Effect of Equilibrated pH and Indigenous Spoilage Microorganisms on the Inhibition of Proteolytic Clostridium botulinum Toxin Production in Experimental Meals under Temperature Abuse.

Science.gov (United States)

Golden, Max C; Wanless, Brandon J; David, Jairus R D; Lineback, D Scott; Talley, Ryan J; Kottapalli, Bala; Glass, Kathleen A

2017-08-01

Clostridium botulinum is a foreseeable biological hazard in prepared refrigerated meals that needs to be addressed in food safety plans. The objective of this study was to evaluate the effect of product composition and storage temperature on the inhibition of botulinum toxin formation in nine experimental meals (meat, vegetable, or carbohydrate based). Treatments were inoculated with proteolytic C. botulinum, vacuum packaged, cooked at 90°C for 10 min, and assayed for botulinum toxin in samples stored at 25°C for up to 96 h for phase 1, or at 25°C for 12 h and then transferred to 12.5°C for up to 12 and 6 weeks in phases 1 and 2, respectively. For phase 1, none of the treatments (equilibrated pH 5.8) supported toxin production when stored at 25°C for 48 h, but toxin production was observed in all treatments at 72 h. For the remaining experiments with storage at 12.5°C, toxin production was dependent on equilibrated pH, storage time, and growth of indigenous spoilage microorganisms. In phase 1, no gross spoilage and no botulinum toxin was detected for any treatment (pH ≤5.8) stored at 12.5°C for 12 weeks. In phase 2, gross spoilage varied by commodity, with the brussels sprouts meal with pH 6.5 showing the most rapid spoilage within 2 weeks and botulinum toxin detected at 5 and 6 weeks for the control and cultured celery juice treatments, respectively. In contrast, spoilage microbes decreased the pH of a pH 5.9 beef treatment by 1.0 unit, potentially inhibiting C. botulinum through 6 weeks at 12.5°C. None of the other treatments with pH 5.8 or below supported toxin production or spoilage. This study provides validation for preventive controls in refrigerated meals. These include equilibrated product pH and storage temperature and time to inhibit toxin formation by proteolytic C. botulinum, but the impact of indigenous microflora on safety and interpretation of challenge studies is also highlighted.

Rapid measurement of meat spoilage using fluorescence spectroscopy

Science.gov (United States)

Wu, Binlin; Dahlberg, Kevin; Gao, Xin; Smith, Jason; Bailin, Jacob

2017-02-01

Food spoilage is mainly caused by microorganisms, such as bacteria. In this study, we measure the autofluorescence in meat samples longitudinally over a week in an attempt to develop a method to rapidly detect meat spoilage using fluorescence spectroscopy. Meat food is a biological tissue, which contains intrinsic fluorophores, such as tryptophan, collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) etc. As meat spoils, it undergoes various morphological and chemical changes. The concentrations of the native fluorophores present in a sample may change. In particular, the changes in NADH and FAD are associated with microbial metabolism, which is the most important process of the bacteria in food spoilage. Such changes may be revealed by fluorescence spectroscopy and used to indicate the status of meat spoilage. Therefore, such native fluorophores may be unique, reliable and nonsubjective indicators for detection of spoiled meat. The results of the study show that the relative concentrations of all above fluorophores change as the meat samples kept in room temperature ( 19° C) spoil. The changes become more rapidly after about two days. For the meat samples kept in a freezer ( -12° C), the changes are much less or even unnoticeable over a-week-long storage.

Evaluation of the spoilage potential of bacteria isolated from chilled chicken in vitro and in situ.

Science.gov (United States)

Wang, Guang-Yu; Wang, Hu-Hu; Han, Yi-Wei; Xing, Tong; Ye, Ke-Ping; Xu, Xing-Lian; Zhou, Guang-Hong

2017-05-01

Microorganisms play an important role in the spoilage of chilled chicken. In this study, a total of 53 isolates, belonging to 7 species of 3 genera, were isolated using a selective medium based on the capacity to spoil chicken juice. Four isolates, namely Aeromonas salmonicida 35, Pseudomonas fluorescens H5, Pseudomonas fragi H8 and Serratia liquefaciens 17, were further characterized to assess their proteolytic activities in vitro using meat protein extracts and to evaluate their spoilage potential in situ. The in vitro studies showed that A. salmonicida 35 displayed the strongest proteolytic activity against both sarcoplasmic and myofibrillar proteins. However, the major spoilage isolate in situ was P. fragi H8, which exhibited a fast growth rate, slime formation and increased pH and total volatile basic nitrogen (TVBN) on chicken breast fillets. The relative amounts of volatile organic compounds (VOCs) originating from the microorganisms, including alcohols, aldehydes, ketones and several sulfur compounds, increased during storage. In sum, this study demonstrated the characteristics of 4 potential spoilage bacteria on chilled yellow-feather chicken and provides a simple and convenient method to assess spoilage bacteria during quality management. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes of Bacterial Diversity Depend on the Spoilage of Fresh Vegetables

Directory of Open Access Journals (Sweden)

Dong Hwan Lee

2011-04-01

Full Text Available Almost 10~30% of vegetables were discarded by the spoilage from farms to tables. After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. This investigation was conducted to extent the knowledge of relationship the spoilage of vegetables and the diversity of microbes. The total aerobic bacterial numbers in fresh lettuce, perilla leaf, and chicory were 2.6~2.7×106, 4.6×105, 1.2×106 CFU/g of fresh weight, respectively. The most common bacterial species were Pseudomonas spp., Alysiella spp., and Burkholderia spp., and other 18 more genera were involved in. After one week of incubation of those vegetables at 28℃, the microbial diversity had been changed. The total aerobic bacterial numbers increased to 1.1~4.6×108, 4.9×107, and 7.6×108 CFU/g of fresh weight for lettuce, perilla leaf, and chicory that is about 102 times increased bacterial numbers than that before spoilage. However, the diversity of microbes isolated had been simplified and fewer bacterial species had been isolated. The most bacterial population (~48% was taken up by Pseudomonas spp., and followed by Arthrobacter spp. and Bacillus spp. The spoilage activity of individual bacterial isolates had been tested using axenic lettuce plants. Among tested isolates, Pseudomonas fluorescence and Pantoea agglomerans caused severe spoilage on lettuce.

Thymus vulgaris (red thyme and Caryophyllus aromaticus (clove essential oils to control spoilage microorganisms in pork under modified atmosphere

Directory of Open Access Journals (Sweden)

Serena D'Amato

2016-08-01

Full Text Available In recent years, it has been confirmed that essential oils (EOs exert antimicrobial activity as they are able to inhibit cell growth and inactivate microbial cells. The application of biopreservation strategies by means of EOs opens up interesting perspectives in the food industry, including meat production. The paper aims to evaluate the effects of Thymus vulgaris (red thyme and Caryophyllus aromaticus (cloves EOs on the development of the spoilage population of fresh pork packaged under modified atmosphere (MAP. In particular, the research was focused on Brochothrix thermosphacta, a specific spoilage microorganism of fresh meat packed in anaerobic conditions or under MAP. Amongst seven EOs, those that showed the highest antimicrobial activity on 5 B. thermosphacta strains in vitro were: cloves [minimum inhibitory concentration (MIC 0.6-2.5 mg/mL], savory (MIC 2.5-5.0 mg/mL, and red thyme (MIC 2.5 to 20 mg/mL. Red thyme and cloves EOs were selected for meat treatment, by increasing the dose at 20 and 40 mg/mL respectively, to take into account the matrix effect that can reduce EO availability. In spite of the minor efficacy observed in vitro, 40 mg/mL red thyme EO strongly limited the growth of B. thermosphacta in pork samples up to day 6 of storage [below 3.0 Log colony forming unit (CFU/g, starting from 2.0 Log CFU/g at time 0], and exerted an antimicrobial effect also on the aerobic mesophilic count. Good results were obtained also with 20 mg/mL red thyme EO. The control of B. thermosphacta growth through EOs encourages research on alternative methods for extending the shelf life of fresh meat under MAP.

The Effect of High Hydrostatic Pressure on Microorganisms in Food Preservation

OpenAIRE

M. Arici

2006-01-01

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. High-pressure treatments are receiving a great deal of attention for the inactivation of microorganisms in food processing, pressure instead of temperature is used as stabilizing factor. High hydrostatic pressure treatment is the most studied alternative process, many works reported successful results in inactivating a wide range of microorganisms under ...

Emerging Preservation Techniques for Controlling Spoilage and Pathogenic Microorganisms in Fruit Juices

Science.gov (United States)

Aneja, Kamal Rai; Dhiman, Romika; Aggarwal, Neeraj Kumar; Aneja, Ashish

2014-01-01

Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Thermal pasteurization is used commercially by fruit juice industries for the preservation of fruit juices but results in losses of essential nutrients and changes in physicochemical and organoleptic properties. Nonthermal pasteurization methods such as high hydrostatic pressure, pulsed electric field, and ultrasound and irradiations have also been employed in fruit juices to overcome the negative effects of thermal pasteurization. Some of these techniques have already been commercialized. Some are still in research or pilot scale. Apart from these emerging techniques, preservatives from natural sources have also shown considerable promise for use in some food products. In this review article, spoilage, pathogenic microflora, and food borne outbreaks associated with fruit juices of last two decades are given in one section. In other sections various prevention methods to control the growth of spoilage and pathogenic microflora to increase the shelf life of fruit juices are discussed. PMID:25332721

Emerging Preservation Techniques for Controlling Spoilage and Pathogenic Microorganisms in Fruit Juices

Directory of Open Access Journals (Sweden)

Kamal Rai Aneja

2014-01-01

Full Text Available Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Thermal pasteurization is used commercially by fruit juice industries for the preservation of fruit juices but results in losses of essential nutrients and changes in physicochemical and organoleptic properties. Nonthermal pasteurization methods such as high hydrostatic pressure, pulsed electric field, and ultrasound and irradiations have also been employed in fruit juices to overcome the negative effects of thermal pasteurization. Some of these techniques have already been commercialized. Some are still in research or pilot scale. Apart from these emerging techniques, preservatives from natural sources have also shown considerable promise for use in some food products. In this review article, spoilage, pathogenic microflora, and food borne outbreaks associated with fruit juices of last two decades are given in one section. In other sections various prevention methods to control the growth of spoilage and pathogenic microflora to increase the shelf life of fruit juices are discussed.

Emerging preservation techniques for controlling spoilage and pathogenic microorganisms in fruit juices.

Science.gov (United States)

Aneja, Kamal Rai; Dhiman, Romika; Aggarwal, Neeraj Kumar; Aneja, Ashish

2014-01-01

Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Thermal pasteurization is used commercially by fruit juice industries for the preservation of fruit juices but results in losses of essential nutrients and changes in physicochemical and organoleptic properties. Nonthermal pasteurization methods such as high hydrostatic pressure, pulsed electric field, and ultrasound and irradiations have also been employed in fruit juices to overcome the negative effects of thermal pasteurization. Some of these techniques have already been commercialized. Some are still in research or pilot scale. Apart from these emerging techniques, preservatives from natural sources have also shown considerable promise for use in some food products. In this review article, spoilage, pathogenic microflora, and food borne outbreaks associated with fruit juices of last two decades are given in one section. In other sections various prevention methods to control the growth of spoilage and pathogenic microflora to increase the shelf life of fruit juices are discussed.

Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria

Czech Academy of Sciences Publication Activity Database

Pastorková, E.; Žáková, T.; Landa, Přemysl; Nováková, J.; Vadlejch, J.; Kokoška, L.

2013-01-01

Roč. 161, č. 3 (2013), s. 209-213 ISSN 0168-1605 R&D Projects: GA MŠk(CZ) LD11005 Institutional research plan: CEZ:AV0Z50380511 Keywords : Phenolic compound * Antimicrobial activity * Wine spoilage microorganism Subject RIV: GM - Food Processing Impact factor: 3.155, year: 2013

Meat spoilage during distribution.

Science.gov (United States)

Nychas, George-John E; Skandamis, Panos N; Tassou, Chrysoula C; Koutsoumanis, Konstantinos P

2008-01-01

Meat spoilage during distribution can be considered as an ecological phenomenon that encompasses the changes of the available substrata (e.g., low molecular compounds), during the prevailing of a particular microbial association, the so-called specific spoilage organisms (SSO). In fact, spoilage of meat depends on an even smaller fraction of SSO, called ephemeral spoilage organisms (ESO). These ESO are the consequence of factors that dynamically persist or imposed during, e.g., processing, transportation and storage in the market. Meanwhile spoilage is a subjective judgment by the consumer, which may be influenced by cultural and economic considerations and background as well as by the sensory acuity of the individual and the intensity of the change. Indeed, when spoilage progresses, most consumers would agree that gross discoloration, strong off-odors, and the development of slime would constitute the main qualitative criteria for meat rejection. On the other hand, meat industry needs rapid analytical methods or tools for quantification of these indicators to determine the type of processing needed for their raw material and to predict remaining shelf life of their products. The need of an objective evaluation of meat spoilage is of great importance. The use of metabolomics as a potential tool for the evaluation of meat spoilage can be of great importance. The microbial association of meat should be monitored in parallel with the estimation of changes occurring in the production and/or assimilation of certain compounds would allow us to evaluate spoilage found or produced during the storage of meat under different temperatures as well as packaging conditions.

Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage

Directory of Open Access Journals (Sweden)

Joyce Regina de Barros

2010-12-01

Full Text Available This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1 0.1% food grade phosphoric acid; 2 5.0 mg/L nisin; 3 0.1% phosphoric acid and 5.0 mg/L nisin; and 4 sterile water (control. The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10 °C for 56 days. The experiments were performed according to a full factorial design 2³, totalizing 8 treatments that were repeated in 3 blocks. Aerobic plate counts and lactic acid bacteria analysis were conducted at 1, 14, 28, 42 and 56 days of storage. Treatment of casings with phosphoric acid 0.1% alone did not inhibit the growth of lactic acid bacteria and reduced the aerobic plate count by 1 log. The activity of nisin against lactic acid bacteria was enhanced by the addition of phosphoric acid, demonstrating a synergistic effect. Furthermore nisin activity was more evident at lower storage temperature (4 ºC. Therefore treatment of the natural casings with nisin and phosphoric acid, combined with low storage temperature, are obstacles that present a potential for controlling the growth of lactic acid bacteria in vacuum packaged sausage.

Resistance of pathogenic and spoilage microorganisms to disinfectants in the presence of organic matter and their residual effect on stainless steel and polypropylene.

Science.gov (United States)

Iñiguez-Moreno, Maricarmen

2018-04-23

The effectiveness of disinfectants can vary according to the microorganism, type of residues and surface. Hence, the aim of this study was to determine the effectiveness of four disinfectants in the presence of organic matter and their residual effect on stainless steel grade 304 (SS) and polypropylene B (PP-B). The disinfectant effectiveness in the presence of meat extract, yolk egg and whole milk was determined according to AOAC and UNE-EN 1040:2015; the residual effect was realized according to UNE-EN 13697:2015, using approved strains. The disinfectant effectiveness was affect at different grades depending on the organic matter present; disinfectant A (400μgmL -1 , fifth generation quaternary ammonium compound, QAC) was most effective in the presence of 10% meat extract, while the disinfectant C (200μgmL -1 , peracetic acid) had better activity in the presence of 10% egg yolk and whole milk. In the evaluation of residual effect onto SS and PP-B, the QAC had the better effect, reducing 6 Log 10 CFU mL -1 of Listeria monocytogenes ATCC 19111 24h after their application. Conversely, the disinfectants had no residual effect against Pseudomonas aeruginosa ATCC 15442. The antimicrobial activity of disinfectants tested against pathogenic and spoilage microorganisms was affected according to the type of organic matter. Disinfectant A had a more residual effect than the other disinfectants evaluated. Moreover, the residual effect of a disinfectant is greater on SS than on PP-B and dependent on the microorganism tested. Copyright © 2018. Published by Elsevier Ltd.

Combined Effect of Thermosonication and Slightly Acidic Electrolyzed Water to Reduce Foodborne Pathogens and Spoilage Microorganisms on Fresh-cut Kale.

Science.gov (United States)

Mansur, Ahmad Rois; Oh, Deog-Hwan

2015-06-01

This study evaluated the efficacy of individual treatments (thermosonication [TS+DW] and slightly acidic electrolyzed water [SAcEW]) and their combination on reducing Escherichia coli O157:H7, Listeria monocytogenes, and spoilage microorganisms (total bacterial counts [TBC], Enterobacteriaceae, Pseudomonas spp., and yeast and mold counts [YMC]) on fresh-cut kale. For comparison, the antimicrobial efficacies of sodium chlorite (SC; 100 mg/L) and sodium hypochlorite (SH; 100 mg/L) were also evaluated. Each 10 g sample of kale leaves was inoculated to contain approximately 6 log CFU/g of E. coli O157:H7 or L. monocytogenes. Each inoculated or uninoculated samples was then dip treated with deionized water (DW; control), TS+DW, and SAcEW at various treatment conditions (temperature, physicochemical properties, and time) to assess the efficacy of each individual treatment. The efficacy of TS+DW or SAcEW was enhanced at 40 °C for 3 min, with an acoustic energy density of 400 W/L for TS+DW and available chlorine concentration of 5 mg/L for SAcEW. At 40 °C for 3 min, combined treatment of thermosonication 400 W/L and SAcEW 5 mg/L (TS+SAcEW) was more effective in reducing microorganisms compared to the individual treatments (SAcEW, SC, SH, and TS+DW) and combined treatments (TS+SC and TS+SH), which significantly (P 3.24 log CFU/g, respectively. The results suggest that the combined treatment of TS+SAcEW has the potential as a decontamination process in fresh-cut industry. © 2015 Institute of Food Technologists®

Use of a MS-electronic nose for prediction of early fungal spoilage of bakery products.

