Glucose Fermentation Research Articles

Pararoseburia lenta gen. nov., sp. nov. isolated from human faeces.

A strictly anaerobic, motile bacterium, designated as strain NSJ-9T, was isolated from human faeces. Cells were Gram-negative, non-spore-forming, non-pigmented, and spiral-shaped or slightly curved rods with flagella. Optimal growth in M2GSC medium was observed at 37 °C (growth range 30-45 °C) and pH 6.5-7.0 (growth range 6.5-7.5) under anaerobic conditions. Phylogenetic analysis of the 16S rRNA gene revealed that strain NSJ-9T formed a distinct phylogenetic lineage that reflects a new genus in the family Lachnospiraceae, with high levels of similarity to Roseburia hominis A2-183T (95.2 %), Roseburia cecicola ATCC 33874T (95.2 %), Pseudobutyrivibrio ruminis DSM 9787T (95.2 %), Pseudobutyrivibrio xylanivorans MZ 5T (94.8%) and Roseburia faecis M72/1T (94.4 %). Genomic similarity (average nucleotide identity and digital DNA-DNA hybridization) values between strain NSJ-9T and its phylogenetic neighbours were below 71 and 31 %, respectively, indicating that strain NSJ-9T represented a novel species. The average amino acid identity and the percentage of conserved proteins between strain NSJ-9T and other related members of the family Lachnospiraceae were below 63 and 50 %, respectively, supporting that strain NSJ-9T was a member of a new genus. The predominant cellular fatty acids of strain NSJ-9T were C16 : 0 and C17 : 0 2-OH, and major polar lipids were glycolipids. The end products of glucose fermentation were acetate, propionate, iso-butyrate, butyrate and valerate. Phylogenetic and phylogenomic lineage, pairwise determined genome identity analysis suggested that strain NSJ-9T represents a novel genus in the family Lachnospiraceae. The genome size of strain NSJ-9T is 2.56 Mbp with 44.9 mol% G+C content. Collectively, the genotypic and phenotypic differences between phylogenetic relatives suggested strain NSJ-9T represented a novel species of a new genus, for which the name Pararoseburia lenta gen. nov., sp. nov. is proposed. The type strain of Pararoseburia lenta is NSJ-9T (=CGMCC 1.32469T=KCTC 15957T).

Coproduction of xylooligosaccharides and monosaccharides from hardwood by a combination of acetic acid pretreatment, mechanical refining and enzymatic hydrolysis

Sequential biorefinery treatments of acetic acid (HAC) pretreatment, Papir Forsknings Institutet (PFI) milling and enzymatic hydrolysis were demonstrated for coproduction of xylooligosaccharides (XOS) and fermentable monosaccharides. Results indicated that 36.2% XOS (50.8% X2-X3) and 17.0% low DP xylans were achieved using a HAC pretreatment with a combined severity factor of 0.78. The HAC pretreatment resulted in a XOS-rich prehydrolyzate with a low molecular weight of 1.28 kDa. The endo-xylanase hydrolysis was conducted on the pretreatment liquor to elevate XOS yield and the content of higher-value X2-X3. Moreover, fermentable glucose production from the pretreated residue increased by 2.3 folds when introducing an additional step of PFI refining prior to enzymatic digestion. Properties of substrate including cellulose accessibility, crystallite size, crystalline index and water retention value were in close relationships with enzymatic digestibility. The implementation of proposed biorefinery process will give more insights into the efficient construction of a wood-derived sugar platform.

