Mixture Of Glucose Research Articles

Rapid quantitative detection of glucose using biological sensor system as combined with electrochemical data treatment

ABSTRACT In this paper, glucose quantitative detection by biological sensor and electrochemical capacitance data treatment was studied. The taste cells were fixed on carbon screen-printed electrode. Electrochemical capacitance responses of cell-based sensor to sucrose in different concentrations and related mixtures were measured. Glucose quantitative analysis results demonstrated that the proposed method had quantitative determination abilities toward glucose and related mixtures. The signal-to-noise ratio index presented qualitative discrimination abilities to different glucose mixtures. Negative control results indicated that the receptor-free cells showed no perception ability for glucose. The proposed method is promising in sugar rapid detection.

Catalytic Conversion of High Fructose Corn Syrup to Methyl Lactate with Coo@Silicalite-1

Methyl lactate (MLA), a versatile biomass platform, was typically produced from the catalytic conversion of high-priced fructose in most research studies. High fructose corn syrup (HFCS) is a mixture of glucose, fructose, and water, and an economical substitute for fructose to produce MLA due to the much lower cost of separation and drying processes. However, the transformation of HFCS to MLA is still a challenge due to its complex components and the presence of water. In this work, the catalytic conversion of HFCS to MLA over CoO@silicalite-1 catalyst synthesized via a straightforward post citric acid treatment has been reported. The maximum MLA yield reached 43.8% at 180 oC for 18 h after optimizing the reaction conditions and Co loading. Interestingly, adding extra 3% water could further increase the MLA yield, implying that our CoO@silicalite-1 catalyst is also capable for upgrading wet HFCS. As a result, the costly drying process of wet HFCS can be avoided. Moreover, the activity of CoO@silicalite-1 catalyst can be regenerated for at least four cycles via facile calcination in air. This study, therefore, will provide a new opportunity to not only solve the HFCS-overproduction issues but also produce value-added MLA.

Impact of In-Ovo Injection of Folic Acid and Glucose on Hatchability and Post-Hatching Performance of Broiler Chicken

The present study was designed to investigate the impact of in-ovo injection of folic acid and glucose on hatching eggs from 55 weeks old broiler breeders. A total number of 900 hatching eggs were collected from Arbor Acres broiler breeders, then, eggs were divided into 6 groups including 1) Negative Control (non-injected, NC), 2) Dry Punch Control (pricked without injecting any solution, DPC), 3) Positive Control (eggs were injected with 0.5 mL normal saline, PC), 4) Folic Acid group (eggs were injected with 0.2 mg/ egg folic acid, FA), 5) Glucose group (eggs were injected with 125 mg/ egg glucose, Glu), and 6) Folic Acid with Glucose group (eggs were injected with 0.2 mg folic acid with 125 mg/ egg glucose, FA+Glu). Each treatment was divided into five replicates of 30 eggs each. Eggs were injected into the albumen under the air sac. After in-ovo injection, the eggs were stored for four days before hatching. After hatching, the chickens were reared in groups according to the treatments. All treatments were divided into 10 replications of 9 chickens in each. In-ovo injection with folic acid decreased the albumen pH significantly to 9.19 after 4 days of injection, while the negative control was 9.43. Hatching quality was severely affected by all in-ovo injection treatments, but no significant differences were found between the treatment groups concerning the hatchability of fertile eggs. Injection treatments had no significant effect on the growth rate or the production number in any of the weeks. Injection of folic acid and (FA+Glu) significantly increased chickens’ body weight at two and four weeks of age. Also, the dressing percentage when using folic acid and (FA+Glu) was significantly increased to 72.1% and 72.5%, respectively, compared to the positive control group (68.3%). In conclusion, our data suggested that in-ovo injection with a mixture of folic acid and glucose (0.2 mg folic acid+ 125 mg/ egg glucose) could be used to enhance carcass characteristics. Further studies should be conducted to find the effects of in-ovo injection folic acid and glucose on different incubation days and at different sites of injection.