Science.gov (United States)

Marín, S; Vinaixa, M; Brezmes, J; Llobet, E; Vilanova, X; Correig, X; Ramos, A J; Sanchis, V

2007-02-28

A MS-based electronic nose was used to detect fungal spoilage (measured as ergosterol concentration) in samples of bakery products. Bakery products were inoculated with different Eurotium, Aspergillus and Penicillium species, incubated in sealed vials and their headspace sampled after 2, 4 and 7 days. Once the headspace was sampled, ergosterol content was determined in each sample. Different electronic nose signals were recorded depending on incubation time. Both the e-nose signals and ergosterol levels were used to build models for prediction of ergosterol content using e-nose measurements. Accuracy on prediction of those models was between 87 and 96%, except for samples inoculated with Penicillium corylophilum where the best predictions only reached 46%.

Microbiological changes, shelf life and identification of initial and spoilage microbiota of sea bream fillets stored under various conditions using 16S rRNA gene analysis.

Science.gov (United States)

Parlapani, Foteini F; Kormas, Konstantinos Ar; Boziaris, Ioannis S

2015-09-01

Sea bream fillets are one of the most important value-added products of the seafood market. Fresh seafood spoils mainly owing to bacterial action. In this study an exploration of initial and spoilage microbiota of sea bream fillets stored under air and commercial modified atmosphere packaging (MAP) at 0 and 5 °C was conducted by 16S rRNA gene sequence analysis of isolates grown on plates. Sensory evaluation and enumeration of total viable counts and spoilage microorganisms were also conducted to determine shelf life and bacterial growth respectively. Different temperatures and atmospheres affected growth and synthesis of spoilage microbiota as well as shelf life. Shelf life under air at 0 and 5 °C was 14 and 5 days respectively, while under MAP it was 20 and 8 days respectively. Initial microbiota were dominated by Pseudomonas fluorescens, Psychrobacter and Macrococcus caseolyticus. Different temperatures and atmospheres affected the synthesis of spoilage microbiota. At the end of shelf life, different phylotypes of Pseudomonas closely related to Pseudomonas fragi were found to dominate in most cases, while Pseudomonas veronii dominated in fillets under MAP at 0 °C. Furthermore, in fillets under MAP at 5 °C, new dominant species such as Carnobacterium maltaromaticum, Carnobacterium divergens and Vagococcus fluvialis were revealed. Different temperature and atmospheric conditions affected bacterial growth, shelf life and the synthesis of spoilage microbiota. Molecular identification revealed species and strains of microorganisms that have not been reported before for sea bream fillets stored under various conditions, thus providing valuable information regarding microbiological spoilage. © 2014 Society of Chemical Industry.

Controlling Brochothrix thermosphacta as a spoilage risk using in-package atmospheric cold plasma.

Science.gov (United States)

Patange, Apurva; Boehm, Daniela; Bueno-Ferrer, Carmen; Cullen, P J; Bourke, Paula

2017-09-01

Brochothrix thermosphacta is the predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta, taking microbial and food environment factors into consideration, and investigated the shelf-life of lamb chop after in-package plasma treatment in modified atmosphere. Community profiling was used to assess the treatment effects on the lamb microflora. ACP treatment (80 kV) for 30s inactivated B. thermosphacta populations below detection levels in PBS, while 5 min treatment achieved a 2 Log cycle reduction using a complex meat model medium and attached cells. The antimicrobial efficacy of plasma was reduced but still apparent on lamb chop surface-inoculated with high concentrations of B. thermosphacta. Lamb chop treated under modified atmosphere exhibited reduced microbial growth over the product shelf-life and community profiling showed no evident changes to the microbial populations after the treatment. The overall results indicated potential of ACP to enhance microbial control leading to meat storage life extension through adjusting the modality of treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and Identification of Spoilage Yeasts in Wine Samples by MALDI-TOF MS Biotyper

Directory of Open Access Journals (Sweden)

Attila Kántor

2015-05-01

Full Text Available Many genera and species of microorganisms can be found in grape musts and wines at various times during the winemaking process. For instance, Saccharomyces, Brettanomyces, and Pediococcus can be found together in wine. There are many species of yeast involved in wine spoilage during storage. Aim of this study was to isolate the spoilage yeasts from wine samples with using special selective agar media and identified on species level by Matrix-Assisted Laser Desorption/Ionization-Time of Fly Mass Spectrometry (MALDI-TOF MS. Six red wines used in this study. We identified 10 yeast species from 152 isolates. The most common species in wine samples was Saccharomyces cerevisiae. We also identified four Candida species, two Zygosaccharomyces species and one species from genus Rhodotorula, Saccharomycodes and Dekkera.

Binary combination of epsilon-poly-L-lysine and isoeugenol affect progression of spoilage microbiota in fresh turkey meat, and delay onset of spoilage in Pseudomonas putida challenged meat.

Science.gov (United States)

Hyldgaard, Morten; Meyer, Rikke L; Peng, Min; Hibberd, Ashley A; Fischer, Jana; Sigmundsson, Arnar; Mygind, Tina

2015-12-23

Proliferation of microbial population on fresh poultry meat over time elicits spoilage when reaching unacceptable levels, during which process slime production, microorganism colony formation, negative organoleptic impact and meat structure change are observed. Spoilage organisms in raw meat, especially Gram-negative bacteria can be difficult to combat due to their cell wall composition. In this study, the natural antimicrobial agents ε-poly-L-lysine (ε-PL) and isoeugenol were tested individually and in combinations for their activities against a selection of Gram-negative strains in vitro. All combinations resulted in additive interactions between ε-PL and isoeugenol towards the bacteria tested. The killing efficiency of different ratios of the two antimicrobial agents was further evaluated in vitro against Pseudomonas putida. Subsequently, the most efficient ratio was applied to a raw turkey meat model system which was incubated for 96 h at spoilage temperature. Half of the samples were challenged with P. putida, and the bacterial load and microbial community composition was followed over time. CFU counts revealed that the antimicrobial blend was able to lower the amount of viable Pseudomonas spp. by one log compared to untreated samples of challenged turkey meat, while the single compounds had no effect on the population. However, the compounds had no effect on Pseudomonas spp. CFU in unchallenged meat. Next-generation sequencing offered culture-independent insight into population diversity and changes in microbial composition of the meat during spoilage and in response to antimicrobial treatment. Spoilage of unchallenged turkey meat resulted in decreasing species diversity over time, regardless of whether the samples received antimicrobial treatment. The microbiota composition of untreated unchallenged meat progressed from a Pseudomonas spp. to a Pseudomonas spp., Photobacterium spp., and Brochothrix thermosphacta dominated food matrix on the expense of low

Electrode Cultivation and Interfacial Electron Transport in Subsurface Microorganisms

Science.gov (United States)

Karbelkar, A. A.; Jangir, Y.; Reese, B. K.; Wanger, G.; Anderson, C.; El-Naggar, M.; Amend, J.

2016-12-01

Continental subsurface environments can present significant energetic challenges to the resident microorganisms. While these environments are geologically diverse, potentially allowing energy harvesting by microorganisms that catalyze redox reactions, many of the abundant electron donors and acceptors are insoluble and therefore not directly bioavailable. Microbes can use extracellular electron transfer (EET) as a metabolic strategy to interact with redox active surfaces. This process can be mimicked on electrode surfaces and hence can lead to enrichment and quantification of subsurface microorganisms A primary bioelectrochemical enrichment with different oxidizing and reducing potentials set up in a single bioreactor was applied in situ to subsurface microorganisms residing in iron oxide rich deposits in the Sanford Underground Research Facility. Secondary enrichment revealed a plethora of classified and unclassified subsurface microbiota on both oxidizing and reducing potentials. From this enrichment, we have isolated a Gram-positive Bacillus along with Gram-negative Cupriavidus and Anaerospora strains (as electrode reducers) and Comamonas (as an electrode oxidizer). The Bacillus and Comamonas isolates were subjected to a detailed electrochemical characterization in half-reactors at anodic and cathodic potentials, respectively. An increase in cathodic current upon inoculation and cyclic voltammetry measurements confirm the hypothesis that Comamonas is capable of electron uptake from electrodes. In addition, measurements of Bacillus on anodes hint towards novel mechanisms that allow EET from Gram-positive bacteria. This study suggests that electrochemical approaches are well positioned to dissect such extracellular interactions that may be prevalent in the subsurface, while using physical electrodes to emulate the microhabitats, redox and geochemical gradients, and the spatially dependent interspecies interactions encountered in the subsurface. Electrochemical

Microbiological spoilage of fish and fish products.

Science.gov (United States)

Gram, L; Huss, H H

1996-11-01

Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative biochemical indicators of spoilage. Shewanella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram-positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish is well understood, much less is known about spoilage of lightly preserved fish products. It is concluded that the spoilage is probably caused by lactic acid bacteria, certain psychotrophic Enterobacteriaceae and/or Photobacterium phosphoreum. However, more work is needed in this area.

Solving Microbial Spoilage Problems in Processed Foods

Science.gov (United States)

Clavero, Rocelle

This chapter surveys common microbial food spoilage processes. The chapter is organized by food products and includes sections addressing spoilage in meat, poultry, fish; dairy products (milk, butter, cheese); beverage products; bakery products; canned foods; fruit and confectionery products; and emulsions. It addresses the isolation and identification of spoilage organisms and provides several case studies as examples. It introduces various organisms responsible for spoilage including Gram-positive lactic acid bacteria, Gram-negative aerobic bacteria, yeasts, molds, and fungal contaminants. Throughout the chapter, attention is given to when, where, and how spoilage organisms enter the food processing chain. Troubleshooting techniques are suggested. The effect (or lack of effect) of heating, dehydration, pH change, cooling, and sealing on various organisms is explained throughout. The chapter contains four tables that connect specific organisms to various spoilage manifestations in a variety of food products.

Microbiological spoilage of fish and fish products

DEFF Research Database (Denmark)

Gram, Lone; Huss, Hans Henrik

1996-01-01

Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...... biochemical indicators of spoilage. Shewanzella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram......- positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish...

The use of ionizing radiation to reduce food spoilage by microorganisms

International Nuclear Information System (INIS)

Mosquera, Monica; Gomezjurado, Silvia; Munoz, Ricardo

1990-01-01

The contamination of Aspergillus flavus is studied in yellow maize, Zea mays, Peanuts, Arachis hipoguea, L.; Casabe, Yuca. Manhot esculenta, D.C. The contents of aflotoxines B 1 , B 2 , G 1 and G 2 is analized in food stuffs of popular consumption. The samples with higher contamination of A. flavus were irradiated with 1-3 KGy, and combined processes with gamma irradiation were assayed with previous and separate treatments with ammonia and hipochlorite. Thus, it was possible to lower the contamination of this fungus from 10 3 u.f.c/g to 10. Separate edible mushrooms of species Boletus edulis, were radurized with gamma irradiation dose of 2 KGy. It was possible to reduce the contamination of 10 7 microorganism/gram, to the value 10 3 - 10 2 microorganism/gram. The microbial contamination of 18 species and aromatic herbs is also studied. The contaminating fungi of these food products as well as of the edible mushrooms, were identified as Penicillum, Geortrichum, Mucor, Galdosporium and yeasts of Canida sp. The optimal irradiation doses of same species and tea herbs, are determined. At the same time de d10 irradiation doses for pure stubs of main microorganisms are determined. To reduce the microbial contamination of many foodstuffs to maximun permisible values it is proposed thesi technology eitherwith only irradiation, or with combined treatments with irradiation

Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage.

Science.gov (United States)

Johanningsmeier, Suzanne D; Franco, Wendy; Perez-Diaz, Ilenys; McFeeters, Roger F

2012-07-01

by spoilage microorganisms in reduced salt, even with pH as low as 3.2. Efforts to reduce salt in commercial brining operations will need to include control measures for this increased susceptibility to spoilage. Lactobacillus buchneri was identified as a potential causative agent and could be used as a target in development of such control measures. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

Effect of elevated oxygen and carbon dioxide on the surface growth of vegetable-associated micro-organisms

NARCIS (Netherlands)

Amanatidou, A.; Smid, E.J.; Gorris, L.G.M.

1999-01-01

The impact of a novel type of Modified Atmosphere (MA), referred to as high O2-MA, on micro-organisms associated with the spoilage of minimally-processed vegetables was studied. Pure cultures of Pseudomonas fluorescens, Enterobacter agglomerans, Aureobacterium strain 27, Candida guilliermondii, C.

Undergraduate Laboratory Exercises Specific to Food Spoilage Microbiology

Science.gov (United States)

Snyder, Abigail B.; Worobo, Randy W.; Orta-Ramirez, Alicia

2016-01-01

Food spoilage has an enormous economic impact, and microbial food spoilage plays a significant role in food waste and loss; subsequently, an equally significant portion of undergraduate food microbiology instruction should be dedicated to spoilage microbiology. Here, we describe a set of undergraduate microbiology laboratory exercises that focus…

Phytochemical profiles and antimicrobial activity of aromatic Malaysian herb extracts against food-borne pathogenic and food spoilage microorganisms.

Science.gov (United States)

Aziman, Nurain; Abdullah, Noriham; Noor, Zainon Mohd; Kamarudin, Wan Saidatul Syida Wan; Zulkifli, Khairusy Syakirah

2014-04-01

Preliminary phytochemical and flavonoid compounds of aqueous and ethanolic extracts of 6 aromatic Malaysian herbs were screened and quantified using Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The herbal extracts were tested for their antimicrobial activity against 10 food-borne pathogenic and food spoilage microorganisms using disk diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of herbal extracts were determined. In the phytochemical screening process, both aqueous and ethanolic extracts of P. hydropiper exhibited presence of all 7 tested phytochemical compounds. Among all herbal extracts, the aqueous P. hydropiper and E. elatior extracts demonstrated the highest antibacterial activity against 7 tested Gram-positive and Gram-negative bacteria with diameter ranging from 7.0 to 18.5 mm and 6.5 to 19 mm, respectively. The MIC values for aqueous and ethanolic extracts ranged from 18.75 to 175 mg/mL and 0.391 to 200 mg/mL, respectively while the MBC/MFC values for aqueous and ethanolic extracts ranged from 25 to 200 mg/mL and 3.125 to 50 mg/mL, respectively. Major types of bioactive compounds in aqueous P. hydropiper and E. elatior extracts were identified using RP-HPLC instrument. Flavonoids found in these plants were epi-catechin, quercetin, and kaempferol. The ability of aqueous Persicaria hydropiper (L.) H. Gross and Etlingera elatior (Jack) R.M. Sm. extracts to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential. Hence these herbal extracts may be used as natural preservative to improve the safety and shelf-life of food and pharmaceutical products. © 2014 Institute of Food Technologists®

Classification of root canal microorganisms using electronic-nose and discriminant analysis

Directory of Open Access Journals (Sweden)

Özbilge Hatice

2010-11-01

Full Text Available Abstract Background Root canal treatment is a debridement process which disrupts and removes entire microorganisms from the root canal system. Identification of microorganisms may help clinicians decide on treatment alternatives such as using different irrigants, intracanal medicaments and antibiotics. However, the difficulty in cultivation and the complexity in isolation of predominant anaerobic microorganisms make clinicians resort to empirical medical treatments. For this reason, identification of microorganisms is not a routinely used procedure in root canal treatment. In this study, we aimed at classifying 7 different standard microorganism strains which are frequently seen in root canal infections, using odor data collected using an electronic nose instrument. Method Our microorganism odor data set consisted of 5 repeated samples from 7 different classes at 4 concentration levels. For each concentration, 35 samples were classified using 3 different discriminant analysis methods. In order to determine an optimal setting for using electronic-nose in such an application, we have tried 3 different approaches in evaluating sensor responses. Moreover, we have used 3 different sensor baseline values in normalizing sensor responses. Since the number of sensors is relatively large compared to sample size, we have also investigated the influence of two different dimension reduction methods on classification performance. Results We have found that quadratic type dicriminant analysis outperforms other varieties of this method. We have also observed that classification performance decreases as the concentration decreases. Among different baseline values used for pre-processing the sensor responses, the model where the minimum values of sensor readings in the sample were accepted as the baseline yields better classification performance. Corresponding to this optimal choice of baseline value, we have noted that among different sensor response model and

Modeling growth of specific spoilage organisms in tilapia ...

African Journals Online (AJOL)

Tilapia is an important aquatic fish, but severe spoilage of tilapia is most likely related to the global aquaculture. The spoilage is mostly caused by specific spoilage organisms (SSO). Therefore, it is very important to use microbial models to predict the growth of SSO in tilapia. This study firstly verified Pseudomonas and Vibrio ...