Optimisation of enzymatic fermented glucose production of wild cocoyam starch using response surface methodology

<p>​The enzymatic fermentation of starch from non-edible sources using Aspergillus niger could help supplement the increasing glucose demand within the Nigeria food supply chain. Also, response surface methodology could help optimise the glucose production of starch hydrolysed from cocoyam tubers. In this work, we evaluated and optimized the enzymatic-fermented glucose production of wild cocoyam starch using response surface methodology. Wild cocoyam starch was hydrolyzed using A. niger isolated from the soil. The optimization process involved temperature, time, pH, and enzyme dosage, alongside the kinetics and thermodynamics of enzymatic hydrolysis. Optimum conditions for glucose yield of 95 % by enzyme hydrolysis included: temperature = 35 °C; time = 5 days; pH = 5.5; and enzyme dosage =0.16 g/mL, with wild cocoyam showing promising as substrate. The F-value of quadratic model terms appeared statistically significant (F= 65.42, p<0.0001). Fourier Transform Infra-Red Spectrometer (FTIR) and Gas Chromatography-Mass Spectrophotometer (GC-MS) analyses confirmed characteristic bands of glucose as industrially promising with 60% purity. Further, the enzymatic hydrolysis adhered to Michaelis-Menten kinetic model with maximum reaction rate of 82.6 ml/day at 35 °C.</p>

Mild Organosolv Delignification of Residual Aspen Bark after Extractives Isolation as a Step in Biorefinery Processing Schemes.

European aspen (Populus tremula (L.) (Salicaceae)) bark is a promising raw material in multi-step biorefinery schemes due to its wide availability and higher content of secondary metabolites in comparison to stem wood biomass. The main objective of this study was to investigate the major cell wall component-enriched fractions that were obtained from aspen bark residue after extractives isolation, primarily focusing on integration of separated lignin fractions and cellulose-enriched bark residue into complex valorization pathways. The “lignin first” biorefinery approach was applied using mild organosolv delignification. The varying solvent systems and process conditions for optimal delignification of residual aspen bark biomass were studied using a response surface methodology approach. The conditions for maximum process desirability at which the highest amount of lignin-enriched fraction was separated were as follows: 20-h treatment time at 117 °C, butanol/water 4:1 (v/v) solvent system with solid to liquid ratio of 1 to 10. At optimal separation conditions, lignin-enriched fraction exhibited a higher content of β–O–4 linkages vs. C–C linkages content in its structure as well as a high amount of hydroxyl groups, being attractive for its further valorization. At the same time, the content of glucose in products of cellulose-enriched residue hydrolysis was 52.1%, increased from 10.3% in untreated aspen bark. This indicates that this fraction is a promising raw material for obtaining cellulose and fermentable glucose. These results show that mild organosolv delignification of extracted tree bark can be proposed as a novel biorefinery approach for isolation of renewable value-added products with various application potentials.

Abstract IA023: Selection for a glycolytic phenotype

Abstract In early breast carcinogenesis, neoplastic cells grow in multiple layers towards the lumens of ducts, which subjects the periluminal cells to harsh conditions of low oxygen, low pH, and nutrient deprivation. Adaptation to these harsh conditions is a pre-requisite for survival of incipient tumor cells and also responsible for selecting cells with a more aggressive phenotype. Based on the first principle of Darwinian evolution, common phenotypes of cancer cells must have conferred a selective advantage at some point during their evolutionary trajectory. Adaptations are initially acute and reversible, but eventually Darwinian selection results in cells with hardwired phenotypes. A prominent example of this is aerobic glycolysis, or the Warburg Effect (WE), wherein cells are hard-wired to ferment glucose, even in the presence of oxygen. WE provides and evolutionary advantage which leads to higher fitness of the cancer cells, who have acquired mechanisms of adaptation, such as autophagy and lysosome redistribution. Notably, a WE is highly correlated with a cancer’s metastatic potential and poor outcome. Hence, a major question in carcinogenesis is: “What are the mechanisms by which a harsh microenvironment eventually selects for hard-wired (heritable) phenotypes, such as a WE?”. Rather than simply selection of pre-existing phenotypes, we contend that the microenvironment actively induces phenotypic diversity through a systematic set of epigenetic and genetic alterations. Citation Format: Mehdi Damaghi. Selection for a glycolytic phenotype [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr IA023.

