Isotopic Labelling Experiments and Enzymatic Preparation of Iso-Casbenes with Casbene Synthase from Ricinus communis

Isotopic labelling experiments gave insights into the enzyme mechanism of casbene synthase from Ricinus communis, showing a clear stereochemical course for the cyclisation reaction, in agreement with the reported absolute...

Effect of Soil Probiotic on Water Quality and Soil Quality Maintenance and Growth of Freshwater Fish Pangasius hypophthalmus

In recent decades, various procedures have been introduced to improve the conditions of the cultural ponds' conditions in aquaculture. Numerous biological products, including live bacterial inocula, preparation of enzymes, extracts of plant products, and many others, are being promoted to induce water and soil quality conditioners in aquaculture ponds. However, several studies have shown no significant effect of bacterial inoculums, and also the treatment with enzymatic preparation led to an enhancement of microbial mineralization of organic matter, but no effective net production of fish was observed. Probiotics have recently been applied to aquaculture. Probiotics are the live cells or a substrate that induce its benefits by stimulating growth, digestion, and active immune response. Probiotics can also improve water and soil quality. The current study summarizes the role of commercial probiotic ‘Super-PS’ on water quality and soil quality maintenance during the culture of freshwater fish Pangasius hypophthalmus fingerlings.

Enzymatic Preparation of Bioactive Peptides Exhibiting ACE Inhibitory Activity from Soybean and Velvet Bean: A Systematic Review

The Angiotensin-I-converting enzyme (ACE) is a peptidase with a significant role in the regulation of blood pressure. Within this work, a systematic review on the enzymatic preparation of Angiotensin-I-Converting Enzyme inhibitory (ACEi) peptides is presented. The systematic review is conducted by following PRISMA guidelines. Soybeans and velvet beans are known to have high protein contents that make them suitable as sources of parent proteins for the production of ACEi peptides. Endopeptidase is commonly used in the preparation of soybean-based ACEi peptides, whereas for velvet bean, a combination of both endo- and exopeptidase is frequently used. Soybean glycinin is the preferred substrate for the preparation of ACEi peptides. It contains proline as one of its major amino acids, which exhibits a potent significance in inhibiting ACE. The best enzymatic treatments for producing ACEi peptides from soybean are as follows: proteolytic activity by Protease P (Amano-P from Aspergillus sp.), a temperature of 37 °C, a reaction time of 18 h, pH 8.2, and an E/S ratio of 2%. On the other hand, the best enzymatic conditions for producing peptide hydrolysates with high ACEi activity are through sequential hydrolytic activity by the combination of pepsin-pancreatic, an E/S ratio for each enzyme is 10%, the temperature and reaction time for each proteolysis are 37 °C and 0.74 h, respectively, pH for pepsin is 2.0, whereas for pancreatin it is 7.0. As an underutilized pulse, the studies on the enzymatic hydrolysis of velvet bean proteins in producing ACEi peptides are limited. Conclusively, the activity of soybean-based ACEi peptides is found to depend on their molecular sizes, the amino acid residues, and positions. Hydrophobic amino acids with nonpolar side chains, positively charged, branched, and cyclic or aromatic residues are generally preferred for ACEi peptides.