Mathematical modeling of growth Salmonella and spoilage microorganisms in raw oysters

Science.gov (United States)

The main objective of this study was to develop primary and secondary models to describe the growth of Salmonella as well as background microorganisms in fresh shucked oysters. The cocktail of two Salmonella serotypes, S. Typhimurium (CICC22956) and S. Enteritidis (CICC21482), was inoculated to raw...

Kinetics of spoilage fermentation in radurized fish and optimization of irradiation process

International Nuclear Information System (INIS)

Tukenmez, I.; Ersen, M.S.; Bakioglu, A.T.

1997-01-01

Kinetic studies on radiation-inactivation and the postirradiation growth of spoilage microorganisms during chill storage and their product formation inradurized fish were carried out. Anchovy (Engraulis encrasicholus) samples unirradiated, and those irradiated at 1,2 and 3 kGy doses of gamma radiation were stored at +2 o C for 21 days. Microbiological analyses of mesophilic, psycrophilic and total bacterial counts (TBC) and chemical analyses of trimethylamine (TMA) and total volatile bases (TVB) of the samples were done immediately after irradiation and periodically during storage. Radiation induced inactivations of bacteria were expressed with a first-order decreasing kinetics. A spoilage fermentation modeling was used to evaluate the quality control parameters of radurized fish in which the increase in TBC of survivor microorganisms during storage was described by a first-order growth with a lag phase and the production of TMA and TVB was described by a growth associated product formation. Examinations of the dose effects on the kinetic parameters resulted in that the relation between the product formation rate constants and the irradiation dose represented a parabolic function which was satisfactorily used to determine optimum irradiation dose. Optimum irradiation dose was found 1.719+- 0.471 kGy with TVB data resulting in an extended shelf-life of 15-16 days of fish. It is suggested that the kinetic evaluation method developed in this study may be substitute for or used with the analytical estimate in use comprising microbiological chemical and organoleptic controls for quality assessment and dose optimization of radurization processing of fish and other sea foods.(2 tab s. and 24 refs.)

Isolation and Identification of Spoilage Fungi Associated With Rice ...

African Journals Online (AJOL)

The spoilage fungi isolated were Aspergillus species, Rhizopus, Penicilluim, Fusarium, Eurotium, Mucor, Geotrichum, Alternaria, Cladosporium and Actinomyces species. The predominant spoilage fungi in the grains were Aspergillus species. The populations of some spoilage fungi isolated from the grains were not high ...

American lobsters (Homarus americanus not surviving during air transport: evaluation of microbial spoilage

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Erica Tirloni

2016-05-01

Full Text Available Eighteen American lobsters (Homarus americanus, dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters’ meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these notsurviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1% and Photobacterium spp. (24.1%, and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3% and lipolytic ability (75.5%, suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

American Lobsters (Homarus Americanus) not Surviving During Air Transport: Evaluation of Microbial Spoilage.

Science.gov (United States)

Tirloni, Erica; Stella, Simone; Gennari, Mario; Colombo, Fabio; Bernardi, Cristian

2016-04-19

Eighteen American lobsters ( Homarus americanus ), dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters' meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these not-surviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1%) and Photobacterium spp. (24.1%), and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3%) and lipolytic ability (75.5%), suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

Influence of some physical treatments and natural food preservatives on the diversity of microorganisms in certain Egyptian juices

International Nuclear Information System (INIS)

Abu El-Naga, M.N.Z.I.

2009-01-01

Foods begin to lose their quality from the moment they are harvested through changes resulting from physical, chemical, enzymatic, or microbiological reactions. Food preservation prevents deteriorative reaction, extending the shelf life and assuring its safety. Microorganisms and enzymes are the main agents responsible for food spoilages and therefore the targets of preservation techniques. The i deal m ethod of food preservation has the following characteristics: It improves shelf life and safety by inactivating spoilage and pathogenic microorganisms. It dose not leave residues. It is cheap and convenient to apply. It encounters no objection from consumers and legislators. One of the major advances in human history was the ability to preserve food. It was the perquisite to man setting down in one place instead of moving from place to place in the never ending hunt for fresh food. The earliest preservation technologies developed were drying, smoking, chilling and heating. The use of various compounds such as salts and spices to preserve food was also used in ancient times

Fossil micro-organisms evidenced by electronic microscopy

Energy Technology Data Exchange (ETDEWEB)

Prashnowsky, A.A.; Oberlies, F.; Burger, K.

1983-04-01

Fossil microorganisms in colonies and in the form of isolated cells (iron bacteria, fungi, actinomycetes etc.) were detected by electron microscopy of rocks containing remains of plant roots, carbonaceous substance, and strata of clay iron stone with ooids. These findings suggest an environment favourable to bacterial activity during sedimentation in the Upper Carboniferous and during the later processes of peat and coal formation. They also suggest that bacterial processes are an important factor in coal formation. Accurate data on coal formation can only be obtained by systematic biochemical studies. Analyses of the defined organic substances provide a better understanding of the conversion processes of the original substances. For example, the results of sterine analysis provide information on the mycoplancton, phytoplancton and zooplancton of the Upper Carboniferous. For some types of rock, the ratio of saponifiable to non-saponifiable constituents of the organic compounds yield information on stability under various geochemical conditions. The interactions between the various groups of microorganisms also play a major role in the solution of ecological problems.

Short communication: quantification of the transmission of microorganisms to milk via dirt attached to the exterior of teats

NARCIS (Netherlands)

Vissers, M.M.M.; Driehuis, F.; Giffel, M.C.T.; Jong, de P.; Lankveld, J.M.G.

2007-01-01

Pathogens and spoilage microorganisms can be transmitted to milk via dirt (e.g., feces, bedding material, soil, or a combination of these) attached to the exterior of the cows¿ teats. To determine the relevance of this pathway and to perform quantitative microbial risk analysis of the microbial

Characterization of spoilage bacteria in pork sausage by PCR-DGGE analysis

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Francesca Silva Dias

2013-09-01

Full Text Available To investigate microbial diversity and identify spoilage bacteria in fresh pork sausages during storage, twelve industrial pork sausages of different trademarks were stored at 4 ºC for 0, 14, 28 and 42 days, 80% relative humidity and packaged in sterile plastic bags. Microbiological analysis was performed. The pH and water activity (a w were measured. The culture-independent method performed was the Polymerase Chain Reaction - Denaturing Gradient Gel Electrophoresis (PCR-DGGE. The culture-dependent method showed that the populations of mesophilic bacteria and Lactic Acid Bacteria (LAB increased linearly over storage time. At the end of the storage time, the average population of microorganisms was detected, in general, at the level of 5 log cfu g-1. A significant (P < 0.005 increase was observed in pH and a w values at the end of the storage time. The PCR-DGGE allowed a rapid identification of dominant communities present in sausages. PCR-DGGE discriminated 15 species and seven genera of bacteria that frequently constitute the microbiota in sausage products. The most frequent spoilage bacteria identified in the sausages were Lactobacillus sakei and Brochothrix thermosphacta. The identification of dominant communities present in fresh pork sausages can help in the choice of the most effective preservation method for extending the product shelf-life.

Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

Science.gov (United States)

Proulx, J; Hsu, L C; Miller, B M; Sullivan, G; Paradis, K; Moraru, C I

2015-09-01

Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc

Formation of Guaiacol by Spoilage Bacteria from Vanillic Acid, a Product of Rice Koji Cultivation, in Japanese Sake Brewing.

Science.gov (United States)

Ito, Toshihiko; Konno, Mahito; Shimura, Yoichiro; Watanabe, Seiei; Takahashi, Hitoshi; Hashizume, Katsumi

2016-06-08

The formation of guaiacol, a potent phenolic off-odor compound in the Japanese sake brewing process, was investigated. Eight rice koji samples were analyzed, and one contained guaiacol and 4-vinylguaiacol (4-VG) at extraordinarily high levels: 374 and 2433 μg/kg dry mass koji, respectively. All samples contained ferulic and vanillic acids at concentrations of mg/kg dry mass koji. Guaiacol forming microorganisms were isolated from four rice koji samples. They were identified as Bacillus subtilis, B. amyloliquefaciens/subtilis, and Staphylococcus gallinarum using 16S rRNA gene sequence. These spoilage bacteria convert vanillic acid to guaiacol and ferulic acid to 4-VG. However, they convert very little ferulic acid or 4-VG to guaiacol. Nine strains of koji fungi tested produced vanillic acid at the mg/kg dry mass koji level after cultivation. These results indicated that spoilage bacteria form guaiacol from vanillic acid, which is a product of koji cultivation in the sake brewing process.

Saccharomyces cerevisiae variety diastaticus friend or foe?-spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization.

Science.gov (United States)

Meier-Dörnberg, Tim; Kory, Oliver Ingo; Jacob, Fritz; Michel, Maximilian; Hutzler, Mathias

2018-06-01

Saccharomyces cerevisiae variety diastaticus is generally considered to be an obligatory spoilage microorganism and spoilage yeast in beer and beer-mixed beverages. Their super-attenuating ability causes increased carbon dioxide concentrations, beer gushing and potential bottle explosion along with changes in flavor, sedimentation and increased turbidity. This research shows clear differences in the super-attenuating properties of S. cerevisiae var. diastaticus yeast strains and their potential for industrial brewing applications. Nineteen unknown spoilage yeast cultures were obtained as isolates and characterized using a broad spectrum of genetic and phenotypic methods. Results indicated that all isolates represent genetically different S. cerevisiae var. diastaticus strains except for strain TUM PI BA 124. Yeast strains were screened for their super-attenuating ability and sporulation. Even if the STA1 gene responsible for super-attenuation by encoding for the enzyme glucoamylase could be verified by real-time polymerase chain reaction, no correlation to the spoilage potential could be demonstrated. Seven strains were further characterized focusing on brewing and sensory properties according to the yeast characterization platform developed by Meier-Dörnberg. Yeast strain TUM 3-H-2 cannot metabolize dextrin and soluble starch and showed no spoilage potential or super-attenuating ability even when the strain belongs to the species S. cerevisiae var. diastaticus. Overall, the beer produced with S. cerevisiae var. diastaticus has a dry and winey body with noticeable phenolic off-flavors desirable in German wheat beers.

Spoilage of vegetable crops by bacteria and fungi and related health hazards.

Science.gov (United States)

Tournas, V H

2005-01-01

After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. The most common bacterial agents are Erwinia carotovora, Pseudomonas spp., Corynebacterium, Xanthomonas campestris, and lactic acid bacteria with E. carotovora being the most common, attacking virtually every vegetable type. Fungi commonly causing spoilage of fresh vegetables are Botrytis cinerea, various species of the genera Alternaria, Aspergillus, Cladosporium, Colletotrichum, Phomopsis, Fusarium, Penicillium, Phoma, Phytophthora, Pythium and Rhizopus spp., Botrytis cinerea, Ceratocystis fimbriata, Rhizoctonia solani, Sclerotinia sclerotiorum, and some mildews. A few of these organisms show a substrate preference whereas others such as Botrytis cinerea, Colletotrichum, Alternaria, Cladosporium, Phytophthora, and Rhizopus spp., affect a wide variety of vegetables causing devastating losses. Many of these agents enter the plant tissue through mechanical or chilling injuries, or after the skin barrier has been broken down by other organisms. Besides causing huge economic losses, some fungal species could produce toxic metabolites in the affected sites, constituting a potential health hazard for humans. Additionally, vegetables have often served as vehicles for pathogenic bacteria, viruses, and parasites and were implicated in many food borne illness outbreaks. In order to slow down vegetable spoilage and minimize the associated adverse health effects, great caution should be taken to follow strict hygiene, good agricultural practices (GAPs) and good manufacturing practices (GMPs) during cultivation, harvest, storage, transport, and marketing.

Bioleaching of electronic scrap by mixed culture of moderately thermophilic microorganisms

Science.gov (United States)

Ivǎnuş, D.; ǎnuş, R. C., IV; Cǎlmuc, F.

2010-06-01

A process for the metal recovery from electronic scrap using bacterial leaching was investigated. A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages (AMDs) samples collected from several sulphide mines in Romania, and the bioleaching of electronic scrap was conducted both in shake flask and bioreactor. The results show that in the shake flask, the mixture can tolerate 50 g/L scrap after being acclimated to gradually increased concentrations of scrap. The copper extraction increases obviously in bioleaching of scrap with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min, 74% copper can be extracted in the pulp of 50 g/L scrap after 20 d. Compared with copper extractions of mesophilic culture, unacclimated culture and acclimated culture without addition of yeast extract, that of accliniated culture with addition of yeast extract is increased by 53%, 44% and 16%, respectively. In a completely stirred tank reactor, the mass fraction of copper and total iron extraction reach up to 81% and 56%, respectively. The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from electronic scrap effectively.

Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

Science.gov (United States)

Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

2015-01-01

The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples. PMID:26221105

Monitoring of psychrotrophic microorganisms in raw milk

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Radka Burdychová

2008-01-01

Full Text Available The group of psychrotrophic microorganisms belongs to the microorganisms representing a risk for human health as well as a risk of milk and milk products spoilage. Some genus are considered to be significant producers of proteolytic and lipolytic enzymes. In this work, we analysed raw milk samples (n = 109 originated from 26 different suppliers from the area of North and Middle Moravia. The screening was performed from March 2007 to February 2008. The total bacterial counts (TBC ranged between 3.2 × 103 to 8.3 × 106 CFU/ml. The psychrotrophic bacterial counts (PBC ranged between 1.0 × 103 to 8.2 × 106 CFU/ml. Total of 48.62 % and 48.62 % of samples exceeded the hygienic limit in raw milk for TBC and PBC, respectively. The correlation between TBC and PBC was highly significant (r = 0.87.Significantly higher (P < 0.05 numbers of psychrotrophic microorganisms were detected in summer months. The identification of isolates was carried out and all strains were sreened for ability to produce proteolytic and lipolytic enzymes. The most commonly identified genus in raw milk was of the genus Pseudomonas. The ability to produce proteases or lipases was found at 76 % identified bacterial strains.

Microbiological Spoilage of High-Sugar Products

Science.gov (United States)

Thompson, Sterling

The high-sugar products discussed in this chapter are referred to as chocolate, sugar confectionery (non-chocolate), liquid sugars, sugar syrups, and honey. Products grouped in the sugar confectionery category include hard candy, soft/gummy candy, caramel, toffee, licorice, marzipan, creams, jellies, and nougats. A common intrinsic parameter associated with high-sugar products is their low water activity (a w), which is known to inhibit the growth of most spoilage and pathogenic bacteria. However, spoilage can occur as a result of the growth of osmophilic yeasts and xerophilic molds (Von Richter, 1912; Anand & Brown, 1968; Brown, 1976). The a w range for high-sugar products is between 0.20 and 0.80 (Banwart, 1979; Richardson, 1987; Lenovich & Konkel, 1992; ICMSF, 1998; Jay, Loessner, & Golden, 2005). Spoilage of products, such as chocolate-covered cherries, results from the presence of yeasts in the liquid sugar brine or the cherry. Generally, the spoiled product will develop leakers. The chocolate covering the cherry would not likely be a source of yeast contamination.

Stress tolerance in fungi - to kill a spoilage yeast.

NARCIS (Netherlands)

Smits, G.J.; Brul, S.

2005-01-01

The fungal spoilage of ingredients of food manufacture is an economic problem, often causes product loss and may constitute a health hazard. To effectively combat fungal food spoilage, a mechanistic understanding of tolerance for, and adaptation to, the preservation method used is crucial. Both are

Mycology and spoilage of retail cashew nuts | Adebajo | African ...

African Journals Online (AJOL)

All the species recovered induced detectable loss in weights of the milled nuts, though to varying extents and would be expected to cause considerable spoilage of the nuts. Key words: Cashew nut, Anacardium occidentale, fungal count, mycology, Aspergillus sp., Penicillium sp., spoilage. African Journal of Biotechnology ...

Effect of different storage temperatures on bacterial spoilage of ...

African Journals Online (AJOL)

This study determined the bacterial organisms associated with Oreochromis niloticus spoilage at two storage temperatures (6 and 20°C) and also assessed the ability of the individual bacterial isolates to cause spoilage at the two storage temperatures. Bacteriological analysis revealed the association of five bacteria ...

The Occurrence of Beer Spoilage Lactic Acid Bacteria in Craft Beer Production.

Science.gov (United States)

Garofalo, Cristiana; Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Aquilanti, Lucia; Clementi, Francesca

2015-12-01

Beer is one of the world's most ancient and widely consumed fermented alcoholic beverages produced with water, malted cereal grains (generally barley and wheat), hops, and yeast. Beer is considered an unfavorable substrate of growth for many microorganisms, however, there are a limited number of bacteria and yeasts, which are capable of growth and may spoil beer especially if it is not pasteurized or sterile-filtered as craft beer. The aim of this research study was to track beer spoilage lactic acid bacteria (LAB) inside a brewery and during the craft beer production process. To that end, indoor air and work surface samples, collected in the brewery under study, together with commercial active dry yeasts, exhausted yeasts, yeast pellet (obtained after mature beer centrifugation), and spoiled beers were analyzed through culture-dependent methods and PCR-DGGE in order to identify the contaminant LAB species and the source of contamination. Lactobacillus brevis was detected in a spoiled beer and in a commercial active dry yeast. Other LAB species and bacteria ascribed to Staphylococcus sp., Enterobaceriaceae, and Acetobacter sp. were found in the brewery. In conclusion, the PCR-DGGE technique coupled with the culture-dependent method was found to be a useful tool for identifying the beer spoilage bacteria and the source of contamination. The analyses carried out on raw materials, by-products, final products, and the brewery were useful for implementing a sanitization plan to be adopted in the production plant. © 2015 Institute of Food Technologists®

Production of gaba (γ - aminobutyric acid by microorganisms: a review

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Radhika Dhakal

2012-12-01

Full Text Available GABA (γ-aminobutyric acid is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB, which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods.