Efficient catalytic removal of COS and H2S over graphitized 2D micro-meso-macroporous carbons endowed with ample nitrogen sites synthesized via mechanochemical carbonization

Developing a suitable catalyst for the elimination of highly toxic carbonyl sulfide (COS) and hydrogen sulfide (H2S) is of great significance in terms of industrial safety and environmental protection. We demonstrate here the facile synthesis of graphitized 2D micro-meso-macroporous carbons by one-step carbonization of a mixture of urea and glucose at 700–900 °C. The as-synthesized graphitized catalysts, designated as 2D-NHPC-x (x = urea/glucose mass ratio), are endowed with an ultra-high concentration (12.9–20.2 wt%) of stable and versatile nitrogen sites (e.g. pyrrole and pyridine) which are anchored on the surface via stable covalent bonding. As a result, the 2D-NHPC-x are active in catalytic hydrolysis of COS on pyrrolic N to H2S, and the H2S can be subsequently captured on pyridinic N and converted to elemental sulfur at ambient conditions over the same materials. Among the prepared catalysts, 2D-NHPC-x can catalytically hydrolysize 91% of COS to H2S at 30 °C, whereas the conversion ratio over the common catalysts g-C3N4 and Fe2O3 are below 6.0%. Furthermore, these catalysts also exhibit H2S conversion and sulfur selectivity of nearly 100% at 180 °C with long-time durability, which is higher than those of the most reported carbon-based catalysts. In contrast, the H2S capacities of activated carbon, ordered mesoporous carbons (OMC) and N-doped OMC are 3.9, 1.5 and 2.39 mmol g−1, respectively. Both the experimental and theoretical results are disclosed that 2D-NHPC-x are superior to the nitrogen-doped porous materials ever applied in simultaneous catalytic elimination of both COS and H2S.

Phytochemical, antibacterial, antioxidant and cytoxicity investigation of Tarenna grandiflora.

The phytochemical investigation of Tarenna grandiflora led to the isolation of 18 known compounds ofwhich were four flavones, three anthraquinones, one phenyl propanoic derivative, five triterpenoids, four steroids and a mixture of glucose. Luteolin (1) and soranjidiol (6) were allylated and/or prenylated to give four new semisynthesized derivatives which were fully characterized as 7,3',4'-O-triallylluteolin (1a), luteolin-7,3',4'-O-triprenyls (1b), luteolin-5,7,3',4'-O-tetraprenyls (1c) and 6-O-allylsoranjidiol (6a). Their structures were established using spectroscopic analysis including 1D, 2D NMR and MS data. The cytotoxic, antioxidant and antimicrobial activities of extracts, fractions, isolated compounds and semi-synthesized derivatives were evaluated. The petroleum ether and EtOAc extracts exhibited good cytotoxic potency on KB-3-1cell line with IC50 of >0.1 and 0.025mg/mL respectively, while compounds 1b and 11 were the most active (IC50>0.0001M). Compounds 1 and 3 showed the best antioxidant activities (45.5 and 55.8µM); while compounds 9 and 12 showed the best antibacterial activities with MICs values ranges from 8.55 to 132µM.

Simultaneous induction of anthocyanin and peroxidase by sucrose in hypocotyls and roots of Chinese red radish seedlings

Anthocyanin and peroxidase (POD) are important active compounds in Chinese red radish (Raphanus sativus L.). The effects of exogenous sucrose, mixture of fructose and glucose (F/G 1:1), and mannose on anthocyanin accumulation and POD activity were investigated in hypocotyls and roots of red radish seedlings. Sucrose was most effective in inducing anthocyanin accumulation and POD activity in both organs, followed by F/G; mannose caused only a little increase of anthocyanin content and POD activity in hypocotyls, but a decrease in roots. The distribution of anthocyanin accumulation was different between hypocotyls and roots in the presence or absence of sucrose. Anthocyanin was clearly induced in root tips and cortex under exogenous sucrose. Accumulation of anthocyanin was closely correlated to the increase of endogenous sucrose content rather than glucose or fructose content. Sucrose significantly induced the expressions of late anthocyanin biosynthetic genes by up-regulating Raphanus sativus myeloblastosis 1 and Raphanus sativus transparent testa 8 in both organs. The POD activity significantly increased following the remarkable accumulation of anthocyanin in hypocotyls under exogenous sucrose, which may be partially required for anthocyanin oxidation. In roots, the high POD activity might lead to a low anthocyanin content by degrading anthocyanin and diverting the metabolic flux to lignin synthesis.

