SCREENING AND MOLECULAR CHARACTERIZATION OF BACILLUS SP PR01 FOR THE PRODUCTION OF PROTEASE ENZYME
The current study was attempted to isolate and characterize the protease producing Bacillus sp. Among the 3 strains isolated from soil sample collected f rom kuppam region, Chennai, India. One strain (PR01) exhibited potent proteolytic activity. Based on the morphological, biochemical and molecular characterization, the isolate (PR01) was identified as Bacillus sp. The strain was designated as Bacillus sp P R01. The maximum growth of Bacillus sp PR01was observed at pH 7. The optimum temperature for the growth of Bacillus sp PR01 was found to be 27 ° C an d incubation time for 2 days. The maximum growth was noted when yeast extract was used as a nitrogen source a nd dextrose was used as the carbon source. The production of enzyme Bacillus sp PR01 was carried out in production medium. The t otal protein concentration was determined and the specific activity was also performed by casein hydrolysis assay.
Technological and sensorial evaluation of Lactobacillus strains as starter cultures in fermented sausages.
The performance of several lactobacilli strains isolated from naturally fermented sausages as starter cultures was evaluated. Microbiological, physical and chemical changes, in addition to sensorial aspects were studied. From the 12 different strains tested, 10 were capable of leading the fermentation in every batch throughout the process. The monitoring of the inoculated strains was easily carried out by plasmid profiles and by checking the pH rate drop of the sausages, which was slower for the non-inoculated lots. Treatment using natural fermentation resulted in a product where hydrogen sulphide odours, which could be related to the higher content of Enterobacteriaceae throughout the ripening process, diminished its overall acceptability. The lots seeded with different L. sake strains were found to be low in acid in sensory evaluation, correlating with a low lactic acid content. In contrast, the L. plantarum lot gave rise to an overacidified product related to having the highest amount of lactic acid at the end of the process. As a general rule lactobacilli strains isolated from meat origins are good candidates as starter cultures in the manufacture of dry-fermented sausages and produce satisfactory products depending on the specific strains used more than on the species.
Calyculins and Related Marine Natural Products as Serine-Threonine Protein Phosphatase PP1 and PP2A Inhibitors and Total Syntheses of Calyculin A, B, and C
Calyculins, highly cytotoxic polyketides, originally isolated from the marine sponge Discodermia calyx by Fusetani and co-workers, belong to the lithistid sponges group. These molecules have become interesting targets for cell biologists and synthetic organic chemists. The serine/threonine protein phosphatases play an essential role in the cellular signalling, metabolism, and cell cycle control. Calyculins express potent protein phosphatase 1 and 2A inhibitory activity, and have therefore become valuable tools for cellular biologists studying intracellular processes and their control by reversible phosphorylation. Calyculins might also play an important role in the development of several diseases such as cancer, neurodegenerative diseases, and type 2-diabetes mellitus. The fascinating structures of calyculins have inspired various groups of synthetic organic chemists to develop total syntheses of the most abundant calyculins A and C. However, with fifteen chiral centres, a cyano-capped tetraene unit, a phosphate-bearing spiroketal, an anti, anti, anti dipropionate segment, an α-chiral oxazole, and a trihydroxylated γ-amino acid, calyculins reach versatility that only few natural products can surpass, and truly challenge modern chemists’ asymmetric synthesis skills.