by Itaconic Acid: A Derivative of Natural Organisms with Wide Industrial Applications
Formation and Discovery
Itaconic acid is an unsaturated dicarboxylic acid that is produced naturally by certain fungi species when grown on substrates that containing sugars. It was first isolated in 1926 by Giulio Cesare Traverso from the fermentation broth of Aspergillus itaconicus. This fungus species is regarded as the prototype producer of methylidenesuccinic acid. Since its discovery, methylidenesuccinic acid production has been studied extensively using different fungal species like Aspergillus terreus which is considered as one of the best industrial producers.
Chemical Structure and Properties
Itaconic acid, chemically known as methylenesuccinic acid, has the molecular formula C5H6O4. Its IUPAC name is (2S,3S)-2-methylidenebutanedioic acid. It contains two carboxyl groups and a methylene group between them making it an unsaturated dicarboxylic acid. Methylenesuccinic acid is a white crystalline solid at room temperature with a characteristic mildly sour taste. It is highly soluble in water, partially soluble in ethanol and insoluble in organic solvents. Its melting point is around 252°C and it has a density of around 1.52 g/cm3. Due to the presence of carboxyl and methylene functional groups, methylenesuccinic acid has strong acidity and reactivity.
Production via Fermentation
Currently, industrial production of methylenesuccinic acid uses fermentation process involving selected strains of Aspergillus terreus or Ustilago maidis fungi. In the fermentation process, sugar sources like glucose are fed to the fungal culture along with necessary nutrients in a bioreactor under controlled conditions. The fungi metabolize the sugar and produce methylenesuccinic acid as a secondary metabolite. After fermentation, methylenesuccinic acid is extracted from the broth using separation techniques like liquid-liquid extraction or ion-exchange followed by purification. Typical fermentation process yields 50-80 g/L methylenesuccinic acid concentration within 3-5 days. Continuous efforts are being made to develop high yielding fungal strains and optimize fermentation conditions to improve yield and productivity.
Applications and Derivatives
Due to its unsaturated dicarboxylic acid structure, methylenesuccinic acid finds wide applications both as chemical intermediate and end product. Some of the major applications of itaconic acid are:
– Resins and polymers: Itaconic acid is copolymerized with other monomers to produce materials with special properties. Used in manufacturing unsaturated polyester resins, methacrylate resins, synthetic latex and superabsorbent polymers.
– Chelating agents: Derivatives of methylenesuccinic acid act as chelating agents for metal ions and have applications as water softeners and in agriculture.
– Synthetic lubricant: Ester derivatives of methylenesuccinic acid with alcohols like hexadecanol are used as biodegradable lubricant base stocks.
– Paper sizing: Methylenesuccinic acid and its copolymers are used for surface sizing of paper to improve quality and durability.
– Agrochemicals: Developed as green substitutes for toxic pesticides/herbicides through conjugation with active agents.
– Cosmetics: Used in formulations due to film forming, moisturizing and chelating properties.
– Pharmaceuticals: Shows antimicrobial activity. Potential applications under investigation includes treatment of fungal infections.
Research is ongoing towards commercial production of other industrially important itaconic acid derivatives like itaconamate, itaconimide and itaconolan for diverse applications.
Economic Aspects
Asia Pacific region dominates currently due to presence of manufacturing facilities in China and India. However, North America and Europe are also growing markets. Major companies involved includes Itaconix Corporation, Qingdao Kehai Biochemistry Co., Ltd., Zhejiang Guoguang Biochemistry Co., Ltd., Jinan Huaming Biochemistry Co. Ltd., and Alpha Chemika. Further capacity expansions are planned to meet the rising demand from end user industries like construction, transportation and packaging. Various government initiatives promoting bio-based chemicals also support the market growth. Overall, methylenesuccinic acid is projected to play an increasing role as a sustainable building block chemical in future.
Conclusion
In summary, methylenesuccinic acid is a naturally occurring unsaturated dicarboxylic acid having wide industrial applicability due to its unique chemical structure and reactivity. Through economical fermentation based production and value adding derivatization, it serves as a renewable substitute for petrochemicals in plastics, polymers and other sectors. Continuous R&D promises new derivatized products and applications thereby expanding the industrial significance of this biobased platform chemical.