In-situ synthesis of Co nanoparticles encapsulated in mesoporous Co, N-codoped graphene-like carbon hybrid as an efficient oxygen reduction electrocatalyst

Rational design and construction of robust electrocatalysts towards oxygen reduction reaction (ORR) are vital for energy conversion devices. Here, we report a hierarchically engineered Co nanoparticle (NP) encapsulated in Co, N codoped graphene-like carbon sample (Co@NC) via direct pyrolyzing the mixture of glucose, dicyandiamide and cobalt salt. Benefiting from the Co-N4 moiety and high content of doped N species (8.81 at.%) which highly dispersed on the large Co NP modified carbon surface, Co@NC sample delivers remarkable ORR catalytic performance with an onset potential of 0.98 V and a half-wave potential of 0.86 V together with robust durability, which outperforms the benchmark Pt/C catalyst and most of published Co-Nx-C samples in alkali. This facile mass-producible strategy undoubtedly provides an avenue to achieve highly active and durable practical-oriented electrocatalytic catalysts for wide electrochemical energy devices.

A universal sugar-blowing approach to synthesize fluorescent nitrogen-doped carbon nanodots for detection of Hg(II)

Fluorescent carbon nanodots (CDs) have been considered as promising materials for fluorescent sensing applications. However, preparation of CDs-based materials by a universal approach with high product yield is highly required. Herein, a novel sugar-blowing approach was reported to facilely synthesize nitrogen-doped CDs (N-CDs) by directly heating the mixture of glucose and dicyandiamide (DCDA) in the absence of any solvents. As a typical blowing agent to trigger sugar-blowing process, DCDA also serves as an ideal nitrogen dopant for N-CDs. For fluorescent sensing applications, a remarkable fluorescence quenching at 441 nm of N-CDs dispersion was observed after introduction of Hg(II). Consequently, as-synthesized N-CDs behaves as a highly sensitive fluorescent probe for Hg(II) detection with low detection limit of 50 nM and good selectivity. More importantly, our proposed approach is universal for synthesize fluorescent N-CDs from a wide of sugar precursors (glucose, fructose, maltose and lactose) and blowing agents (DCDA, melamine, urea, hexamethylenetetramine). The strategy demonstrated here provides insights into the rational design and synthesis of CDs-based functional materials for large-scale applications in various fields.

Role of Follicle Size, IGF-I, Glucose and Hormones on Nuclear Maturation Events of Awassi Sheep Oocytes (Ovis aries)

This experiment aimed to study the combined effect of each of the follicle size, insulin-like growth factor (IGF-I), glucose and hormones (growth hormone (GH) and luteinizing hormone (LH)) on different phases of in vitro nuclear maturation of Awassi sheep oocytes. Follicles diameters were divided into two main groups: small follicles (SF): 1-2 mm and large follicles (LF): >2 mm. The levels (μg/ml) of Insulin-Like Growth Factor (IGF-I), GH, LH and glucose (mM) were determined according to two increasing shared concentrations (A:5,5,1 and 50; B:10,5.5,5 and 100 respectively). The maturation events were monitored at 7-time intervals (0,3,6,9,12,21 and 27 hours). Before incubation (0 - hour time interval), the oocytes in SF group outperformed their counterparts of LF group in the germinal vesicle phase (92.45% Vs 74.46%; p=0.01). Down to the 6- hour time interval, the oocytes in B solution achieved the highest rates (24.52%; LF group), After 9 hours of incubation, the differences appeared clearly in the prometaphase -1(p=0.05) as half of the number of oocytes in B solution reached the stage (53.84%; LF group), the rates did not exceed 31.37% (A solution; SF group). In the 12 - hour time interval, the pro -metaphase-1 rates across the four groups reached the values :34.00% (A solution; SF group), 40.00% (B solution; LF group), 53.84% (A solution; SF group) and 58.49% (B solution; LF group) respectively. Upon 21- hour time interval, oocytes across the different groups showed a significant difference in metaphase-I (p=0.01) with the superiority of oocytes of B solution (33.96%; LF group). At the 24- hour time interval, the rates of oocytes involved in the metaphase-II were sub-intermediate and ranged between 20.00% and 36.00% without statistical significance. The final time interval (27- hours of incubation) showed a significant difference in the rates of the metaphase-II (p=0.002), as the oocytes of B solution showed a great superiority (84.61%; LF group). It is concluded from this study that the maturation of oocytes derived from large follicles (>2 mm) in a mixture of IGF-I, GH, LH (μg/ml) and glucose (mM) with the levels 10,5.5,5 and 100 respectively led to a significant increase in the rates of metaphase-II.

