Micro Organism

To study the decrease of enteric micro-organisms including viable nematode eggs, enteroviruses, faecal indicators (Escherichia coli and enterococci) and pathogenic bacteria (Listeria monocytogenes, Salmonella sp. and Clostridium perfringens) of a rural sewage sludge when it is composted for 7 months in mixture with straw. Methods and Results: Numbers of the test organisms and the physico-chemical parameters were measured on a monthly basis on the mixture, on the compost after being turned, and on the pile in three positions representing the part by which air is incoming, the bottom of the pile and the part through which air is outgoing. The lowest temperature in the pile was observed at the bottom, where it did not exceed 50°C against 66°C in the two other areas. There were no significant differences between the three areas in terms of micro-organism survival. Infectious enteroviruses were inactivated rapidly and were not found after the first turning whereas some genomes were detected until after the third turning. Escherichia coli and enterococci presented a similar survival rate and their number decreased by 4 log 10 whereas Salmonella decayed at a greater rate than L. monocytogenes. The numbers of C. perfringens decreased gradually to reach a final concentration in the mature compost of about 10 2 CFU g )1 dry matter (d.m.), which was similar to that of the faecal indicators. Conclusions: The hygienic effect of sludge composting in mixture with straw results in a significant reduction of enteric micro-organisms, the concentration of the faecal indicators in the final product being <64 most probable number g )1 d.m. The concentrations of Salmonella, enteroviruses and viable nematode eggs in the final product were not detectable which is in accordance with the French legislation. Significance and Impact of the Study: The results which pointed out the different behaviour of the test microorganisms reflect the difficulty to propose a relevant indicator of hygienization. Otherwise, they show that composting is an efficient means for hygienization of sludge of rural wastewater treatment, where the straw is available close to their place of production.

Resumen: En este trabajo se presentan los hábitos de higiene y el conocimiento que tiene un conjunto de 69 alumnos de Educación Infantil (4-6 años) sobre microorganismos y se analiza la posible influencia sobre ellos de dos propuestas didácticas diferentes (tradicional -grupo control-y con indagación -grupo experimental-). La información se obtuvo en tres momentos diferentes -pre-intervención didáctica, post intervención y dos meses después-, mediante dibujos de los niños, un cuestionario aplicado oral e individualmente con preguntas cerradas y abiertas y un cuestionario dirigido a las familias. Se detectan indicios de que el alumnado reconoce a los microorganismos como seres vivos. Tras la intervención no se encuentran diferencias estadísticamente significativas entre el grupo experimental y el control. Dos meses después se observa una mejora en el grupo control respecto a algunos hábitos de higiene y en el grupo experimental se recuerda el proceso de indagación con placas de Petri. Estos resultados abren nuevos interrogantes.

We have developed a multi-species microbial assay, MARA, for assessing the (eco)toxic risks of chemical compounds and for the determination of their toxic fingerprints. The main advantages with MARA are (1) the simultaneous testing on several microbial strains; (2) the concept of toxic fingerprinting; (3) the simple and inexpensive handling and reading of the test. The toxic activity is measured in parallel on 11 different microorganisms lyophilised in a microplate. A concentration gradient of the chemical to be tested is added and growth is indicated through the reduction of tetrazolium red (TTC). The microplates are read by a common flatbed scanner or a microplate spectrophotometer. The array of the 11 different inhibition values constitute a toxic fingerprint, characteristic for each type of chemical compound, and it is shown that the assay can distinguish between 12 standard chemicals. Both the reproducibility (CV ≈ 20%) and the sensitivity are similar to other toxicity tests based on microorganisms .

