Yeast species either require oxygen for aerobic cellular respiration (obligate aerobes) or are anaerobic, but also have aerobic methods of energy production (facultative anaerobes). (lutheransatcmu.org)
Fermentation and anaerobic respiration are two types of cellular respiration mechanisms that are used to produce ATP for the functioning of the cell. (zestrestaurant.co.za)
Cellular respiration is a catabolic pathway in which glucose is completely oxidized, yielding CO 2 and the high-energy, reduced electron carriers NADH and FADH 2, and ATP. (zestrestaurant.co.za)
Cellular respiration is the biochemical process that converts 'food energy' (from the chemical bonds of macromolecules) into chemical energy in the form of adenosine triphosphate (ATP). (jove.com)
To facilitate uptake and conversion of glucose at low extracellular concentrations, activity of high-affinity transporters ( K M ~ 1 mM) is required, in combination with hexokinase activity to 'trap' the sugar inside the cell in its phosphorylated form and therefore maintain a glucose concentration gradient over the cellular membrane [ 15 ]. (biomedcentral.com)
During the electron transfer chain in cellular respiration, the NADH turns into NAD+ while donating an electron. (stackexchange.com)
Metabolize pentose sugars2
Some species can metabolize pentose sugars like ribose,[17] alcohols, and organic acids. (lutheransatcmu.org)
Unfortunately, baker's yeast is unable to efficiently metabolize pentose sugars, particularly D-xylose, which accounts for up to 35% of total sugars in xylan-rich lignocellulosic biomass such as hard woods and straw [ 3 ]. (biomedcentral.com)
Glucose (Glc), a monosaccharide (or simple sugar ), is an important carbohydrate in biology . (wikidoc.org)
Two stereoisomers of the aldohexose sugars are known as glucose, only one of which ( D -glucose) is biologically active. (wikidoc.org)
Glucose is one of these sugars, and L and D -glucose are two of the stereoisomers. (wikidoc.org)
The glycolytic pathway converts one hexose (a six-carbon carbohydrate such as glucose) into two triose molecules (three-carbon carbohydrate) such as pyruvate, to produce a net total of two molecules of ATP (four produced, two consumed) and two molecules of nicotinamide adenine dinucleotide (NADH). (jove.com)
Introduction of heterologous glucose- or fructose-proton symporters in an hxt 0 yeast background strain (derived from CEN.PK2-1C) restored growth on the corresponding sugar under aerobic conditions. (biomedcentral.com)
To apply this strategy to increase the ethanol yield on sucrose, we constructed a platform strain in which all genes encoding hexose transporters, disaccharide transporters and disaccharide hydrolases were deleted, after which a combination of a glucose-proton symporter, fructose-proton symporter and extracellular invertase ( SUC2 ) were introduced. (biomedcentral.com)
1 g L −1 , Crabtree effect), which is remarkable since respiration yields substantially more ATP per molecule of dissimilated glucose [ 3 , 4 ]. (biomedcentral.com)
In such environments, the high extracellular glucose concentration can drive the uptake of glucose by yeast cells via diffusion, which is exemplified by the occurrence of many hexose transporters with a facilitated diffusion mechanism in S. cerevisiae . (biomedcentral.com)
These factors include sugar transporters and invertases as well as metabolites, including sucrose and glucose, which function as signalling molecules to modulate gene expression. (sun.ac.za)
Partial breakdown into lactic acid or ethanol and CO2 Note: Bacteria have many different pathways for carbohydrate metabolism based on the enzymes they are able to produce. (studylib.net)
In anaerobic cultures, a higher ethanol yield can be achieved when transport of hexoses is proton-coupled, because of the lower net ATP yield of sugar dissimilation. (biomedcentral.com)
After evolution, the resulting strain exhibited a 16.6% increased anaerobic ethanol yield (from 1.51 to 1.76 mol mol hexose equivalent −1 ) and 46.6% decreased biomass yield on sucrose. (biomedcentral.com)
This study provides a proof-of-concept for the replacement of the endogenous hexose transporters of S. cerevisiae by hexose-proton symport, and the concomitant decrease in ATP yield, to greatly improve the anaerobic yield of ethanol on sugar. (biomedcentral.com)
Yeasts lack chlorophyll and are unable to manufacture by photosynthesis from inorganic substrates the organic compounds required for growth, as do higher plants, algae, and even some bacteria. (biologydiscussion.com)
