Characterization and regulatory properties of a single hexokinase from the citric acid accumulating fungus Aspergillus niger

Steinböck, Ferdinand; Choojun, Sukjai; Held, Irmtraud; Roehr, M.; Kubicek, Christian P.

doi:10.1016/0304-4165(94)90138-4

Cited by 33 publications

(16 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hexokinase is more abundant than other enzymes in A. niger, and it has an affinity for glucose over fructose in a ratio of 1000:1. Citrate inhibits glucokinase non-competitively (Steinböck et al 1994). Schreferl-Kunar et al (1989) showed that mutation can be used to produce an A. niger strain with higher affinity for sucrose growth .…”

Section: Biochemistry Of Citric Acid Production By Aspergillus Niger mentioning

confidence: 99%

See 1 more Smart Citation

Overview of citric acid production from Aspergillus niger

Show

Oladele

Siew

et al. 2015

Frontiers in Life Science

219

126

View full text Add to dashboard Cite

Citric acid has high economic potential owing to its numerous applications. It is mostly produced by microbial fermentation using Aspergillus niger. In view of surges in demand and growing markets, there is always a need for the discovery and development of better production techniques and solutions to improve production yields and the efficiency of product recovery. To support the enormous scale of production, it is necessary and important for the production process to be environmentally friendly by utilizing readily available and inexpensive agro-industrial waste products, while maintaining high production yields. This article reviews the biochemistry of citric acid formation, choices of citric-acid producing microorganisms and raw materials, fermentation strategies, the effects of various fermentation conditions, citric acid recovery options and the numerous applications of citric acid, based on information drawn from the literature over the past 10 years.

show abstract

Section: Biochemistry Of Citric Acid Production By Aspergillus Niger mentioning

confidence: 99%

“…In 2012, China was responsible for 59% of the global production of citric acid (Angumeenal & Venkappayya 2013). According to estimations, the market value of citric acid will continue to grow and will soon exceed $2 billion (van der Straat et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Overview of citric acid production from Aspergillus niger

Show

Oladele

Siew

et al. 2015

Frontiers in Life Science

219

126

View full text Add to dashboard Cite

show abstract

“…Yeast hexokinases PI and PI1 (Derechin et al, 1966;Easterby and Rosemeyer, 1972) and A. niger hexokinase (Steinbock et al, 1994) have been shown to be dimers. The quaternary structure of yeast glucokinase is less clear, since Maitra (1970) reported a molecular mass in the range 144-200 kDa.…”

Section: Discussionmentioning

confidence: 99%

“…Steinbock et al (1994) reported the existence of a single hexokinase in A. niger which was purified and characterised. The evidence presented in the current report indicates the presence of at least two hexosephosphorylating enzymes in A. niger.…”

mentioning

confidence: 99%

Cloning and Biochemical Characterisation of an Aspergillus Niger Glucokinase

Panneman

Ruijter

Broeck

et al. 1996

European Journal of Biochemistry

View full text Add to dashboard Cite

The Aspergillus niger glucokinase gene glkA has been cloned using a probe generated by polymerase chain reaction with degenerate oligonucleotides. The DNA sequence of the gene was determined, and the deduced amino acid sequence shows significant similarity to other eukaryotic hexokinase and glucokinase proteins, in particular to the Saccharomyces cerevisiae glucokinase protein. The encoded protein was purified from a multicopy glkA transformant, and extensively characterised. The protein has a molecular mass of 54536 Da and a PI of 5.2. The enzyme has high affinity for glucose (K, 0.063 mM at pH 7.5) and a relatively low affinity for fructose (K, 120 mM at pH 7.5), and in vivo fructose phosphorylation by glucokinase is consequently negligible. The configurations at C1 and C4 of the substrate appear to be essential for substrate specificity. The A. niger glucokinase shows non-competitive inhibition by ADP towards ATP and uncompetitive inhibition by ADP towards glucose. The k,,, (turnover number) decreases rapidly below pH 7.5 (56% at pH 7.0 and 17% at pH 6.5) and this may have important implications for the in vivo regulation of activity. In addition, proof is provided for the presence of a second hexosephosphorylating enzyme in A. niger. This enzyme is probably a hexokinase, since unlike glucokinase, this activity is inhibited by trehalose 6-phosphate.