ObjectiveA clinical prospective study was designed to evaluate microbiological, cytomorphometric and clinical efficacy of low‐level laser therapy (LLLT) as an adjunct to periodontal therapy in the treatment of chronic periodontitis.MethodsSixty subjects were included and randomly assigned into 2 groups: SRP (scaling root planning) group (n = 30) and LLLT + SRP group (n = 30). Clinical parameters were measured before intervention, after the fifth treatment, and after a month. All subjects received oral hygiene instructions and full‐mouth conservative periodontal treatment (removal of dental plaque followed by SRP). Afterwards, in group II, Kavo LLLT (980 nm, 0.2 W, 6 J/cm2) was applied. Subgingival samples were collected at baseline and after the fifth treatment to quantify Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola by polymerase chain reaction (PCR). Gingival swabs were taken, and direct sme...

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

Microbial biosensors have been developed for voltammetric determination of various substances. This paper describes the development of a new biosorption based microbial biosensor for determination of Cu 2+. The developed biosensor is based on carbon paste electrode consisting of whole cells of Circinella sp. Cu 2+ was preconcentrated on the electrode surface at open circuit and then cathodically detected with the reduction of Cu 2+. The voltammetric responses were evaluated with respect to percentage cell loading in the carbon paste, preconcentration time, pH of preconcentration solution, scan rate and interferences. The optimum response was realized by biosensor constructed using 5 mg of dry cell weight per 100 mg of carbon paste in pH 5.5 preconcentration solution. Under the optimum experimental conditions, the developed microbial biosensor exhibited an excellent current response to Cu 2+ over a linear range from 5.0 × 10 −7 to 1.0 × 10 −5 M (r 2 = 0.9938) with a detection limit of 5.4 × 10 −8 M (S/N = 3). The microbial biosensor had good sensitivity and reproducibility (R.S.D. 4.3%, n = 6). Finally, the applicability of the proposed microbial biosensor to voltammetric determination of Cu 2+ in real sample was also demonstrated and validated with atomic absorption spectrophotometric (AAS) method.

BackgroundPrevious studies of paper machine operators have to a large extent focused on endotoxins as a possible health hazard, but not culturable micro‐organisms (MOs).MethodsBased on exposure assessment in 11 paper mills workers exposed to culturable bio‐aerosols were grouped in three exposure groups. 781 exposed and 285 unexposed workers completed a questionnaire that provided data pertaining to infections and associated symptoms.ResultsConcentrations of culturable bacteria in process waters varied in the range 104–106 colony forming units (cfu)/ml, and in bio‐aerosols concentrations varied typically in the range 104–&gt; 105 cfu/m3. Operators exposed to bio‐aerosols reported higher cumulative incidence of symptoms associated with infections compared to the reference population (ORs = 1.7–5.9), and the group of highest exposed workers reported higher cumulative incidence than the group of lowest exposed (ORs = 1.2–3.6).ConclusionExposure to bio‐aerosols containing culturable MOs ...

Probiotics are alive microorganisms , generally bacteria but also yeasts than, when ingested alive in suYcient amount, they have a positive eVect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or sanitary eVect. Microorganisms used in animal feed in the EU are mainly bacterial strains of Gram-positive bacteria belonging to the types Bacillus, Enterococcus, Lactobacillus, Pediococcus, Streptococcus and strains of yeast belonging to the Saccharomyces cerevisiae species and kluyveromyces. While most of the species and genera are apparently safe, certain microorganisms may be problematic, particularly the enterococci, which may harbour transmissible antibiotic resistance determinants and bacilli, specially those belonging to the Bacillus cereus group that are known to produce enterotoxins and an emetic toxin. The history and the current legislation in the European Union on probiotics feed additives including the requirements for the safety assessment for the target animal species, consumers, workers, and environment are presented.

