Aspergillus terreus - Wikipedia
Aspergillus terreusis a textbook example of an industrially relevant filamentous fungus. biochemistry and morphology related to the formation of these two Aspergillus terreus Itaconic acid Lovastatin Metabolites . The initial pH values published in relation with itaconic acid production vary significantly. Gao, Q., Liu, J., Liu, L.M., Relationship between morphology and itaconic acid production by Aspergillus terreus. J. Microbiol. Biotechnol. 24(2), – Relationship between morphology and citric acid production in submerged Pfeifer VF, Vojnovich C, Heger EN (). ltaconic acid by fermentation with Aspergillus terreus. Enhancing itaconic acid production by Aspergillus terreus.
Fungal morphology and metabolite production in submerged mycelial processes. Papagianni M, Mattey M. Morphological development of Aspergillus niger in submerged citric acid fermentation as a function of the spore inoculum level.
Application of neural network and cluster analysis for characterization of mycelial morphology. Aspergillus niger morphology and citric acid production in submerged batch fermentation: Rychtera M, Wase D. The growth of Aspergillus terreus and the production of itaconic acid in batch and continuous cultures.
The influence of pH. Morphological characterization of recombinant strains of Aspergillus oryzae producing alpha-amylase during batch cultivations. An inoculum technique for the production of fungal pellets. Changes in morphology of Rhizopus chinensis in submerged fermentation and their effect on production of mycelium-bound lipase.
Enhancing itaconic acid production by Aspergillus terreus. Morphology engineering - osmolality and its effect on Aspergillus niger morphology and productivity.
- Relationship between morphology and itaconic acid production by Aspergillus terreus.
- Production of itaconic acid by Aspergillus terreus in 20-liter fermentors
Morphology and rheology in filamentous cultivations. Significance of seed culture methods on mycelial morphology and production of a novel anti-cancer anthraquinone by marine mangrove endophytic fungus Halorosellinia sp.
Development of chemically defined media supporting high cell density growth of Ketogulonicigenium vulgare and Bacillus megaterium.
Optimization of fumaric acid production by Rhizopus delemar based on the morphology formation. When Cargill and Pfizer in the U. A, and the French company Rhodia stopped production of IA, China became the largest producer with companies like Qingdao Kehai Biochemistry having an annual output capacity of 20, tonnes. A host of factors have led to this decline in IA production and notable among them are the slow rate of development of viable end use applications, its relatively high price and stable petroleum prices which will make its use to replace the relatively cheaper petroleum-based polyacrylamide uneconomical.
History Of Itaconic Acid Production Itaconic acid was historically produced by various chemical methods: Maleic anhydride is also used in the production of IA but the process has not yet achieved industrialization.
None of these or other processes compete favourably with the fermentative production process [ 22 ], and IA is now almost entirely produced by fermentation of sugars by Aspergillus terreus [ 23 ]. Itaconic acid was first discovered to be a biological metabolite when it found to be produced by a strain of Aspergillus which was subsequently named Aspergillus itaconicus [ 24 ] while Calam et al.
At the same institute, preliminary attempts were also made to develop a biotechnical process for IA production [ 27 ]. Later, optimised industrial processes were established providing the limited market with IA. The main developments in IA production occurred within the next two decades. Based on the number of scientific publications recorded, it can be inferred that the interest in IA production then declined.
Output of publications relating to itaconic acid on Science Direct production showing growing interest.
Itaconic Acid Biosynthesis The process of the biosynthesis of itaconic acid has been a subject of academic discourse and is only recently being agreed upon.
InKinoshita [ 24 ] suggested that IA was produced in A. This was supported by tracer studies of Bentley and Thiesse [ 29 - 31 ] who discovered the presence of a cis-aconitate decarboxylase CAD enzyme which was proposed to catalyse the production of IA.
Inthe CAD gene was identified by Kanamasa and co-workers [ 33 ] who used it to transform Saccharomyces cerevisiae, proving that the gene was indeed responsible for the production of the CAD enzyme, and that the CAD enzyme catalysed the production of IA. The review by Klement and Buchs [ 35 ] thoroughly discusses the details of IA biosynthesis and regulation in A. Figure 3 shows a smiplified pathway for IA production in A.
A simplified metabolic pathway towards itaconate production from glucose Adapted from Klement and Buchs [ 35 ]. Itaconic Acid Fermentative Production Submerged fermentation The conditions for the production of IA by Aspergillus terreus by submerged fermentation SF are similar to those of citric acid production by A.
These conditions include the availability of an excess of readily metabolizable carbon source, high levels of dissolved oxygen, limiting amounts of metal ions and an ammonium-based nitrogen source. Microorganisms A number of microorganisms have been screened and studied for itaconic acid production.
Fermentative Itaconic Acid Production
Since it was observed that A. Aspergillus terreus Strains The most widely used strain in IA production is a native strain known as A.
Aspergillus terreus IMI is another native strain which yielded 5. In spite of these yields recorded in literature, the need for even higher yields has necessitated strain improvement as a result of which most high-yielding strains available in literature today are modified strains.
To improve IA production, both strain mutagenesis and genetic modification have been explored on A. The transcription of CAD1 the gene encoded cis-aconitic acid decarboxylase in the mutant strain was five times stronger than that of IFO, which was believed to account for the improved performance [ 33 ]. Reddy and Singh [ 42 ] mutated A. They obtained two improved mutants: A wild type strain of A.
This modified pfkA gene encoded for a shorter and more active 6-phospho-fructokinase enzyme fragment. They obtained transformants that accumulated higher amounts of IA than the native strain, albeit after a longer lag phase. The IA obtained from the best transformant A was Other microorganisms Various organisms possess various inherent benefits which they can impart on the IA fermentation process.
The ideal organism will be one with yields as high as or even surpass A. These desired qualities can be imparted into a host organism through genetic manipulation and a few attempts have yielded encouraging results.
It was detected in the fermentation broth of an Ustilago zeae strain while screening several Ustilago strains for the production of ustilagic acid [ 44 ]. Tkacz and Lange [ 49 ] proposed a strategy of introducing the cis-aconitate decarboxylase gene into a citric acid producing strain e.
This was investigated by Li et al. Similarly, an increase in IA yields up to a factor of was obtained by targeting the key enzymes in IA synthesis, aconitase and CAD, to the right cellular compartments in A.
Similarly Escherichia coli could be genetically modified for IA synthesis [ 52 ]. Glucose is an easily metabolizable substrate for A. Sucrose is also a commonly used substrate.