Synergistic Effect of Platinum Single Atoms and Nanoclusters Boosting Electrocatalytic Hydrogen Evolution

Maximizing atomic utilization of precious metal-based catalysts is of great significance in heterogeneous catalysis, also becoming a useful strategy to develop efficient electrocatalysts for hydrog...

Glucose-lactose mixture feeds in industry-like conditions: a gene regulatory network analysis on the hyperproducing Trichoderma reesei strain Rut-C30

BackgroundThe degradation of cellulose and hemicellulose molecules into simpler sugars such as glucose is part of the second generation biofuel production process. Hydrolysis of lignocellulosic substrates is usually performed by enzymes produced and secreted by the fungus Trichoderma reesei. Studies identifying transcription factors involved in the regulation of cellulase production have been conducted but no overview of the whole regulation network is available. A transcriptomic approach with mixtures of glucose and lactose, used as a substrate for cellulase induction, was used to help us decipher missing parts in the network of T. reesei Rut-C30.ResultsExperimental results on the Rut-C30 hyperproducing strain confirmed the impact of sugar mixtures on the enzymatic cocktail composition. The transcriptomic study shows a temporal regulation of the main transcription factors and a lactose concentration impact on the transcriptional profile. A gene regulatory network built using BRANE Cut software reveals three sub-networks related to i) a positive correlation between lactose concentration and cellulase production, ii) a particular dependence of the lactose onto the β-glucosidase regulation and iii) a negative regulation of the development process and growth.ConclusionsThis work is the first investigating a transcriptomic study regarding the effects of pure and mixed carbon sources in a fed-batch mode. Our study expose a co-orchestration of xyr1, clr2 and ace3 for cellulase and hemicellulase induction and production, a fine regulation of the β-glucosidase and a decrease of growth in favor of cellulase production. These conclusions provide us with potential targets for further genetic engineering leading to better cellulase-producing strains in industry-like conditions.

Interdependence of Escherichia coli formate dehydrogenase and hydrogen-producing hydrogenases during mixed carbon sources fermentation at different pHs

The impact of the four membrane-bound [NiFe]-hydrogenases (Hyd) of Escherichia coli on total H2-oxidizing activity during fermentation of a mixture of glucose, glycerol and formate at different pHs was examined. It was shown that Hyd-2 had a major contribution to total Hyd activity at pH 7.5 in early-stationary phase (24 h) cells, while the main contribution was made by Hyd-3 in late-stationary phase (72 h). Hyd-4-dependent Hyd activity could be demonstrated at pH 6.5 in cells lacking Hyd-1, Hyd-2 and Hyd-3. at pH 7.5 Hyd-4-dependent formate dehydrogenase (FDH-H) activity was demonstrated. Growth properties and fermentation end product patterns during 72 h demonstrated that the cells retained viability deep into stationary phase. Our findings emphasize the importance of formate in modulating H2 metabolism, presumably by contributing to maintain redox, pH and pmf balance. This is important for regulating and enhancing H2 production when a mixture of carbon sources is applied.

(Invited) Sodium Insertion Carbon Materials As “Beyond Li-GIC”