This study was performed from February to April 2006; several visits were made to abattoirs in the north of Iran for Hypoderma spp infestation. Necropsy inspection of slaughtered and skinned animals were carried out by examination of the inner skin surface and subcutaneous tissues. Warbles were isolated by squeezing nodules from subcutaneous tissues. In the case of abscess presence, aseptic sample were taken from abscesses. The parasitological and bacteriological examinations were performed on the samples. The results indicated that 104 out of 958 of slaughtered animals were infested to Hypoderma spp in which 48 (46.15 %), 34 (32.69 %) and 22 (21.15 %) were infested to Hypoderma bovis, Hypoderma lineatum and both species, respectively. Following bacterial analysis, the following bacteria were isolated: Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus, Staphylococcus epidermidis and Klebsiella pneumonia.

Probiotics are alive microorganisms , generally bacteria but also yeasts than, when ingested alive in suYcient amount, they have a positive eVect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or sanitary eVect. Microorganisms used in animal feed in the EU are mainly bacterial strains of Gram-positive bacteria belonging to the types Bacillus, Enterococcus, Lactobacillus, Pediococcus, Streptococcus and strains of yeast belonging to the Saccharomyces cerevisiae species and kluyveromyces. While most of the species and genera are apparently safe, certain microorganisms may be problematic, particularly the enterococci, which may harbour transmissible antibiotic resistance determinants and bacilli, specially those belonging to the Bacillus cereus group that are known to produce enterotoxins and an emetic toxin. The history and the current legislation in the European Union on probiotics feed additives including the requirements for the safety assessment for the target animal species, consumers, workers, and environment are presented.

The influence of temperature and O2 concentration on respiration and shelf life of fresh-cut watermelon was investigated. Product stored at selected temperatures from 1 to 30 °C showed increasing respiration and reduced shelf life with increasing temperature. Oxygen depletion and CO2 evolution were measured using a closed system method and rates of O2 consumption and CO2 production were computed. A mathematical model found to predict the CO2 production as function of temperature and O2 showed an elevated rate of CO2 production at about 14% O2 or lower. A modified atmosphere trial that compared product stored at 7 to 9 °C in air with product at either 14% or 8% O2 revealed increased respiration in the latter treatments, suggesting a relatively high anaerobic compensation point (ACP) at &gt;14% O2. Our results suggest limited applicability of modified atmosphere packaging (MAP) for this product. Fresh-cut watermelon had extended shelf life and reduced respiration rate when stored at 1...

Probiotics are alive microorganisms , generally bacteria but also yeasts than, when ingested alive in suYcient amount, they have a positive eVect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or sanitary eVect. Microorganisms used in animal feed in the EU are mainly bacterial strains of Gram-positive bacteria belonging to the types Bacillus, Enterococcus, Lactobacillus, Pediococcus, Streptococcus and strains of yeast belonging to the Saccharomyces cerevisiae species and kluyveromyces. While most of the species and genera are apparently safe, certain microorganisms may be problematic, particularly the enterococci, which may harbour transmissible antibiotic resistance determinants and bacilli, specially those belonging to the Bacillus cereus group that are known to produce enterotoxins and an emetic toxin. The history and the current legislation in the European Union on probiotics feed additives including the requirements for the safety assessment for the target animal species, consumers, workers, and environment are presented.

We have developed a multi-species microbial assay, MARA, for assessing the (eco)toxic risks of chemical compounds and for the determination of their toxic fingerprints. The main advantages with MARA are (1) the simultaneous testing on several microbial strains; (2) the concept of toxic fingerprinting; (3) the simple and inexpensive handling and reading of the test. The toxic activity is measured in parallel on 11 different microorganisms lyophilised in a microplate. A concentration gradient of the chemical to be tested is added and growth is indicated through the reduction of tetrazolium red (TTC). The microplates are read by a common flatbed scanner or a microplate spectrophotometer. The array of the 11 different inhibition values constitute a toxic fingerprint, characteristic for each type of chemical compound, and it is shown that the assay can distinguish between 12 standard chemicals. Both the reproducibility (CV ≈ 20%) and the sensitivity are similar to other toxicity tests based on microorganisms .

