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Introduction: An attractive and novel proposal for the application of enzymatic inversion of sucrose on industrial scale is constituted by ß-fructosidase from Thermotoga maritima (BfrA) expressed in Pichia pastoris and immobilized on calcium alginate (PpABfrA), because the high thermostability and thermoactivity of this biocatalyst. Objective: To determine the operational conditions for the industrial scale-up of enzymatic hydrolysis of sucrose in a glucose production facility, based on the optimal experimental variables and the requirements for auxiliary facilities. Materials and Methods: Design of experiments and optimization of the behavior of the experimental variables influencing the percentage of hydrolysis achieved with the thermostable biocatalyst PpABfrA were combined. The experimental reactive conditions were scaled and the technology for this inversion method insertion was selected, with its corresponding consumptions. Results and Discussion: The optimum reaction time was 12 h for a sucrose concentration of 1.75 M, where 85.6 % inversion is achieved. In turn, keeping the biocatalyst shear constant in the reactor was selected as the most successful scaling criterion. With the technological conception of this stage, a hydrolysis capacity of 201.6 t of sucrose in 11 days was estimated, where 16 inversion cycles are carried out with 2.10 t of biocatalyst, in an effective reaction volume of 24 m³. Conclusions: The operational parameters determined on industrial scale for the insertion of this technology, ensure an increase the yield and quality of obtained glucose. [ABSTRACT FROM AUTHOR]

In this paper, the acidic pretreatment of microalgal biomass is investigated, and the solubilized biomass and hydrolyzed sugars were evaluated. The process is analyzed through the severity factor approach (acidic combined severity factor (ACSF)). A suitable kinetic model is developed and applied, and it is shown that the severity factor theory works. A discussion and comparison are presented with respect to the literature methods, which are mainly related to lignocellulosic biomass. In the case of microalgae, reaction orders for biomass and acid are shown to be the main parameters, and no other assumptions are needed. Two regions of the acidic treatment process have to be evaluated: low and high reactivity regions. Furthermore, a suitable experimental design is required in order to provide an appropriate reaction spectrum to obtain a good estimation of the kinetic parameters. A logarithmic severity factor range (ln ACSF) between 5 and 6 is able to solubilize around 80% of biomass and to hydrolyze more than 90% of sugars present in the biomass. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) can be extracted from cellulosic materials through the degradation of non-crystalline cellulose domains in the feedstock via acid hydrolysis. However, the sugars released from the hydrolysis process cannot be easily recovered from the acid waste stream. In this study, cellulases were used to preferentially degrade non-crystalline domains with the objectives of recovering sugars and generating a feedstock with concentrated CNC precursors for a more efficient acid hydrolysis process. Filter paper and wood pulp substrates were enzyme-treated for 2-10 h to recover 20-40 wt % glucose. Substantial xylose yield (6-12 wt %) was generated from wood pulp. CNC yields from acid hydrolysis of cellulases-treated filter paper, and wood pulp improved by 8-18% and 58-86%, respectively, when compared with the original substrate. It was thought that CNC precursors accumulated in the cellulases-treated feedstock due to enzymatic digestion of the more accessible non-crystalline celluloses. Therefore, acid hydrolysis from enzyme-treated feedstock will require proportionally less water and reagents resulting in increased efficiency and productivity in downstream processes. This study demonstrates that an enzymatically-mediated process allows recovery of fermentable sugars and improves acid hydrolysis efficiency for CNC production. [ABSTRACT FROM AUTHOR]

BACKGROUND Spraying selenium (Se) fertilizer is an effective method for Se-enriched fruit production. Sugar content in fruit is the major factor determining berry quality. However, changes in sugar metabolism in response to Se fertilizer are unclear. Hence, this study was conducted to identify the effects of Se fertilizer on sugar metabolism and related enzyme activities of grape berries. Additionally, production of leaves with and without Se fertilizer was also investigated. RESULTS Acid invertase ( AI) activity, total soluble sugar and Se content in berries, and photosynthetic rate in leaves produced under Se fertilizer treatments were higher than that of control. Glucose and fructose were the primary sugars in berries, with a trace of sucrose. In both berries and leaves, neutral invertase activity was lower than AI, there was no significant difference in neutral invertase, sucrose synthase and sucrose phosphate synthase between Se fertilizer-treated and control. In berries, AI showed a significant positive correlation with glucose and fructose; also Se content was significantly correlated with sugar content. CONCLUSION AI played an important role in the process of sugar accumulation in berries; high AI activity in berries and photosynthetic rate in leaves could explain the mechanism by which Se fertilizer affected sugar accumulation in berries. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, comparative evaluation of acid- and alkali pretreatment of sweet sorghum bagasse (SSB) was carried out for sugar production after enzymatic hydrolysis. Results indicated that enzymatic hydrolysis of alkali-pretreated SSB resulted in higher production of glucose, xylose and arabinose, compared to the other alkali concentrations and also acid-pretreated biomass. Response Surface Methodology (RSM) was, therefore, used to optimize parameters, such as alkali concentration, temperature and time of pretreatment prior to enzymatic hydrolysis to maximize the production of sugars. The independent variables used during RSM included alkali concentration (1.5-4%), pretreatment temperature (125-140 °C) and pretreatment time (10-30 min) were investigated. Process optimization resulted in glucose and xylose concentration of 57.24 and 10.14 g/L, respectively. Subsequently, second stage optimization was conducted using RSM for optimizing parameters for enzymatic hydrolysis, which included substrate concentration (10-15%), incubation time (24-60 h), incubation temperature (40-60 °C) and Celluclast concentration (10-20 IU/g-dwt). Substrate concentration 15%, (w/v) temperature of 60 °C, Celluclast concentration of 20 IU/g-dwt and incubation time of 58 h led to a glucose concentration of 68.58 g/l. Finally, simultaneous saccharification fermentation (SSF) as well as separated hydrolysis and fermentation (SHF) was evaluated using Pichia kudriavzevii HOP-1 for production of ethanol. Significant difference in ethanol concentration was not found using either SSF or SHF; however, ethanol productivity was higher in case of SSF, compared to SHF. This study has established a platform for conducting scale-up studies using the optimized process parameters. [ABSTRACT FROM AUTHOR]