Butanol–isopropanol fermentation with oxygen-tolerant Clostridium beijerinckii XH29

Acetone–butanol–ethanol (ABE) fermentation is a traditional way for solvents production through bioconversion by Clostridium species. It is still a challenge to obtain metabolic engineering strains with high ABE yield. Screening strains with remarkable characteristics from nature and improving ABE yield by mutation are viable approaches. Clostridium beijerinckii XH 0906, a newly isolated strain, produces butanol and isopropanol (BI) as the main end-products (9.1 g/L BI) during fermentation with glucose as the sole carbon source. The screening process for this strain was performed under aerobic conditions rather than anaerobic environment. Thus, it is a robust stain capable of oxygen-tolerant BI fermentation. Furthermore, C. beijerinckii XH 0906 fermented xylose and glucose simultaneously to produce BI. A mutant strain obtained by ultraviolet (UV) mutagenesis, C. beijerinckii XH 29, had improved BI production capacity and could produce 17.0 g/L BI and 18.4 g/L BI using glucose or corn stover hydrolysate, respectively as the carbon source. Interestingly, C. beijerinckii XH 29 also produced up to 19.3 g/L isopropanol through fermentation of a glucose–acetone mix. These results indicate that C. beijerinckii XH 29 is an excellent BI producer with great potential for industrial applications.Graphical

A Microphysiometric System Based on LAPS for Real-Time Monitoring of Microbial Metabolism

Macronutrients (carbohydrates, fat and protein) are the cornerstones of daily diet, among which carbohydrates provide energy for the muscles and central nervous system during movement and exercise. The breakdown of carbohydrates starts in the oral cavity, where they are primarily hydrolyzed to glucose and then metabolized to organic acids. The end products may have an impact on the oral microenvironment, so it is necessary to monitor the process of microbial metabolism and to measure the pH change. Although a pH meter has been widely used, it is limited by its sensitivity. We then introduce a light addressable potentiometric sensor (LAPS), which has been used in extracellular acidification detection of living cells with the advantages of being objective, quantitative and highly sensitive. However, it is difficult to use in monitoring bacterial metabolism because bacteria cannot be immobilization on the LAPS chip as easily as living cells. Therefore, a microphysiometric system integrated with Transwell insert and microfluidic LAPS chip was designed and constructed to solve this problem. The decrease in pH caused by glucose fermentation in Lactobacillus rhamnosus was successfully measured by this device. This proves the feasibility of the system for metabolism detection of non-adhere targets such as microorganisms and even 3D cells and organoids.

Carbohydrate-to-protein ratio regulates hydrolysis and acidogenesis processes during volatile fatty acids production

In this study, the typical model solubilized and hydrolyzed substrates of protein and carbohydrate were anaerobically fermented at different carbohydrate-to-protein (Car/Pro) ratios to examine volatile fatty acids (VFAs) production and substrate consumption. The highest VFAs yields of 0.71 and 0.72 mg COD/mg CODsubstrate both occurred at Car/Pro ratio of 1 by BSA-dextran and amino acids (AAs)-glucose fermentation, respectively. The limiting processes were hydrolysis and acidogenesis for the higher Car/Pro ratio of 3 and lower Car/Pro ratio of 0.25, respectively. An inhibitory effect of AAs accumulation was found, and VFAs production could be raised by 25.5% through quartic fed-batch strategy. There existed a significant relationship between activity of hydrolytic and acid-forming enzymes and acidogenic metabolism efficiency, which could be fitted by first-order kinetic and Logistic-based models. Understanding the effects of Car/Pro ratio on VFAs production is of guiding significance for regulating hydrolysis and acidogenesis processes during anaerobic fermentation of organic wastes.

