Isotachophoretic quantification of total viable bacteria on meat and surfaces.

Background: The quantification of microbes, particularly live bacteria, is of utmost importance in assessing the quality of meat products. In the context of meat processing facilities, prompt identification and removal of contaminated carcasses or surfaces is crucial to ensuring the continuous production of safe meat for human consumption. The plate count method and other traditional detection methods are not only labour-intensive but also time-consuming taking 24-48 h.

Performance evaluation of commercially available swabs for environmental monitoring: Uptake and release efficiency.

Safety and the quality of products rely on proper cleanliness procedures and good manufacturing practices in the production environment. The use of swabs for the collection of samples from surfaces has been a common practice in industries, medicine and forensic studies. To accommodate these different purposes, many varieties of swabs have been introduced into the market, and it is important to assess the performance of these swabs before incorporating into an environmental monitoring procedure.

Isotachophoresis for rapid transformation of Escherichia coli.

A frequent limitation of electroporation (EP) and chemical transformation (CT) are the need of tedious and time-consuming procedures for inducing transformation competence, the substantial number of cells required, and the low transformation yields typically achieved. Here, we show a new and rapid electrokinetic method for transformation of small number of noncompetent Escherichia coli TOP10 cells (2-3 × 10 ) at room temperature. Escherichia coli TOP10 cells and plasmid DNA are sequentially injected into a 50 μm ID capillary and focused into 11.

Effect of peroxyacetic acid treatment and bruising on the bacterial community and shelf-life of baby spinach.

The importance of leaf integrity, i.e. the effects of bruising (mechanical damage), and sanitisation with peroxyacetic acid (PAA) on bacterial communities of ready-to-eat baby spinach remains unclear.

Effect of glucose, pH and lactic acid on Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens within a commercial heat-shrunk vacuum-package film.

Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens are common spoilage organisms found within the microbiome of refrigerated vacuum-packaged (VP) beef. Extending and predicting VP beef shelf-life requires knowledge about how spoilage bacteria growth is influenced by environmental extrinsic and intrinsic factors. Multifactorial effects of pH, lactic acid (LA) and glucose on growth kinetics were quantified for C.

qPCR quantification of Carnobacterium maltaromaticum, Brochothrix thermosphacta, and Serratia liquefaciens growth kinetics in mixed culture.

Quantifying growth kinetics of specific spoilage microorganisms in mixed culture is required to describe the evolution of food microbiomes. A qPCR method was developed to selectively amplify individual meat spoilage bacteria, Carnobacterium maltaromaticum, Brochothrix thermosphacta and Serratia liquefaciens, within a broth medium designed to simulate the composition of beef. An optimized method of DNA extraction was produced for standard curve construction.

Characterisation of the Brochothrix thermosphacta sortase A enzyme.

Gram-positive bacteria utilise class A sortases to coat the surface of their cells with a diversity of proteins that facilitate interactions with their environment and play fundamental roles in cell physiology and virulence. A putative sortase A gene was identified in the genome of the poorly studied meat spoilage bacterium Brochothrix thermosphacta. To understand how this bacterium mediates interactions with its environment, an N-terminal truncated, His-tagged variant of this protein (His6-BtSrtA) was expressed and purified.

Genomic and metabolic characterization of spoilage-associated Pseudomonas species.

Pseudomonas are common spoilage agents of aerobically stored fresh foods. Their ability to cause spoilage is species- and may be strain-specific. To improve our understanding of the meat and milk spoilage agents Pseudomonas fragi and Pseudomonas lundensis, we sequenced the genomes of 12 P.

Vibrioferrin production by the food spoilage bacterium Pseudomonas fragi.

Pseudomonas fragi is a meat and milk spoilage bacterium with high iron requirements; however, mechanisms of iron acquisition remain largely unknown. The aim of this work was to investigate siderophore production as an iron acquisition system for P. fragi.

Isotachophoretic Fluorescence in Situ Hybridization of Intact Bacterial Cells.

A counter-pressure-assisted capillary isotachophoresis method in combination with a sieving matrix and ionic spacer was used to perform in-line fluorescence in situ hybridization (FISH) of bacterial cells. A high concentration of sieving matrix (1.8% w/v HEC) was introduced at one end of the capillary, and the bacterial cells were suspended in the spacer electrolyte for injection.

Application of electrolysed oxidising water as a sanitiser to extend the shelf-life of seafood products: a review.

Electrolysed oxidising water (E.O. water) is produced by electrolysis of sodium chloride to yield primarily chlorine based oxidising products.

Insight into the Genome of Brochothrix thermosphacta, a Problematic Meat Spoilage Bacterium.

is a dominant but poorly studied meat spoilage organism. It is a close relative of the foodborne pathogen , and constitutes the second genus in the family. Here, the genomes of 12 strains were sequenced, assembled into draft genomes, characterized, and compared with the genomes of and Phenotypic properties including biogenic amine production and antibiotic and heavy metal susceptibilities were tested.

Microbial and sensorial models for head-on and gutted (HOG) Atlantic Salmon (Salmo salar) stored from 0 to 15 °C.

Predictive models offer efficient means to manage the quality and safety of highly perishable seafood. Salmon is an increasingly popular seafood, and relies on well managed domestic and international supply chains to minimize growth of spoilage and pathogenic bacteria. While the literature describes predictive models for smoked and modified atmosphere packaged salmon, there are no reported models for spoilage bacteria and Listeria monocytogenes on head-on and gutted (HOG) aerobically-stored Atlantic salmon.

