Influence of substrate on beta-galactosidase production by Kluyveromyces strains

The aim of the present research was to investigate the influence of culture conditions on the levels of β-galactosidase (EC 3.2.1.23) activity produced by Kluyveromyces strains. Interest was focused on evaluating enzyme activity levels when lactose or cheese whey was employed as substrate in culture medium formulation. From an overall look at the obtained results, the tested strains were found to be able to produce β-galactosidase at promising levels. The use of cheese whey, either for strain maintenance and production trials, allowed to obtain a high cell yield associated with β-galactosidase production. The maximum β-galactosidase volumetric activity, EA max 66.5 IU/ml, corresponding to 3184 EAspec IU/g cell dw, was obtained with K. marxianus MIM 782 at 37 °C and 72 h incubation

Quality of life, coping ability, and metabolic control in patients with type 1 diabetes managed by group care and a carbohydrate counting program.

Group care is a clinical-pedagogic model in which traditional routine visits are substituted by sessions of group education. This approach improves quality of life and metabolic control in patients with type 2 diabetes (1) but only quality of life in those with type 1 diabetes (2). The latter must match multiple daily insulin administrations with blood glucose monitoring, dietary intake, and energy expenditure (3). We hypothesized that to improve their coping strategies, patients with type 1 diabetes need more specific training in the technical aspects of day-to-day management of insulin therapy. To verify this, we studied the effects of embedding a carbohydrate counting program within group care on quality of life, knowledge

Purified sakacin A shows a dual mechanism of action against Listeria spp: proton motive force dissipation and cell wall breakdown

Sakacin A was purified to homogeneity through simple chromatographic procedures from cultures of Lactobacillus sakei DSMZ 6333 grown on a low-cost medium. The highly purified protein dissipated both transmembrane potential (\u394\u3a8) and transmembrane pH gradient (\u394pH) in Listeria cells in a very intense, rapid, and energy-dependent fashion. On a slower timescale, purified sakacin A also showed a lytic activity toward isolated cell walls of Listeria. Mass spectrometry was used to analyze the products of sakacin A action on cell walls, evidencing that sakacin A acts on various types of bonds within peptoglycans

Purified sakacin A shows a dual mechanism of action against Listeria spp: proton motive force dissipation and cell wall breakdown

Sakacin A was purified to homogeneity through simple chromatographic procedures from cultures of Lactobacillus sakei DSMZ 6333 grown on a low-cost medium. The highly purified protein dissipated both transmembrane potential (ΔΨ) and transmembrane pH gradient (ΔpH) in Listeria cells in a very intense, rapid, and energy-dependent fashion. On a slower timescale, purified sakacin A also showed a lytic activity toward isolated cell walls of Listeria. Mass spectrometry was used to analyze the products of sakacin A action on cell walls, evidencing that sakacin A acts on various types of bonds within peptoglycans

Effects of the different time length of heat treatments in E. coli K12 in raw shelled walnuts

Introduction: Escherichia coli (E. coli) are found in the environment, in animals, and are found on everyday food items. E. coli bacteria are very diverse and can live in different environments which can cause many problems in our food supply. E. coli can grow and survive in low water activity food like walnuts, and are also known to survive thermal heat treatments. Purpose: This study focuses on the effects of thermal heat on E. coli on walnuts and the duration of time it takes to kill the gram negative bacteria. Methods: The oven was set to 280⁰F, treatment one was a ten minute duration and treatment two was a twenty minute duration. The raw, shelled walnuts were inoculated with 107 CFU/ml E. coli concentration, divided into 10 gram bunches and were treated to the thermal heat. Once both treatments were applied to the inoculated walnuts they were placed in a stomacher bag for one minute. Three dilutions were applied; 10-2, 10-3, 10-4, and were placed on three different media plates; PCA, PDA, McConkey, and placed incubator at 95⁰F, for optimum growth. During the three day experiment a total of 270 plates, with a negative control, positive control, treatment one and treatment two were plated. Results: During the duration of this experiment there was no growth for the negative control. The positive control showed a two log reduction during the three days. Both treatments showed a decline in E. coli growth. The p-values for PCA <.0001, PDA < .001, and McConkey < .0002, all show that these treatments were significant. Therefore, using thermal heat Killed E. coli, and we reject the null hypothesis. Significance: The results of this study demonstrated the presence of E. coli on walnuts was killed with treatments one, and two

Evaluating the effects of black pepper and white vinegar on E. coli K12 in round steak

Introduction: Escherichia Coli is one of the most well-known pathogens due to its persistence even in modern countries. Raw or undercooked meat possess one of the greater opportunities for infection. Safe at-home procedures to decontaminate meat becomes necessary to reduce E. Coli prevalence. Effective procedures that do not hinder quality are ideal solutions. Purpose: The objective of this study was to determine if application of vinegar or pepper hindered and/or reduced the presence of E. Coli on whole beef. Methods: McConkey, PDA, and PCA plates were used to detect amount of E. Coli, Yeast and Molds, and total microbial colonies. 4 samples of whole muscle beef were used. 3 were inoculated with 300ul of E. Coli and the 4th was kept as a negative control. One inoculated sample was the positive control and the remaining two were exposed to either 250ml of white vinegar or 5g of pepper. 10g samples were taken from each piece of beef and sampled over the course of 7 days for growth. Results: Of the two treatments, vinegar showed a statistically significant reduction in E. Coli, yeast, and mold growth. The reduction occurred within the first 24 hours of treatment and then maintained itself throughout the remainder of the experiment. Pepper showed no significant reduction in E. Coli growth. Significance: The results of this study suggest that a piece of whole muscle beef marinated with vinegar for as little as 24 hours significantly decreases the likelihood of E. Coli infection. This allows for, when using a white vinegar marinade, the safe consumption of undercook or contaminated meat

Effects of formic acid and garlic powder on Escherichia coli in K-12 growth in raw ground beef

Introduction: Escherichia coli (E. coli) is becoming an increasingly difficult problem in meat processing facilities as well for handlers and sellers of ground meat products. There is increasing interest in new methods to combat microbial growth without affecting the final product. Purpose: The objective of this study was to observe the effects of formic acid and garlic powder on E.coli growth in ground beef. Methods: The study consisted of two samples of ground beef, one was inoculated with E.coli and one was a control. There were two separate treatments one with 1% garlic and the other with 1% formic acid. Samples were plated and enumerated for total plate counts, yeast and molds, and E.coli ; each at three different dilutions over a seven day period. Results: From all of the samples we found that this amount of garlic had no effect on any microbial growth in ground hamburger, however formic acid had a significant effect on all microbial growth in ground hamburger. Our data was calculated with a P value of less than 0.05. Our control sample of hamburger did end up getting contaminated possibly through air or poor lab practices. Significance: The results of this lab showed that the amount of garlic used had no effect however formic acid worked to significantly reduce microbial growth