The use of semiconductor photocatalysis for treatment of water and air has been the topic of intense research activity over the past 20 years. This powerful process has also been extended to the disinfection of environments contaminated with pathogenic microorganisms. This review summarizes recent developments concerned with the photocatalytic treatment of water contaminated with pathogenic microorganisms presenting a potential hazard to animals and human beings.

We have developed a multi-species microbial assay, MARA, for assessing the (eco)toxic risks of chemical compounds and for the determination of their toxic fingerprints. The main advantages with MARA are (1) the simultaneous testing on several microbial strains; (2) the concept of toxic fingerprinting; (3) the simple and inexpensive handling and reading of the test. The toxic activity is measured in parallel on 11 different microorganisms lyophilised in a microplate. A concentration gradient of the chemical to be tested is added and growth is indicated through the reduction of tetrazolium red (TTC). The microplates are read by a common flatbed scanner or a microplate spectrophotometer. The array of the 11 different inhibition values constitute a toxic fingerprint, characteristic for each type of chemical compound, and it is shown that the assay can distinguish between 12 standard chemicals. Both the reproducibility (CV ≈ 20%) and the sensitivity are similar to other toxicity tests based on microorganisms .

The use of semiconductor photocatalysis for treatment of water and air has been the topic of intense research activity over the past 20 years. This powerful process has also been extended to the disinfection of environments contaminated with pathogenic microorganisms. This review summarizes recent developments concerned with the photocatalytic treatment of water contaminated with pathogenic microorganisms presenting a potential hazard to animals and human beings.

Probiotics are alive microorganisms , generally bacteria but also yeasts than, when ingested alive in suYcient amount, they have a positive eVect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or sanitary eVect. Microorganisms used in animal feed in the EU are mainly bacterial strains of Gram-positive bacteria belonging to the types Bacillus, Enterococcus, Lactobacillus, Pediococcus, Streptococcus and strains of yeast belonging to the Saccharomyces cerevisiae species and kluyveromyces. While most of the species and genera are apparently safe, certain microorganisms may be problematic, particularly the enterococci, which may harbour transmissible antibiotic resistance determinants and bacilli, specially those belonging to the Bacillus cereus group that are known to produce enterotoxins and an emetic toxin. The history and the current legislation in the European Union on probiotics feed additives including the requirements for the safety assessment for the target animal species, consumers, workers, and environment are presented.

Background It is not always easy to advise people who inject drugs (PWID) on how to prepare their drugs in a way that is associated with reduced harm. This is particularly true for pharmaceutical drugs that are not meant to be injected. Our objective was to find “good preparation practices” for slow release morphine sulphate capsules, namely preparation methods that reduce harm, that are evidence-based and acceptable to PWID. Methods In the laboratory, morphine sulphate capsules were prepared using both a cold and lukewarm preparation technique, two contact and stirring durations (1 min and 20 s) and 4 different filters (cotton filter, Sterifilt, Sterifilt+ and a wheel filter). The following outcomes were compared: particle reduction and morphine content in the filtrate, as well as filtration ease and time. Results The lukewarm method and a stirring and contact time of 1 min were associated with a considerably higher morphine yield than both the cold method and the stirring time of ...

Probiotics are alive micro-organisms, generally bacteria but also yeasts than, when ingested alive in suYcient amount, they have a positive eVect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or sanitary eVect. Micro-organisms used in animal feed in the EU are mainly bacterial strains of Gram-positive bacteria belonging to the types Bacillus, Enterococcus, Lactobacillus, Pediococcus, Streptococcus and strains of yeast belonging to the Saccharomyces cerevisiae species and kluyveromyces. While most of the species and genera are apparently safe, certain micro-organisms may be problematic, particularly the enterococci, which may harbour transmissible antibiotic resistance determinants and bacilli, specially those belonging to the Bacillus cereus group that are known to produce enterotoxins and an emetic toxin. The history and the current legislation in the European Union on probiotics feed additives including the requirements for the safety assessment for the target animal species, consumers, workers, and environment are presented.