Production of gaba (γ - Aminobutyric acid) by microorganisms: a review.

Science.gov (United States)

Dhakal, Radhika; Bajpai, Vivek K; Baek, Kwang-Hyun

2012-10-01

GABA (γ-aminobutyric acid) is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB), which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods.

Bacterial spoilage of fresh meat in some selected Lagos markets ...

African Journals Online (AJOL)

A study of the bacteria associated with spoilage of fresh meat was carried out. The flora causing spoilage of meat include Alcaligenes liquefaciens, Bacillus subtilis, Clostridium perfringes, Escherichia coli, Klebsiella pneumoniae, Lactobacillus sp., Micrococcus varians, Pseudomonas aeruginosa, Sarcina sp. Serratia ...

Prevention of fungal spoilage in food products using natural compounds: A review.

Science.gov (United States)

Ribes, Susana; Fuentes, Ana; Talens, Pau; Barat, Jose Manuel

2017-04-10

The kingdom Fungi is the most important group of microorganism contaminating food commodities, and chemical additives are commonly used in the food industry to prevent fungal spoilage. However, the increasing consumer concern about synthetic additives has led to their substitution by natural compounds in foods. The current review provides an overview of using natural agents isolated from different sources (plants, animals, and microorganisms) as promising antifungal compounds, including information about their mechanism of action and their use in foods to preserve and prolong shelf life. Compounds derived from plants, chitosan, lactoferrin, and biocontrol agents (lactic acid bacteria, antagonistic yeast, and their metabolites) are able to control the decay caused by fungi in a wide variety of foods. Several strategies are employed to reduce the drawbacks of some antifungal agents, like their incorporation into oil-in-water emulsions and nanoemulsions, edible films and active packaging, and their combination with other natural preservatives. These strategies facilitate the addition of volatile agents into food products and, improve their antifungal effectiveness. Moreover, biological agents have been investigated as one of the most promising options in the control of postharvest decay. Numerous mechanisms of action have been elucidated and different approaches have been studied to enhance their antifungal effectiveness.

Characterization and control of Mucor circinelloides spoilage in yogurt.

Science.gov (United States)

Snyder, Abigail B; Churey, John J; Worobo, Randy W

2016-07-02

Consumer confidence in the food industry is severely affected by large-scale spoilage incidents. However, relatively little research exists on spoilage potential of members of the fungal subphylum Mucormycotina (e.g. Mucor), which includes dimorphic spoilage organisms that can switch between a yeast-like and hyphal phase depending on environmental conditions. The presence of Mucor circinelloides in yogurt may not cause spoilage, but growth and subsequent changes in quality (e.g. container bloating) can cause spoilage if not controlled. The purpose of this study was to evaluate the effects on M. circinelloides of pasteurization regimen, natamycin concentrations, and storage temperature in yogurt production, as measured by fungal proliferation and carbon dioxide production. A strain of M. circinelloides isolated from commercially spoiled yogurt showed greater yogurt-spoilage potential than clinical isolates and other industrial strains. D-values and z-values were determined for the spoilage isolate in milk as an evaluation of the fungus' ability to survive pasteurization. Natamycin was added to yogurt at 0, 5, 10, 15, and 20ppm (μg/ml) to determine its ability to inhibit M. circinelloides over the course of month-long challenge studies at 4°C, 15°C, and 25°C. Survivors were recovered on acidified PDA and carbon dioxide levels were recorded. The D-values at 54°C, 56°C, and 58°C for hyphae/sporangiospores were (in min) 38.31±0.02, 10.17±0.28, and 1.94±0.53, respectively, which yielded a z-value of 3.09°C. The D-values at 51°C, 53°C, and 55°C for yeast-like cells were (in min) 14.25±0.12, 6.87±1.19, and 2.44±0.35, respectively, which yielded a z-value of 0.34°C. These results indicated that M. circinelloides would not survive fluid milk pasteurization if contamination occurred prior to thermal treatment. CO2 production was only observed when M. circinelloides was incubated under low-oxygen conditions, and occurred only at temperatures above 4�

Rapid and quantitative detection of the microbial spoilage of meat by fourier transform infrared spectroscopy and machine learning.

Science.gov (United States)

Ellis, David I; Broadhurst, David; Kell, Douglas B; Rowland, Jem J; Goodacre, Royston

2002-06-01

Fourier transform infrared (FT-IR) spectroscopy is a rapid, noninvasive technique with considerable potential for application in the food and related industries. We show here that this technique can be used directly on the surface of food to produce biochemically interpretable "fingerprints." Spoilage in meat is the result of decomposition and the formation of metabolites caused by the growth and enzymatic activity of microorganisms. FT-IR was exploited to measure biochemical changes within the meat substrate, enhancing and accelerating the detection of microbial spoilage. Chicken breasts were purchased from a national retailer, comminuted for 10 s, and left to spoil at room temperature for 24 h. Every hour, FT-IR measurements were taken directly from the meat surface using attenuated total reflectance, and the total viable counts were obtained by classical plating methods. Quantitative interpretation of FT-IR spectra was possible using partial least-squares regression and allowed accurate estimates of bacterial loads to be calculated directly from the meat surface in 60 s. Genetic programming was used to derive rules showing that at levels of 10(7) bacteria.g(-1) the main biochemical indicator of spoilage was the onset of proteolysis. Thus, using FT-IR we were able to acquire a metabolic snapshot and quantify, noninvasively, the microbial loads of food samples accurately and rapidly in 60 s, directly from the sample surface. We believe this approach will aid in the Hazard Analysis Critical Control Point process for the assessment of the microbiological safety of food at the production, processing, manufacturing, packaging, and storage levels.

Involvement of bacterial quorum-sensing signals in spoilage of bean sprouts

DEFF Research Database (Denmark)

Rasch, Maria; Andersen, Jens Bo; Nielsen, Kristian Fog

2005-01-01

Bacterial communication signals, acylated homoserine lactones (AHLs), were extracted from samples of commercial bean sprouts undergoing soft-rot spoilage. Bean sprouts produced in the laboratory did not undergo soft-rot spoilage and did not contain AHLs or AHL-producing bacteria, although...... the bacterial population reached levels similar to those in the commercial sprouts, 10(8) to 10(9) CFU/g. AHL-producing bacteria (Enterobacteriaceae and pseudomonads) were isolated from commercial sprouts, and strains that were both proteolytic and pectinolytic were capable of causing soft-rot spoilage in bean...... sprouts. Thin-layer chromatography and liquid chromatography-high-resolution mass spectrometry revealed the presence of N-3-oxo-hexanoyl-l-homoserine lactone in spoiled bean sprouts and in extracts from pure cultures of bacteria. During normal spoilage, the pH of the sprouts increased due to proteolytic...

Activity of R(+) limonene on the maximum growth rate of fish spoilage organisms and related effects on shelf-life prolongation of fresh gilthead sea bream fillets.

Science.gov (United States)

Giarratana, Filippo; Muscolino, Daniele; Beninati, Chiara; Ziino, Graziella; Giuffrida, Alessandro; Panebianco, Antonio

2016-11-21

R(+)limonene (LMN) is the major aromatic compound in essential oils obtained from oranges, grapefruits, and lemons. The improvement of preservation techniques to reduce the growth and activity of spoilage microorganisms in foods is crucial to increase their shelf life and to reduce the losses due to spoilage. The aim of this work is to evaluate the effect of LMN on the shelf life of fish fillets. Its effectiveness was preliminarily investigated in vitro against 60 strains of Specific Spoilage Organisms (SSOs) and then on gilt-head sea bream fillets stored at 2±0.5°C for 15days under vacuum. LMN showed a good inhibitory effect against tested SSOs strains. On gilt-head sea bream fillets, LMN inhibited the growth SSOs effectively, and its use resulted in a shelf-life extension of ca. 6-9days of treated fillets, compared to the control samples. The LMN addition in Sparus aurata fillets giving a distinctive smell and like-lemon taste to fish fillets that resulted pleasant to panellists. Its use contributed to a considerable reduction of fish spoilage given that the fillets treated with LMN were still sensory acceptable after 15days of storage. LMN may be used as an effective antimicrobial system to reduce the microbial growth and to improve the shelf life of fresh gilt-head sea bream fillets. Copyright © 2016 Elsevier B.V. All rights reserved.

Production of gaba (γ – Aminobutyric acid) by microorganisms: a review

Science.gov (United States)

Dhakal, Radhika; Bajpai, Vivek K.; Baek, Kwang-Hyun

2012-01-01

GABA (γ-aminobutyric acid) is a four carbon non-protein amino acid that is widely distributed in plants, animals and microorganisms. As a metabolic product of plants and microorganisms produced by the decarboxylation of glutamic acid, GABA functions as an inhibitory neurotransmitter in the brain that directly affects the personality and the stress management. A wide range of traditional foods produced by microbial fermentation contain GABA, in which GABA is safe and eco-friendly, and also has the possibility of providing new health-benefited products enriched with GABA. Synthesis of GABA is catalyzed by glutamate decarboxylase, therefore, the optimal fermentation condition is mainly based on the biochemical properties of the enzyme. Major GABA producing microorganisms are lactic acid bacteria (LAB), which make food spoilage pathogens unable to grow and act as probiotics in the gastrointestinal tract. The major factors affecting the production of GABA by microbial fermentation are temperature, pH, fermentation time and different media additives, therefore, these factors are summarized to provide the most up-dated information for effective GABA synthesis. There has been a huge accumulation of knowledge on GABA application for human health accompanying with a demand on natural GABA supply. Only the GABA production by microorganisms can fulfill the demand with GABA-enriched health beneficial foods. PMID:24031948

Beer spoilage bacteria and hop resistance.

Science.gov (United States)

Sakamoto, Kanta; Konings, Wil N

2003-12-31

For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

Spoilage potential of Paenibacillussp. in Brazilian raw milk

Directory of Open Access Journals (Sweden)

José Carlos Ribeiro Júnior

2016-04-01

Full Text Available ABSTRACT: Bacterial spores are widespread in the environment and can contaminate milk. Spores are resistant to thermal conditions and your germination reduces milk shelf-life because the aerobic bacteria that are sporulated produce proteases and lipases. The aim of this study was identify Paenibacillus sp., the spoilage microbiota, arising from the germination of spores in raw milk and your spoilage potential. Twenty different milk samples were treated at 80°C/12min and plated to isolate spore-forming bacteria. These strains were picked in milk agar and tributyrin agar for verification of their potential proteolytic and lipolytic activities, respectively. Amplification and sequencing of the 16S rRNA gene of the strains for identification by similarity to the DNA sequences deposited in GenBank was performed. One hundred and thirty-seven isolates were obtained, of which 40 (29.2% showed spoilage activity for milk. Of these, three (7.5% were identified as strains of Paenibacillus sp., and all were lipolytic. Paenibacillus sp. have been identified as primarily responsible for the spoilage of pasteurized milk with a long shelf-life in other countries. To increase the shelf-life of Brazilian pasteurized milk, it is important to identify the sporulated microbes to determine their origin and to control the contamination of milk by vegetative forms such as spores.

Behaviour of co-inoculated pathogenic and spoilage bacteria on poultry following several decontamination treatments.

Science.gov (United States)

Alonso-Hernando, Alicia; Capita, Rosa; Alonso-Calleja, Carlos

2012-10-01

The potential of chemical decontaminants to cause harmful effects on human health is among the causes of the rejection of antimicrobial treatments for removing surface contamination from poultry carcasses in the European Union. This study was undertaken to determine whether decontaminants might give a competitive advantage to pathogenic bacteria on poultry and involve a potential risk to consumer. A total of 144 chicken legs were co-inoculated with similar concentrations of pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica serotype Enteritidis or Escherichia coli) and spoilage bacteria (Brochothrix thermosphacta or Pseudomonas fluorescens). Samples were dipped for 15min in solutions (w/v) of trisodium phosphate (12%; TSP), acidified sodium chlorite (1200ppm; ASC), citric acid (2%; CA), peroxyacids (220ppm; PA) or chlorine dioxide (50ppm; CD), or were left untreated (control). Microbiological analyses were carried out on day 0 and every 24h until day 7 of storage (at 10±1°C). The modified Gompertz equation was used as the primary model to fit observed data. TSP, ASC and CA were effective in extending the lag phase (L, ranging from 1.47±1.34days to 4.06±1.16days) and in decreasing the concentration of bacteria during the stationary phase (D, ranging from 2.46±0.51 log(10) cfu/cm(2) to 8.64±0.53 log(10) cfu/cm(2)), relative to the control samples (L values ranging from 0.59±0.38days and 2.52±2.28days, and D values ranging from 6.32±0.89 log(10) cfu/cm(2) to 9.39±0.39 log(10) cfu/cm(2), respectively). Both on untreated and on most decontaminated samples the overgrowth of spoilage bacteria among the species tested was observed throughout storage, suggesting that spoilage would occur prior to any noteworthy increase in the levels of pathogenic microorganisms. However, L. monocytogenes counts similar to, or higher than, those for spoilage bacteria were observed on samples treated with TSP, ASC or CA, suggesting that these

The occurrence of spoilage yeasts in cream-filled bakery products.

Science.gov (United States)

Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Cardinali, Federica; Pasquini, Marina; Aquilanti, Lucia; Clementi, Francesca

2017-04-01

Filling creams can provide an adequate substrate for spoilage yeasts because some yeasts can tolerate the high osmotic stress in these products. To discover the source of spoilage of a cream-filled baked product, end products, raw materials, indoor air and work surfaces were subjected to microbiological and molecular analyses. The efficacy of disinfectants against spoilage yeasts was also assessed. The analyses on end products revealed the presence of the closest relatives to Zygosaccharomyces bailii with counts ranging from 1.40 to 4.72 log cfu g -1 . No spoilage yeasts were found in the indoor air and work surfaces. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis, carried out directly on filling creams collected from unopened cans, showed the presence of bands ascribed to the closest relatives to Z. bailii sensu lato, although with counts products, reliable and sensitive methods must be used. Moreover, hygiene and the application of good manufacturing practices represent the most efficient way for the prevention and minimization of cross-contamination. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Metabolic strategies of beer spoilage lactic acid bacteria in beer.

Science.gov (United States)

Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

2016-01-04

Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

Importance of Photobacterium phosphoreum in relation to spoilage of modified atmosphere-packed fish products

DEFF Research Database (Denmark)

Dalgaard, Paw; Mejlholm, Ole; Christiansen, T.J.

1997-01-01

Occurrence and growth of Photobacterium phosphoreum were studied in 20 experiments with fresh fish from Denmark, Iceland and Greece. The organism was detected in all marine fish species but not in fish from fresh water. Growth of P. phosphoreum to high levels (>10(7) cfu g(-1)) was observed in most...... products and the organism is likely to be of importance for spoilage of several modified atmosphere-packed (MAP) marine fish species when stored at chill temperatures. Some microbiological methods recommended for control of fish products by national and international authorities are inappropriate...... for detection of psychrotolerant and heat-labile micro-organisms like P. phosphoreum. These methods have been used in many previous studies of MAP fish and this could explain why, contrary to the findings in the present study, P. phosphoreum in general was not detected previously in spoiled MAP fish....

Development and validation of a colorimetric sensor array for fish spoilage monitoring

DEFF Research Database (Denmark)

Morsy, Mohamed K.; Zor, Kinga; Kostesha, Natalie

2016-01-01

their color changes in response to compounds present in fresh products (hexanal, 1-octane-3-ol) used as negative controls. The colorimetric sensor array was used to follow fish spoilage over time at room temperature for up to 24 h as well as at 4 °C for 9 days. Additionally, fish decay was monitored using......Given the need for non-destructive methods and sensors for food spoilage monitoring, we have evaluated sixteen chemo-sensitive compounds incorporated in an array for colorimetric detection of typical spoilage compounds (trimethylamine, dimethylamine, cadaverine, putrescine) and characterized...

Beer spoilage bacteria and hop resistance

NARCIS (Netherlands)

Sakamoto, K; Konings, WN

2003-01-01

For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

Science.gov (United States)

Valence, Florence; Mounier, Jérôme

2017-01-01

Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio) preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially) new hurdle technologies to control their occurrence in dairy foods. PMID:28788096

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

Directory of Open Access Journals (Sweden)

Lucille Garnier

2017-07-01

Full Text Available Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially new hurdle technologies to control their occurrence in dairy foods.

Bacterial spoilage profiles to identify irradiated fish

International Nuclear Information System (INIS)

Alur, M.D.; Venugopal, V.; Nerkar, D.P.; Nair, P.M.

