A new protein immobilization and purification system has been developed based on the use of polyhydroxyalkanoates (PHAs, or bioplastics), which are biodegradable polymers accumulated as reserve granules in the cytoplasm of certain bacteria. The N-terminal domain of the PhaF phasin (a PHA-granule-associated protein) from Pseudomonas putida GPo1 was used as a polypeptide tag (BioF) to anchor fusi...

We have isolated a mutant of E. coli whose maximal rate of synthesis of lac mRNA is 25-fold greater than that of its parental wild-type strain. The mutant also shows alterations in the kinetics of beta-galactosidase synthesis, the functional half-life of beta-galactosidase mRNA, and the properties of lac repressor.

We examined the effects of a fragment of the substrate binding domain of DnaK on protein refolding from chemically denatured states. The fragment DnaK384-638, containing a full-length substrate binding domain, tightly binds to the unfolded protein in solution. The effects of DnaK384-638 on the reactivation of beta-galactosidase and luciferase were examined at low substrate concentration and low...

Salmonella chromogenic medium (SCM; Oxoid, Basingstoke, United Kingdom), a new selective chromogenic medium, was compared to DCLS agar (Oxoid) for the detection and presumptive identification of Salmonella species from stool samples. This medium contains two chromogenic substrates, Magenta-cap (5-bromo-6-chloro-3-indolylcaprylate), which is hydrolyzed by Salmonella species to give magenta colon...

In the presence of 0.15% oxgall, the B-galactosidase activity of whole cells of Lactobacillus bulgaricus was increased. However, higher concentrations of oxgall decreased the enzyme activity. In the absence of oxgall, little or no B-galactosidase was exhibited by the whole cells. When the cells were lysed to obtain cell-free extracts prior to assay, there was some decrease in activity of the en...

The genetic and physiological control of ,(galactosidase in Escherichia coli has been the subject of extensive investigations. It has been clearly shown that the presence of this inducible enzyme is dependent on the genic constitution of the cell (Lederberg et al., 1951). In many cases gene mutation has led to a complete loss of ability by the cell to produce the enzyme; in other instances a de...

The results are given of the ortho-nitrophenol test for beta-galactosidase production (ONPG test) on 588 strains of 123 aerobic species of bacteria, representing 30 genera. Apart from some strains of Erwinia herbicola (synonym Chromobacterium typhiflavum) and of Yersinia spp, these strains were not members of the Enterobacteriaceae, in which family the ONPG test is widely used and well document...

Beta-galactosidase (ß-D-galactoside galactohydrolase, EC 3.2.1.23), has tremendous potential in research and application in various fields like food, bioremediation, biosensor, diagnosis and treatment of disorders. The sources of the betagalactosidase are microorganisms, plants and animals. Microbial beta-galactosidase is of much interest because of their thermostability, thermoacidophilic and ...

Growth of Escherichia coli in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the lac operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furthermore, a high concentration of lactose was shown to overcome diauxie in a CR(...

Many gravity load designed (GLD) reinforced concrete (RC) frames are nowadays located in seismic areas. Different strengthening methodologies have been proposed in the past; an innovative technique based on the use of composites was proposed and validated by an experimental program developed at University of Missouri-Rolla. A theoretical approach for the assessment of the subassemblage capacity...