Probiotics are alive micro-organisms, generally bacteria but also yeasts than, when ingested alive in sufficient amount, they have a positive effect on the health going beyond the nutritional ones commonly known. Probiotics may operate through a nutritional and/or health or ...

Background It is not always easy to advise people who inject drugs (PWID) on how to prepare their drugs in a way that is associated with reduced harm. This is particularly true for pharmaceutical drugs that are not meant to be injected. Our objective was to find “good preparation practices” for slow release morphine sulphate capsules, namely preparation methods that reduce harm, that are evidence-based and acceptable to PWID. Methods In the laboratory, morphine sulphate capsules were prepared using both a cold and lukewarm preparation technique, two contact and stirring durations (1 min and 20 s) and 4 different filters (cotton filter, Sterifilt, Sterifilt+ and a wheel filter). The following outcomes were compared: particle reduction and morphine content in the filtrate, as well as filtration ease and time. Results The lukewarm method and a stirring and contact time of 1 min were associated with a considerably higher morphine yield than both the cold method and the stirring time of ...

Polyunsaturated fatty acid (PUFA) degradation by lipoxygenase (LOX) may contribute to postharvest deterioration of vegetables and fruits. In broccoli, modified atmosphere packaging (MAP), automatic misting (AM) and vent packaging (VP) may reduce postharvest deterioration. MAP storage resulted in increased chlorophyll and C-18 polyunsaturated fatty acids (PUFA) in broccoli florets by 96 hr. Reduced chlorophyll, PUFA and soluble protein were observed in nonpackaged (NP) samples. Chlorophyll remained near initial levels in vent packaged (VP) products. AM resulted in increased relative PUFA and reduced losses of soluble protein. VP reduced PUFA and soluble protein. Optimal pH of broccoli floret LOX was 5.5-6.0. Water-soluble LGX activity in MAP and NP samples followed a trend similar to PUFA changes in both samples. No differences were found among treatments when enzyme activity was expressed on soluble protein basis.

To obtain basic information on how microbial cells absorb cadmium from aqueous solution, we examined cadmium absorption in various micro-organisms. Of 51 micro-organism strains tested, we found that some Gram-positive bacteria, such as, Arthrobacter nicotianae and Bacillus subtilis, and some actinomycetes, such as, Streptomyces flavoviridis and S. levoris were highly capable of absorbing cadmium from an aqueous solution. A. nicotianae absorbed the largest amount of cadmium, over 800 μmol cadmium per gram of dry wt. cells. However, cadmium absorption by A. nicotianae was affected by the solution pH, cadmium concentration, and cell density. The absorption of cadmium was very rapid. Some factors that affected cadmium absorption by A. nicotianae cells were also discussed.

Fresh-cut products, also known as lightly or minimally processed products, are highly perishable because a large proportion of their surface area is without epidermis, the outer protective layer of tissue. Temperature, atmosphere, relative humidity and sanitation must be regulated to maintain quality of fresh-cuts. In the 0-10°C range, Q,o of respiration rates ranged from 2.0 to 8.6 among various fresh-cut fruits and vegetables. Low 02 and elevated CO* atmosphere reduced the respiration rate; however, the respiratory quotient approached 3.0 with some fresh-cuts. Film bags or coatings are necessary to maintain high relative humidity. Microorganisms were present in chlorine-washed spinach, and populations increased during storage. Stress from the physical action of processing and low O2 atmosphere affects physiology and biochemistry of the fresh-cuts, which can affect quality and shelf-life. Research in all of these areas is needed to ensure that wholesome, high-quality fresh-cut products are marketed to consumers.