We believe that Na-ion battery is a possible next-generation alternative to Li-ion battery because sodium, the most Earth-abundant alkali, is providing comparable performance of insertion materials to lithium counterpart. To realize comparable energy storage to Li-ion, development of high capacity sodium insertion materials is of a key issue because of inevitable low-voltage operation of Na-ion. Since the demonstration of 3-volt Na-ion battery [1], our group has studied non-graphitizable carbon (hard carbon) and sodium-containing layered 3d transition-metal oxides, Na x MeO2 (Me = 3d transition metal), as promising electrode materials for Na-ion battery. In this study, we present our achievement and recent progress on high capacity sodium insertion materials.Among Na x MeO2 materials, Mn-based layered oxides deliver high reversible capacities of > 200 mAh g-1 [2]. For example, orthorhombic Na2/3MnO2 delivers 216 mAh g-1 with an average discharge voltage of 2.74 V, leading to 590 Wh (kg oxide)-1. Our group also studied influence of the crystal polymorphism from a fundamental aspect and found insufficient electrochemical properties of undistorted Na2/3MnO2 [3]. For improving electrochemical performances of Mn-based layered oxide, partial substitution for Mn site was efficient for NaNi1/2Mn1/2O2. Mg and Ti co-substituted NaNi1/2Mn1/2O2 exhibits better cycle stability than that of non-substituted one.Hard carbon is broadly known as one of the most promising negative electrode materials for Na-ion batteries because of the low-operation voltage and high capacities. Generally, hard carbon includes small graphitic domains and micropores which are randomly distributed in the structure, and their microstructures influence electrochemical properties. Thus, much effort has been devoted to optimizing microstructures suitable for Na storage by changing synthesis conditions such as carbon sources and heat-treatment temperatures [4-6]. Recently, we successfully synthesized high-capacity hard carbon via MgO-templated carbon technique [7]; pyrolyzing a mixture of Mg gluconate and glucose and heat-treatment above 1300 ºC under our optimized condition. The hard carbon electrode delivered an extremely high capacity, ca. 480 mAh g-1, corresponding to apparent composition of NaC4.6 with a high initial coulombic efficiency of 88% [8]. The capacity was mainly achieved in the low potential plateau region at ca. 0.1 V, in which Na+ ions are inserted/extracted into/from internal pores. We believe further optimization of the synthesis conditions provides higher capacity with low-voltage operation; i.e. higher energy density comparable to alloy electrode materials. Reference s : [1] S. Komaba, et al., Adv. Funct. Mater., 21, 3859 (2011).[2] K. Kubota, S. Komaba, et al., Adv. Energy Mater., 8, 1703415 (2018).[3] S. Kumakura, S. Komaba, et al., Angew. Chem. Int. Ed., 55, 12760 (2016).[4] H. Yamamoto, S. Komaba, et al., J. Mater. Chem. A., 6, 16844 (2018).[5] A. Kano et al., 228th ECS Meeting, MA2016–02, 668 (2016).[6] A. Kamiyama, S. Komaba, et al., ACS Appl. Energy Mater., 3, 135 (2020).[7] T. Morishita, I. Michio, et al., Tanso, 242, 60 (2010).[8] A. Kamiyama, S. Komaba, et al., of 6th Int’l Conf. on Na Batteries, Chicago, Nov-6 2019.

Evaluating the Engineered Saccharomyces cerevisiae With High Spermidine Contents for Increased Tolerance to Lactic, Succinic, and Malic Acids and Increased Xylose Fermentation

Saccharomyces cerevisiae is a promising candidate for production of organic acids as it is more tolerant to these acids than the prokaryotes. However, the large-scale production of organic acids from lignocellulosic biomass is limited by their accumulation in the growth medium and inability of xylose fermentation by S. cerevisiae. Here we showed that high intracellular spermidine (SPD) contents confers enhanced tolerance to lactic, succinic, and malic acids in S. cerevisiae. Specifically, in the presence of 20 g/L malic acid, the maximum specific growth rate and dry cell weight of a S. cerevisiae with two fold higher SPD content were 40% and 36% higher than those of the control strain. When a xylose assimilation pathway was introduced into an engineered strain with high SPD content, the resulting S. cerevisiae strain exhibited 23∼47% higher xylose consumption rate and 6∼16% higher ethanol productivity than those of the control strain during the four times of repeated-batch fermentations using a mixture of glucose and xylose as carbon sources. These results suggest that the strain developed in this study would serve as a platform strain for production of organic acids.

Kinetic Enhancement of Sulfur Cathodes by N-Doped Porous Graphitic Carbon with Bound VN Nanocrystals.

The reaction kinetics of sulfur cathodes generally control the performance of lithium-sulfur (Li-S) batteries. Here, N-doped porous graphitic carbon with bound VN nanocrystals (3D VN@N-PGC), which is synthesized in one pot by heating a mixture of glucose as C source, urea as N source, and NH4 VO3 as V source, is reported to be an superior electrocatalytic cathode host for Li-S batteries. Notably, the VN nanocrystals, strongly bound to the N-PGC network, form via in situ reactions among the thermolytic products of starting materials. The dopant N atoms and bound VN nanocrystals exhibit synergistic electrocatalytic effects to promote the cathode reactions of the Li-S cells. The observed enhancements are supported by density functional theory simulations and by the observation of electrocatalytic N- and V-intermediate species, via X-ray absorption near-edge structure spectroscopy. Li-S cells assembled using 3D VN@N-PGC as cathode host exhibit superior performance in terms of specific capacity (1442mA h g-1 at 0.1 C), rate capability (641mA h g-1 at 4 C), and cycle life (466mA h g-1 after 1700 cycles at 2 C, corresponding to a capacity decay of 0.020% per cycle). The one-pot methodology is facile and scalable and offers a new approach for synthesis of various metal nitride-containing materials for other electrocatalytic applications.