1991-01-01

Effects of low dose gamma-irradiation of fish product on spoilage potentials of bacteria (Aeromonas hydrophila, Salmonella typhimurium, Bacillus megaterium, and Pseudomonas marinoglutinosa) and mixed flora were examined for ability to proliferate in radurized fish and produce volatile acids (TVA) and bases (TVBN). Bacteria proliferated well in unirradiated and irradiated fish, but formation of VA and VB were lower in irradiated than unirradiated counterparts. This was found in Bombay duck, Indian mackerel, white pomfret, seer and shrimp gamma-irradiated at 0 to 5 kGy under ice. TVA and TVBN produced by the organisms or mixed flora from fish were only 30-50% those of controls. A method for identifying radiation-processed fish could evolve based on lower susceptibility of irradiated fish to bacterial spoilage

Reducing Salt in Raw Pork Sausages Increases Spoilage and Correlates with Reduced Bacterial Diversity

Science.gov (United States)

Fougy, Lysiane; Desmonts, Marie-Hélène; Coeuret, Gwendoline; Fassel, Christine; Hamon, Erwann; Hézard, Bernard; Champomier-Vergès, Marie-Christine

2016-01-01

ABSTRACT Raw sausages are perishable foodstuffs; reducing their salt content raises questions about a possible increased spoilage of these products. In this study, we evaluated the influence of salt reduction (from 2.0% to 1.5% [wt/wt]), in combination with two types of packaging (modified atmosphere [50% mix of CO2-N2] and vacuum packaging), on the onset of spoilage and on the diversity of spoilage-associated bacteria. After 21 days of storage at 8°C, spoilage was easily observed, characterized by noticeable graying of the products and the production of gas and off-odors defined as rancid, sulfurous, or sour. At least one of these types of spoilage occurred in each sample, and the global spoilage intensity was more pronounced in samples stored under modified atmosphere than under vacuum packaging and in samples with the lower salt content. Metagenetic 16S rRNA pyrosequencing revealed that vacuum-packaged samples contained a higher total bacterial richness (n = 69 operational taxonomic units [OTUs]) than samples under the other packaging condition (n = 46 OTUs). The core community was composed of 6 OTUs (Lactobacillus sakei, Lactococcus piscium, Carnobacterium divergens, Carnobacterium maltaromaticum, Serratia proteamaculans, and Brochothrix thermosphacta), whereas 13 OTUs taxonomically assigned to the Enterobacteriaceae, Enterococcaceae, and Leuconostocaceae families comprised a less-abundant subpopulation. This subdominant community was significantly more abundant when 2.0% salt and vacuum packaging were used, and this correlated with a lower degree of spoilage. Our results demonstrate that salt reduction, particularly when it is combined with CO2-enriched packaging, promotes faster spoilage of raw sausages by lowering the overall bacterial diversity (both richness and evenness). IMPORTANCE Our study takes place in the context of raw meat product manufacturing and is linked to a requirement for salt reduction. Health guidelines are calling for a reduction in

Reducing Salt in Raw Pork Sausages Increases Spoilage and Correlates with Reduced Bacterial Diversity.

Science.gov (United States)

Fougy, Lysiane; Desmonts, Marie-Hélène; Coeuret, Gwendoline; Fassel, Christine; Hamon, Erwann; Hézard, Bernard; Champomier-Vergès, Marie-Christine; Chaillou, Stéphane

2016-07-01

Raw sausages are perishable foodstuffs; reducing their salt content raises questions about a possible increased spoilage of these products. In this study, we evaluated the influence of salt reduction (from 2.0% to 1.5% [wt/wt]), in combination with two types of packaging (modified atmosphere [50% mix of CO2-N2] and vacuum packaging), on the onset of spoilage and on the diversity of spoilage-associated bacteria. After 21 days of storage at 8°C, spoilage was easily observed, characterized by noticeable graying of the products and the production of gas and off-odors defined as rancid, sulfurous, or sour. At least one of these types of spoilage occurred in each sample, and the global spoilage intensity was more pronounced in samples stored under modified atmosphere than under vacuum packaging and in samples with the lower salt content. Metagenetic 16S rRNA pyrosequencing revealed that vacuum-packaged samples contained a higher total bacterial richness (n = 69 operational taxonomic units [OTUs]) than samples under the other packaging condition (n = 46 OTUs). The core community was composed of 6 OTUs (Lactobacillus sakei, Lactococcus piscium, Carnobacterium divergens, Carnobacterium maltaromaticum, Serratia proteamaculans, and Brochothrix thermosphacta), whereas 13 OTUs taxonomically assigned to the Enterobacteriaceae, Enterococcaceae, and Leuconostocaceae families comprised a less-abundant subpopulation. This subdominant community was significantly more abundant when 2.0% salt and vacuum packaging were used, and this correlated with a lower degree of spoilage. Our results demonstrate that salt reduction, particularly when it is combined with CO2-enriched packaging, promotes faster spoilage of raw sausages by lowering the overall bacterial diversity (both richness and evenness). Our study takes place in the context of raw meat product manufacturing and is linked to a requirement for salt reduction. Health guidelines are calling for a reduction in dietary salt intake

Study on spoilage capability and VBNC state formation and recovery of Lactobacillus plantarum.

Science.gov (United States)

Liu, Junyan; Li, Lin; Li, Bing; Peters, Brian M; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

2017-09-01

The present study aimed at investigating the capability of L. plantarum strain BM-LP14723 to enter into and recover from the viable but nonculturable (VBNC) state and to cause beer spoilage. VBNC state was induced by incubating in beer with subculturing or low temperature treatment. Culturable, total, and viable cells numbers were assessed by MRS agar plate counting, acridine orange direct counting, and Live/Dead BacLight bacterial viability kit, respectively. Organic acids concentrations were measured by reversed-phase high performance liquid chromatography. VBNC L. plantarum cells were detected after 189 ± 1.9 days low temperature treatment or 29 ± 0.7 subcultures in beer. The VBNC L. plantarum retained spoilage capability. Addition of catalase is an effective method for the recovery of the VBNC L. plantarum cells. L. plantarum strain BM-LP14723 is capable of entering into and recovery from the VBNC state and maintained spoilage capability. The current study presented that beer-spoilage L. plantarum can hide both in breweries and during transporting and marketing process and thus lead to beer-spoilage incidents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of electron-beams irradiation for inactivation of microorganisms on spices

International Nuclear Information System (INIS)

Ito, Hitoshi; Islam, Md.S.

1993-01-01

Total aerobic bacteria in spices used in this study were determined to be 1x10 6 to 6x10 7 per gram. A study on the inactivation of microorganisms in spices showed that doses of 6 to 9 kGy of EB (electron-beams) or gamma irradiation were required to reduce the total aerobic bacteria tobelow 10 3 per gram. However, a little increase of resistance was observed on the inactivation of total aerobic bacteria in many spices in case of EB irradiation. These difference of radiation sensitivities between EB and gamma-rays was explained by dose rate effect on oxidation damage to microorganisms from the results of radiation sensitivities of Bacillus pumilus and B. megaterium spores at dry conditions. On the other hand, these high dose rate of EB irradiation suppressed the increase of peroxide values in spices at high dose irradiation up to 80 kGy. Components of essential oils in spices were not changed even irradiated up to 50 kGy with EB and gamma-rays. (author)

Sources of psychrophilic and psychrotolerant clostridia causing spoilage of vacuum-packed chilled meats, as determined by PCR amplification procedure.

Science.gov (United States)

Broda, D M; Boerema, J A; Brightwell, G

2009-07-01

To determine possible preslaughter and processing sources of psychrophilic and psychrotolerant clostridia causing spoilage of vacuum-packed chilled meats. Molecular methods based on the polymerase chain reaction (PCR) amplification of specific 16S rDNA fragments were used to detect the presence of Clostridium gasigenes, Clostridium estertheticum, Clostridium algidicarnis and Clostridium putrefaciens in a total of 357 samples collected from ten slaughter stock supply farms, slaughter stock, two lamb-processing plants, their environments, dressed carcasses and final vacuum-packed meat stored at -0.5 degrees C for 5(1/2) weeks. Clostridium gasigenes, C. estertheticum and C. algidicarnis/C. putrefaciens were commonly detected in farm, faeces, fleece and processing environmental samples collected at the slaughter floor operations prior to fleece removal, but all these micro-organisms were detected in only 4 out of 26 cooling floor and chiller environmental samples. One out of 42 boning room environmental samples tested positive for the presence of C. gasigenes and C. estertheticum, but 25 out of 42 of these samples were positive for C. algidicarnis/C. putrefaciens. Nearly all of the 31 faecal samples tested positive for the presence of C. gasigenes and C. estertheticum; however, only two of these samples were positive for C. algidicarnis and/or C. putrefaciens. Clostridial species that were subject to this investigation were frequently detected on chilled dressed carcasses. The major qualitative and quantitative differences between the results of PCR detection obtained with the primers specific for 'blown pack' -causing clostridia (C. gasigenes and C. estertheticum) and those obtained with primers specific for C. algidicarnis and C. putrefaciens suggest that the control of meat spoilage caused by different groups of meat clostridia is best approached individually for each group. This paper provides information significant for controlling meat spoilage-causing clostridia

Draft genome sequence and annotation of Lactobacillus acetotolerans BM-LA14527, a beer-spoilage bacteria.

Science.gov (United States)

Liu, Junyan; Li, Lin; Peters, Brian M; Li, Bing; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

2016-09-01

Lactobacillus acetotolerans is a hard-to-culture beer-spoilage bacterium capable of entering into the viable putative nonculturable (VPNC) state. As part of an initial strategy to investigate the phenotypic behavior of L. acetotolerans, draft genome sequencing was performed. Results demonstrated a total of 1824 predicted annotated genes, with several potential VPNC- and beer-spoilage-associated genes identified. Importantly, this is the first genome sequence of L. acetotolerans as beer-spoilage bacteria and it may aid in further analysis of L. acetotolerans and other beer-spoilage bacteria, with direct implications for food safety control in the beer brewing industry. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Exploring lot-to-lot variation in spoilage bacterial communities on commercial modified atmosphere packaged beef.

Science.gov (United States)

Säde, Elina; Penttinen, Katri; Björkroth, Johanna; Hultman, Jenni

2017-04-01

Understanding the factors influencing meat bacterial communities is important as these communities are largely responsible for meat spoilage. The composition and structure of a bacterial community on a high-O 2 modified-atmosphere packaged beef product were examined after packaging, on the use-by date and two days after, to determine whether the communities at each stage were similar to those in samples taken from different production lots. Furthermore, we examined whether the taxa associated with product spoilage were distributed across production lots. Results from 16S rRNA amplicon sequencing showed that while the early samples harbored distinct bacterial communities, after 8-12 days storage at 6 °C the communities were similar to those in samples from different lots, comprising mainly of common meat spoilage bacteria Carnobacterium spp., Brochothrix spp., Leuconostoc spp. and Lactococcus spp. Interestingly, abundant operational taxonomic units associated with product spoilage were shared between the production lots, suggesting that the bacteria enable to spoil the product were constant contaminants in the production chain. A characteristic succession pattern and the distribution of common spoilage bacteria between lots suggest that both the packaging type and the initial community structure influenced the development of the spoilage bacterial community. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antimicrobial effect of essential oils on the seafood spoilage micro-organism Photobacterium phosphoreum in liquid media and fish products

DEFF Research Database (Denmark)

Mejlholm, Ole; Dalgaard, Paw

2002-01-01

Aims: To evaluate the antimicrobial effect of nine essential oils (EO) on P. phosphoreum and determine the effect of oregano oil on the shelf-life of modified atmosphere-packed (MAP) cod fillets. Methods and Results: The antimicrobial effect of EO was studied in a liquid medium and in product...... storage trials. Oils of oregano and cinnamon had strongest antimicrobial activity, followed by lemongrass, thyme, clove, bay, marjoram, sage and basil oils. Oregano oil (0.05%, v/w) reduced growth of P. phosphoreum in naturally contaminated MAP cod fillets and extended shelf-life from 11-12 d to 21-26 d...... at 2degreesC. Conclusions: Oregano oil reduced the growth of P. phosphoreum and extended the shelf-life of MAP cod fillets. Significance and Impact of the Study: Mild and natural preservation using EO can extend the shelf-life of MAP seafood through inhibiting the specific spoilage organism P...

Effect of different packaging materials containing poly-[2-(tert-butylamino) methylstyrene] on the growth of spoilage and pathogenic bacteria on fresh meat.

Science.gov (United States)

Dohlen, S; Braun, C; Brodkorb, F; Fischer, B; Ilg, Y; Kalbfleisch, K; Lorenz, R; Kreyenschmidt, M; Kreyenschmidt, J

2017-09-18

The objective of this study was to investigate the effect of novel antimicrobial packaging materials containing poly-[2-(tertbutylamino) methylstyrene] (poly(TBAMS)) on the growth of typical spoilage and pathogenic bacteria present on meat. The antimicrobial activity of materials containing different poly(TBAMS) concentrations was determined by comparing the bacterial counts on reference and sample materials at different temperatures and times and in the presence of meat components. Storage tests with poultry fillets and veal cutlets were conducted with samples vacuum packaged in the reference foil and foil containing 10% poly(TBAMS). After specific time intervals, typical spoilage microorganisms, total viable count (TVC), sensory changes and pH value were analysed. The results of the different poly(TBAMS) containing packaging materials showed an increase of the antimicrobial activity with an increasing amount of poly(TBAMS) in the base polymer. A high antimicrobial activity against inoculum of spoilage and pathogenic organisms typical for meat products was detected of a multilayer foil containing 10% poly(TBAMS) in the inner layer after 24h at 7°C. Gram positive-bacteria were more sensitive to poly(TBAMS) foil than gram-negative bacteria. In storage tests however, over the entire storage, a significant effect of this poly(TBAMS) foil on microbial growth on chicken breast fillets and veal cutlets could not be identified. Poly(TBAMS) packaging materials showed very good antimicrobial properties against a wide range of bacteria. However, for a significant inhibition of microbial growth on fresh meat, a higher amount of poly(TBAMS) was necessary to prolong the shelf life of meat. Copyright © 2017 Elsevier B.V. All rights reserved.

Lactobacilli and tartrazine as causative agents of red-color spoilage in cucumber pickle products.

Science.gov (United States)

Pérez-Díaz, I M; Kelling, R E; Hale, S; Breidt, F; McFeeters, R F

2007-09-01

The cucumber pickling industry has sporadically experienced spoilage outbreaks in pickled cucumber products characterized by development of red color on the surface of the fruits. Lactobacillus casei and Lactobacillus paracasei were isolated from 2 outbreaks of this spoilage that occurred about 15 y apart during the last 3 decades. Both organisms were shown to produce this spoilage when inoculated into pickled cucumbers while concomitantly degrading the azo dye tartrazine (FD&C yellow nr 5). This food dye is used as a yellow coloring in the brine cover solutions of commercial pickled cucumber products. The red color does not occur in the absence of tartrazine, nor when turmeric is used as a yellow coloring in the pickles. Addition of sodium benzoate to the brine cover solutions of a pickled cucumber product, more specifically hamburger dill pickles, prevented growth of these lactic acid bacteria and the development of the red spoilage.

Predicting and preventing mold spoilage of food products.

Science.gov (United States)

Dagnas, Stéphane; Membré, Jeanne-Marie

2013-03-01

This article is a review of how to quantify mold spoilage and consequently shelf life of a food product. Mold spoilage results from having a product contaminated with fungal spores that germinate and form a visible mycelium before the end of the shelf life. The spoilage can be then expressed as the combination of the probability of having a product contaminated and the probability of mold growth (germination and proliferation) up to a visible mycelium before the end of the shelf life. For products packed before being distributed to the retailers, the probability of having a product contaminated is a function of factors strictly linked to the factory design, process, and environment. The in-factory fungal contamination of a product might be controlled by good manufacturing hygiene practices and reduced by particular processing practices such as an adequate air-renewal system. To determine the probability of mold growth, both germination and mycelium proliferation can be mathematically described by primary models. When mold contamination on the product is scarce, the spores are spread on the product and more than a few spores are unlikely to be found at the same spot. In such a case, models applicable for a single spore should be used. Secondary models can be used to describe the effect of intrinsic and extrinsic factors on either the germination or proliferation of molds. Several polynomial models and gamma-type models quantifying the effect of water activity and temperature on mold growth are available. To a lesser extent, the effect of pH, ethanol, heat treatment, addition of preservatives, and modified atmospheres on mold growth also have been quantified. However, mold species variability has not yet been properly addressed, and only a few secondary models have been validated for food products. Once the probability of having mold spoilage is calculated for various shelf lives and product formulations, the model can be implemented as part of a risk management

Spoilage and shelf-life extension of fresh fish and shellfish.

Science.gov (United States)

Ashie, I N; Smith, J P; Simpson, B K

1996-01-01

Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish-processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low-dose irradiation, ultra-high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.

A Comparative Evaluation of Adherence of Microorganism to Different Types of Brackets: A Scanning Electron Microscopic Study.

