesulfonates, that is, Yb(OTf)₃, Sc(OTf)₃, Ho(OTf)₃, Sm(OTf)₃, Nd(OTf)₃ as catalysts in DMSO. It is found that the catalytic activity increases with decreasing ionic radius of rare earth metal cations. Among the examined catalysts, Sc(OTf)₃ exhibits the highest catalytic activity. Fructose conversion of 100% and a HMF yield of 83.3% are obtained at 120 °C after 2 h by using Sc(OTf)₃ as the catalyst. Moreover, the catalytic dehydration of fructose was also carried out in different solvents, for example, DMA, 1,4-dioxane, and a mixture of PEG-400 and water. The results show that among the solvents DMSO is the most efficient in promoting the dehydration of fructose to HMF, and no rehydration byproducts such as levulinic acid and formic acid are detected.     

Efficient microwave-assisted synthesis of 5-hydroxymethylfurfural from concentrated aqueous fructose

Studies on the HCl-catalysed microwave-assisted dehydration of highly concentrated aqueous fructose (27 wt %) to 5-hydroxymethylfurfural (HMF) revealed a significant increase in the fructose conversion rate over the conventional heated systems. Water, being the most benign solvent and therefore ideal for green and sustainable chemistry, normally is a poor solvent for the dehydration process resulting in low HMF selectivities and yields. However, reaction at 200 °C with microwave irradiation with a short reaction time of only 1 s resulted in good HMF selectivity of 63% and fructose conversion of 52%, while prolonged irradiation for 60 s (or more) resulted in nearly full fructose conversion (95%) but lower HMF yield (53%). Decreasing the fructose concentration significantly improved the HMF selectivity, but possibly made the production route less attractive from an industrial point of view due to the resultant low throughput.     

Inulin enrichment by fermentation in a flocculating yeast reactor

Summary Simultaneous production of ethanol and fructose enriched syrups was obtained from Jerusalem artichoke extract using a Saccharomyces diastaticus flocculating yeast in a continuous gas-lift reactor with internal biomass recycle. This allowed the production of 42 g/L of ethanol and 70 g/L of inulin containing up to 92% fructose (fructose/glucose ratio of 11). These results can be compared to the batch and chemostat fermentations which gave a higher ethanol concentration but a lower fructose enrichment. Mass transfert limitations can explain both the productivity decrease and the selectivity improvement in the gas-lift reactor.     

鹰嘴豆孢克鲁维酵母利用菊芋原料同步糖化与发酵生产乙醇

菊芋含有大量的菊粉多糖,且种植简单、产量高,是极具开发价值的替代玉米等粮食作物生产燃料乙醇的原料。文中研究了鹰嘴豆孢克鲁维酵母Y179利用菊芋原料同步糖化与发酵生产乙醇。鹰嘴豆孢克鲁维酵母Y179具有高效分泌菊粉酶的能力,摇瓶试验显示Y179酵母能够利用完全由菊芋原料配制而成的培养基良好生长并发酵产生乙醇。通气及温度对乙醇产量影响明显,相对厌氧环境对Y179酵母发酵产乙醇具有促进作用,30℃发酵温度相对37℃和42℃更有利于乙醇产量提高。种子液培养时间及接种量对乙醇产量影响较小。在5 L发酵罐中以10%(V/V)量接入预培养36 h的Y179种子液,发酵液完全由菊芋干粉配制而成,总糖含量22%(W/V),30℃不通气,300 r/min搅拌,发酵144 h时,乙醇浓度达到12.3%(V/V),糖醇转化效率86.9%,糖利用率大于93.6%。初步研究结果显示鹰嘴豆孢克鲁维酵母Y179在利用菊芋原料生产乙醇方面具有良好应用前景。