Bioconversion of lignocellulosic biomass into bacterial nanocellulose: challenges and perspectives

Nanocellulose has various outstanding properties and great potential for replacing petrochemical products. The utilization of lignocellulose to produce nanocellulose is of great significance to the sustainable development of the economy and society. However, the direct extraction of nanocellulose from lignocellulose by chemical method is challenged by toxic chemicals utilization, energy and time consumption, and waste water generation. Therefore, this paper addressed the conversion of lignocellulosic biomass into bacterial nanocellulose (BNC) by the biological method. Moreover, this article highlights the recent advances in potentials and challenges of lignocellulosic biomass for BNC production through the bioconversion process, including biomass pretreatment, enzymatic hydrolysis, glucose and xylose fermentation, GA accumulation, and inhibitor tolerant. The development in metabolic and evolutionary engineering to enhance the production capacity of BNC-producing strain is also discussed. It is expected to provide guidance on the effective bioproduction of nanocellulose from lignocellulosic biomass.

Mutants with Enhanced Cellobiose-Fermenting Ability from Thermotolerant Kluyveromyces marxianus DMKU 3-1042, Which Are Beneficial for Fermentation with Cellulosic Biomass

Several cellulose-hydrolysis enzymes are required for eco-friendly utilization of cellulose as renewable biomass, and it would therefore be beneficial if fermenting microbes can provide such enzymes without genetic engineering. Thermotolerant and multisugar-fermenting Kluyveromyces marxianus is one of the promising yeasts for high-temperature fermentation and has genes for putative oligosaccharide-degradation enzymes. Mutants obtained after multiple mutagenesis showed significantly higher activity than that of the parental strain for cellobiose fermentation. The efficient strains were found to have amino acid substitutions and frame-shift mutations in 26-28 genes including 3 genes for glucose transporters. These strains grown in a cellobiose medium showed higher β-glucosidase than that of the parental strain and greatly reduced glucose utilization. The introduction of KTH2 for a glucose transporter into one of the efficient mutants reduced the cellobiose fermentation activity of the mutant. The results suggest that release from glucose repression significantly promotes the uptake of cellobiose. Co-culture of one efficient strain and the parental strain allowed good fermentation of both glucose and cellobiose, suggesting that the efficient strains are useful for conversion of cellulosic biomass to ethanol.

Mixotrophic co-utilization of glucose and carbon monoxide boosts ethanol and butanol productivity of continuous Clostridium carboxidivorans cultures

In this study, continuous cultivations of C.carboxidivorans to study heterotrophic and mixotrophic conversion of glucose and H2, CO2, and CO were established. Glucose fermentations at pH 6 showed a high ratio of alcohol-to-acid production of 2.79 mol mol−1. While H2 or CO2 were not utilized together with glucose, CO feeding drastically increased the combined alcohol titer to 9.1 g l−1. Specifically, CO enhanced acetate (1.9-fold) and ethanol (1.7-fold) production and triggered chain elongation to butanol (1.5-fold) production but did not change the alcohol:acid ratio. Flux balance analysis showed that CO served both as a carbon and energy source, and CO mixotrophy displayed a carbon and energy efficiency of 45 and 77%, respectively. This study expands the knowledge on physiology and metabolism of C.carboxidivorans and can serve as the starting point for rational engineering and process intensification to establish efficient production of alcohols and acids from carbon waste.

The Autonomous Glycyl Radical Protein GrcA Restores Activity to Inactive Full-Length Pyruvate Formate-Lyase In Vivo.