Intact jicama (Pachyrhizus erosus) roots are chilling sensitive, but quality of fresh-cut pieces (1.8 × 4.5 cm cylinders) was best maintained at low storage temperatures (0 to 5°C). Respiration rates of different piece sizes were similar, and averaged 2, 7 and 10 µL CO 2 •g-1 •h-1 at 0°C, 5°C and 10°C, respectively. Storage in air at 5°C to 10°C resulted in surface browning and was associated with increases in phenolics and phenylalanine ammonia lyase and polyphenol oxidase activities. High CO 2 atmospheres (5 to 10%) at 5°C were very effective in retarding microbial growth and discoloration. The source of jicama root notably affected the quality and shelf-life of the fresh-cut pieces. Fresh-cut pieces from stored roots (2 wk at 19 to 22°C) had lower visual quality and crispness during subsequent storage than did pieces from recently harvested roots.

The use of semiconductor photocatalysis for treatment of water and air has been the topic of intense research activity over the past 20 years. This powerful process has also been extended to the disinfection of environments contaminated with pathogenic microorganisms. This review summarizes recent developments concerned with the photocatalytic treatment of water contaminated with pathogenic microorganisms presenting a potential hazard to animals and human beings.

&mdash; Brood provisions from Centris flavofasciata and Xylocopa californica arizonensis, larval feces and pollen collected by X c arizonensis, and the alimentary canal of adult female Crawfordapis luctuosa were examined for microorganisms , particularly spore-forming bacteria belonging to the genus Bacillus. Bacillus species were associated with some samples from all 3 bees. Brood provisions of C flavofasciata contained B licheniformis. Bacillus cereus, B subtilis, and an unidentified Bacillus similar to B sphaericus were isolated from the gut of Crawfordapis. Pollen collected by X c arizonensis contained B circulans, B pumilus, and B subtilis. The latter species was also associated with provisions of a young carpenter bee larva. These results and our previous findings on microflora of Anthophora sp, Apis mellifera, Centris pallida, Melipona fasciata, and a necrophage of the genus Trigona demonstrate that Bacillus species are common associates of Apoidea and could participate both in metabolic conversion of food and in the control of competing and/or spoilage microorganisms. Apoidea / microorganism / Bacillus * Mention of a proprietary product or company name does not constitute an endorsement by the US Department of Agriculture.

&mdash; Brood provisions from Centris flavofasciata and Xylocopa californica arizonensis, larval feces and pollen collected by X c arizonensis, and the alimentary canal of adult female Crawfordapis luctuosa were examined for microorganisms , particularly spore-forming bacteria belonging to the genus Bacillus. Bacillus species were associated with some samples from all 3 bees. Brood provisions of C flavofasciata contained B licheniformis. Bacillus cereus, B subtilis, and an unidentified Bacillus similar to B sphaericus were isolated from the gut of Crawfordapis. Pollen collected by X c arizonensis contained B circulans, B pumilus, and B subtilis. The latter species was also associated with provisions of a young carpenter bee larva. These results and our previous findings on microflora of Anthophora sp, Apis mellifera, Centris pallida, Melipona fasciata, and a necrophage of the genus Trigona demonstrate that Bacillus species are common associates of Apoidea and could participate both in metabolic conversion of food and in the control of competing and/or spoilage microorganisms. Apoidea / microorganism / Bacillus * Mention of a proprietary product or company name does not constitute an endorsement by the US Department of Agriculture.

Microbial biosensors have been developed for voltammetric determination of various substances. This paper describes the development of a new biosorption based microbial biosensor for determination of Cu 2+. The developed biosensor is based on carbon paste electrode consisting of whole cells of Circinella sp. Cu 2+ was preconcentrated on the electrode surface at open circuit and then cathodically detected with the reduction of Cu 2+. The voltammetric responses were evaluated with respect to percentage cell loading in the carbon paste, preconcentration time, pH of preconcentration solution, scan rate and interferences. The optimum response was realized by biosensor constructed using 5 mg of dry cell weight per 100 mg of carbon paste in pH 5.5 preconcentration solution. Under the optimum experimental conditions, the developed microbial biosensor exhibited an excellent current response to Cu 2+ over a linear range from 5.0 × 10 −7 to 1.0 × 10 −5 M (r 2 = 0.9938) with a detection limit of 5.4 × 10 −8 M (S/N = 3). The microbial biosensor had good sensitivity and reproducibility (R.S.D. 4.3%, n = 6). Finally, the applicability of the proposed microbial biosensor to voltammetric determination of Cu 2+ in real sample was also demonstrated and validated with atomic absorption spectrophotometric (AAS) method.

