Enzymatic reactions environmental effects

Temperature and moisture are two of the most important environmental variables that affect microbial growth, survival, and activity. At optimal temperature and moisture conditions, chemical and enzymatic reactions in the cell will occur the most rapidly and growth and activity will be the highest. However, below and above these optimal conditions, microbial activity decreases. The microbial degradation of. v-triazines appears to follow the same pattern. The effect of soil moisture and temperature on the degradation of terbutryn was evaluated by Chu-Huang et al. (1975). They reported that after 20 weeks of incubation above 10°C and at 14% soil moisture, phytotoxic levels of terbutryn to wheat were not detected in Teller sandy loam soil. 

The rate of an enzymatic reaction is affected by a number of environmental factors, such as solvent, ionic strength, temperature, pH, and presence of inhibitor/activator. Some of these effects are described below. 

SPQR can be used to provide mechanistic information about chemical and enzymatic reactions. They are useful in the prediction of chemical reactivities and properties, of physical properties and of biological activities. This has led to their very extensive use in the design of medicinal drugs and pesticides. This involves not only maximization of activity and minimization of side effects, but desirable properties such as improved solubility, longer shelf life and controlled release. They have also become an important method in environmental science, where they can be used to predict toxicities and other properties of environmental interest. Finally, SPQR provide an effective, efficient and convenient method for storing the experimental results of studies on the variation of measured properties as a function of structural change. 

Waste oils, from restaurants and household disposals and being creating serious problems of environmental control and food safety, have been considered as good raw material for biodiesel production. Immobilized Candida antarctica lipase was found to be effective for the methanolysis of waste oil. A three-step methanolysis protocol could be used to protect lipase from inactivation by methanol. Compared with one-step reaction, it needs a longer time to reach the reaction equilibrium. So, efforts should be made to increase enzymatic reaction rate. Reports on the enhancement of the activity of certain enzymes by applying ultrasonic irradiation on the enzymes led us to investigate its effects on the enzymatic transesterification of waste oil to biodiesel in a solvent free system. 

Inorganic phosphors are potential labels for time-resolved luminescence staining and assays in aqueous environment [23, 52-55]. The lanthanide phosphors have essentially infinite shelf life, no toxicity, no photobleaching, and are unaffected by environmental conditions such as pH, temperature, enzymatic reactions, or solvent effects. Their major drawback is that the luminescence per lanthanide ion is significantly less than from the dye-doped or dye nanoparticles due to the weak absorption of individual ions partly compensated by their higher number. Inorganic nanoparticles, however, can be prepared readily in large quantities with relatively simple methods. The size of the nanoparticles can be controlled from low nanometer scale to several hundred nanometers with a narrow size distribution. 

This method has been applied, for example, for the modeling of enzymatic reactions including environmental effects [190-193]. 

Our results based in the use of Grote-Hynes theory indicate that the transmission coefficients are systematically larger for the enzymatic reactions than for the counterpart processes in aqueous solution. Although the ratio between both quantities is small, discarding then any consideration about an important contribution of dynamical effects to catalysis, this systematic observation points to a general characteristic of enzymatic processes if the enzymatic active site is prepared to stabilize the TS, then less environmental motions would be required to evolve the... 

Because practically all aromatic organic pollutants that release phenols or anilines in the course of their degradation could bind HS through enzymatic catalysis, methods employing enzyme-catalyzed polymerization reactions minimizing their presence by partial removal in aquatic and terrestrial environments might be utilized in pollution control. This can have a remarkable effect in environmental engineering practice. 

---