show abstract

“…The specificity for ADP is also reflected in the high affinity found for this compound, i.e. the K m value of 0.033 mM is the among the lowest reported (15)(16)(17)(18)(19)(20)(21)(22)(23)(24). The reason for the ADP dependence may lie in the ability to activate sugars at conditions of low energy charge, e.g.…”

mentioning

confidence: 99%

Purification and Characterization of a Novel ADP-dependent Glucokinase from the Hyperthermophilic Archaeon Pyrococcus furiosus

Kengen

Tuininga

Bok

et al. 1995

Journal of Biological Chemistry

125

108

View full text Add to dashboard Cite

Pyrococcus furiosus uses a modified Embden-Meyerhof pathway during growth on poly-or disaccharides. Instead of the usual ATP-dependent glucokinase, this pathway involves a novel ADP-dependent (AMP-forming) glucokinase. The level of this enzyme and some other glycolytic enzymes appeared to be closely regulated by the substrate. Growth on cellobiose resulted in a high specific activity of 0.96 units mg ؊1, whereas on pyruvate a 10-fold lower activity was found. The ADPdependent glucokinase was purified 1350-fold to homogeneity. The oxygen-stable enzyme had a molecular mass of 93 kDa and was composed of two identical subunits (47 kDa). The glucokinase was highly specific for ADP, which could not be replaced by ATP, phosphoenolpyruvate, GDP, PP i , or polyphosphate. D-Glucose could be replaced only by 2-deoxy-D-glucose, albeit with a low efficiency. The K m values for D-glucose and ADP were 0.73 and 0.033 mM, respectively. An optimum temperature of 105°C and a half-life of 220 min at 100°C are in agreement with the requirements of this hyperthermophilic organism. The properties of the glucokinase are compared to those of less thermoactive gluco/hexokinases. During the past decade, an increasing number of microorganisms have been described that have their optimum growth temperature above 80°C (1, 2). Except for two bacterial genera, all of the more than 50 hyperthermophilic species isolated thus far are classified as Archaea (formerly Archaebacteria), the third domain of life (3).Because of its favorable culturing conditions, Pyrococcus furiosus is the best studied anaerobic hyperthermophile to date. Next to some polypeptides and polysaccharides, P. furiosus is able to use maltose and cellobiose as simple substrates (4 -6). These disaccharides are transported into the cell, hydrolyzed to glucose, and fermented to mainly acetate, alanine, H 2 , and CO 2 (7). Initially, P. furiosus was believed to use a novel nonphosphorylated type of Entner-Doudoroff pathway, called pyroglycolysis (5,8). However, recent 13 C in vivo NMR data were not consistent with a major role for the pyroglycolysis (9, 10). The 13 C labeling pattern suggested that an Embden-Meyerhoflike pathway was most likely to be involved (9). Conventional glucokinase and phosphofructokinase could, however, not be detected in cell-free extracts (5). Remarkably, two novel sugar kinases were recently discovered that required ADP instead of ATP (9). In contrast to the key enzymes of the pyroglycolysis, the specific activities of both kinases were sufficiently high to envisage a major catabolic role. Instead of a classical NAD-dependent glyceraldehyde-3-phosphate dehydrogenase, P. furiosus was recently shown to harbor a novel tungsten-containing glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (11). The presence of an enzyme that converts glyceraldehyde-3-phosphate instead of glyceraldehyde also substantiates the operation of a modified Embden-Meyerhof pathway instead of the pyroglycolysis. The discovery of the novel type of kinases and the tungsten proteins in ...

show abstract

Characterization and regulatory properties of a single hexokinase from the citric acid accumulating fungus Aspergillus niger

Cited by 33 publications

References 35 publications

Overview of citric acid production from Aspergillus niger

Overview of citric acid production from Aspergillus niger

Cloning and Biochemical Characterisation of an Aspergillus Niger Glucokinase

Purification and Characterization of a Novel ADP-dependent Glucokinase from the Hyperthermophilic Archaeon Pyrococcus furiosus

Contact Info

Product

Resources

About