An Original Halo-Alkaline Protease from Bacillus halodurans Strain US193: Biochemical Characterization and Potential Use as Bio-Additive in Detergents

Catalytic, kinetic and thermodynamic properties of free and immobilized caseinase on mica glass-ceramics

“…Optimal pH for free and nanoparticle enzyme activity was determined by measuring the activity at different pH values ranging from 4.5 to 8.0 in 0.2 M of the phosphate buffer. The relative activities were determined [27].…”

“…The thermal inactivation of free and nanoparticle protease was evaluated by incubation at temperatures 40, 50, 60 and 70 °C for defined time intervals (15, 30, 45 and 60 min) in absence of substrate [27]. Then, the samples were cooled to stop heat inactivation and the residual activities were determined.…”

“…The enzyme (free and immobilized) was pre-incubated at 30 °C for 1 h with 10 mM of various additives and inhibitors as sodium dodecyl sulfate (SDS), phenylmethylsulfonyl fluoride (PMSF),-p-Chloromercuribenzoic acid ( p CMB), Iodoacetic acid (IAA), Ethylenediaminetetraacetic acid (EDTA), Dimethyl sulfoxide (DMSO) and some metal ions with different concentrations [27]. The reaction without additive was taken as 100% activity (control).…”

Identification of a New Serine Alkaline Peptidase from the Moderately Halophilic Virgibacillus natechei sp. nov., Strain FarDT and its Application as Bioadditive for Peptide Synthesis and Laundry Detergent Formulations

“…Likewise, the protease from strain VIT P14 showed a complete inhibition against PMSF after an incubation at 37°C for 30 min [34]; however, the protease from strain MTCC 6729 retained 35% of its activity against 5 mM PMSF and totally inhibited against 10 mM PMSF [33]. The essential serine residue was often described for the alkaline salt-stable proteases from the halophilic Bacillus strains [22, 23], while the peptidase SAPV retained all of its activity towards the trypsin competitive reagents, the chymotrypsin alkylating agent, the zinc protease inhibitor, and the acid and thiol reagents. In fact, the SBTI, TLCK, TPCK, benzamidine, DTNB, ld -DTT, 2-ME, NEM, iodoacetamide, leupeptin, pepstatin A, MIA, EPNP, and 1,10-phenanthroline monohydrate had almost no effect on the activity.…”

“…Salt-stable peptidases are the most widely used biocatalysts in laundry and dishwashing detergents where the high salt concentration is the desirable assurance of protease used in detergent, as NaCl is a key ingredient in the granulation process prior to addition of the protease in the detergent formulation [20, 21]. Research is in progress to isolate halophilic microorganisms that produce enzymes with this desired property [22, 23]. The assessment of bacterial diversity of an Algerian saline lake revealed the presence of a novel specie of a genus Virgibacillus , namely Virgibacillus natechei sp.…”