High-efficiency hydrolysis of lignocellulose is critical for the production of second-generation bioethanol. In the present work, the acid hydrolysis of cellulose in ionic liquids (ILs) 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), 1-allyl-3-methylimidazolium chloride ([Amim]Cl), and 1-ethyl-3-methylimidazolium chloride ([Emim]Cl), respectively, was investigated and aqueous two-phase systems were constructed by adding salt solutions to ILs to recover glucose from cellulose hydrolyzates in the ILs. The effects of reaction temperature, reaction time and acid consumption on the cellulose hydrolysis efficiencies in the ILs were determined. The optimal cellulose hydrolysis conditions in ILs were found to be [Bmim]Cl, a reaction time of 0.5 h, an acid consumption of 0.25 mL/g (cellulose) and a reaction temperature of 100 °C. The yield of glucose under the optimal hydrolysis conditions reached 92.88%. IL-based aqueous two-phase systems were formed by adding NaOH, K 3 PO 4 , or K 2 HPO 4 into the ILs containing glucose or cellulose hydrolyzates, which were able to partition the glucose into the bottom salt-rich phase. Under the optimum condition, 4 vol 50% NaOH or K 3 PO 4 solution was able to partition 90% glucose, resulting in 16 g/L glucose in the salt-rich phase that could be further used for ethanol fermentation. [ABSTRACT FROM AUTHOR]

The aim of the research was to evaluate the effect of combined treatments on fermentable sugar production from rapeseed straw. An optimum condition was found to be the combination of hydrothermal pretreatment at 180 °C for 45 min and post-treatment by 2% NaOH at 100 °C for 2 h, which was based on the quantity of monosaccharides released during enzymatic hydrolysis. As compared with the raw material without treatment, the combination of hydrothermal pretreatment and alkali post-treatment resulted in a significant increase of the saccharification rate by 5.9 times. This process potentially turned rapeseed straw into value added products in accordance with the biorefinery concept. [ABSTRACT FROM AUTHOR]

This paper presents a kinetic study of invertase, a specific fructofuranosidase cloned from the Leishmania major genome. The kinetic parameters of the β- d -fructofuranosidase from Leishmania major (BfrA) were determined using Thin-Layer Chromatography (TLC) and UV-densitometry (TLC@UV) specifically developed for the separation and detection of three carbohydrates namely sucrose, glucose and fructose. Separation was performed on TLC silica gel 60 F254 plates impregnated with sodium bisulphate and citrate and heated prior to development. This fast and easy separation was performed with two successive developments using ACN/H 2 O 80/20 (v/v) as mobile phase. Sensitive and repeatable derivatization of sugars was achieved by dipping the plates in a solution of 4-aminobenzoic acid. Quantification was performed by UV-detection. The method was validated according to ICH guidelines Q2(R1) in terms of specificity, limits of detection and quantification, precision and robustness (with n = 3 replicates and CV ≤10%). The characterization of BfrA reaction kinetic was performed by monitoring the accumulation of either glucose or fructose detected by TLC@UV. Hydrolysis of sucrose was described by the Michaelis-Menten kinetic parameters ( K M ; V m a x ) respectively equal to 63.09 ± 7.590 mM; 0.037 ± 0.00094 mM/min using glucose production and 83.01 ± 14.39 mM; 0.031 ± 0.0021 mM/min monitoring fructose. Hydrolyses of three alternative substrates, raffinose, stachyose and inulin, were also compared and the regiospecificity of the reaction was characterized. This TLC@UV method is shown to be suitable for the refined kinetic analysis of different reactions related to the hydrolysis of sugars. [ABSTRACT FROM AUTHOR]

Hydrothermal pretreatment solubilizes about 65% of the hemicelluloses in sugarcane bagasse. However, nearly 80% of the xylose recovered from the hemicellulosic hydrolysate is present as xylooligosaccharides (XO’s), which cannot be directly fermented into pentose (C5) ethanol. In this work a kinetic study of the post hydrolysis process considering the use of three acids – sulfuric, oxalic and maleic – was performed. Xylose and furfural post-hydrolysis profiles showed the reaction time in which xylose peaked with minimum furfural production. Among the three studied acids, sulfuric acid showed the fastest kinetics of post-hydrolysis with XO’s being fully hydrolyzed in less than 1 h reaction time. C5 fermentation experiments showed that the detoxified post-hydrolysates fermented with ethanol yields ranging from 0.10 to 0.31 g ethanol g −1 reducing sugars. Most samples were fermented from 48 to 72 h of experiment with productivities ranging from 0.02 to 0.43 g ·L −1 ·h −1 . [ABSTRACT FROM AUTHOR]

The β-fructofuranosidase from the yeast Schwanniomyces occidentalis (Ffase) produces the prebiotic sugars 6-kestose and 1-kestose by transfructosylation of sucrose, which makes it of biotechnological interest. In this study, the hydrolase and transferase activity of this enzyme was kinetically characterized and its potential to synthesize new fructosylated products explored. A total of 40 hydroxylated compounds were used as potential fructosyl-acceptor alternatives to sucrose. Only 17 of them, including some monosaccharides, disaccharides, and oligosaccharides as well as alditols and glycosides were fructosylated. The best alternative acceptors were the alditols. The major transfer product of the reaction including mannitol was purified and characterized as 1-O-β- d-fructofuranosyl- d-mannitol, whose maximum concentration reached 44 g/L, representing about 7.3 % of total compounds in the mixture and 89 % of all products generated by transfructosylation. The reactions including erythritol produced 35 g/L of an isomer mixture comprising 1- and 4-O-β- d-fructofuranosyl- d-erythritol. In addition, Ffase produced 24 g/L of the disaccharide blastose by direct fructosylation of glucose, which makes it the first enzyme characterized from yeast showing this ability. Thus, novel fructosylated compounds with potential applications in food and pharmaceutical industries can be obtained due to the Ffase fructosyl-acceptor promiscuity. [ABSTRACT FROM AUTHOR]

The hydrogen over-producing Escherichia coli HD701, a hydrogenase up-regulated strain, has the potential for industrial-scale hydrogen production; however, this strain is unable to metabolize sucrose which is a major constituent of many waste organic materials that can be used as feedstock for industrial hydrogen production. Invertase from Sacharomyces cervacea (yeast) was partially purified and characterized where its apparent optimum temperature when using short reaction period (15 min) was 55 °C; however the enzyme couldn't continue active due to its short half-life time at such high temperature. In contrast, a lower optimum temperature (35 °C) was recorded when using long reaction period (5 h) where the enzyme showed long half-life time and stability at such degree of temperature. Consequently, a concomitant hydrolysis of sucrose by yeast invertase and hydrogen production by E. coli at 35 °C was conducted and showed a high potency for industrial application with a hydrogen yield of 0.48 mole hydrogen/mole reducing sugars using batch fermentation at optimum sucrose concentration of 10 g/L. The described approach might be applicable for biotechnologies of other bio-products by E. coli from sucrose as a carbon source. [ABSTRACT FROM AUTHOR]

