Purification and characterization of the protease enzymes of Streptomyces thermovulgaris grown in rapemeal-derived media

When grown in a particulate-free, protein-rich medium derived from rapemeal (termed medium B), Streptomyces thermovulgaris produced multiple protease enzymes. The main protease activity was attributed to two types of serine protease, denoted as SV1 and SV2. A metallo protease component (SV3) and an azocaseinase component (SV4) were also present. Protease SV1 had a molecular weight of 30 kDa and a pI of 5.8. Protease SV2 was characterized by a high thermostability in the presence of calcium ions and had a pI of 8.4. This enzyme had a molecular weight of 60 kDa, but we suggest that this is the dimeric form, with 30 kDa being the monomer unit. The method chosen for initial downstream processing influenced both the yield and type of protease purified. When cell-free supernatant fluid was concentrated using ultrafiltration, rather than acetone precipitation, a higher percentage and a greater range of proteases were recovered. The medium used for the growth of Strep. thermovulgaris also appeared to affect the type of protease produced. A more diverse range of proteases were produced on rapemeal-derived medium when compared to yeast extract medium

A region of a Sym plasmid of Rhizobium leguminosarum biovar phaseoli has similarity to prokaryotic insertion sequences and to eukaryotic integrases

Near the nod and nif genes of the Sym plasmid pRP2JI of Rhizobium leguminosarum biovar phaseoli are three open reading frames whose deduced polypeptide products have similarities to those of genes in bacterial insertion sequences. The similarity of one of these ORFs was significantly greater to that of the integrase region of pol proteins of eukaryotic retroviruses and transposable elements in animals and plants than it was to the transposases of prokaryotic insertion sequences. In the noncoding region of the IS-like element, there was a sequence similar to that which had been identified close to nod genes in Azorhizobium caulinodans

Hilbert transform of voltammetric data

This article challenges the common view that improvements in critical thinking are best pursued by investigations in informal logic. From the perspective of research in psychology and neuroscience, hu-man inference is a process that is multimodal, parallel, and often emo-tional, which makes it unlike the linguistic, serial, and narrowly cog-nitive structure of arguments. At-tempts to improve inferential prac-tice need to consider psychological error tendencies, which are patterns of thinking that are natural for peo-ple but frequently lead to mistakes in judgment. This article discusses two important but neglected error ten-dencies: motivated inference and fear-driven inference