For instance, the transformation of plants with a yeast-derived invertase targeted to different subcellular compartments has led to the elucidation of several key aspects of sugar metabolism, including phloem loading mechanisms, the regulation of photosynthesis by sugars, the importance of sugar-metabolism compartmentation with regards to sucrose biosynthesis, storage and distribution, as well as the role of cell-wall invertase in phloem unloading and sink strength. (sun.ac.za)
Sucrose1
Transcript levels of the sucrose transporter NtSUT1 and hexose transporter NtMST1 encoding genes increased significantly in the source leaves and roots of Vac-Inv lines, whereas increased NtMst1 transcript levels were also detected in the roots of Apo-Inv lines. (sun.ac.za)
Fermentation occurs in the absence of oxygen (anaerobic conditions), and in the presence of beneficial microorganisms (yeasts, molds, and bacteria) that obtain their energy through fermentation. (zestrestaurant.co.za)
They use hexose sugars as … Fermentation occurs in the absence of oxygen (anaerobic conditions), and in the presence of beneficial microorganisms (yeasts, molds, and bacteria) that obtain their energy through fermentation. (zestrestaurant.co.za)
Fermentation may occur in some prokaryotes as the only means of respiration or in the multicellular organisms like human beings at the time of stress when there is lack of oxygen. (zestrestaurant.co.za)
Transgenic lines overproducing the yeast-derived invertase in either the vacuole (Vac-Inv) or apoplast (Apo-Inv) were utilised to analyse the effect of the altered sugar levels in sink and source organs on the expression of sugar transporters, as well as the endogenous cell wall invertase and inhibitors in these plants. (sun.ac.za)
The inherently higher robustness and tolerance of S. cerevisiae to various inhibitors gives it a head start in programs aimed at developing strains with extreme inhibitor tolerance, able to efficiently ferment hexoses and pentoses in concentrated lignocellulose hydrolysates [ 6 ]. (biomedcentral.com)
Yeast species2
Unlike bacteria, there are no known yeast species that grow only anaerobically (obligate anaerobes). (lutheransatcmu.org)
Although there are various species of bacteria, filamentous fungi and other yeast species that are naturally capable of efficiently metabolizing D-xylose, they lack the other crucial advantages of the yeast S. cerevisiae , which have made it the most prominent industrial microorganism. (biomedcentral.com)
Transporters1
In the yeast Saccharomyces cerevisiae , which is widely applied for industrial bioethanol production, uptake of hexoses is mediated by transporters with a facilitated diffusion mechanism. (biomedcentral.com)
Biochemical1
the disease-causing bacterium was isolated and its morphological, physiological and biochemical characters were determined. (liverpool.ac.uk)
Mechanisms1
Moreover, the sugar-negative platform strain constructed in this study acts as a valuable starting point for future studies on sugar transport or development of cell factories requiring specific sugar transport mechanisms. (biomedcentral.com)
Yeasts1
The emergence of Crabtree-positive yeasts 100-150 million years ago probably coincided with the emergence of fruit-bearing plants, providing a sugar-rich niche in which these yeasts evolved [ 9 , 10 ]. (biomedcentral.com)
Metabolism1
The genetic transformation of plants and the subsequent development of transgenic lines with disturbed sugar metabolism have made an unprecedented impact on the study of sugar translocation and -partitioning. (sun.ac.za)
Glycolysis1
The word glycolysis originates from the Latin glyco (sugar) and lysis (breakdown). (jove.com)
The factors governing sugar partitioning co-ordinate its distribution in response to intrinsic and environmental signals. (sun.ac.za)
Means1
The name comes from the Greek word glykys ( γλυκύς ), which means "sweet", plus the suffix "-ose" which denotes a sugar . (wikidoc.org)
Activity2
The proton motive force is maintained by export of protons by a plasma membrane H + -ATPase, and therefore this sugar transport system requires net investment of ATP for its activity [ 20 ]. (biomedcentral.com)
These transgenic lines displayed varying increases in invertase activity, altered sugar levels and consequently disturbed sink-source interactions and sugar partitioning. (sun.ac.za)
Study2
In this study, the facilitated diffusion transport system for hexose sugars of S. cerevisiae was replaced by hexose-proton symport. (biomedcentral.com)
In this study, a similar strategy of transgenic plant analysis was employed to expand our insight into the regulation of sugar partitioning. (sun.ac.za)