White blush on the surface of peeled carrots is a major cosmetic disadvantage in marketing this lightly processed, ready-to-eat product. The loss of quality is exacerbated by surface dehydration. To maintain good appearance, edible coatings consisting of emulsions incorporating caseinates with beeswax, stearic acid or acetylated monoglyceride were tested. All except the latter increased water vapor resistance. Sodium caseinate-stearic acid was particularly effective in ameliorating the disorder.

The medical complications of injecting preparations from crushed tablets can be severe, and most can be attributed to the injection of insoluble particles and micro-organisms. Previously we have shown that most of the particles can be removed by filtration, but it was not known whether bacteria could also be filtered in the presence of a high particle load. This study aims to determine the feasibility of filtration to remove bacteria from injections prepared from tablets. Injections were prepared from crushed slow-release morphine tablets, in mixed bacterial suspensions of Staphylococcus aureus, Streptococcus pyogenes and Pseudomonas aeruginosa. The injection suspensions were passed through syringe filters of porosity 0.45 or 0.20 μm, or combined 0.8 then 0.2 μm, and the bacterial load was counted. Bacterial concentrations in unfiltered injections were 2.5-4.3 × 10(6) colony forming units mL(-1) . Both the 0.20 and 0.45 μm filters blocked unless a prefilter (cigarette filter) was us...

Fresh-cut produce has a huge following in today's supermarkets. The trend follows the need to decrease preparation time as well as the desire to follow the current health guidelines for consumption of more whole "heart-healthy" foods. Additionally, consumers are able to enjoy a variety of fresh produce regardless of the local season because produce is now shipped world-wide. However, most fruits decompose rapidly once their natural packaging has been disrupted by cutting. In addition, some intact fruits have limited shelf-life which, in turn, limits shipping and storage. Therefore, a basic understanding of how produce microstructure relates to texture and how microstructure changes as quality deteriorates is needed to ensure the best quality in the both the fresh-cut and the fresh produce markets. Similarities between different types of produce include desiccation intolerance which produces wrinkling of the outer layers, cracking of the cuticle and increased susceptibility to pathogen invasion. Specific examples of fresh produce and their corresponding ripening and storage issues, and degradation are shown in scanning electron micrographs.

Measurement, analysis, and modeling of respiration rate (RR) of fresh produce are fundamental for the engineering design of MAP. This study investigates the effect of type of cutting (sliced in circular shape, batons in rectangular shape, and shredded into thin strips) on the respiration rate of carrots at different temperatures (4, 8, 12, 16, and 20 • C) with ambient atmosphere. The higher respiration rates were found for shredded carrots and the lowest for whole carrots at all the temperatures tested. The RR increased from 9 ± 1 to 26 ± 3, 10 ± 1 to 53 ± 2, 11 ± 1 to 55 ± 2, and 18 ± 1 to 75 ± 3 mL of O 2 per kilogram hour for whole, sliced, baton, and shredded carrots, respectively, as the temperature increased from 4 to 20 • C. On an average, RO 2 and RCO 2 were increased by 85% and 64%, 100% and 72%, and 151% and 124% for sliced, baton, and shredded carrots, respectively, compared to the RR values of whole carrots. The temperature dependence of RR followed an Arrhenius-type relationship for all types of carrots, with activation energies in the range of 35 ± 3 to 62 ± 2 kJ/mol. Type of cut was the major factor for both RO 2 and RCO 2 , with shredded carrots having the highest rates and whole carrots the lowest. RR of whole carrots did not vary during storage, whereas it increased for cut carrots and especially for shredded carrots. The respiratory quotient (RQ) increased with temperature and did not vary during storage in all types of carrots, except the RQ of whole carrots decreased significantly over time.