Oxidation of glucose and arabinose mixtures over Au/Al2O3

Oxidation of a mixture of glucose and arabinose over 1% Au deposited on alumina was investigated in a semi-batch reactor varying pH, temperature and partial pressure of oxygen. Elevation of the latter enhancing the rate induced also losses in selectivity to aldonic acids. A kinetic model representing the catalytic oxidation reactions of arabinose and glucose along with respective isomerization to fructose and ribulose was developed. Calculations based on the model were able to describe experimental data in a reliable way.

The disruption of the MAPKK gene triggering the synthesis of flavonoids in endophytic fungus Phomopsis liquidambaris.

Flavonoids, which are mainly extracted from plants, are important antioxidants and play an important role in human diseases. However, the growing market demand is limited by low productivity and complex production processes. Herein, the flavonoids biosynthesis pathway of the endophytic fungus Phomopsis liquidambaris was revealed. The mitogen-activated protein kinase kinase (MAPKK) of the strain was disrupted using a newly constructed CRISPR-Cas9 system mediated by two gRNAs which was conducive to cause plasmid loss. The disruption of the MAPKK gene triggered the biosynthesis of flavonoids against stress and resulted in the precipitation of flavonoids from fermentation broth. Naringenin, kaempferol and quercetin were detected in fed-batch fermentation with yields of 5.65mg/L, 1.96mg/L and 2.37mg/L from P. liquidambaris for dry cell weigh using the mixture of glucose and xylose and corn steep powder as carbon source and nitrogen source for 72h, respectively. The biosynthesis of flavonoids was triggered by disruption of MAPKK gene in P. liquidambaris and the mutant could utilize xylose.

Investigation of electro-oxidation of glucose at gold nanoparticles/carbon composites prepared in the presence of halide ions

In this study, the carbon powder supported gold nanoparticles composites (AuNPs/C) were prepared via the chemical reduction method by employing sodium citrate or a complex mixture of glucose and ascorbic acid as reducing agents in the presence of small amounts of different halide ions (Cl–, Br–, I–). The electrocatalytic activity of the synthesized composites was evaluated for the electro-oxidation of glucose in an alkaline medium using cyclic voltammetry, whereas the morphology and composition of composites were characterized using field emission scanning electron microscopy and inductively coupled plasma optical emission spectroscopy. The electrochemical measurements demonstrate the enhanced electrocatalytic performance of the AuNPs/C composites prepared by the help of different reducing agents coupled with halide ions for the electro-oxidation of glucose as compared to that of composites that were synthesized by the use only of the reducing agents barely. The AuNPs/C composites synthesized with the presence of KCl, KBr or KI additive in the reaction mixture generate the increased glucose electro-oxidation current density values; furthermore, the glucose electro-oxidation potential is shifted to more negative values as compared to those obtained on the synthesized composites without halide additive.

Electric Field-Driven Direct Interspecies Electron Transfer for Bioelectrochemical Methane Production from Fermentable and Non-Fermentable Substrates

The bioelectrochemical methane production from acetate as a non-fermentable substrate, glucose as a fermentable substrate, and their mixture were investigated in an anaerobic sequential batch reactor exposed to an electric field. The electric field enriched the bulk solution with exoelectrogenic bacteria (EEB) and electrotrophic methanogenic archaea, and promoted direct interspecies electron transfer (DIET) for methane production. However, bioelectrochemical methane production was dependent on the substrate characteristics. For acetate as the substrate, the main electron transfer pathway for methane production was DIET, which significantly improved methane yield up to 305.1 mL/g chemical oxygen demand removed (CODr), 77.3% higher than that in control without the electric field. For glucose, substrate competition between EEB and fermenting bacteria reduced the contribution of DIET to methane production, resulting in the methane yield of 288.0 mL/g CODr, slightly lower than that of acetate. In the mixture of acetate and glucose, the contribution of DIET to methane production was less than that of the single substrate, acetate or glucose, due to the increase in the electron equivalent for microbial growth. The findings provide a better understanding of electron transfer pathways, biomass growth, and electron transfer losses depending on the properties of substrates in bioelectrochemical methane production.

Overexpression of Mutant Galactose Permease (ScGal2_N376F) Effective for Utilization of Glucose/Xylose or Glucose/ Galactose Mixture by Engineered Kluyveromyces marxianus.

Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.