Biocatalytic potential of Fusarium globulosum lipase in selective acetylation/deacetylation reactions and in ester synthesis

Biotransformation: a green and efficient way of antioxidant synthesis

Antioxidant compounds play a vital role in human physiology. They prevent the oxidation of biomolecules by scavenging free radicals produced during physiochemical processes and/or as a result of several pathological states. A balance between the reactive oxygen species (free radicals) and antioxidants is essential for proper physiological conditions. Excessive free radicals cause oxidative stress which can lead to several human diseases. Therefore, synthesis of the effective antioxidants is crucial in managing the oxidative stress. Biotransformation has evolved as an effective technique for the production of structurally diverse molecules with a wide range of biological activities. This methodology surpasses the conventional chemical synthesis due to the fact that enzymes, being specific in nature, catalyze reactions affording products with excellent regio- and stereoselectivities. Structural transformation of various classes of compounds such as alkaloids, steroids, flavonoids, and terpenes has been carried out through this technique. Several bioactive molecules, especially those having antioxidant potential have also been synthesized by using different biotransformation techniques and enzymes. Hydroxylated, glycosylated, and acylated derivatives of phenols, flavonoids, cinnamates, and other molecules have proven abilities as potential antioxidants. A critical review of the biotransformation of these compounds into potent antioxidant metabolites is presented here.

Production of Alkaline Lipase by Corynebacterium paurometabolum, MTCC 6841 Isolated from Lake Naukuchiatal, Uttaranchal State, India

A moderately psychrophilic bacterium Corynebacterium paurometabolum MTCC 6841 (gram positive, short rod type) producing extracellular alkaline lipase was isolated from Lake Naukuchiatal, Uttaranchal, India. The bacterium was able to grow within a broad range of pH (5-10). Soyabean oil and olive oil served as the best carbon sources for lipase production. The bacterium preferred inorganic nitrogenous compounds, NaNO3 and KNO3, over organic nitrogenous compound for its growth. Maximum lipase production occurred at 25 degrees C and 8.5 pH. The enzyme activity was found to be maximum at the same values of temperature and pH. The enzyme was reasonably stable in the presence of various organic solvents. No significant effect of Ca+, Cu++, Fe++, Na+, K+, Mg++, Mn+, NH4+, Co++ ions over enzyme activity was detected. Treatment with EDTA reduced the activity to nearly one half.