High pressure microorganisms

Recovery. The principal purpose of recovery is to remove nonproteinaceous material from the enzyme preparation. Enzyme yields vary, sometimes exceeding 75%. Most industrial enzymes are secreted by a microorganism, and the first recovery step is often the removal of whole cells and other particulate matter (19) by centrifugation (20) or filtration (21). In the case of ceU-bound enzymes, the harvested cells can be used as is or dismpted by physical (eg, bead mills, high pressure homogenizer) and/or chemical (eg, solvent, detergent, lysozyme [9001 -63-2] or other lytic enzyme) techniques (22). Enzymes can be extracted from dismpted microbial cells, and ground animal (trypsin) or plant (papain) material by dilute salt solutions or aqueous two-phase systems (23). 

Cellular fossils can be studied under the microscope, and more recently, laser Raman spectroscopy has been used (see below). The platelets often show cells with sizes, shapes, cell structure and colony shapes similar to those of today s microorganisms. These properties could not have survived if the rocks had been heated to temperatures above 420 K, and the fossils also would not have withstood high pressures. 

Lactic acid is prepared by the fermentation of carbohydrates, such as glucose, sucrose, and lactose, with Bacillus acidi lacti or related microorganisms. On a commercial scale, whey, corn starch, potatoes, or molasses are used as a source of carbohydrate. Lactic acid may also be prepared synthetically by the reaction between acetaldehyde and carbon monoxide at 130-200°C under high pressure, or by the hydrolysis of hexoses with sodium hydroxide. 

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