Lactic industrial production

Fermentation of lactic acid to yield propionic acid, carbon dioxide, acetic acid, and succinic acid is important for proper eye formation and flavor development in Emmental, Gruyere, and Swiss-type cheese varieties. This fermentation is associated with Propionibacterium spp. subspecies of Propionibacterium freudenreichii are of greatest significance. These organisms can also be used for industrial production of vitamin Bi2 and propionic acid. 

The industrial production of lactic acid [34, 35], which dates back to 1881, is undergoing a remarkable transition. Lactic acid used to be a fairly mature fine chemical that was produced, in the mid 1990s, at a volume of 50-70 kt a1 worldwide. A major share (25 kt a-1, including simple esters etc.) is used in the food industry. 

First production of neat lactic acid by industrial fermentation Public wastewater treatment plants Industrial production of butanol and acetone by aseptic fermentation... 

Rhizopus oryzae is an indispensable microorganism in industrial fermentation, as it is widely employed to produce L-lactic acid as well as other organic acids. This organism is able to produce only one stereospecific product (L-lactic acid), rather than a racemic mixture and can, therefore, fulfill the need for producing a food additive to be used as both acidulant and preservative. During L-lactic acid fermentation many other metabolites can be produced as by-products. These include fumaric acid, malic acid, ethanol, and the like. However, these metabolites can greatly influence the downstream process and the quality of the L(+)-lactic acid produced. Fumaric acid is the main by-product, as a result of a special metabolic pathway in L-lactic acid production by R. oryzae (Wang et al., 2005). 

One of the most important processes in the production of biochemicals is the 40,000 tons/yr lactic acid production involving the Lactobacillus oxidation of lactose. The MBR productivity increased eightfold compared to a conventional batch reactor with a 19-fold increased biomass concentration. Even a 30-fold increased production of ethanol was found upon coupling the Saccharomyces cerevisiae fermentation to a membrane separation. Other successful industrial applications involve the pathogen-free production of growth hormones, the synthesis of homochiral cyanohydrins, the production of 1-aspartic acid, phenyl-acetylcarbinol, vitamin B12, and the bio transformation of acrylonitrile to acrylamide. 

A basic guideline in a choice of corrosion environments during the test of RubCon specimens was their wide spreading into industrial production. Such environments were water, 30% and 70% solutions of sulfuric acid, 5% solutions of phosphoric and acetic acids, 3% solution of nitric acid, 3% and 30% solutions of hydrochloric acid, 10% solutions of lactic and lemon acids, caustic soda and caustic potash, diesel fuel, acetone, 25% water solution of ammonia, 30% solution of copper vitriol, and a saturated solution of sodium chloride. Chemical resistance of RubCon was estimated on test specimens measuring 4 x 4 x 16 cm [21-23],... 

Skory, C. D. (2003). Lactic acid production by Saccharomyces cerevisiae expressing a Rhizopus orizae lactate dehydrogenase gene. Journal of Industrial Microbiology Biotechnology., 30, 22 27. 

Amino acids, citric acid, lactic acid, propanediol, penicillin G, synthetic drug intermediates, and therapeutic proteins are among the industrially relevant products of fermentation and cell culture that have been targets for metabolic engineering. Some ofthis work has been adopted by industry (see [72], section 16.4.1). The major aim was to optimize the yields of industrial products, which was efficiently realized with Corynebacterium glutamicum for lysine and tryptophan, and at the Dupont company for 1,3-propane diol production [107-109]. 

A. SbdergSrd, M. Stolt, Industrial production of high molecular weight poly(lactic acid), in R. Auras, L.T. Lim, S.E.M. Selke, H. Tsuji (Eds.), Poly(Lactic Acid) Synthesis, Structures, Properties, Processing, and Applications, John Wiley Sons, New York, 2010, pp. 27-41. 

Although already discovered in 1780 by the Swedish chemist Carl Wilhelm Scheele,who isolated the lactic acid from sour milk, lactic acid has attracted more recently a great deal of attention due to its widespread applications, mainly in food, chemical, cosmetic, and pharmaceutical industries. Also, it has a great potential for the production of biodegradable and biocompatible polylactic acid (PLA) and, besides 3-hydroxypropionic acid, as an intermediate for sugar-based acrylic acid. Lactic acid production can be achieved either by chemical synthesis routes or by fermentative production (lactic acid fermentation). By the chemical synthesis route, a racemic mixture of DL-lactic acid is usually... 

Food preservatives are yet another product of industrial fermentation. Organic acids, particularly lactic and citric acids, are extensively used as food preservatives. Some of these preservatives (such as citric acid) are used as flavoring agents. A mixture of two bacterial species (Lactobacillus and Streptococcus) is usually used for industrial production of lactic acid. The mold Asper Uus niger is used for citric acid manufacturing. Another common preservative is the protein nisin. Nisin is produced via fermentation by the bacterium Lactococcus lactis. It is employed in the dairy industry especially for production of processed cheese. 

Because it tolerates acid, yeast may serve as an alternative to bacteria, which is usually used in industry for lactic acid production. Lactic acid is widely used as a food preservative. 

Lactic acid was discovered in 1780 by the experimental chemist Carl Wilhelm Scheele, who isolated acid of milk from sour whey [12, 13]. A further description of the history of lactic acid by Holten and Benninga shows that industrial production of lactic acid started in the United States in the 1880s [14, 15]. Avery patented and applied a process of fermentation of vegetable sugars [16]. The actual application was the use of a mixture of calcium lactate and lactic acid as baking powder. Unfortunately, this application was not a big success, but other applications in food and textile dyeing were developed. 

The phosphoketolase pathway is a route where a is transformed to a C5 sugar (and CO2) and split into a C2 and a C3 molecule. The C3 molecule is then converted to lactic acid whereas the C2 molecule is converted to acetate or ethanol. In the same traditional view, C5 sugars were regarded as leading to this heterofermentative metabolism, which is less interesting from the point of view of industrial production as a lot of acetic acid or ethanol is produced simultaneously. Although some bacteria seem to fit well in this paradigm, more recent literature has shown that this view is oversimplified and somewhat obsolete for a number of reasons. 

INDUSTRIAL PRODUCTION OF HIGH MOLECULAR WEIGHT POLY(LACTIC ACID)... 

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