Science.gov (United States)

Shashidhar, E P; Sahitya, M; Sunil, T; Murthy, Anup R; Rani, M S

2015-09-01

The purpose of this study was to evaluate and compare the adherence of microorganism to different types of brackets using the scanning electron microscope (SEM). A double-blinded study was undertaken to evaluate and adherence of microorganisms to different types of brackets using SEM. At random, 12 patients reporting for treatment to the department of Orthodontics VS Dental College and Hospital were selected. Four types of brackets were included in the present study stainless steel, titanium, composite, and ceramic. Brackets were bonded to teeth of the patient on all the four quadrants. The teeth included for bonding were lateral incisor, canine, first premolar, and second premolar. The brackets were left for 72 h. After 72 h brackets were debonded, and they were evaluated by SEM for adherence of microorganism in the slot and tie wings surface. The SEM images were graded, and the adherence of microorganism to the brackets in the surfaces and the four different quadrants were recorded. There is a significant difference in adherence of microorganisms to the various types of brackets (P 0.05) included in the study. The interaction of bracket/surface, bracket/quadrant, surface/quadrants was analyzed, there was no significance of comparison of bracket/surfaces/quadrant but the interaction of bracket/quadrant was found to be significant (bracket/surfaces/quadrant was also found to be significant (bracket material and the least adherence of microorganisms was observed with the titanium bracket material. The adherence of microorganisms is relatively more in the slot area, when compare to the tie wings surface maximum adherence of microorganism is observed in the upper left quadrant and least adherence of microorganism is observed in the lower right quadrant. There is a significant difference in adherence of microorganisms to various types of brackets and the surfaces included in the study. There is no significant difference in the adherence of microorganism to the bracket

Stereo and scanning electron microscopy of in-shell Brazil nut (Bertholletia excelsa H.B.K.): part two-surface sound nut fungi spoilage susceptibility.

Science.gov (United States)

Scussel, Vildes M; Manfio, Daniel; Savi, Geovana D; Moecke, Elisa H S

2014-11-01

This work reports the in-shell Brazil nut spoilage susceptible morpho-histological characteristics and fungi infection (shell, edible part, and brown skin) through stereo and scanning electron microscopies (SEM). The following characteristics related to shell (a) morphology-that allow fungi and insects' entrance to inner nut, and (b) histology-that allow humidity absorption, improving environment conditions for living organisms development, were identified. (a.1) locule in testae-the nut navel, which is a cavity formed during nut detaching from pods (located at 1.0 to 2.0/4th of the shell B&C nut faces linkage). It allows the nut brown skin (between shell and edible part) first contact to the external environment, through the (a.2) nut channel-the locule prolongation path, which has the water/nutrients cambium function for their transport and distribution to the inner seed (while still on the tree/pod). Both, locule followed by the channel, are the main natural entrance of living organisms (fungi and insects), including moisture to the inner seed structures. In addition, the (a.3) nut shell surface-which has a crinkled and uneven surface morphology-allows water absorption, thus adding to the deterioration processes too. The main shell histological characteristic, which also allows water absorption (thus improving environment conditions for fungi proliferation), is the (b.1) cell wall porosity-the multilayered wall and porous rich cells that compose the shell faces double tissue layers and the (b.2) soft tissue-the mix of tissues 2 faces corner/linkage. This work also shows in details the SEM nut spoilage susceptible features highly fungi infected with hyphae and reproductive structures distribution. © 2014 Institute of Food Technologists®

The viable but nonculturable state induction and genomic analyses of Lactobacillus casei BM-LC14617, a beer-spoilage bacterium.

Science.gov (United States)

Liu, Junyan; Li, Lin; Peters, Brian M; Li, Bing; Chen, Lequn; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

2017-10-01

This study aimed to investigate the viable but nonculturable (VBNC) state and genomic features of a beer-spoilage strain, Lactobacillus caseiBM-LC14617. Induction on the VBNC state of L. casei strain BM-LC14617 was conducted by both low-temperature storage and continuous passage in beer, and formation of VBNC state was detected after 196 ± 3.3 days and 32 ± 1.6 subcultures, respectively. Resuscitation of VBNC cells was successfully induced by addition of catalase, and culturable, VBNC, and resuscitated cells shared similar beer-spoilage capability. Whole genome sequencing was performed, and out of a total of 3,964 predicted genes, several potential VBNC and beer-spoilage-associated genes were identified. L. casei is capable of entering into and resuscitating from the VBNC state and possesses beer-spoilage capability. The genomic characterization yield insightful elucidation of VBNC state for L. casei. This study represents the first evidence on VBNC state induction of L. casei and beer-spoilage capability of VBNC and resuscitated cells. Also, this is the first genomic characterization of L. casei as a beer-spoilage bacterium. The current study may aid in further study on L. casei and other beer-spoilage bacteria, and guide the prevention and control of beer spoilage. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Moulds in food spoilage

DEFF Research Database (Denmark)

Filtenborg, Ole; Frisvad, Jens Christian; Thrane, Ulf

1996-01-01

There is an increasing knowledge and understanding of the role played by moulds in food spoilage. Especially the discovery of mycotoxin production in foods has highligh-ted the importance of moulds in food quality. It is, however, only within the last 5-10 years that major progresses have been made...... the associated or critical funga and has been shown to consist of less than 10 species. In this paper the associated funga is described for the following foods: Citrus and pomaceous fruits, potato and yam tubers, onions, rye, wheat, rye bread, cheese and fermented sausages and whenever possible the selective...

Molecular Methods for Identification of Microorganisms in Traditional Meat Products

Science.gov (United States)

Cocolin, Luca; Dolci, Paola; Rantsiou, Kalliopi

Traditional fermentations are those that have been used for centuries and even pre-date written historical records. Fermentation processes have been developed to upgrade plant and animal materials, to yield a more acceptable food, to add flavor, to prevent the growth of pathogenic and spoilage microorganisms, and to preserve food without refrigeration (Hesseltine & Wang, 1980). Among fermented foods, sausages are the meat products with a longer history and tradition. It is often assumed that sausages were invented by the Sumerians, in what is Iraq today, around 3000 BC. Chinese sausage làcháng, which consisted of goat and lamb meat, was first mentioned in 589 BC. Homer, the poet of The Ancient Greece, mentioned a kind of blood sausage in the Odyssey (book 20, verse 25), and Epicharmus (ca. 550 BC-ca. 460 BC) wrote a comedy entitled “The Sausage”.

Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals

NARCIS (Netherlands)

Helmond, Mariette; Nierop Groot, Masja N.; Bokhorst-van de Veen, van Hermien

2017-01-01

Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7 °C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow

Bacterial spoilage of meat and cured meat products

NARCIS (Netherlands)

Borch, E.; Kant-Muermans, M.L.T.; Blixt, Y.

1996-01-01

The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products. The predominant bacteria associated with spoilage of refrigerated

Microbiological, chemical and sensory spoilage analysis of raw Atlantic cod (Gadus morhua) stored under modified atmospheres.

Science.gov (United States)

Kuuliala, L; Al Hage, Y; Ioannidis, A-G; Sader, M; Kerckhof, F-M; Vanderroost, M; Boon, N; De Baets, B; De Meulenaer, B; Ragaert, P; Devlieghere, F

2018-04-01

During fish spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO 2 /O 2 /N 2 ) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7-7.5 log). Monitoring of early spoilage thus calls for sensitivity for low VOC concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Occurrence and growth of yeasts in processed meat products - implications for potential spoilage

DEFF Research Database (Denmark)

Nielsen, Dennis Sandris; Jacobsen, Tomas; Jespersen, Lene

2008-01-01

of the processed meat products. The yeast microflora was complex with 4-12 different species isolated from the different production sites. In general, Candida zeylanoides, Debaryomyces hansenii and the newly described Candida alimentaria were found to be the dominant yeast species. In addition, three putatively......Spoilage of meat products is in general attributed to bacteria but new processing and storage techniques inhibiting growth of bacteria may provide opportunities for yeasts to dominate the microflora and cause spoilage of the product. With the aim of obtaining a deeper understanding of the potential...... role of yeast in spoilage of five different processed meat products (bacon, ham, salami and two different liver patés), yeasts were isolated, enumerated and identified during processing, in the final product and in the final product at the end of shelf life. Yeasts were isolated along the bacon...

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans

OpenAIRE

Junyan Liu; Yang Deng; Brian M. Peters; Lin Li; Bing Li; Lequn Chen; Zhenbo Xu; Mark E. Shirtliff

2016-01-01

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA1...

Microorganisms involved in MIC

Energy Technology Data Exchange (ETDEWEB)

Sorensen, K. [Danish Technological Institute (Denmark)

2011-07-01

Microbiologically influenced corrosion (MIC) is a widespread problem that is difficult to detect and assess because of its complex mechanism. This paper presents the involvement of microorganisms in MIC. Some of the mechanisms that cause MIC include hydrogen consumption, production of acids, anode-cathode formation and electron shuttling. A classic bio-corrosive microorganism in the oil and gas industry is sulphate-reducing prokaryotes (SRP). Methanogens also increase corrosion rates in metals. Some of the phylogenetic orders detected while studying SRP and methanogens are archaeoglobales, clostridiales, methanosarcinales and methanothermococcus. There were some implications, such as growth of SRP not being correlated with growth of methanogens; methanogens were included in MIC risk assessment. A few examples are used to display how microorganisms are involved in topside corrosion and microbial community in producing wells. From the study, it can be concluded that, MIC risk assessment includes system data and empirical knowledge of the distribution and number of microorganisms in the system.

Technical feasibility for electron beam application on maize seeds disinfection for maize cultivation in Brazil

International Nuclear Information System (INIS)

Zago, Claudia; Rela, Paulo Roberto

2007-01-01

Among the man made activities agriculture plays a fundamental rule on the interference with environment; new alternatives for clean technologies are being searched in order to reduce the impact and degradation of the environment. This work presents a feasibility study to implement in Brazil a technology using electron beam treatment to disinfect maize seeds avoiding the spoilage from pathogens microorganisms. This technology was developed in Germany by Fraunhofer Institut FEP (Dresden) and the private company Schmidt-Seeger AG. It was patented as 'e-ventus'. Concerning to the technical feasibility it shows to be quite useful due to the results of the experiments performed in other countries with maize seeds and properly for the large amount to be treated in the country. Under the environmental management it is quite advantageous when compared with the traditional technology that uses chemical seed dressing agents. Nevertheless for a large scale commercial application it is necessary a cost analyse comparison study between the traditional technology and the alternative using electron beam. (author)

Antibacterial Activity of Zataria multiflora Boiss Essential Oil against Some Fish Spoilage Bacteria

OpenAIRE

Mohammad Hashemi; Saber Barkhori-Mehni; Saeed Khanzadi; Mohammad Azizzadeh

2017-01-01

Background: The aim of this study was to investigate antimicrobial effect of Zataria multiflora Boiss essential oil (EO) against six fish spoilage bacteria for evaluation of its potential utilization in the preservation of minimally processed fish products. Methods: Firstly, GC-MS analysis of the EO was performed to determine its chemical composition. Then, antibacterial effect of the EO in a range of 0.031 to 4 mg/ml was tested against different fish spoilage bacteria such as Aeromonas h...

Past and Future of Non-Saccharomyces Yeasts: From Spoilage Microorganisms to Biotechnological Tools for Improving Wine Aroma Complexity

Science.gov (United States)

Padilla, Beatriz; Gil, José V.; Manzanares, Paloma

2016-01-01

It is well established that non-Saccharomyces wine yeasts, considered in the past as undesired or spoilage yeasts, can enhance the analytical composition, and aroma profile of the wine. The contribution of non-Saccharomyces yeasts, including the ability to secret enzymes and produce secondary metabolites, glycerol and ethanol, release of mannoproteins or contributions to color stability, is species- and strain-specific, pointing out the key importance of a clever strain selection. The use of mixed starters of selected non-Saccharomyces yeasts with strains of Saccharomyces cerevisiae represents an alternative to both spontaneous and inoculated wine fermentations, taking advantage of the potential positive role that non-Saccharomyces wine yeast species play in the organoleptic characteristics of wine. In this context mixed starters can meet the growing demand for new and improved wine yeast strains adapted to different types and styles of wine. With the aim of presenting old and new evidences on the potential of non-Saccharomyces yeasts to address this market trend, we mainly review the studies focused on non-Saccharomyces strain selection and design of mixed starters directed to improve primary and secondary aroma of wines. The ability of non-Saccharomyces wine yeasts to produce enzymes and metabolites of oenological relevance is also discussed. PMID:27065975

Efficacy of lactoferricin B in controlling ready-to-eat vegetable spoilage caused by Pseudomonas spp.

Science.gov (United States)

Federico, Baruzzi; Pinto, Loris; Quintieri, Laura; Carito, Antonia; Calabrese, Nicola; Caputo, Leonardo

2015-12-23

The microbial content of plant tissues has been reported to cause the spoilage of ca. 30% of chlorine-disinfected fresh vegetables during cold storage. The aim of this work was to evaluate the efficacy of antimicrobial peptides in controlling microbial vegetable spoilage under cold storage conditions. A total of 48 bacterial isolates were collected from ready-to-eat (RTE) vegetables and identified as belonging to Acinetobacter calcoaceticus, Aeromonas media, Pseudomonas cichorii, Pseudomonas fluorescens, Pseudomonas jessenii, Pseudomonas koreensis, Pseudomonas putida, Pseudomonas simiae and Pseudomonas viridiflava species. Reddish or brownish pigmentation was found when Pseudomonas strains were inoculated in wounds on leaves of Iceberg and Trocadero lettuce and escarole chicory throughout cold storage. Bovine lactoferrin (BLF) and its hydrolysates (LFHs) produced by pepsin, papain and rennin, were assayed in vitro against four Pseudomonas spp. strains selected for their heavy spoiling ability. As the pepsin-LFH showed the strongest antimicrobial effect, subsequent experiments were carried out using the peptide lactoferricin B (LfcinB), well known to be responsible for its antimicrobial activity. LfcinB significantly reduced (P ≤ 0.05) spoilage by a mean of 36% caused by three out of four inoculated spoiler pseudomonads on RTE lettuce leaves after six days of cold storage. The reduction in the extent of spoilage was unrelated to viable cell density in the inoculated wounds. This is the first paper providing direct evidence regarding the application of an antimicrobial peptide to control microbial spoilage affecting RTE leafy vegetables during cold storage.

Broth and agar hop-gradient plates used to evaluate the beer-spoilage potential of Lactobacillus and Pediococcus isolates.

Science.gov (United States)

Haakensen, M; Schubert, A; Ziola, B

2009-03-15

Identification of the beer-spoilage Lactobacillus and Pediococcus bacteria has largely taken two approaches; identification of spoilage-associated genes or identification of specific species of bacteria regardless of ability to grow in beer. The problem with these two approaches is that they are either overly inclusive (i.e., detect all bacteria of a given species regardless of spoilage potential) or overly selective (i.e., rely upon individual, putative spoilage-associated genes). Our goal was to design a method to assess the ability of Lactobacillus and Pediococcus to spoil beer that is independent of speciation or genetic background. In searching for a method by which to differentiate between beer-spoilage bacteria and bacteria that cannot grow in beer, we explored the ability of lactobacilli and pediococci isolates to grow in the presence of varying concentrations of hop-compounds and ethanol in broth medium versus on agar medium. The best method for differentiating between bacteria that can grow in beer and bacteria that do not pose a threat as beer-spoilage organisms was found to be a hop-gradient agar plate containing ethanol. This hop-gradient agar plate technique provides a rapid and simple solution to the dilemma of assessing the ability of Lactobacillus and Pediococcus isolates to grow in beer, and provides new insights into the different strategies used by these bacteria to survive under the stringent conditions of beer.

Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast.

Science.gov (United States)

Lentz, Michael; Harris, Chad

2015-10-15

Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces ' metabolism of hydroxycinnamic acids (HCAs) present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus . These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p -coumaric acid, a trait not shared among the spoilage strains.

Spoilage fungi and their mycotoxins in commercially marketed chestnuts

DEFF Research Database (Denmark)

Overy, David Patrick; Seifert, K.A.; Savard, M.E.

2003-01-01

A nationwide survey was carried out to assess mould spoilage of Castanea sativa nuts sold in Canadian grocery stores in 1998-99. Morphological and cultural characters, along with secondary metabolite profiles derived from thin-layer chromatography, were used to sort and identify fungi cultured from...

Plasma inactivation of food-related microorganisms in liquids

International Nuclear Information System (INIS)

Marsili, Lisa; Espie, Steven; Anderson, J.G.John G.; MacGregor, S.J.Scott J.

2002-01-01

This paper reports on a plasma process that inactivates microorganisms in liquids through the application of high-voltage pulses. These pulses result in breakdown of the gas and liquid layers, producing many active species such as UV photons, ozone, free radicals and free electrons. Several test microorganisms representing a range of problematic microorganisms were investigated. Significant reductions in microbial population were achieved, demonstrating the effectiveness of using the plasma discharge process to treat contaminated liquids

Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast

Directory of Open Access Journals (Sweden)

Michael Lentz

2015-10-01

Full Text Available Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces’ metabolism of hydroxycinnamic acids (HCAs present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus. These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p-coumaric acid, a trait not shared among the spoilage strains.