Five chip sizes of freshly harvested hybrid poplar, ranging from 0.2 × 0.2 cm to 2.0 × 1.5 cm, plus an equal mixture of all the particles, were used to determine the influence of initial particle size on sugar recovery after steam explosion pretreatment and enzymatic hydrolysis. It was found that there is essentially no effect of particle size or particle size heterogeneity on sugar recovery. Enzymatic digestibility of solids from all the particles showed similar yields ranging from 78 to 82% glucan conversion after 72 h. The overall sugar recovery from all the samples ranged from 87 to 90% and 61–64% for glucose and xylose respectively and was not influenced by particle size. An unsteady heat transfer model was used to assess the intra-particle temperature profile of the wood during pretreatment. It was found that all the wood chips, regardless of size, are essentially isothermal. This supports the experimental result of no significant difference in sugar yields among different particle sizes. Steam pretreatment appears to be a robust method that can accommodate a wide range of particle sizes. [ABSTRACT FROM AUTHOR]

The invertase positive Yarrowia lipolytica A-101-B56-5 strain was analyzed for simultaneous production of citric acid (CA) and invertase in four media of different composition. The analysis was carried out as bioreactor batch cultures with sucrose as carbon source. The highest CA concentration (157 g/L) was noted in medium A (250 g sucrose, 7.50 g NH4Cl, 0.10 g KH2PO4, 5.00 g MgSO4×7H2O and 3.0 g yeast extract in 1 L). The yield of CA from consumed substrate reached 0.698 g/g, the volumetric productivity was 0.785 g/L/h and the specific production rate reached 0.018 g/g/h. In terms of invertase biosynthesis, the best medium was the rich medium D (150 g sucrose, 3.0 g yeast extract, 5.0 g malt extract and 5.0 g peptone in 1 L). The total invertase activity obtained in this medium reached 124 000 U/L. The final CA concentration in this medium was lower than in medium A, however, it presented the highest volumetric productivity (1.281 g/L/h), specific production rate (0.065 g/g/h) as well as the highest yield from biomass (4.704 g/g). This culture was also the shortest (72 h) among all tested processes. Surprisingly, the highest amount of secreted invertase (48.7%), calculated from the total invertase activity, was obtained for the process in medium A, and was six times higher than in the other media. This phenomenon was dependent on sucrose concentration, the accumulated biomass and the osmotic pressure of the medium. [ABSTRACT FROM AUTHOR]

During pretreatment, the pretreatment pH often plays an important role in removing hemicelluloses and lignin for improving the conversion of biomass to sugars. In this study, corn stover was subjected to magnesium bisulfite pretreatment (MBSP) under various pH conditions. The obtained data showed that the hemicelluloses and lignin were solubilized by MBSP, which led to changes in the structural and chemical properties of the pretreated material. The pretreatment pH could alter the existing forms of SO2, and magnesium bisulfite was the most effective reagent for removing lignin. A relatively neutral MBSP (pH 5.13) not only considerably improved the enzymatic hydrolysis yield (80.18%), but also produced a large amount of high-value xylo-oligosaccharides in the spent liquor. Furthermore, only the hemicellulose removal showed a linear relationship with the enzymatic hydrolysis yield. These results suggest that removal of all the lignin might not be necessary to improve the hydrolysis efficiency. [ABSTRACT FROM AUTHOR]

With the decreased demand for pulp and paper worldwide, the reorganization of pulp and paper mills for cellulosic sugar production is possible. To maximize cellulosic sugar production from the wood pulp with minimum resources, the effects of pH, buffer system, temperature, enzyme loadings, pulp concentrations, and mixing modes on enzymatic hydrolysis were investigated, one factor at a time. Temperature played an important role in enzymatic hydrolysis. When the temperature was lower than 45 °C, the sugar production declined dramatically to almost half of the maximum value. Increasing enzyme dosage, increasing pulp concentration, and adding xylanase increased sugar production. The intermittent manual mixing mode generated higher concentrations of sugars and could be used for large-scale production. At pilot-scale, the diverted pulp for the pulping process was directly hydrolyzed without any treatment, and the residue after hydrolysis was hydrolyzed by adding fresh enzymes. This study provides insight on economically feasible enzymatic hydrolysis of wood pulp at large-scale cellulosic sugar production. [ABSTRACT FROM AUTHOR]

The effectiveness of microwave-assisted sodium hydroxide pretreatments to enhance the saccharification performance of pineapple waste was evaluated. Microwave alkali pretreatments for short exposure times (up to 60 s) significantly improved the yield of the enzymatic hydrolysis compared with non-pretreated waste. The greatest increase of fermentable (35.7%) and total sugars (33.5%) was obtained at 6.375 W/g for 5 s. However, longer exposure times resulted in sugar degradation and released fermentation inhibitors, such as phenols or hydroxymethylfurfural (HMF), as a consequence of thermal degradation. Nevertheless, the obtained phenols values were not sufficient to inhibit subsequent fermentation. Scanning electron microscope (SEM) images confirmed that applying microwaves for short exposure times promoted structural changes that improved enzymatic hydrolysis. By contrast, an increase in the severity of the treatment led to a compacted structure, which hindered access to enzymes and consequently reduced the release of sugars into the medium. [ABSTRACT FROM AUTHOR]

In South Africa, approximately 3 × 106 tons of sugarcane bagasse is produced annually by 14 factories located on the north coast of KwaZulu- Natal. It is one of the most readily available lignocellulosic materials for ethanol production through enzymatic saccharification and hydrolysis. Pre-treatment enables disruption of the naturally resistant structure of lignocellulosic biomass to make the cellulose accessible to hydrolysis for conversion to biofuels. In this study, pre-treatment of depithed bagasse and mill-run bagasse was done using acid (3% H2SO4 v/v) followed by alkali (4% NaOH w/v), and the pre-treated solid was subjected to enzymatic hydrolysis. The effects of different conditions for enzymatic saccharification such as enzyme dose, reaction time, and amount of surfactant were studied in detail. The pre-treated substrate (10% w/v) when hydrolysed using 30 FPU/gds/40 FPU/g dry substrate (gds) with 0.4% (v/v) Tween® 80 for 20 h resulted in 608 mg/gds (depithed bagasse) and 604 mg/gds (mill-run bagasse) total reducing sugars. [ABSTRACT FROM AUTHOR]

Complete hydrolysis of κ-carrageenan produces two sugars, D-galactose and 3,6-anhydro-D-galactose (D-AnG). At present, however, we do not know how carrageenan-degrading microorganisms metabolize D-AnG. In this study, we investigated the metabolic pathway of D-AnG degradation by comparative genomic analysis of Cellulophaga lytica LIM-21, Pseudoalteromonas atlantica T6c, and Epulopiscium sp. N.t. morphotype B, which represent the classes Flavobacteria, Gammaproteobacteria, and Clostridia, respectively. In this bioinformatic analysis, we found candidate common genes that were believed to be involved in D-AnG metabolism. We then experimentally confirmed the enzymatic function of each gene product in the D-AnG cluster. In all three microorganisms, D-AnG metabolizing genes were clustered and organized in operon-like arrangements, which we named as the dan operon (3,6- d- anhydro-galactose). Combining bioinformatic analysis and experimental data, we showed that D-AnG is metabolized to pyruvate and D-glyceraldehyde-3-phosphate via four enzyme-catalyzed reactions in the following route: 3,6-anhydro-D-galactose → 3,6-anhydro-D-galactonate → 2-keto-3-deoxy-D-galactonate (D-KDGal) → 2-keto-3-deoxy-6-phospho-D-galactonate → pyruvate + D-glyceraldehyde-3-phosphate. The pathway of D-AnG degradation is composed of two parts: transformation of D-AnG to D-KDGal using two D-AnG specific enzymes and breakdown of D-KDGal to two glycolysis intermediates using two DeLey-Doudoroff pathway enzymes. To our knowledge, this is the first report on the metabolic pathway of D-AnG degradation. [ABSTRACT FROM AUTHOR]