During glucose fermentation, Escherichia coli and many other microorganisms employ the glycyl radical enzyme (GRE) pyruvate formate-lyase (PflB) to catalyze the coenzyme A-dependent cleavage of pyruvate to formate and acetyl-coenzyme A (CoA). Due to its extreme reactivity, the radical in PflB must be controlled carefully and, once generated, is particularly susceptible to dioxygen. Exposure to oxygen of the radical on glycine residue 734 of PflB results in cleavage of the polypeptide chain and consequent inactivation of the enzyme. Two decades ago, a small 14-kDa protein called YfiD (now called autonomous glycyl radical cofactor [GrcA]) was shown to be capable of restoring activity to O2-inactivated PflB in vitro; however, GrcA has never been shown to have this function in vivo. By constructing a strain with a chromosomally encoded PflB enzyme variant with a G734A residue exchange, we could show that cells retained near-wild type fermentative growth, as well as formate and H2 production; H2 is derived by enzymatic disproportionation of formate. Introducing a grcA deletion mutation into this strain completely prevented formate and H2 generation and reduced anaerobic growth. We could show that the conserved glycine at position 102 on GrcA was necessary for GrcA to restore PflB activity and that this recovered activity depended on the essential cysteine residues 418 and 419 in the active site of PflB. Together, our findings demonstrate that GrcA is capable of restoring in vivo activity to inactive full-length PflB and support a model whereby GrcA displaces the C-terminal glycyl radical domain to rescue the catalytic function of PflB. IMPORTANCE Many facultative anaerobic microorganisms use glycyl radical enzymes (GREs) to catalyze chemically challenging reactions under anaerobic conditions. Pyruvate formate-lyase (PflB) is a GRE that catalyzes cleavage of the carbon-carbon bond of pyruvate during glucose fermentation. The problem is that glycyl radicals are destroyed readily, especially by oxygen. To protect and restore activity to inactivated PflB, bacteria like Escherichia coli have a small autonomous glycyl radical cofactor protein called GrcA, which functions to rescue inactivated PflB. To date, this proposed function of GrcA has only been demonstrated in vitro. Our data reveal that GrcA rescues and restores enzyme activity to an inactive full-length form of PflB in vivo. These results have important implications for the evolution of radical-based enzyme mechanisms.

Xylo-oligosaccharides, fermentable sugars, and bioenergy production from sugarcane straw using steam explosion pretreatment at pilot-scale

This study investigated the production of xylo-oligosaccharides (XOS) from sugarcane straw (SCS) using steam explosion (SE) pretreatment at pilot-scale, as well as co-production of fermentable sugars and lignin-rich residues for bioethanol and bioenergy, respectively. SE conditions 200 °C; 15 bar; 10 min led to 1) soluble XOS yields of up to 35 % (w/w) of initial xylan with ∼50 % of the recovered XOS corresponding to xylobiose and xylotriose, considered the most valuable sugars for prebiotic applications; 2) fermentable glucose yields from the enzymatic hydrolysis of SE-pretreated SCS of up to ∼78 %; 3) increase in the energy content of saccharified SCS residues (16 %) compared to the untreated material. From an integrated biorefinery perspective, it demonstrated the potential use of SCS for the production of value-added XOS ingredients as well as liquid and solid biofuel products.

METABOLIC PATHWAY MODIFICATION FOR PRODUCTION OF XYLITOL FROM GLUCOSE IN ESCHERICHIA COLI

Glucose is a cheap and readily available substrate for production of large-scale chemicals. Synthesis of xylitol, a high demand chemical in global market is currently done by using xylose, which contributes to its high operational cost. Studies on production of xylitol from glucose have explored several approaches, from sequential fermentation to multiple and single gene expression. Xylitol-5-phosphate dehydrogenase (XPDH), is an enzyme that enables conversion of glucose to xylitol in a single step fermentation. This study explores conversion of xylitol from glucose in E. coli by the expression of xpdh from Clostridium difficile with modifications in metabolic pathways to enhance xylitol production. The xpdh gene was carried by pACYC-Duet-1 expression vector and induced by the addition of IPTG. Initial screening of E. coli expressing xpdh (NA116) was done by shake-flask fermentation for 24 hours and its metabolites were analyzed by HPLC. NA116 was able to produce 0.273 g/L xylitol from 4.33 g/L consumed glucose in 24 hours. Further metabolic pathway modification to eliminate competing pathways yielded four mutants, NA207 (∆rpiA), NA208 (∆rpiB), NA209 (∆pgi) and NA211 (∆rpi∆Apgi). Screening of mutants for xylitol production showed that highest xylitol production from glucose was achieved by NA211 with almost double the amount of the original strain, 0.585 g/L. This showed successful xylitol conversion from glucose in a single fermentation in E. coli with improved yield through metabolic pathway modification.