Proteomic Insight into Functional Changes of Proteorhodopsin-Containing Bacterial Species Psychroflexus torquis under Different Illumination and Salinity Levels.

The extremely psychrophilic proteorhodopsin-containing bacterial species Psychroflexus torquis is considered to be a model sea-ice microorganism, which has adapted to an epiphytic lifestyle. So far, not much is known about proteorhodopsin-based phototrophy and associated life strategies of sea ice bacteria, although it has been previously shown that P. torquis can gain growth advantage from light using a proteorhodopsin proton pump, the activity of which is influenced by environmental salinity.

Counter-pressure-assisted ITP with electrokinetic injection under field-amplified conditions for bacterial analysis.

Counter-pressure was used to extend the duration of field-amplified sample injection in isotachophoresis (FASI-ITP) in order to improve the detection of bacterial cells. Using 0.51-μm negatively charged encapsulated fluorescent beads as a model, the counter-pressure, injection and separation voltages, and times were optimized.

The use of microbial gene abundance in the development of fuel remediation guidelines in polar soils.

Terrestrial fuel spills in Antarctica commonly occur on ice-free land around research stations as the result of human activities. Successful spill clean-ups require appropriate targets that confirm contaminated sites are no longer likely to pose environmental risk following remediation. These targets are based on knowledge of the impacts of contaminants on the soil ecosystem and on the response of native biota to contamination.

Phytoremediation of hydrocarbon contaminants in subantarctic soils: an effective management option.

Accidental fuel spills on world heritage subantarctic Macquarie Island have caused considerable contamination. Due to the island's high latitude position, its climate, and its fragile ecosystem, traditional methods of remediation are unsuitable for on-site clean up. We investigated the tolerance of a subantarctic native tussock grass, Poa foliosa (Hook.

Extensive gene acquisition in the extremely psychrophilic bacterial species Psychroflexus torquis and the link to sea-ice ecosystem specialism.

Sea ice is a highly dynamic and productive environment that includes a diverse array of psychrophilic prokaryotic and eukaryotic taxa distinct from the underlying water column. Because sea ice has only been extensive on Earth since the mid-Eocene, it has been hypothesized that bacteria highly adapted to inhabit sea ice have traits that have been acquired through horizontal gene transfer (HGT). Here we compared the genomes of the psychrophilic bacterium Psychroflexus torquis ATCC 700755(T), associated with both Antarctic and Arctic sea ice, and its closely related nonpsychrophilic sister species, P.

Light-stimulated growth of proteorhodopsin-bearing sea-ice psychrophile Psychroflexus torquis is salinity dependent.

Proteorhodopsins (PRs) are commonly found in marine prokaryotes and allow microbes to use light as an energy source. In recent studies, it was reported that PR stimulates growth and survival under nutrient-limited conditions. In this study, we tested the effect of nutrient and salinity stress on the extremely psychrophilic sea-ice bacterial species Psychroflexus torquis, which possesses PR.

Rapid and sensitive microbial analysis by capillary isotachophoresis with continuous electrokinetic injection under field amplified conditions.

A highly sensitive capillary isotachophoresis method with LIF detection for microbial analysis was developed. This allowed the reliable analysis of Escherichia coli bacteria with a LOD of 14 cells in a sample volume of 100 μL, or 1.35 × 10(2) cell/mL, which is 47 times lower than reported by CE-LIF and 148 times lower than CE-UV with on-line concentration.

Capillary electrophoretic system of ribonucleic acid molecules.

Over the past two decades, capillary electrophoresis (CE) has been the subject of extensive development and progress in various DNA based sieving electrophoresis applications, namely Sanger sequencing, forensic short tandem repeat (STR) analysis, clinical genotype screening (SNP), and phylogenetic fingerprinting. Yet, this trend has not been emulated in the RNA field. This review will highlight the development and key analysis parameters of RNA electrophoresis by CE and provide possible explanations for the low research interest in this area.

Capillary electrophoresis ribosomal RNA single-stranded conformation polymorphism: a new approach for characterization of low-diversity microbial communities.

Capillary electrophoresis (CE) has been the principle system for nucleic acid analysis since the early 1990s due to its inherent advantages such as fast analysis time, high resolution and efficiency, minimal sample requirement, high detection sensitivity, and automation. In the past few decades, microbial community fingerprinting methods such as terminal restriction fragment length polymorphism and single-stranded conformation polymorphism (SSCP) have migrated to CE to utilize its advantages over conventional slab gel electrophoresis. Recently, a gel-based direct rRNA fingerprint method was demonstrated.

Use of a blocking primer allows selective amplification of bacterial DNA from microalgae cultures.

The production of algae is a crucial component of many aquaculture systems and the role of bacteria in this process is an important although complex one. We report the development of a new blocking primer that allowed PCR amplification of bacterial DNA in the presence of algal chloroplast DNA.

Evaluation of quantitative polymerase chain reaction to assess nosZ gene prevalence in mixed microbial communities.

The usefulness of quantitative polymerase chain reaction (QPCR) to measure nosZ gene prevalence in a multi-template reaction was assessed by comparing 19 nosZ template DNA samples and 91 model communities. Efficiencies of the QPCR varied but were not significantly different among nosZ genotypes and were not linked to genetic distance from Ralstonia eutropha. nosZ genotype QPCR efficiencies obtained from isolated denitrifiers were higher (84.