Biorefineries aim to convert biomass into a spectrum of products ranging from biofuels to specialty chemicals. To achieve economically sustainable conversion, it is crucial to streamline the catalytic and downstream processing steps. In this work, a route that combines bio- and electrocatalysis to convert glucose into bio-based unsaturated nylon-6,6 is reported. An engineered strain of Saccharomyces cerevisiae was used as the initial biocatalyst for the conversion of glucose into muconic acid, with the highest reported muconic acid titer of 559.5 mg L−1 in yeast. Without any separation, muconic acid was further electrocatalytically hydrogenated to 3-hexenedioic acid in 94 % yield despite the presence of biogenic impurities. Bio-based unsaturated nylon-6,6 (unsaturated polyamide-6,6) was finally obtained by polymerization of 3-hexenedioic acid with hexamethylenediamine. [ABSTRACT FROM AUTHOR]

An enzyme free potentiometric sensor for reducing sugars (glucose and fructose) based on molecularly imprinted polymer (MIP) modified on glassy carbon electrode was systematically investigated. It was expected to work like a solid ion selective electrode (ISE) where the specific carrier are the imprinted sites. The polymer for the selective recognition of glucose and fructose were synthesized by coelectropolymerizing the 3-hydroxyphenyl boronic acid and phenol with reducing sugar (glucose or fructose) complex. The phenol could not only provide more hydroxyl but also promote the electron transfer because of its benzene ring structure and oxygen. The principle of reducing sugars detection at the MIP modified glassy carbon electrode (MIP/GCE) was to form a covalent binding which was reversible when changing the binding conditions and had a quick response to the electrochemical potential of the fabricated sensor. The imprinted polymer films covered on the electrode surface could improve the sensitivity of the sensor response remarkably. Under the optimal experimental conditions, the potential change and the concentration of glucose and fructose were linearly related from 0.75 to 18 mM. The detection limit of glucose and fructose was 0.23 mM and 0.35 mM, respectively. In addition, we had successfully evaluated the applicability of the sensitive sensor according to detect reducing sugars in practical samples. [ABSTRACT FROM AUTHOR]

Wheat straw is a potential feedstock in biorefinery for sugar production. However, the cellulose, which is the major source of sugar, is protected by lignin. Ozonolysis deconstructs the lignin and makes cellulose accessible to enzymatic digestion. In this study, the change in lignin concentration with different ozonolysis times (0, 1, 2, 3, 5, 7, 10, 15, 20, 30, 60 min) was fit to two different kinetic models: one using the model developed by Garcia-Cubero et al. (2012) and another including an outer mass transfer barrier or “cuticle” region where ozone mass transport is reduced in proportion to the mass of unreacted insoluble lignin in the cuticle. The kinetic parameters of two mathematical models for predicting the soluble and insoluble lignin at different pretreatment time were determined. The results showed that parameters derived from the cuticle-based model provided a better fit to experimental results compared to a model without a cuticle layer. [ABSTRACT FROM AUTHOR]

The major carbohydrate in red macroalgae is agarose, which is composed of d -galactose and 3,6-anhydro- l -galactose (AHG). So far, agarose saccharification was most efficiently achieved by prehydrolysis using a weak acid and subsequent enzymatic hydrolysis into monomeric sugars. However, this process requires rigorous neutralization after acid prehydrolysis, resulting in the formation of salts. Moreover, residual agarotriose is not further hydrolyzed by currently available β-agarases. In this study, we aimed at eliminating or minimizing the neutralization step by using a low-concentration acid-base buffer such as 20 mM (0.3%, w/v) Tris–HCl for hydrothermal pretreatment of agar at 170 °C for 10 min. In order to hydrolyze agarotriose, an agarolytic β-galactosidase acting on odd-numbered agarooligosaccharides, was introduced into the enzymatic saccharification. Using these chemical and enzymatic processes, the monomeric sugar yields of 44.9% for galactose and 44.8% for AHG on the basis of their theoretical maximum amounts from the initial agar were obtained. [ABSTRACT FROM AUTHOR]

This study aims to determine the optimum parameters for the invert sugar obtaining, using the acid hydrolysis at t °C. The inversion reaction has been applied to 3 samples of sugar solution of different concentration (P1: SU = 70%, P2: SU = 75%, P3: SU = 80%). For obtaining the invert sugar syrup, different inversion temperatures have been used (t1 = 80°C, t2 = 90°C, t3 = 100°C). The inversion has been done in the presence of the citric acid (c = 0.5 g citric acid / 100 ml solution). The invert sugar is used as a total or partial substitute of the glucose syrup in the confectionery manufacture. Added in the sucrose syrup, it contributes to increase the dry matter/substances content and prevents the binding molecules of sucrose together, so it has the role of anti-crystallization. Based on this study, we have determined the optimum parameters for the invert sugar obtaining, depending on the content in reducing substances of the samples after the inversion operation. As a conclusion, we have got the following results: The inversion process carried out with maximum efficiency for the following samples: sample P1 with a reducing matters content of 40.64% at the temperature of 80°C; sample P2 with a reducing matters content of 45.2% at the temperature of 90°C; sample P3 with a reducing matters content of 76.40% at the temperature of 100°C. [ABSTRACT FROM AUTHOR]

In the production of beverages, cookies, and candies, citric acid is often used as preservative or flavoring agent. Due to the sensitivity in stability of saccharose concerning pH and temperature, it is necessary to know how these two parameters affect the inversion of sugar and therefore the changes in the characteristics of saccharose crystallization. It can be shown that the inversion speed increases with increasing temperature. Also, the exposure time to the acid as well as the amount of acid lead to an increased inversion and therefore need to be controlled in industrial processes. With a temperature difference of 10 °C, inversion increases by the use of 2.13 % citric acid, e.g., by more than 250 %. The metastable zone shifts, but does not change in its width while inversion takes place and the solubility and nucleation curves are shifted to lower temperatures. [ABSTRACT FROM AUTHOR]

Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose phosphate synthase (SPS), soluble acid (SAI) and cell wall (CWI) invertases are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and qRT-PCR. Quantitative RT-PCR at four crop stages revealed high CWI expression in upper internodes of CoJ64, which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in top and bottom internodes and declined significantly only in top internodes as the crop matured. Overall, CWI expression was higher in CoJ64 than in BO91. During crop growth, there was no significant change in SPS expression in bottom internodes in CoJ64, whereas in BO91 it decreased significantly. Apart from a significant decrease in expression of SuSy in mature bottom internodes of BO91, there was no significant change. Similar SAI expression was observed with both end-point and RT-PCR, except for significantly increased expression in top internodes of CoJ64 with maturity. SAI, being a major sucrose hydrolysing enzyme, was also monitored with end-point PCR expression in internode tissues of CoJ64 and BO91, with higher expression of SAI in BO91 at early crop stages. Enzyme inhibitors, e.g. manganese chloride (Mn++), significantly suppressed expression of SAI in both early- and late-maturing varieties. Present findings enhance understanding of critical sucrose metabolic gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, through employing these genes, improvement of sugarcane sucrose content is possible. [ABSTRACT FROM AUTHOR]

The specific elimination of lignin derivatives from wood hydrolysate without sugar loss has great practical significance to biorefinery and bioenergy. In the present study, a process consisting of calcium hydroxide and anion exchange resin treatments was developed for the purpose of selective removal of lignin from wood prehydrolysis liquor (PHL). Particular emphasis was made on the ionization of phenolic lignin, and the subsequent binding to metallic salts. It was observed that phenolic hydroxyl groups (PhOH) in lignin played an important role in lignin removal. The results showed that up to 95.2% lignin was removed from PHL with 78.8% sugar recovery. This suggested that the proposed process is highly specific to lignin, and therefore can be envisaged as a great contribution to wood-sugar production or bioenergy conversion. [ABSTRACT FROM AUTHOR]

In this study, pretreatment liquor of acid-stored green and yellowish barley silage was used for fermentative acetone-butanol-ethanol (ABE) production. Further, the catalytic oxidation of biobutanol over Pt catalysts was studied to investigate the behaviour of butanol as a fuel in the combustion engine. After the hydrothermal treatment of green and yellowish barley silage followed by enzymatic hydrolysis, approximately 88% and 100% of the available sugars were recovered, respectively. Batch fermentations of pretreatment barley silage liquor, supplemented with gelatinised barley grain, showed good fermentability with total ABE concentrations of 9.0 g/L and 10.9 g/L. Butanol yields of 0.20, 0.17 and ABE yields of 0.28, 0.26 (g/g monosaccharide) were obtained, respectively. In catalytic activity measurements, the conversion of biobutanol became appreciable in the 120-140°C range, whereas conversions greater than 95% were obtained over 200 °C. Selectivities were also high, although formation of by-products, such as butyraldehyde, was observed. [ABSTRACT FROM AUTHOR]

Inhibitors released by the breakdown of plant cell walls prevent efficient conversion of sugar into ethanol. The aim of this study was to develop a fast and reliable inhibitor sensitivity assay for ethanologenic yeast strains. The assay comprised bespoke 96-well plates containing inhibitors in isolation or combination in a format that was compatible with the Phenotypic Microarray Omnilog reader (Biolog, hayward, CA, USA). A redox reporter within the assay permits analysis of inhibitor sensitivity in aerobic and/or anaerobic conditions. Results from the assay were verified using growth on spot plates and tolerance assays in which maintenance of viability was assessed. The assay allows for individual and synergistic effects of inhibitors to be determined. It was observed that the presence of both acetic and formic acid significantly inhibited the yeast strains assessed, although this impact could be partially mitigated by buffering to neutral pH. Scheffersomyces stipitis, Candida spp., and Pichia guilliermondii demonstrated increased sensitivity to short chain weak acids at concentrations typically present in lignocellulosic hydrolysates. S. cerevisiae exhibited robustness to short chain weak acids at these concentrations. However, S. stipitis, Candida spp., and P. guilliermondii displayed increased tolerance to HMF when compared to that observed for S. cerevisiae. The results demonstrate that the phenotypic microarray assay developed in the current study is a valuable tool that can be used to identify yeast strains with desirable resistance to inhibitory compounds found in lignocellulosic hydrolysates. [ABSTRACT FROM AUTHOR]

Highlights: [•] New mutant T. Koningii MF6 was developed with enhanced cellulase production. [•] High sugar yield of 770–844mg/g OPEFB was obtained at high OPEFB loading. [•] High cellulose to glucose conversion (>84%) was obtained at high solid loading. [•] Sugar titer reached 125.5g/L at 72h and 135.1g/L at 96h for 16% (w/v) OPEFB. [Copyright &y& Elsevier]

Sugar metabolism and sugar signalling are not only critical for plant growth and development, but are also important for stress responses. However, how sugar homeostasis is involved in plant defence against pathogen attack in the model crop rice remains largely unknown. In this study, we observed that the grains of gif1, a loss-of-function mutant of the cell wall invertase gene GRAIN INCOMPLETE FILLING 1 ( GIF1), were hypersusceptible to postharvest fungal pathogens, with decreased levels of sugars and a thinner glume cell wall in comparison with the wild-type. Interestingly, constitutive expression of GIF1 enhanced resistance to both the rice bacterial pathogen Xanthomonas oryzae pv. oryzae and the fungal pathogen Magnaporthe oryzae. The GIF1-overexpressing ( GIF1- OE) plants accumulated higher levels of glucose, fructose and sucrose compared with the wild-type plants. More importantly, higher levels of callose were deposited in GIF1- OE plants during pathogen infection. Moreover, the cell wall was much thicker in the infection sites of the GIF1- OE plants when compared with the wild-type plants. We also found that defence-related genes were constitutively activated in the GIF1- OE plants. Taken together, our study reveals that sugar homeostasis mediated by GIF1 plays an important role in constitutive and induced physical and chemical defence. [ABSTRACT FROM AUTHOR]

Inthis study a forest biorefinery concept based on larch woodwas technically and economically evaluated. Two slightly differentcases of a larch-based biorefinery were compared to conventional kraftpulping. The wood chips of Larix sibirica(Lebed.) were pre-extracted (PE) and washed with water prior topulping, in order to generate an additional sugar side-stream. Thesugars were hydrolyzed into monosugars, which were then fermentedby Bacillus coagulansinto lactic acid.The lactic acid needs to be purified before sold to the market. Bypulping the pre-extracted wood chips with anthraquinone (AQ) and polysulfide(PS), the pulp yield loss was reduced. The pulp was then bleached(O-D0-Ep-D1-P). The products of this larch biorefinery are bleachedsoftwood pulp and lactic acid. Three process cases were simulated:conventional kraft pulping, PE-PSAQ with 0.5% PS, and PE-PSAQ with2% PS, in terms of mass and energy balances. Considering the availabilityof larch resources, this kind of a biorefinery could suitably be locatedin Siberia, Russia. Market prices were collected, and based on thesimulation results, cash flows were determined. Sensitivity analysiswas carried out, and investment costs were estimated. Based on thesimulation with the addition of a lactic acid production line to anexisting pulp mill, the payback time for the investment costs wouldbe about 16 months. [ABSTRACT FROM AUTHOR]

