Microorganisms industrial applications

Natural products with industrial applications can be produced by the metabolism of living organisms (plants, animals or microorganisms). The most economically natural compounds produced by microorganisms, other than enzymes and recombinant proteins, are the low molecular weight primary and secondary metabolites. ... 

Advantages of RBCs include the ability to sustain shock loads because of high microorganism concentrations, ease of expansion because of modular design, and low power consumption, which may be particularly attractive for industrial application. Full-scale RBC installations in refineries have performances in removal of oxygen-demanding pollutants comparable to activated sludge systems [5]. 

For industrial applications of microorganisms, bacteria and fungi are especially important. Therefore, they are discussed in more detail in the following sections. 

Brazilian Law 9279/96. According to the latter provision, all or part of living things are not patentable, except transgenic microorganisms that meet the three patentability requirements (novelty, inventive step, and industrial application) set forth in Article 8 of the law and that are not mere discoveries. 

From the time when microbial systems were first exploited as cell factories, there has been a constant attempt to improve their properties or their performance in terms of yield and productivity. The technology of manipulating and improving microorganisms to enhance their metabolic capabilities for biotechnological applications is referred to as strain improvement [126, 127], and in order to develop optimal yeast strains for industrial applications, several traits have to be improved. 

Enzymes are proteins that are synthesized in the cells of plants, animals, or microorganisms. Most enzymes used in industrial applications are now obtained from microorganisms. Cofactors or coenzymes are small, heat-stable, organic molecules that may readily dissociate from the protein and can often be removed by dialysis. These coenzymes frequently contain one of the B vitamins examples are tetrahydrofolic acid and thiamine pyrophosphate. 

Whole-cell based biocatalysis utilizes an entire microorganism for the production of the desired product. One of the oldest examples for industrial applications of whole-cell biocatalysis is the production of acetic acid from ethanol with an immobilized Acetobacter strain, which was developed nearly 200 yr ago. The key advantage of whole-cell biocatalysis is the ability to use cheap and abundant raw materials and catalyze multistep reactions. Recent advances in metabolic engineering have brought a renaissance to whole-cell biocatalysis. In the following sections, two novel industrial processes that utilize whole-cell biocatalysis are discussed with emphasis on the important role played by metabolic engineering. 

Since the inactivation of bacteria follows an exponential decay process with a limiting value tending towards zero, the absolute sterility can never be obtained. The D,g value is the absorbed dose required to reduce a microbial population to 10% of its initial value, so that in industrial applications, a SAL value of 10" is reached after 3 x D value. For drugs, a dose of 25 kGy (or kJ kg ) is generally higher than 6 x D,g value and achieves the minimum SAL required of 10 . Many reviews demonstrated that for drugs with low bioburdens (initial contamination by microorganisms), sterilization was achieved with doses even lower than 15 kGy. 

All microorganisms producing D-aminoacylases commonly produce L-aminoacy-lases as well. Therefore, to reach high optical purity of the D-amino acids produced from the respective N-acetyl-D,L-amino acids, the D-aminoacylases have to be separated from the L-aminoacylases (Table 12.3-13). However, this is a disadvantage in view of an industrial application since additional purification steps lead to more expensive enzymes and thus add costs to the whole production process. This is one of several reasons why it is widely accepted today that the production of D-amino acids by enzyme-catalyzed hydrolysis of D,L-hydantoins seems to be more promising than the D-aminoacylase route via N-acetyl-D,L-amino acids. The enzyme-catalyzed synthesis of D-amino acids from the respective D,L-hydantoins is described in Chapter 12.4. 

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