A cyclic process for enzymatic hydrolysis and fermentation of lactic acid pretreated reed

This research aims to explore a green, economical and recyclable pretreatment method to enhance the enzymatic digestibility of reed. In this study, lactic acid (LA) as a kind of weak organic acid was used to pretreat reed. The results of orthogonal experiments showed that temperature was the most dominant influencing factor for the pretreatment process. Linear experiments conducted the optimum temperature for LA pretreatment of reed was 150 °C. Under this condition, the lignin removal reached 90.46%, glucan recovery was 89.80%, glucan digestibility was 66.43%, and the final sugar yields reached 60.70%. LA fermentation using the liquid obtained from enzymatic hydrolysis. The sugar acids conversion rate was 37.89%, which was 17.05% higher than that obtained by fermentation of pure glucose. Moreover, the product lactic acid can be widely used either as feed or to prepare polylactic acid and it also can continue to be used in the pretreatment of reed.

Ultrafast alkaline deep eutectic solvent pretreatment for enhancing enzymatic saccharification and lignin fractionation from industrial xylose residue

An aspirational pretreatment method for efficient fractionation and tailored valorization of large industrial biomass can ensure the realizability of sustainable biorefinery strategies. In this study, an ultrafast alkaline deep eutectic solvents (DES) pretreatment strategy was developed to efficiently extract the lignin nanoparticles and retain cellulose residues that could be readily enzymatic saccharified to obtain fermentative glucose for the bioenergy production from industrial xylose residue. Results showed that the DES pretreatment had excellent delignification performance and the regenerated DES lignin nanoparticles exhibited well-preserved structures and excellent antioxidant activity, as well as low molecular weights and relatively uniform size distribution, which could facilitate downstream catalytic degradation for production of chemicals and preparation of lignin-based materials. Under the optimal condition (DES pretreatment: 80 °C, 10 min; saccharification: 10 FPU/g, 5 wt%, 100 mg/g Tween 80), the glucose yield of 90.12% could be achieved, which was dramatically increased compared to raw materials.

Formate Dehydrogenase Improves the Resistance to Formic Acid and Acetic Acid Simultaneously in Saccharomyces cerevisiae.

Bioethanol from lignocellulosic biomass is a promising and sustainable strategy to meet the energy demand and to be carbon neutral. Nevertheless, the damage of lignocellulose-derived inhibitors to microorganisms is still the main bottleneck. Developing robust strains is critical for lignocellulosic ethanol production. An evolved strain with a stronger tolerance to formate and acetate was obtained after adaptive laboratory evolution (ALE) in the formate. Transcriptional analysis was conducted to reveal the possible resistance mechanisms to weak acids, and fdh coding for formate dehydrogenase was selected as the target to verify whether it was related to resistance enhancement in Saccharomyces cerevisiae F3. Engineered S. cerevisiae FA with fdh overexpression exhibited boosted tolerance to both formate and acetate, but the resistance mechanism to formate and acetate was different. When formate exists, it breaks down by formate dehydrogenase into carbon dioxide (CO2) to relieve its inhibition. When there was acetate without formate, FDH1 converted CO2 from glucose fermentation to formate and ATP and enhanced cell viability. Together, fdh overexpression alone can improve the tolerance to both formate and acetate with a higher cell viability and ATP, which provides a novel strategy for robustness strain construction to produce lignocellulosic ethanol.