Some date palm cultivars grown in Pakistan were biochemically characterized and the effect of fruit maturity on radical scavenging capacity (DPPH), total phenolic contents (TPC), specific activity of antioxidant enzymes, sugars profile and soluble protein contents was assessed. Higher range of differences in composition of studied phytochemicals was recorded among different cultivars. Antiradical efficiency (AE), TPC, antioxidant enzymes and soluble protein contents were recorded higher at khalal stage thereafter, declined at rutab then finally at tamar stage. The amount of glucose (11.32-32.50%) and fructose (10.95-32.41%) started accumulation from khalal stage and were in higher composition at tamar stage due to hydrolysis and inversion of sucrose (10.82-3.1%) contents. The results concluded that variation in biochemical attributes primarily influenced by type of cultivars and different fruit developmental stages. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mechanical refining improved the enzymatic hydrolysis sugar recovery. [•] The increase in sugar recovery correlated with the water retention value. [•] Mechanical refiners with different mechanisms affected the biomass digestibility differently. [•] A maximum in absolute enzymatic hydrolysis improvement due to refining was observed. [•] The maximum occurred at conditions that produced intermediate hydrolysis conversions. [Copyright &y& Elsevier]

The article focuses on a study that discusses effect of steam explosion pretreatment on sugar Production by Enzymatic Hydrolysis. Topics discussed include effect of pretreatment on sugar under different temperature, structural properties of reed straw grass to analyze increased sugar yield and use of Fourier transform infrared spectrophotometry (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) to investigate steam explosion-induced changes.

Thermobifida fusca is a moderately thermophilic soil bacterium belonging to Actinobacteria. It has been known for its capability to degrade plant cell wall polymers except lignin and pectin. To know whether it can produce enzymes to facilitate lignin degradation, the extracellular proteins bound to sugarcane bagasse were harvested and identified by liquid chromatography tandem mass spectrometry. Among the identified proteins, a putative copper-containing polyphenol oxidase of 241 amino acids, encoded by the locus Tfu_1114, was thought to presumably play a role in lignin degradation. This protein (Tfu1114) was thus expressed in E. coli and characterized. Similarly to common laccases, Tfu1114 is able to catalyze the oxidation reaction of phenolic and nonphenolic lignin related compounds such as 2,6-dimethoxyphenol and veratryl alcohol. More interestingly, it can significantly enhance the enzymatic hydrolysis of bagasse by xylanase and cellulase. Tfu1114 is stable against heat, with a half-life of 4.7 h at 90 °C, and organic solvents. It is sensitive to ethylenediaminetetraacetic acid and reducing agents but resistant to sodium azide, a potent inhibitor of laccases. Atomic absorption spectroscopy indicated that the ratio of copper to the protein monomer is 1, instead of 4, a feature of classical laccases. All these data suggest that Tfu1114 is a novel oxidase with laccase-like activity, potentially useful in biotechnology application. [ABSTRACT FROM AUTHOR]

A series of sulfonic acid-functionalized carbon materials (C–SO3H), including poly(p-styrenesulfonic acid)-grafted carbon nanotubes (CNT-PSSA), poly(p-styrenesulfonic acid)-grafted carbon nanofibers (CNF-PSSA), benzenesulfonic acid-grafted CMK-5 (CMK-5-BSA), and benzenesulfonic acid-grafted carbon nanotubes (CNT-BSA), have been studied for fructose dehydration to 5-hydroxymethylfurfural (HMF) and fructose alcoholysis to alkyl levulinate. A study for optimizing the reaction conditions such as the catalyst loading, the reaction time, and the temperature has been performed. Under the optimal conditions, high HMF and ethyl levulinate yields of up to 89% and 86%, respectively, are obtained. The catalytic activities of C–SO3H for the conversions of fructose into both HMF and ethyl levulinate follow the order of their acid strength. The relationship between the catalytic activity and acid density of C–SO3H shows a linear correspondence in the fructose dehydration to HMF. The facile separation, ease of recovery, and high thermal stability make the developed C–SO3H efficient and environment-friendly catalytic materials for transforming biomass carbohydrate into fine chemicals. [ABSTRACT FROM AUTHOR]

Heterogeneous graphene oxide (GO)-based catalysts with sulfonic acid (SO3H) functional groups (GO–SO3H) were used for the selective decomposition of the hexose sugars, glucose and fructose into levulinic acid (LA), which has been used as a platform chemical for various value-added derivatives. The GO–SO3H catalysts gave high yields of around 78% for LA and showed good reuse compatibility with reliable performance. The chemical transformation patterns for hexose sugar decompositions are affected by the temperature, the density of acid sites, and the type of catalyst. The high catalytic performance of GO–SO3H was shown to result from the higher density of Brønsted acid sites in the GO, compared with the Lewis acid sites in other AC–SO3H catalysts. The morphology, surface characteristics, and other physiochemical properties were evaluated using several characterization techniques. [ABSTRACT FROM AUTHOR]

The global diffusion of the so-called Western diet, which is enriched in fat and carbohydrates, such as fructose, has been proposed to be an underlying cause of the increased prevalence of metabolic conditions, including nonalcoholic fatty liver disease (NAFLD). This Smart Card summarizes the main metabolic and hepatic histological features of rodent models fed with diets combining high fat and fructose [ABSTRACT FROM AUTHOR]

Biomass pretreatment using certain ionic liquids (ILs), such as 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), can be highly effective at reducing the recalcitrance of lignocellulosic biomass to enzymatic degradation. However, current commercial enzyme cocktails, derived from filamentous fungi and developed for dilute acid pretreatment, are inhibited by the most effective ILs used for pretreatment and require excessive amounts of water to remove the ILs from biomass after pretreatment in order to be effective. The associated IL recycling and waste disposal costs of this process pose significant economic and process engineering challenges for the commercial scale-up of IL pretreatment-based technologies. For the first time, we have demonstrated a one-pot, wash-free process that combines IL pretreatment and saccharification into a single vessel. After treating the switchgrass with [C2mim][OAc] and dilution with water to a final IL concentration of 10–20%, the pretreatment slurry was directly hydrolyzed using a thermostable IL tolerant enzyme cocktail previously developed at the Joint BioEnergy Institute (JBEI). This one-pot process liberated 81.2% glucose and 87.4% xylose (monomers and oligomers) at 72 h at 70 °C with an enzyme loading of 5.75 mg g−1 of biomass at 10% [C2mim][OAc]. Glucose and xylose were selectively separated by liquid–liquid extraction with over 90% efficiency, thus eliminating extensive water washing as a unit operation. This study opens avenues for developing more efficient and cost effective processes for product recovery and IL recycling. [ABSTRACT FROM AUTHOR]

