Microorganism solvent

Secondary direct food additives permitted in food for human consumption include polymers and polymer adjuvants for food treatment, enzyme preparations and microorganisms, solvents, lubricants, release agents and related substances, and other products that come in contact with food only temporarily. 

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). 

Biotechnological processes may be divided into fermentation processes and biotransformations. In a fermentation process, products are formed from components in the fermentation broth, as primary or secondary metabolites, by microorganisms or higher cells. Product examples are amino acids, vitamins, or antibiotics such as penicillin or cephalosporin. In these cases, co-solvents are sometimes used for in situ product extraction. 

Bioprocess plants are an essential part of food, fine chemical and pharmaceutical industries. Use of microorganisms to transform biological materials for production of fermented foods, cheese and chemicals has its antiquity. Bioprocesses have been developed for an enoimous range of commercial products, as listed in Table 1.1. Most of the products originate from relatively cheap raw materials. Production of industrial alcohols and organic solvents is mostly originated from cheap feed stocks. The more expensive and special bioprocesses are in the production of antibiotics, monoclonal antibodies and vaccines. Industrial enzymes and living cells such as baker s yeast and brewer s yeast are also commercial products obtained from bioprocess plants. 

In some cases, microorganisms can transform a contaminant, but they are not able to use this compound as a source of energy or carbon. This biotransformation is often called co-metabolism. In co-metabolism, the transformation of the compound is an incidental reaction catalyzed by enzymes, which are involved in the normal microbial metabolism.33 A well-known example of co-metabolism is the degradation of (TCE) by methanotrophic bacteria, a group of bacteria that use methane as their source of carbon and energy. When metabolizing methane, methanotrophs produce the enzyme methane monooxygenase, which catalyzes the oxidation of TCE and other chlorinated aliphatics under aerobic conditions.34 In addition to methane, toluene and phenol have been used as primary substrates to stimulate the aerobic co-metabolism of chlorinated solvents. 

The suspension of microbial cells in a solvent such as aqueous acidic acetonitrile is a procedure used routinely in soft ionization mass spectrometric investigations of microorganisms. This is particularly the case in MALDI-MS studies where whole-cell suspensions have been analyzed directly without separating the cellular residue. By contrast, ESMS is usually carried out with cell-free supernatants after analyte separation by LC. Some workers71 report that partial lysis of the cells occurs due to the acidic conditions employed in such techniques and that this results in the release of proteins and peptides from... 

One of the main obstacles for whole-cell microbial transformation in an organic solvent is its biocompatibility, which has led to screening for organic-solvent-tolerant microorganisms. Numerous organic-solvent-tolerant microorganisms have been found and their tolerance mechanisms have been reviewed [14,33,34]. Two-phase biotransformation systems have been successfully implemented for the production of pharmaceutically relevant metabolites. 

Kurane, R., and Tsubata, T., Method for obtaining organic solvent-resistant, microorganisms and organic solvent-resistant microorganisms obtainable by the method. Patent No. US5804435. 1998, Sep. 08. 

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