Effect of microbial cell-free meat extract on the growth of spoilage bacteria.

Science.gov (United States)

Nychas, G-J E; Dourou, D; Skandamis, P; Koutsoumanis, K; Baranyi, J; Sofos, J

2009-12-01

This study examined the effect of microbial cell-free meat extract (CFME) derived from spoiled meat, in which quorum sensing (QS) compounds were present, on the growth kinetics (lag phase, and growth rate) of two spoilage bacteria, Pseudomonas fluorescens and Serratia marcescens. Aliquots of CFME from spoiled meat were transferred to Brain Heart Infusion broth inoculated with 10(3) CFU ml(-1) of 18 h cultures of Ps. fluorescens or Ser. marcescens, both fresh meat isolates; CFME derived from unspoiled fresh meat ('clean' meat) served as a control. Changes in impedance measurements were monitored for 48 h, and the detection time (Tdet) was recorded. It was found that in the absence of CFME containing QS compounds the Tdet was shorter (P meat. The rate of growth of Ps. fluorescens, recorded as the maximum slope rate of conductance changes (MSrCC), after Tdet, was higher (P meat. Similar results in MSrCC of impedance changes were obtained for Ser. marcescens. The study indicated that the growth rate (expressed in MSrCC units) of meat spoilage bacteria in vitro was enhanced in samples supplemented with CFME containing QS compounds compared to control samples (i.e., without CFME or with CFME from 'clean' meat). This behaviour may explain the dominant role of these two bacteria in the spoilage of meat. These results illustrate the potential effect of signalling compounds released during storage of meat on the behaviour of meat spoilage bacteria. Understanding such interactions may assist in the control of fresh meat quality and the extension of its shelf life.

Influence of some physical treatments and natural food preservatives on the diversity of microorganisms in certain egyptian juices

International Nuclear Information System (INIS)

Abu El-Naga, M.N.Z.I.

2009-01-01

Foods begin to lose their quality from the moment they are harvested.Microorganisms are the main agents responsible for food spoilages . Food preservation prevents deteriorative reaction, extending the shelf life and assuring its safety. The uses of chemical preservatives have harmful effects in long term application. So, the purpose of this article is to use the natural treatments instead of chemical preservatives or application of high temperature which cause losses of some essential nutrients of the juice. In this study the following treatments were investigated: 1. Gamma irradiation . the lethal effect of ionizing radiation on the microorganisms is primarily due to DNA damage, which destroys the reproductive capabilities and other functions of the cell. 2. Pasteurized temperatures(90 degree c).Heat can damage protein, lipids, and nucleic acids of microorganisms and destabilize their membranes.3.The natural preservatives : nisin, citric acid, lactic acid, cinnamon, combination treatments : it was performed between the previous treatments.The best results obtained from our experiments for preserving the fruit juice were performed by combing the pasteurized temperature 90 degree C for 30 sec with gamma irradiation (0.2 K Gy). Or using 200 μg/ml of nisin in combination with 2% (w/v) of citric acid and pasteurized temperature 90 degree C for 30 sec.

Effect of High Intensity Ultrasound Treatment on the Growth of Food Spoilage Bacteria

Directory of Open Access Journals (Sweden)

Ksenija Markov

2013-01-01

Full Text Available The aim of this study is to determine the effect of high intensity ultrasound (amplitude, temperature and treatment time on the inactivation of food spoilage bacteria Escherichia coli 3014, Staphylococcus aureus 3048, Salmonella sp. 3064, Listeria monocytogenes ATCC 23074 and Bacillus cereus 30. The model suspensions of bacteria were treated with 12.7-mm ultrasonic probe operated at 600 W nominal power (ultrasonic treatment implemented at 20 kHz and at amplitudes of 60, 90 and 120 µm. Also, treatment time of 3, 6 and 9 min and temperature of 20, 40 and 60 °C were used. The results were statistically processed with STATGRAPHICS Centurion computer program and response surface methodology. All three parameters studied seem to substantially affect the inactivation of bacteria in pure culture. The results also indicate increased inactivation of microorganisms under longer period of treatments, particularly in combination with higher temperature and/or amplitude. After ultrasonic treatment at 60 °C, 9 min and 120 μm, the viability of cells was not confirmed for Escherichia coli 3014, Staphylococcus aureus 3048, Salmonella sp. 3064 and Listeria monocytogenes ATCC 23074. Under the mentioned conditions the highest inactivation (3.48 log CFU/mL of Bacillus cereus 30 was obtained.

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans.

Science.gov (United States)

Liu, Junyan; Deng, Yang; Peters, Brian M; Li, Lin; Li, Bing; Chen, Lequn; Xu, Zhenbo; Shirtliff, Mark E

2016-11-07

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA14528 under normal, mid-term and VPNC states were performed using RNA-sequencing (RNA-seq) and further bioinformatics analyses. GO function, COG category, and KEGG pathway enrichment analysis were conducted to investigate functional and related metabolic pathways of the differentially expressed genes. Functional and pathway enrichment analysis indicated that heightened stress response and reduction in genes associated with transport, metabolic process, and enzyme activity might play important roles in the formation of the VPNC state. This is the first transcriptomic analysis on the formation of the VPNC state of beer spoilage L. acetotolerans.

Enhancement of uranium-accumulating ability of microorganisms by irradiation

Energy Technology Data Exchange (ETDEWEB)

Sakaguchi, Takashi; Nakajima, Akira; Tsuruta, Takehiko [Miyazaki Medical Coll., Kiyotake (Japan)

1998-01-01

Some microorganisms having excellent ability to accumulate uranium were isolated, from soil and water systems in and around the Ningyo-toge Station of Power Reactor and Nuclear Fuel Development Corporation. The enhancement of uranium-accumulating ability of microorganisms by electron-beam irradiation was examined, and the ability of JW-046 was increased 3-5% by the irradiation. The irradiation affect the growth of some of microorganisms tested. (author)

Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals.

Science.gov (United States)

Helmond, Mariette; Nierop Groot, Masja N; van Bokhorst-van de Veen, Hermien

2017-07-03

Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7°C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow in the starch-rich environment of pasteurized and chilled meals. Growth of the Paenibacillus isolates appeared to be delayed by decreased (5.5%, corresponding with an a w meal on spore inactivation, heat-inactivation kinetics were determined and D-values were calculated. According to these kinetics, pasteurization up to 90°C, necessary for inactivation of vegetative spoilage microorganisms and pathogens, does not significantly contribute to the inactivation of Paenibacillus spores in the meals. Furthermore, outgrowth of pasteurized spores was determined in the mixed rice-vegetable meal at several temperatures; P. terrae FBR-61 and P. pabuli FBR-75 isolates did not substantially increase in numbers during storage at 2°C, but had a significant increase within a month of storage at 4°C or within several days at 22°C. Overall, this work shows the importance of Paenibacillus species as spoilage microorganisms of pasteurized, chilled RTE meals and that the meals' matrix, processing conditions, and storage temperature are important hurdles to control microbial meal spoilage. Copyright © 2017 Elsevier B.V. All rights reserved.

Technical feasibility for electron beam application on maize seeds disinfection for maize cultivation in Brazil

Energy Technology Data Exchange (ETDEWEB)

Zago, Claudia [Proenco Brasil Ltda. (Brazil)]. E-mail: clauzago@uol.com.br; Rela, Paulo Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (brazil). Centro de Tecnologia das Radiacoes]. E-mail: prela@ipen.br

2007-07-01

Among the man made activities agriculture plays a fundamental rule on the interference with environment; new alternatives for clean technologies are being searched in order to reduce the impact and degradation of the environment. This work presents a feasibility study to implement in Brazil a technology using electron beam treatment to disinfect maize seeds avoiding the spoilage from pathogens microorganisms. This technology was developed in Germany by Fraunhofer Institut FEP (Dresden) and the private company Schmidt-Seeger AG. It was patented as 'e-ventus'. Concerning to the technical feasibility it shows to be quite useful due to the results of the experiments performed in other countries with maize seeds and properly for the large amount to be treated in the country. Under the environmental management it is quite advantageous when compared with the traditional technology that uses chemical seed dressing agents. Nevertheless for a large scale commercial application it is necessary a cost analyse comparison study between the traditional technology and the alternative using electron beam. (author)

Bioactive packaging using antioxidant extracts for the prevention of microbial food-spoilage.

Science.gov (United States)

Moreira, Diana; Gullón, Beatriz; Gullón, Patricia; Gomes, Ana; Tavaria, Freni

2016-07-13

Bioactive food packaging is an innovative approach for the prevention of the growth of food-spoilage microorganisms. Four active extracts from agroindustrial subproducts (Eucalyptus wood, almond shells, corn cobs and grape pomace) with demonstrated antioxidant activity have been investigated for bestowing antimicrobial activity to bioactive packaging. To carry out this evaluation, the antioxidant extracts were tested against five food pathogenic bacteria, namely, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. The results obtained showed that all the tested extracts inhibited the growth of all five pathogenic bacteria. From the analysis of the minimal bactericidal concentrations (MBCs), the Eucalyptus wood extract was the most active, being necessary only 2% (v/v) to inhibit Pseudomonas aeruginosa, Listeria monocytogenes, and Staphylococcus aureus, whereas almond shells extract were less active requiring 4% (w/v) to inhibit the growth of Escherichia coli and Pseudomonas aeruginosa and the extract from corn cobs was bactericidal against Escherichia coli and Staphylococcus aureus at a concentration of 4% (w/v). After checking their antimicrobial activity, the antioxidant extracts have been incorporated into sodium alginate films and the maintenance of their antimicrobial properties was confirmed. This work showed that the antioxidant extracts from agroindustrial byproducts exhibited antimicrobial activity and were suitable for incorporation into edible films that could be used in bioactive packaging systems.

Antibacterial Activity of Zataria multiflora Boiss Essential Oil against Some Fish Spoilage Bacteria

Directory of Open Access Journals (Sweden)

Mohammad Hashemi

2017-09-01

Full Text Available Background: The aim of this study was to investigate antimicrobial effect of Zataria multiflora Boiss essential oil (EO against six fish spoilage bacteria for evaluation of its potential utilization in the preservation of minimally processed fish products. Methods: Firstly, GC-MS analysis of the EO was performed to determine its chemical composition. Then, antibacterial effect of the EO in a range of 0.031 to 4 mg/ml was tested against different fish spoilage bacteria such as Aeromonas hydrophila, Pseudomonas aeruginosa, Pseudomonas fluorescens, Shewanella putrefaciens, Escherichia coli and Bacillus subtilis by broth microdilution method to determine minimum inhibitory (MIC and minimum bactericidal (MBC concentrations. Results: GC-MS results showed that phenolic components such as carvacrol (51.55% and thymol (25.49% were predominant constituents of the EO. Zataria multiflora Boiss EO exhibited strong antimicrobial activity against all tested bacteria. Shewanella Putrefaciens was the most sensitive bacteria with MBC value of 0. 5 mg/ml. Conclusion: According to the results, this EO could be used as an important natural alternative to prevent bacterial growth in food specially seafood products to preserve them against bacterial spoilage.

Biofouling of marbles by oxygenic photosynthetic microorganisms.

Science.gov (United States)

Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

2015-08-01

Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

Bioactive proteins against pathogenic and spoilage bacteria

Directory of Open Access Journals (Sweden)

Mahmoud Z. Sitohy

2014-10-01

activities equivalent to or higher than the activity of penicillin, with the basic sub-unit exhibiting the highest activity, followed by glycinin.; β-conglycinin exhibited the lowest level of activity with a MIC of 50, 100 and 1000 μg/mL, respectively. The IC50% values of the basic subunit, glycinin and β-conglycinin, against Listeria monocytogenes, were 15, 16 and 695 μg/mL; against Bacillus subtilis the values were 17, 20, and 612 μg/mL; and against Salmonella Enteritidis the values were 18, 21 and 526 μg/mL, respectively. Transmission electron microscopy images of L. monocytogenes and S. Enteritidis exhibited an increase in cell size and a separation of the cell wall from the cell membrane when treated with glycinin or basic sub-unit. The scanning electron microscopy of B. subtilis indicated signs of an irregular, wrinkled outer surface as well as the fragmentation, adhesion, and aggregation of damaged cells or cellular debris when treated with glycinin or the basic subunits; however not with penicillin. The proliferation of L. monocytogenes, S. Enteritidis and Escherichia coli O157:H7-when artificially inoculated in raw milk ,stored at 4 or 25 °C was significantly (P<0·05 reduced by the glycinin sub-unit and nisin (0·5% w/v; but they were only slightly reduced by β-conglycinin and moderately reduced by lysozyme. The two substances (MSP and MCP exhibited a concentration-dependent inhibitory action against two of the studied bacteria with a minimum inhibitory concentration of approximately 100 µg/mL. The supplementation of raw milk with esterified legume proteins (MSP and MCP has significantly (p < 0.05 reduced the levels of TBC, PBC and PSC in raw milk stored at a temperature of 4 °C. This potentially will delaythe onset of spoilage of by four days. Conclusion: Both glycinin and the basic sub-unit have a more swift antimicrobial action than that of penicillin. Basic sub-units exhibited the highest efficiency at killing bacterial cells, followed by glycinin

Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.

Science.gov (United States)

Kaktcham, Pierre Marie; Temgoua, Jules-Bocamdé; Ngoufack Zambou, François; Diaz-Ruiz, Gloria; Wacher, Carmen; Pérez-Chabela, María de Lourdes

2017-02-01

The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml -1 or 8 log c.f.u g -1 ) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.

Synergistic interface behavior of strontium adsorption using mixed microorganisms.

Science.gov (United States)

Hu, Wenyuan; Dong, Faqin; Yang, Guangmin; Peng, Xin; Huang, Xiaojun; Liu, Mingxue; Zhang, Jing

2017-08-10

The proper handling of low-level radioactive waste is crucial to promote the sustainable development of nuclear power. Research into the mechanism for interactions between bacterium and radionuclides is the starting point for achieving successful remediation of radionuclides with microorganisms. Using Sr(II) as a simulation radionuclide and the mixed microorganisms of Saccharomyces cerevisiae and Bacillus subtilis as the biological adsorbent, this study investigates behavior at the interface between Sr(II) and the microorganisms as well as the mechanisms governing that behavior. The results show that the optimal ratio of mixed microorganisms is S. cerevisiae 2.0 g L -1 to B. subtilis 0.05 g L -1 , and the optimal pH is about 6.3. Sr(II) biosorption onto the mixed microorganisms is spontaneous and endothermic in nature. The kinetics and the equilibrium isotherm data of the biosorption process can be described with pseudo-second-order equation and the Langmuir isotherm equation, respectively. The key interaction between the biological adsorbent and Sr(II) involves shared electronic pairs arising from chemical reactions via bond complexation or electronic exchange, and spectral and energy spectrum analysis show that functional groups (e.g., hydroxyl, carboxyl, amino, amide) at the interface between the radionuclide and the mixed microorganisms are the main active sites of the interface reactions.

Molecular comparisons for identification of food spoilage yeasts and prediction of species that may develop in different food products

Science.gov (United States)

Spoilage of foods and beverages by yeasts is often characterized by objectionable odors, appearance, taste, texture or build-up of gas in packaging containers, resulting in loss of the product. Seldom is human health compromised by products spoiled by yeasts even though some spoilage is caused by sp...

Modelling the effect of ethanol on growth rate of food spoilage moulds

NARCIS (Netherlands)

Dantigny, P.; Guilmart, A.; Radoi, F.; Bensoussan, M.; Zwietering, M.H.

2005-01-01

The effect of ethanol (E) on the radial growth rate (¿) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium

Motion of magnetotactic microorganisms

International Nuclear Information System (INIS)

Esquivel, D.M.S.; Barros, H.G. de P.L. de.

1985-01-01

Magnetic moments for different magnetotactic microorganisms are obtained by electron microscopy analyses and studies of motion by optical microscopy. The results are analysed in terms of a model due to C.Bean. The considerations presented suggest that magnetotaxy is an efficient mechanism for orientation only if the time for reorientation is smaller than the cycles of environmental perturbations. (Author) [pt

Single-walled carbon nanotube/metalloporphyrin composites for the chemiresistive detection of amines and meat spoilage.

Science.gov (United States)

Liu, Sophie F; Petty, Alexander R; Sazama, Graham T; Swager, Timothy M

2015-05-26

Chemiresistive detectors for amine vapors were made from single-walled carbon nanotubes by noncovalent modification with cobalt meso-arylporphyrin complexes. We show that through changes in the oxidation state of the metal, the electron-withdrawing character of the porphyrinato ligand, and the counteranion, the magnitude of the chemiresistive response to ammonia could be improved. The devices exhibited sub-ppm sensitivity and high selectivity toward amines as well as good stability to air, moisture, and time. The application of these chemiresistors in the detection of various biogenic amines (i.e. putrescine, cadaverine) and in the monitoring of spoilage in raw meat and fish samples (chicken, pork, salmon, cod) over several days was also demonstrated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

Science.gov (United States)

Cao, Rong; Zhao, Ling; Liu, Qi

2017-04-01

The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

Effect of Some Plant Extracts on the Microbial Spoilage of Cajanus ...