The objective of this extensive series of experiments, involving more than 2800 field cage tests with potted mango trees, was to assess pre-release supplements to enhance the mating success of sterile male Bactrocera dorsalis and Bactrocera correcta. We examined the effects of different pre-release diets and methyl eugenol (ME), both independently and in combination. Tests were carried out more than 15 and 18 days for B. dorsalis and B. correcta, respectively, each day increasing the age of sterile flies. To evaluate the effect of different pre-release diets on males, no-choice mating tests were conducted with sterile males of increasing age and mature sterile females. Sterile males fed up to 2 days of age on sugar-yeast hydrolysate combinations achieved significantly more matings than males fed only water in B. dorsalis and more matings than males fed only sugar, only yeast hydrolysate or only water in B. correcta. To examine the effect of ME on mating performance, 2-, 3-, 4- or 5-day-old sterile males were given or not given access to ME for 1 h, followed by the sugar-protein diet until the day of the mating test. Mating performance tests were carried out with ME-exposed and non-exposed sterile males competing with mature wild males for wild females. Results showed a significant mating advantage of ME-exposed over non-exposed sterile males, although at younger ages they were still less competitive than wild males. The interaction of sugar-yeast hydrolysate diet and ME as pre-release treatments for 2- and 3-day-old sterile males was assessed in terms of male sexual competitiveness. Overall, the combination showed an additive effect on increased mating success in B. dorsalis sterile males when competing a wild males for wild females, while in B. correcta males the drastic improvement in mating success was mainly linked to the ME exposure. [ABSTRACT FROM AUTHOR]

Abstract: A simple process of biotransformation carried out in a batch reactor in the presence of native enzyme undergoing deactivation independent of substrate concentration has been analyzed. An analytical expression has been derived enabling answering the question how much of enzyme can be saved if instead of commonly applied isothermal conditions an optimal temperature control without its limitations were used. An effect of the quotient of the activation energy on the magnitude of such benefits has also been considered. It has also been proved that the reaction kinetics has no influence on the derived expression. Based on an example of sucrose hydrolysis by immobilized invertase the obtained result has been verified. [Copyright &y& Elsevier]

The production of cellulosic ethanol from biomass is considered a promising alternative to reliance on diminishing supplies of fossil fuels, providing a sustainable option for fuels production in an environmentally compatible manner. The conversion of lignocellulosic biomass to biofuels through a biological route usually suffers from the intrinsic recalcitrance of biomass owing to the complicated structure of plant cell walls. Currently, a pretreatment step that can effectively reduce biomass recalcitrance is generally required to make the polysaccharide fractions locked in the intricacy of plant cell walls to become more accessible and amenable to enzymatic hydrolysis. Dilute acid and hydrothermal pretreatments are attractive and among the most promising pretreatment technologies that enhance sugar release performance. This review highlights our recent understanding on molecular structure basis for recalcitrance, with emphasis on structural transformation of major biomass biopolymers (i.e., cellulose, hemicellulose, and lignin) related to the reduction of recalcitrance during dilute acid and hydrothermal pretreatments. The effects of these two pretreatments on biomass porosity as well as its contribution on reduced recalcitrance are also discussed. [ABSTRACT FROM AUTHOR]

Background: The enzymatic hydrolysis step converting lignocellulosic materials into fermentable sugars is recognized as one of the major limiting steps in biomass-to-ethanol process due to the low efficiency of enzymes and their cost. Xylanases have been found to be important in the improvement of the hydrolysis of cellulose due to the close interaction of cellulose and xylan. In this work, the effects of carbohydrate-binding module (CBM family II) of the xylanase 11 from Nonomuraea flexuosa (Nf Xyn11) on the adsorption and hydrolytic efficiency toward isolated xylan and lignocellulosic materials were investigated. Results: The intact family 11 xylanase of N. flexuosa clearly adsorbed on wheat straw and lignin, following the Langmuir-type isotherm. The presence of the CBM in the xylanase increased the adsorption and hydrolytic efficiency on insoluble oat spelt xylan. But the presence of the CBM did not increase adsorption on pretreated wheat straw or isolated lignin. On the contrary, the CBM decreased the adsorption of the core protein to lignin containing substrates, indicating that the CBM of N. flexuosa xylanase did not contribute to the non-productive adsorption. Conclusion: The CBM of the N. flexuosa xylanase was shown to be a xylan-binding module, which had low affinity on cellulose. The CBM of the N. flexuosa xylanase reduced the non-specific adsorption of the core protein to lignin and showed potential for improving the hydrolysis of lignocellulosic materials to platform sugars. [ABSTRACT FROM AUTHOR]

Background: Woody biomass is one of the most abundant biomass feedstocks, besides agriculture residuals in the United States. The sustainable harvest residuals and thinnings alone are estimated at about 75 million tons/year. These forest residuals and thinnings could produce the equivalent of 5 billion gallons of lignocellulosic ethanol annually. Softwood biomass is the most recalcitrant biomass in pretreatment before an enzymatic hydrolysis. To utilize the most recalcitrant lignocellulosic materials, an efficient, industrially scalable and cost effective pretreatment method is needed. Results: Obtaining a high yield of sugar from recalcitrant biomass generally requires a high severity of pretreatment with aggressive chemistry, followed by extensive conditioning, and large doses of enzymes. Catchlight Energy's Sugar process, CLE Sugar, uses a low intensity, high throughput variation of bisulfite pulping to pretreat recalcitrant biomass, such as softwood forest residuals. By leveraging well-proven bisulfite technology and the rapid progress of enzyme suppliers, CLE Sugar can achieve a high yield of total biomass carbohydrate conversion to monomeric lignocellulosic sugars. For example, 85.8% of biomass carbohydrates are saccharified for un-debarked Loblolly pine chips (softwood), and 94.0% for debarked maple chips (hardwood). Furan compound formation was 1.29% of biomass feedstock for Loblolly pine and 1.10% for maple. At 17% solids hydrolysis of pretreated softwood, an enzyme dose of 0.075 g Sigma enzyme mixture/g dry pretreated (unwashed) biomass was needed to achieve 8.1% total sugar titer in the hydrolysate and an overall prehydrolysate liquor plus enzymatic hydrolysis conversion yield of 76.6%. At a much lower enzyme dosage of 0.044 g CTec2 enzyme product/g dry (unwashed) pretreated softwood, hydrolysis at 17% solids achieved 9.2% total sugar titer in the hydrolysate with an overall sugar yield of 85.0% in the combined prehydrolysate liquor and enzymatic hydrolysate. CLE Sugar has been demonstrated to be effective on hardwood and herbaceous biomass, making it truly feedstock flexible. Conclusions: Different options exist for integrating lignocellulosic sugar into sugar-using operations. A sugar conversion plant may be adjacent to a CLE Sugar plant, and the CLE Sugar can be concentrated from the initial 10% sugar as needed. Concentrated sugars, however, can be shipped to remote sites such as ethanol plants or other sugar users. In such cases, options for shipping a dense form of sugars include (1) pretreated biomass with enzyme addition, (2) lignocellulosic sugar syrup, and (3) lignocellulosic sugar solid. These could provide the advantage of maximizing the use of existing assets. [ABSTRACT FROM AUTHOR]