The aim of this work was to evaluate the photokilling efficiency of synthesized titanium dioxide nanoparticles in suspension. Two strains of Escherichia coli, Lactobacillus casei rhamnosus and Staphylococcus aureus were used as probes to test the photokilling activities of the nanoparticles. The toxicity effects of TiO2 nanoparticles on the environment were determined by a standard test using gram-negative bioluminescent bacteria Vibrio fischeri. The antimicrobial activity of these nanoparticles (NPs) was then investigated versus NPs concentration, UV irradiation time and micro- organism strains. We evaluated the LC50 values of the nanoparticles suspension by counting the Colony-Forming Units. Results highlighted the differences in bacteria sensitivity facing photokilling treatment induced by the irradiation of anatase TiO2 nanoparticles suspension. At the concentration of 1 g·L-1 TiO2, tested bacteria were killed after 30 minutes of photo-treatment. Using different TiO2 concentrations, the Staphylococcus aureus gram-positive/catalase-positive bacteria were more resistant than gram-negative/catalase-positive ones or gram-positive/catalase-negative bacteria. An effect of UV irradiation was evaluated by the quantification of hydrogen peroxide generated by the photolysis of water molecules in presence of the nanoparticles with or without the most resistant bacterium (S. aureus). After 30 minutes with UV irradiation in these two conditions, the concentration of hydrogen peroxide was 35 μM in presence of 1.2 g·L-1 TiO2 suspension. This result suggested that the resistance mechanism of S. aureus was not due to an extracelullar H2O2 enzymatic degradation.

The bactericidal action of heterogeneous photocatalysis (UV-A/TiO 2 ) has been tested on Enterobacter cloacae, a microorganism very resistant to UV-A irradiation. Results have been compared with other representative strains of Gram (−) bacilli of different photosensitivity like E. coli, Pseudomonas aeruginosa and Salmonella typhimurium. The TiO 2 photocatalytic technology can inactivate bacteria resistant to oxidative membrane damage caused by direct UV irradiation, like E. cloacae, a common soil and aquatic microorganism, which normally is not affected by low UV-A irradiation intensity. In all cases, sublethal UV-A doses provoked an important lethality in the presence of TiO 2 . Inactivation rates of the microorganisms are compared and some clues on the mechanism of bacteria destruction are discussed.

The use of semiconductor photocatalysis for treatment of water and air has been the topic of intense research activity over the past 20 years. This powerful process has also been extended to the disinfection of environments contaminated with pathogenic micro-organisms. This review summarizes recent developments concerned with the photocatalytic treatment of water contaminated with pathogenic micro-organisms presenting a potential hazard to animals and human beings.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.

The influence of Ca2+ on firmness and membrane lipid structural components was evaluated during storage of shredded (wound-stressed) carrot tissues (Duucus carota L. 'Caropak'). During 10 days of storage at 10°C and 95% RH, Ca*' treatment (applied as 1% w/v CaC12 upon shredding) provided 6-16% greater firmness retention than did a water control treatment. Calcium accentuated net increases in total phospholipid and monogalactosyldiacylglycerol concentrations after 4 and 10 days of storage, and in acylated steryl glycoside concentrations after 4 days of storage. Calcium partially counteracted a net reduction in steryl glycoside concentration which occurred following 4 days of storage, and prevented an increase in the free sterol : phospholipid ratio following 10 days of storage. Calcium preserved membrane integrity of carrot shreds not only by delaying senescence-related membrane lipid changes, but also by apparently augmenting membrane restructuring processes.