Evolution of Robustness to Protein Mistranslation by Accelerated Protein Turnover

Translational errors occur at high rates, and they influence organism viability and the onset of genetic diseases. To investigate how organisms mitigate the deleterious effects of protein synthesis errors during evolution, a mutant yeast strain was engineered to translate a codon ambiguously (mistranslation). It thereby overloads the protein quality-control pathways and disrupts cellular protein homeostasis. This strain was used to study the capacity of the yeast genome to compensate the deleterious effects of protein mistranslation. Laboratory evolutionary experiments revealed that fitness loss due to mistranslation can rapidly be mitigated. Genomic analysis demonstrated that adaptation was primarily mediated by large-scale chromosomal duplication and deletion events, suggesting that errors during protein synthesis promote the evolution of genome architecture. By altering the dosages of numerous, functionally related proteins simultaneously, these genetic changes introduced large phenotypic leaps that enabled rapid adaptation to mistranslation. Evolution increased the level of tolerance to mistranslation through acceleration of ubiquitin-proteasome-mediated protein degradation and protein synthesis. As a consequence of rapid elimination of erroneous protein products, evolution reduced the extent of toxic protein aggregation in mistranslating cells. However, there was a strong evolutionary trade-off between adaptation to mistranslation and survival upon starvation: the evolved lines showed fitness defects and impaired capacity to degrade mature ribosomes upon nutrient limitation. Moreover, as a response to an enhanced energy demand of accelerated protein turnover, the evolved lines exhibited increased glucose uptake by selective duplication of hexose transporter genes. We conclude that adjustment of proteome homeostasis to mistranslation evolves rapidly, but this adaptation has several side effects on cellular physiology. Our work also indicates that translational fidelity and the ubiquitin-proteasome system are functionally linked to each other and may, therefore, co-evolve in nature

Mutations at the Subunit Interface of Yeast Proliferating Cell Nuclear Antigen Reveal a Versatile Regulatory Domain

Acknowledgments We thank Szilvia Minorits for technical assistance. I.U. conceived and designed the project and wrote the manuscript. All authors participated in designing and performing the experiments, and analyzing the results. The authors declare no competing financial interests. This work was also supported by a grant from the National Research, Development and Innovation Office GINOP-2.3.2-15-2016-00001. Funding: This work was supported by Hungarian Science Foundation Grant OTKA 109521 and National Research Development and Innovation Office GINOP-2.3.2-15-2016-00001. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Implementation of food safety management systems along with other management tools (HAZOP, FMEA, Ishikawa, Pareto). the case study of Listeria monocytogenes and correlation with microbiological criteria

The food industry’s failure in planning and designing of and in implementing a Food Safety Management System and its foundation elements leads, in most instances, to compromised food safety and subsequent foodborne illness outbreaks. This phenomenon was noticed, worldwide, for all food processors, but with a much higher incidence in the medium-and small-sized food processing plants. Our study focuses on the importance of Food Safety Management System (FSMS), Critical Control Points Hazard Analysis (HACCP) and the Prerequisite Programs (PRPs) as the foundation of HACCP, in preventing foodborne outbreaks. For emphasis, we make use of the example of organizational food safety culture failures and the lack of managerial engagement which resulted in a multi-state listeriosis outbreak in USA. Moreover, we correlate this with microbiological criteria. Implementation of food safety management systems (ISO 22000:2018) along with incorporation of management tools such as HAZOP, FMEA, Ishikawa and Pareto have proved to be proactive in the maintenance of a positive food safety culture and prevention of cross-contamination and fraud. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/)

Influence of nisin and selected meat additives on the antimicrobial effect of ovotransferrin against Listeria monocytogenes

