Lactic acid laboratory scale production

For laboratory-scale production of casein, HC1 is usually used for acidification acetic or lactic acids are used less frequently. Industrially, HC1 is also usually used H2S04 is used occasionally but the resulting whey is not suitable for animal feeding (MgS04 is a laxative). Lactic acid produced in situ by a culture of lactic acid bacteria is also widely used, especially in New Zealand, the principal producer of casein. 

It is likely that in the near future, starch, oilseed, or leguminous plants will be used to produce PHAs. Other plant materials such as cellulose and starch are already used to make plastics or plastic-like materials. Hemicelluloses have been used directly and/or converted to organic acids for PHA production at a laboratory scale. Thus any waste from the separation of PHA from plants could be hydrolyzed, fermented to lactic, acetic, and propionic acids, and then fed into bioreactors for the production of specialty PHAs. Polylactides and other polymers of organic acids could be produced in the same plant as could polysaccharides. Plant materials may become a major source of plastic materials in the next century with PHAs leading the way. 

Extractive fermentation is a relatively new technology that combines the fermentation process with product separation from beer. This process has been applied to commercial production of both lactic acid and ethanol, and experimental results suggest application to the propionic acid process will overcome some of the barriers indicated above. Solichien et al. (1995) examined a series of microporous membranes and polymer films for performance in membrane-based extraction of propionic and acetic acids with a range of organic solvents and acid-complexing carriers. The hollow-fiber membrane extractors, Celgard X20-400 or X-30, were found to be most satisfactory for laboratory-scale fermentations. Each extractor consisted... 

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