Lactic acid production process

Fig. 8. Conceptual flow diagram for an integrated lactic acid production process...

Bautista, J., Jover, M., Gutierrez, J.F. et al. 2001. Preparation of crawfish chitin by in situ lactic acid production. Process Biochem. 37 229-234. 

FIGURE 1.5 Simplified block scheme of traditional lactic acid production process. 

The LCA for the production of PLA pellets in a cradle-to-gate analysis was provided with an LCA on Ingeo PLA. The PLA was produced with the new lactic acid production process with reduced environmental impacts for the Ingeo production system. The LCA provides energy and water requirements, greenhouse gas emissions, waste generation, and pollution production (Vink, Davies, and Kolstad in 2010) (Madival, Auras, Singh, and Narayan 2009). 

The other bottleneck for lactic acid production is the operating cost. For example, sterilization is necessary for fermentative production. Hence, microorganisms have an optimal fermentation temperature between 30 2°C (John et al., 2007). Therefore it is difficult to avoid contamination if the medium is not sterilized. Qin et al. (2009) have reported the use of a newly isolated thermophilic strain. Bacillus sp. strain 2 to 6, for the unsterilized fermentative production of L-lactic acid. A high yield (97.3%), productivity (4.37g/L/h), and optical purity of L-lactic acid (99.4%) were obtained in batch and fed-batch open fermentations (Qin et al., 2009). This will help to reduce energy consumption and lower labor costs. Moreover, because of the inhibitory effects of a low pH on cell growth and lactic acid production, CaCOs must be added to maintain a constant pH as a consequence, the regeneration of precipitated calcium lactate is observed (Datta and Henry, 2006). To solve this problem, a sodium lactate-tolerant strain. Bacillus sp. Na-2, was obtained by ion-beam implantation and applied during an L-lactic acid production process (Qin et al., 2010). On the other hand, new processes can be applied to prevent the production of calcium lactate, for example, reverse osmosis, ultrafiltration, electrodialysis, and solvent extraction (Datta and Henry, 2006). 

Fig. 1. Conventional process for lactic acid production from dextrose, molasses, or whey.

Membrane-based separation, lactic acid production and, 14 120 Membrane biocompatibility, in hemodialysis, 26 823—824 Membrane bioreactors, 16 26 Membrane-bound enzymes, 10 338 Membrane cell process, 9 620 Membrane cells... 

Mechanism of Action An alkaloid that decreases leukocyte motility, phagocytosis, and lactic acid production. Therapeutic Effect Decreases urate crystal deposits and reduces inflammatory process. 

The most important fermentative reaction used in dairy processing is the homofermentative conversion of lactose to lactic acid. The efficient manufacture of high-quality cultured products, including most cheese varieties, yogurt, and cultured buttermilk, requires a rapid and consistent rate of lactic acid production. Lactic acid helps to preserve, contributes to the flavor, and modifies the texture of these products. Nearly all starter cultures used to produce acidified dairy products contain one or more strains of lactic streptococci, because these organisms can produce the desired acidity without causing detrimental changes in flavor or texture. Strains of lactic streptococci can be classified as... 

A direct relation between lactic acid production and the coirtent of the PtSn alloy in the catalyst is established. A negative effect of tin on the catalyst surface is observed for this process. 

Decreases leukocyte motility, phagocytosis, lactic acid production, resulting in decreased urate crystal deposits, inflammatory process... 

Continuous lactic acid production from whey permeate is carried out in a process that consists of three separate operations in (1) a bioreactor, (2) an ultrafiltered (UF) model, and (3) an ED cell. With the UF process, recycling of all or part of the biomass is achieved. It is also possible to separate low molecular weight metabolites, such as sodium lactate, resulting from lactose fermentation. This product can then be extracted and concentrated continuously by ED. A disadvantage of continuous lactic acid production is, however, that it tends to clog the ultrafiltration membranes, which restricts permeate flow (Bazinet, 2004). 

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). 

Oxygen supply In fungal fermentation oxygen plays an important role in lactic acid production as this fermentation is an aerobic process. 

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. 

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