The objective of this study was to determine the effect of nisin and selected meat additives (salt, lactate, lactate–diacetate combination, and polyphosphate) on the antimicrobial activities of ovotransferrin (OTF) against the growth of Listeria monocytogenes. A Bioscreen C turbidometer (Oy Growth Curves AB Ltd., Helsinki, Finland) was used to evaluate the effect of various concentrations of nisin and individual meat additives on the antilisterial activity of OTF in brain heart infusion (BHI) broth. The concentrations of OTF, meat additives, nisin, and their combinations that proved most inhibitory to L. monocytogenes were selected and their antilisterial effects were tested using frankfurters. Frankfurters were inoculated with L. monocytogenes (˜6.0 log10 cfu/frankfurter); treated with OTF, meat additives, and nisin singly or in combination; and held under vacuum at 4, 10, or 25°C. At 40 mg/mL, OTF strongly suppressed (3.46 log at 4 h and 2.59 log at 12 h) the growth of L. monocytogenes in BHI broth compared with the control. A combination of OTF (40 mg/mL) and nisin (1,000 IU) inhibited the growth of L. monocytogenes in BHI and in frankfurters held at 25°C below the detection limit (1 cfu/mL) at 12 h. However, the antimicrobial effect of OTF (40 mg/mL) alone was not observed in frankfurters at all temperatures used in this study. Nisin (1,000 IU), OTF (40 mg/mL), and nisin (1,000 IU) combination completely inhibited the growth of L. monocytogenes in frankfurters at all temperatures during 3 d. Salt at 0.5 and 1%, lactate at 0.78 and 1.56%, and lactate (1.56%) + diacetate (0.01%) did not alter the inhibitory effect of OTF against the pathogen in BHI, but salt at 2% or polyphosphate at 0.05% negated the growth inhibitory effect of OTF against L. monocytogenes. This study demonstrated that combination of OTF and nisin was effective in controlling L. monocytogenes.This article is published as Moon, S. H., H-D. Paik, S. White, A. Daraba, A. F. Mendonca, and D. U. Ahn. "Influence of nisin and selected meat additives on the antimicrobial effect of ovotransferrin against Listeria monocytogenes." Poultry science 90, no. 11 (2011): 2584-2591. doi:10.3382/ps.2010-01275.</p

Implementation of Food Safety Management Systems along with Other Management Tools (HAZOP, FMEA, Ishikawa, Pareto). The Case Study of Listeria monocytogenes and Correlation with Microbiological Criteria

The food industry’s failure in planning and designing of and in implementing a Food Safety Management System and its foundation elements leads, in most instances, to compromised food safety and subsequent foodborne illness outbreaks. This phenomenon was noticed, worldwide, for all food processors, but with a much higher incidence in the medium- and small-sized food processing plants. Our study focuses on the importance of Food Safety Management System (FSMS), Critical Control Points Hazard Analysis (HACCP) and the Prerequisite Programs (PRPs) as the foundation of HACCP, in preventing foodborne outbreaks. For emphasis, we make use of the example of organizational food safety culture failures and the lack of managerial engagement which resulted in a multi-state listeriosis outbreak in USA. Moreover, we correlate this with microbiological criteria. Implementation of food safety management systems (ISO 22000:2018) along with incorporation of management tools such as HAZOP, FMEA, Ishikawa and Pareto have proved to be proactive in the maintenance of a positive food safety culture and prevention of cross-contamination and fraud.</jats:p

Phosphorylated Curdlan Gel/Polyvinyl Alcohol Electrospun Nanofibres Loaded with Clove Oil with Antibacterial Activity

Fibrous membranes based on natural polymers obtained by the electrospinning technique are a great choice for wound dressings. In order to promote an efficient wound repair, and to avoid antibiotics, antibacterial plant extracts can be incorporated. In the present work, the new electrospun nanofibre membranes based on monobasic phosphate curdlan (PCurd) and polyvinyl alcohol (PVA) were obtained for the first time. To establish the adequate mixing ratio for electrospinning, the behaviour of the PCurd and PVA mixture was studied by viscometry and rheology. In order to confer antimicrobial activity with the nanofibre membrane, clove essential oil (CEO) was incorporated into the electrospun solution. Well-defined and drop-free nanofibres with a diameter between 157 nm and 110 nm were obtained. The presence of CEO in the obtained nanofibres was confirmed by ATR–FTIR spectroscopy, by the phenolic and flavonoid contents, and by the antioxidant activity of the membranes. In physiological conditions, CEO was released from the membrane after 24 h. The in vivo antimicrobial tests showed a good inhibitory activity against E. coli and higher activity against S. aureus. Furthermore, the viability cell test showed the lack of cytotoxicity of the nanofibre membrane with and without CEO, confirming its potential use in wound treatment.</jats:p