An automated and highly efficient method for counting and measuring fluorescent foci in rod‐shaped bacteria

Direct measurements of cells from photo micrographs are becoming increasingly used when investigating the position and/or distribution of chromosomal loci in bacteria. In general, these measurements have been done manually, and without clear definition of how they are made. Here we present a procedure for standardizing the measurement of cell properties from phase contrast images. Furthermore, we present a program using these standardized methods that can measure the intracellular positions of fluorescent foci in bacterial cells faster and with more precision than manual measurement.     

In Vitro Enzymatic Hydrolysis of Phaseolin, the Major Storage Protein of Phaseolus Vulgaris L.

Susceptibility of the major storage protein, phaseolin, to different commercially available proteinases was studied in vitro for 17 varieties of Phaseolus vulgaris L. using electrophoretic techniques. Among serine proteinases, trypsin, subtilisin and pronase E readily hydrolyzed the native phaseolin. while chymotrypsin was less effective. Native phaseolin was markedly resistant to a carboxyl proteinase (pepsin) and somewhat resistant to a thio proteinase (papain). Major breakdown products of native phaseolin subunits were of a similar size irrespective of the enzyme used. and had an approximate MW of 22–25 kilodaltons. SDS-PAGE indicated that heated phaseolin from all the varieties investigated was effectively hydrolyzed by subtilisin, pronase E. pepsin and papain within 30 min, while chymotrypsin and trypsin exhibiting restricted specificity were slightly less effective.     

In Vitro Digestibility of Dry Bean (Phaseolus Vulgaris L.) Proteins: The Role of Heat-Stable Protease Inhibitors

In vitro susceptibility to trypsin of whole bean extracts, and waterand salt-soluble proteins of 11 dry bean (Phaseolus vulgaris L.) varieties were investigated. Whole bean proteins were rapidly digested at a 10:l protein:trypsin ratio. Salt-soluble proteins of beans were more readily and completely hydrolyzed by trypsin than their watersoluble proteins. Of the 8 fractions obtained by DEAE-cellulose column chromatography of Great Northern bean albumins, three were identified to contain heat-stable trypsin and chymotrypsin inhibitory activity. Proteins in these fractions seemed to protect phaseolin from rapid hydrolysis by proteases by virtue of both their inhibitory activity as well as protein:protein interactions.     

Optimized constitutive equation of material property based on inverse modeling for aluminum alloy hydroforming simulation

1Introduction Sheet hydroforming has many advantages such as high drawing ratio,good part surface,and can be applied widely in the versatile and low volume production with miscellaneous materials such as aluminum alloys,high-strength steel,stainless steel…     

Effect of Lenient Steam Injection (LSI) heat treatment of bovine milk on the activities of some enzymes,the milk fat globule and pH

This study investigated the effects of Lenient Steam Injection (LSI) treatment at temperatures 70–150 °C on the enzymatic activities of the indigenous milk enzymes alkaline phosphatase, lactoperoxidase (LPO), xanthine oxidase (XO), lipoprotein lipase (LPL) and plasmin in comparison with two reference heat treatments of 63 °C for 30 s and of 72 °C for 15 s by indirect heating. Milk fat globule (MFG) size distributions and pH were also monitored. Alkaline phosphatase, LPO, XO and LPL activities decreased with increasing LSI temperature. Plasmin activity was increased at temperatures <80 °C and decreased at temperatures above 90 °C. Milk fat globule homogenisation was observed at temperatures above 110–130 °C.     

Reversibility of the Hard-to-Cook Defect in Dry Beans (Phaseolus vulgaris) and Cowpeas (Vigna unguiculata)

The hard-to-cook defect, assumed to be a permanent condition in legume seeds, can be reversed. Dry beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata) which had developed the hard-to-cook defect when stored at 29°C, 65% RH had progressively shorter cooking times after additional storage at 6.5°C, 71% RH. This would suggest that the mechanism(s) leading to development of the defect should be easily reversed. The ability to reverse the hard-to-cook defect in legume seeds would provide several economic and nutritional benefits.     

PREDICTIVE MODELING APPLIED TO GROWTH OF SPOILAGE VIRGIBACILLUS PANTOTHENTICUS ON INDUSTRIAL CRÈME CARAMEL

The aim of this work was to identify the spoilage microorganisms in commercially produced crème caramel and to study their growth kinetic in different conservation conditions. Fifty‐four randomly selected strains were isolated from altered crème caramel samples with typical “medicine smell.” In order to detect the strains that cause the smell alterations, an experimental medium (PM) was prepared with crème caramel. Nineteen out of 28 isolated strains of gram‐positive spore‐former bacteria developed “medicine smell” in PM medium. Of the 19 isolated strains, five were identified as Virgibacillus pantothenticus. One was studied in a fermenter in aerobiosis at 4, 12 and 30C and in anaerobiosis at 30C. The modified Gompertz model was applied. In aerobic conditions, the maximum growth rate decreased with the temperature: μ = 1.68 at 30C and μ = 0.28 at 12C; at 4C, there was neither growth nor alteration. In anaerobic conditions, at 30C the maximum growth rate was lower than in aerobiosis (μ = 0.90), and there was no smell alteration. The appearance of these alterations was independent of the maximum growth rate. “Medicine smell” was a result of piperonal alterations. Microbiological spoilage risk could be reduced with tight control of the temperature in the production chain.