The work develops the simulation of one of the varying proposals in order to make the acid hydrolysis of the process of breaking up of the bagasse, inside the concept of [biorrefinería], in the program Aspen Plus 11.1 looking for an approach to the operation of the process to real scale. The data of the case base feigned they come from studies to scale of laboratory developed by Morales and collaborators, (2011). It also are carried out it with the simulation base an analysis of sensibility of the flow of products of interest in the stage with regard to changes of temperature and pressure in the posterior separation to the reaction. [ABSTRACT FROM AUTHOR]

Sugars, such as sucrose or invert sugar, have been used as tobacco ingredients in American-blend cigarettes to replenish the sugars lost during curing of the Burley component of the blended tobacco in order to maintain a balanced flavor. Chemical-analytical studies of the mainstream smoke of research cigarettes with various sugar application levels revealed that most of the smoke constituents determined did not show any sugar-related changes in yields (per mg nicotine), while ten constituents were found to either increase (formaldehyde, acrolein, 2-butanone, isoprene, benzene, toluene, benzo[ k]fluoranthene) or decrease (4-aminobiphenyl, N-nitrosodimethylamine, N-nitrosonornicotine) in a statistically significant manner with increasing sugar application levels. Such constituent yields were modeled into constituent uptake distributions using simulations of nicotine uptake distributions generated on the basis of published nicotine biomonitoring data, which were multiplied by the constituent/nicotine ratios determined in the current analysis. These simulations revealed extensive overlaps for the constituent uptake distributions with and without sugar application. Moreover, the differences in smoke composition did not lead to relevant changes in the activity in in vitro or in vivo assays. The potential impact of using sugars as tobacco ingredients was further assessed in an indirect manner by comparing published data from markets with predominantly American-blend or Virginia-type (no added sugars) cigarettes. No relevant difference was found between these markets for smoking prevalence, intensity, some markers of dependence, nicotine uptake, or mortality from smoking-related lung cancer and chronic obstructive pulmonary disease. In conclusion, thorough examination of the data available suggests that the use of sugars as ingredients in cigarette tobacco does not increase the inherent risk and harm of cigarette smoking. [ABSTRACT FROM AUTHOR]

We report the study of the dynamics of substrate utilization by the genetic modified strain Yarrowia lipolytica H222-S4(p67ICL1) T5. In contrast to its wild-type equivalent, this recombinant strain is able to excrete the sucrose cleaving enzyme invertase. Both the sucrose degradation rate and the glucose and fructose consumption rate have been investigated. In all experiments, satisfied amounts of invertase were produced so that all sucrose was cleaved into its monomers. While glucose and fructose as sole carbon sources were consumed with the same uptake rate, a clear preference for glucose uptake was detected in cultivations with sucrose as sole carbon source or mixed substrates when compared with fructose. Nevertheless, no real diauxie could be observed because of partly simultaneous consumption of both monosaccharides. Fructose being present in the cultivation medium at the beginning of the fermentation led to the retardation of glucose uptake. This effect was observed for various fructose starting concentrations in the range of 5-85 g/l. [ABSTRACT FROM AUTHOR]

The present study investigates the operational conditions for organosolvent pretreatment and hydrolysis of rice straw. Among the different organic acids and organic solvents tested, acetone was found to be most effective based on the fermentable sugar yield. Optimization of process parameters for acetone pretreatment were carried out. The structural changes before and after pretreatment were investigated by scanning electron microscopy, X-ray diffraction and Fourier transform infrared (FTIR) analysis. The X-ray diffraction profile showed that the degree of crystallinity was higher for acetone pretreated biomass than that of the native. FTIR spectrum also exhibited significant difference between the native and pretreated samples. Under optimum pretreatment conditions 0.458 g of reducing sugar was produced per gram of pretreated biomass with a fermentation efficiency of 39%. Optimization of process parameters for hydrolysis such as biomass loading, enzyme loading, surfactant concentration and incubation time was done using Box-Benhken design. The results indicate that acetone pretreated rice straw can be used as a good feed stock for bioethanol production. [ABSTRACT FROM AUTHOR]

Abstract: Fucoidan was isolated and purified from the brown algae Fucus evanescens and subjected to autohydrolysis to obtain low-molecular-weight fragments. MALDI-TOFMS analysis has shown that monosulfated fucose and more heavily sulfated (up to 5) fucooligosaccharides with polymerization degree (DP) 2, 4 and 6, including galactose-containing sulfated oligosaccharides were the products of autohydrolysis. The structural features of these fragments were elucidated by negative-ion potential lift tandem MALDI-TOF mass-spectrometry using arabinoosazone as a matrix, which allowed reducing the in-source fragmentation. Native fucoidan has been shown to exert anticancer activities in both human malignant melanoma cell lines SK-MEL-28 and SK-MEL-5. Low-molecular-weight fragments exhibited almost no action to cell proliferation in both cell lines and colony formation on SK-MEL-5 cells, but its inhibition activity to the colony formation of SK-MEL-28 cell lines was as high as was demonstrated by native fucoidan (70%). Probably, the inhibiting activity for SK-MEL-28 depended on the presence of sulfates and (1→4)-linked α-l-Fucp residues in the main chain of fucoidan/oligosaccharides. [Copyright &y& Elsevier]

Abstract: A new α-amylase from Anoxybacillus flavothermus (AFA) was found to be effective in hydrolyzing raw starch in production of glucose syrup at temperatures below the starch gelatinization temperature. AFA is very efficient, leading to 77% hydrolysis of a 31% raw starch suspension. The final hydrolysis degree is reached in 2–3h at starch concentrations lower than 15% and 8–24h at higher concentrations. AFA is also very efficient in hydrolyzing the crystalline domains in the starch granule. The major A-type crystalline structure is more rapidly degraded than amorphous domains in agreement with the observed preferential hydrolysis of amylopectin. Amylose–lipid complexes are degraded in a second step, yielding amylose fragments which then re-associate into B-type crystalline structures forming the final α-amylase resistant fraction. The mode of action of AFA and the factors limiting complete hydrolysis are discussed in details. [Copyright &y& Elsevier]