Exploring the limits of carbohydrate conversion and product formation in open mixed culture fermentation

The industrial large-scale application of open mixed culture carbohydrate fermentation processes requires a better understanding of their capacity limits and product spectra. This work aims to explore these limits through the operation of two lab-scale fermenters at increasing influent glucose concentrations in continuous mode and using constant operating conditions (HRT = 20 h; pH 5.4; 30 °C). In one fermenter, glucose concentration increases were slow, in order to determine representative product yields. In the other fermenter, increases were faster, aiming also at gaining other operational insights along with a consistency validation of product yields. Different glucose concentrations led to consistent product yields in both fermenters. Full glucose conversion limit was reached at 33 gCOD Lfeed-1, with 32 mM of undissociated acids present. After glucose fermentation saturation, up to 10.6 gCOD L-1 lactate accumulation was observed. In both reactors, a glucose concentrations of 33 gCOD Lfeed-1 led to the formation of granular biomass, with which full glucose conversion resumed up to 38 gCOD Lfeed-1. In terms of products, at low glucose concentrations with only suspended biomass, the main products were acetate and butyrate, while at higher concentrations with granular biomass, the main products shifted to propionate and valerate. The similar microbial communities and products between both reactors suggest that a shorter startup time to full capacity loading is possible, which is relevant for large scale industrial implementation.

Development of high temperature simultaneous saccharification and fermentation by thermosensitive Saccharomyces cerevisiae and Bacillus amyloliquefaciens

Scarcity of energy and pollution are two major challenges that have become a threat to all living things worldwide. Bioethanol is a renewable, ecological-friendly clean energy that may be utilized to address these issues. This study aimed to develop simultaneous saccharification and fermentation (SSF) process through high temperature-substrate adaptation and co-cultivation of S. cerevisiae with other potential amylolytic strains. In this study, we adapted our previously screened thermosensitive Saccharomyces cerevisiae Dj-3 strain up-to 42 °C and also screened three potential thermotolerant amylolytic strains based on their starch utilization capability. We performed SSF fermentation at high temperature by adapted Dj-3 and amylolytic strains using 10.0% starch feedstock. Interestingly, we observed significant ethanol concentration [3.86% (v/v)] from high temperature simultaneous saccharification and fermentation (HSSF) of adapted Bacillus amyloliquefaciens (C-7) and Dj-3. We attribute the significant ethanol concentration from starch of this HSSF process to C-7’s high levels of glucoamylase activity (4.01 U/ml/min) after adaptation in starch (up-to 42 °C) as well as Dj-3's strong glucose fermentation capacity and also their ethanol stress tolerance capability. This study suggests the significant feasibility of our HSSF process.

Diaminobutoxy-substituted Isoflavonoid (DBI-1) Enhances the Therapeutic Efficacy of GLUT1 Inhibitor BAY-876 by Modulating Metabolic Pathways in Colon Cancer Cells.

Cancer cells undergo significant "metabolic remodeling" to provide sufficient ATP to maintain cell survival and to promote rapid growth. In colorectal cancer cells, ATP is produced by mitochondrial oxidative phosphorylation and by substantially elevated cytoplasmic glucose fermentation (i.e., the Warburg effect). Glucose transporter 1 (GLUT1) expression is significantly increased in colorectal cancer cells, and GLUT1 inhibitors block glucose uptake and hence glycolysis crucial for cancer cell growth. In addition to ATP, these metabolic pathways also provide macromolecule building blocks and signaling molecules required for tumor growth. In this study, we identify a diaminobutoxy-substituted isoflavonoid (DBI-1) that inhibits mitochondrial complex I and deprives rapidly growing cancer cells of energy needed for growth. DBI-1 and the GLUT1 inhibitor, BAY-876, synergistically inhibit colorectal cancer cell growth in vitro and in vivo. This study suggests that an electron transport chain inhibitor (i.e., DBI-1) and a glucose transport inhibitor, (i.e., BAY-876) are potentially effective combination for colorectal cancer treatment.