African Journals Online (AJOL)

The effect of ethanolic extracts of seven plant sources on the microbial spoilage of Cajanus cajan extract was investigated. The results showed that the extracts obtained from Aloe vera, bitter leaf, Gultiferae (garcinia or bitter kola), Ocimum gratissimum (scent leaf) and Zingiber officialae (ginger) were effective against ...

Microorganism immobilization

Science.gov (United States)

Compere, Alicia L.; Griffith, William L.

1981-01-01

Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

Effect of dose rate on inactivation of microorganisms in spices by electron-beams and gamma-rays irradiation

International Nuclear Information System (INIS)

Ito, Hitoshi; Islam, Md.S.

1994-01-01

Total aerobic bacteria in spices used in this study were determined to be 1 x 10 6 to 6 x 10 7 per gram. A study on the inactivation of microorganisms in spices showed that doses of 6-9 kGy of EB (electron-beams) or γ-irradiation were required to reduce the total aerobic bacteria to below 10 3 per gram. However, a little increase of resistance was observed on the inactivation of total aerobic bacteria in many spices in case of EB irradiation. These differences of radiation sensitivities between EB and γ-rays was explained by dose rate effect on oxidation damage to microorganisms from the results of radiation sensitivities of Bacillus pumilus and B. megaterium spores at dry conditions. On the other hand, these high dose rate of EB irradiation suppressed the increase of peroxide values in spices at high dose irradiation up to 80 kGy. However, components of essential oils in spices were not changed even irradiated up to 50 kGy with EB and γ-rays. (author)

The use of chitooligosaccharide in beer brewing for protection against beer-spoilage bacteria and its influence on beer performance.

Science.gov (United States)

Zhao, Xue; Yu, Zhimin; Wang, Ting; Guo, Xuan; Luan, Jing; Sun, Yumei; Li, Xianzhen

2016-04-01

To identify a biological preservative that can protect beer from microbial contamination, which often results in the production of turbidity and off-flavor. The antimicrobial activity of a chitooligosaccharide against beer-spoilage bacteria and its effect on the fermentation performance of brewer's yeast was studied. Chitooligosaccharide with an average 2 kDa molecular weight was the best at inhibiting all tested beer-spoilage bacteria. The application of chitooligosaccharide in the brewing process did not influence the fermentation of brewer's yeast. The change in beer performance induced by the contamination of Lactobacillus brevis could be effectively controlled by application of chitooligosaccharide in the beer brewing process. The experimental data suggested that chitooligosaccharide should be an excellent preservative to inhibit beer-spoilage bacteria in the brewing process and in the end product.

Pulsed electric field processing of different fruit juices: impac of pH and temperature on inactivation of spoilage and pathogenic micro-organisms

NARCIS (Netherlands)

Timmermans, R.A.H.; Nierop Groot, M.N.; Nederhoff, A.L.; Boekel, van M.A.J.S.; Matser, A.M.; Mastwijk, H.C.

2014-01-01

Pulsed electrical field (PEF) technology can be used for the inactivation of micro-organisms and therefore for preservation of food products. It is a mild technology compared to thermal pasteurization because a lower temperature is used during processing, leading to a better retention of the

Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage.

Science.gov (United States)

Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Desmonts, Marie Hélène; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

2015-05-01

The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota.

Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

Science.gov (United States)

Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Hélène Desmonts, Marie; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

2015-01-01

The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota. PMID:25333463

The antimicrobial efficacy and structure activity relationship of novel carbohydrate fatty acid derivatives against Listeria spp. and food spoilage microorganisms.

Science.gov (United States)

Nobmann, Patricia; Smith, Aoife; Dunne, Julie; Henehan, Gary; Bourke, Paula

2009-01-15

Novel mono-substituted carbohydrate fatty acid (CFA) esters and ethers were investigated for their antibacterial activity against a range of pathogenic and spoilage bacteria focussing on Listeria monocytogenes. Carbohydrate derivatives with structural differences enable comparative studies on the structure/activity relationship for antimicrobial efficacy and mechanism of action. The antimicrobial efficacy of the synthesized compounds was compared with commercially available compounds such as monolaurin and monocaprylin, as well as the pure free fatty acids, lauric acid and caprylic acid, which have proven antimicrobial activity. Compound efficacy was compared using an absorbance based broth microdilution assay to determine the minimum inhibitory concentration (MIC), increase in lag phase and decrease in maximum growth rate. Among the carbohydrate derivatives synthesized, lauric ether of methyl alpha-d-glucopyranoside and lauric ester of methyl alpha-d-mannopyranoside showed the highest growth-inhibitory effect with MIC values of 0.04 mM, comparable to monolaurin. CFA derivatives were generally more active against Gram positive bacteria than Gram negative bacteria. The analysis of both ester and ether fatty acid derivatives of the same carbohydrate, in tandem with alpha and beta configuration of the carbohydrate moiety suggest that the carbohydrate moiety is involved in the antimicrobial activity of the fatty acid derivatives and that the nature of the bond also has a significant effect on efficacy, which requires further investigation. This class of CFA derivatives has great potential for developing antibacterial agents relevant to the food industry, particularly for control of Listeria or other Gram-positive pathogens.

Sea salts as a potential source of food spoilage fungi.

Science.gov (United States)

Biango-Daniels, Megan N; Hodge, Kathie T

2018-02-01

Production of sea salt begins with evaporation of sea water in shallow pools called salterns, and ends with the harvest and packing of salts. This process provides many opportunities for fungal contamination. This study aimed to determine whether finished salts contain viable fungi that have the potential to cause spoilage when sea salt is used as a food ingredient by isolating fungi on a medium that simulated salted food with a lowered water activity (0.95 a w ). The viable filamentous fungi from seven commercial salts were quantified and identified by DNA sequencing, and the fungal communities in different salts were compared. Every sea salt tested contained viable fungi, in concentrations ranging from 0.07 to 1.71 colony-forming units per gram of salt. In total, 85 fungi were isolated representing seven genera. One or more species of the most abundant genera, Aspergillus, Cladosporium, and Penicillium was found in every salt. Many species found in this study have been previously isolated from low water activity environments, including salterns and foods. We conclude that sea salts contain many fungi that have potential to cause food spoilage as well as some that may be mycotoxigenic. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Role of plasmids in Lactobacillus brevis BSO 464 hop tolerance and beer spoilage.

Science.gov (United States)

Bergsveinson, Jordyn; Baecker, Nina; Pittet, Vanessa; Ziola, Barry

2015-02-01

Specific isolates of lactic acid bacteria (LAB) can grow in the harsh beer environment, thus posing a threat to brew quality and the economic success of breweries worldwide. Plasmid-localized genes, such as horA, horC, and hitA, have been suggested to confer hop tolerance, a trait required for LAB survival in beer. The presence and expression of these genes among LAB, however, do not universally correlate with the ability to grow in beer. Genome sequencing of the virulent beer spoilage organism Lactobacillus brevis BSO 464 revealed the presence of eight plasmids, with plasmids 1, 2, and 3 containing horA, horC, and hitA, respectively. To investigate the roles that these and the other five plasmids play in L. brevis BSO 464 growth in beer, plasmid curing with novobiocin was used to derive 10 plasmid variants. Multiplex PCRs were utilized to determine the presence or absence of each plasmid, and how plasmid loss affected hop tolerance and growth in degassed (noncarbonated) beer was assessed. Loss of three of the eight plasmids was found to affect hop tolerance and growth in beer. Loss of plasmid 2 (horC and 28 other genes) had the most dramatic effect, with loss of plasmid 4 (120 genes) and plasmid 8 (47 genes) having significant, but smaller, impacts. These results support the contention that genes on mobile genetic elements are essential for bacterial growth in beer and that beer spoilage ability is not dependent solely on the three previously described hop tolerance genes or on the chromosome of a beer spoilage LAB isolate.

Spoilage of lightly salted lumpfish (Cyclopterus lumpus) roe at 5°C

DEFF Research Database (Denmark)

Basby, Merethe; Jeppesen, V.F.; Huss, Hans Henrik

1998-01-01

sulphury, sour odors. The microflora consisted of lactic acid bacteria, Enterobacteriaceae and Vibrio spp. Concentration of lactic acid, acetic acid, trimethylamine and total volatile bases were unrelated to spoilage odors. Volatile sulfur compounds (H2S, probably CS2, CH3SH and CH3CH2SH or CH3SCH3...

Metabolic profiling of meat: assessment of pork hygiene and contamination with Salmonella typhimurium.

Science.gov (United States)

Xu, Yun; Cheung, William; Winder, Catherine L; Dunn, Warwick B; Goodacre, Royston

2011-02-07

Spoilage in meat is the result of the action of microorganisms and results in changes of meat and microbial metabolism. This process may include pathogenic food poisoning bacteria such as Salmonella typhimurium, and it is important that these are differentiated from the natural spoilage process caused by non-pathogenic microorganisms. In this study we investigated the application of metabolic profiling using gas chromatography-mass spectrometry, to assess the microbial contamination of pork. Metabolite profiles were generated from microorganisms, originating from the natural spoilage process and from the artificial contamination with S. typhimurium. In an initial experiment, we investigated changes in the metabolic profiles over a 72 hour time course at 25 °C and established time points indicative of the spoilage process. A further experiment was performed to provide in-depth analysis of the metabolites characteristic of contamination by S. typhimurium. We applied a three-way PARAllel FACtor analysis 2 (PARAFAC2) multivariate algorithm to model the metabolic profiles. In addition, two univariate statistical tests, two-sample Wilcoxon signed rank test and Friedman test, were employed to identify metabolites which showed significant difference between natural spoiled and S. typhimurium contaminated samples. Consistent results from the two independent experiments were obtained showing the discrimination of the metabolic profiles of the natural spoiled pork chops and those contaminated with S. typhimurium. The analysis identified 17 metabolites of significant interest (including various types of amino acid and fatty acid) in the discrimination of pork contaminated with the pathogenic microorganism.

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage.

Science.gov (United States)

Haakensen, Monique; Vickers, David M; Ziola, Barry

2009-09-07

Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol). Use of antimicrobial compounds (e.g., hop-compounds, Penicillin) by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Lactic acid bacteria susceptibility test broth medium (LSM) used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

Fossil Microorganisms and Formation of Early Precambrian Weathering Profiles

Science.gov (United States)

Rozanov, A. Yu; Astafieva, M. M.; Vrevsky, A. B.; Alfimova, N. A.; Matrenichev, V. A.; Hoover, R. B.

2009-01-01

Weathering crusts are the only reliable evidences of the existence of continental conditions. Often they are the only source of information about exogenous processes and subsequently about conditions under which the development of the biosphere occurred. A complex of diverse fossil microorganisms was discovered as a result of Scanning Electron Microscope investigations. The chemical composition of the discovered fossils is identical to that of the host rocks and is represented by Si, Al, Fe, Ca and Mg. Probably, the microorganisms fixed in rocks played the role of catalyst. The decomposition of minerals comprising the rocks and their transformation into clayey (argillaceous) minerals, most likely occurred under the influence of microorganisms. And may be unique weathering crusts of Early Precambrian were formed due to interaction between specific composition of microorganism assemblage and conditions of hypergene transformations. So it is possible to speak about colonization of land by microbes already at that time and about existence of single raw from weathering crusts (Primitive soils) to real soils.

First study on the formation and resuscitation of viable but nonculturable state and beer spoilage capability of Lactobacillus lindneri.

Science.gov (United States)

Liu, Junyan; Li, Lin; Li, Bing; Peters, Brian M; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

2017-06-01

This study aimed to investigate the spoilage capability of Lactobacillus lindneri during the induction and resuscitation of viable but nonculturable (VBNC) state. L. lindneri strain was identified by sequencing the PCR product (amplifying 16S rRNA gene) using ABI Prism 377 DNA Sequencer. During the VBNC state induction by low temperature storage and beer adaption, total, culturable, and viable cells were assessed by acridine orange direct counting, plate counting, and Live/Dead BacLight bacterial viability kit, respectively. Organic acids and diacetyl concentration were measured by reversed-phase high performance liquid chromatography and head dpace gas chromatography, respectively. VBNC state of L. lindneri was successfully induced by both beer adaption and low temperature storage, and glycerol frozen stock was the optimal way to maintain the VBNC state. Addition of catalase was found to be an effective method for the resuscitation of VBNC L. lindneri cells. Furthermore, spoilage capability remained similar during the induction and resuscitation of VBNC L. lindneri. This is the first report of induction by low temperature storage and resuscitation of VBNC L. lindneri strain, as well as the first identification of spoilage capability of VBNC and resuscitated L. lindneri cells. This study indicated that the potential colonization of L. lindneri strain in brewery environment, formation and resuscitation of VBNC state, as well as maintenance in beer spoilage capability, may be an important risk factor for brewery environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proteolytic and lipolytic microbiota of refrigerated raw milk from northeast and southern regions of Brazil

Directory of Open Access Journals (Sweden)

Jose Carlos Ribeiro Junior

2015-12-01

Full Text Available The shelf life of milk and milk derivatives is directly related to the microbiological quality of refrigerated raw milk. Spoilage microorganisms with proteolytic and/or lipolytic properties are primarily responsible for the decrease in the quality of milk, which is reflected in the shelf life of pasteurized milk and all derivatives. The aim of this study was to determine the spoilage microbial load of refrigerated raw milk from the northeast and southern regions of Brazil, which have different climatic and technological conditions of production. We evaluated 46 samples of milk from the state of Paraná in the southern region, and 10 samples of milk from the state of Maranhão in the northeast region, totaling 56 samples collected from November 2013 to November 2014. The producers of Paraná were divided into large (20 or small (26 according to the average daily production. All producers of Maranhão were considered small (<500L/day. The proteolytic and lipolytic microorganism counts were conducted in milk agar and tributyrin agar, respectively. Milk from the large producers of Paraná had average counts of 1.4 × 104 CFU/mL for proteolytic microorganisms and 1.2 × 103 CFU/mL for lipolytics microorganisms, significantly (p <0.05 lower than the small producers in the same state, and the producers of Maranhão. Producers of Maranhao had counts of 1.1 × 105 CFU/mL for proteolytic microorganisms and 2 × 105 CFU/mL for lipolytic microorganisms, with the proteolytic count significantly lower than that of small Paraná producers. The amount of proteolytic and lipolytic spoilage microorganisms in milk is influenced by the adaptation of the microorganisms to cold, promoted by the cooling of milk, which is practiced less frequently in the country’s northeastern region. The amount of spoilage microorganisms is also affected by the implementation of milking hygiene practices, which reduce contamination. Such practices are more frequently and efficiently

Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

DEFF Research Database (Denmark)

Aunsbjerg, Stina Dissing

Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... defined interaction medium (CDIM) was developed allowing growth of protective Lb. paracasei and P. freudenreichii subsp. shermaniii as well as the spoilage fungi, Penicillium spp., Rhodotorula mucilaginosa and Debaryomyces hansenii isolated from fermented dairy products. Lb. paracasei and P....... freudenreichii subsp. shermanii grew in CDIM and showed antifungal properties similar to those observed in milk-based systems. Most of the antifungal effect of the protective bacterial ferment was lost after removal of cells. This was explained by a marked decrease in diacetyl concentration, which...

Microbiological Spoilage of Canned Foods

Science.gov (United States)

Evancho, George M.; Tortorelli, Suzanne; Scott, Virginia N.

Nicolas Appert (1749-1841) developed the first commercial process that kept foods from spoiling in response to an offer from the French government for a method of preserving food for use by the army and navy. Appert, a confectioner and chef, began to experiment in his workshop in Massy, near Paris, but since little was known about bacteriology and the causes of spoilage (Louis Pasteur had yet to formulate the germ theory), much of his work involved trial and error. In 1810, after years of experimenting, he was awarded the prize of 12,000 francs for his method of preservation, which involved cooking foods in sealed jars at high temperatures. He described his method of preserving food in a book published in 1811, "L'Art De Conserver, Pendant Plusiers Annes, Toutes les Substances Animales et Végétales," which translated means "The Art of Preserving All Kinds of Animal and Vegetable Substances for Several Years." He later built a bottling factory and began to produce preserved foods for the people of France and is credited with being the "Father of Canning."

Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage

Directory of Open Access Journals (Sweden)

Ziola Barry

2009-09-01

Full Text Available Abstract Background Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol. Use of antimicrobial compounds (e.g., hop-compounds, Penicillin by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Results Lactic acid bacteria susceptibility test broth medium (LSM used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Conclusion Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

Photocatalytic disinfection of spoilage bacteria Pseudomonas fluorescens and Macrococcus caseolyticus by nano-TiO2

Science.gov (United States)

Photocatalytic disinfection of spoilage bacteria gram-negative (G-) P. fluorescens and gram-positive (G+) M. caseolyticus by nano-TiO2 under different experimental conditions and the disinfection mechanism were investigated. The experimental conditions included the initial bacterial populations, nan...

Micro-Organ Device

Science.gov (United States)

Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

2013-01-01

A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

Amplicon sequencing for the quantification of spoilage microbiota in complex foods including bacterial spores

NARCIS (Netherlands)

Boer, de P.; Caspers, M.; Sanders, J.W.; Kemperman, R.; Wijman, J.; Lommerse, G.; Roeselers, G.; Montijn, R.; Abee, T.; Kort, R.

2015-01-01

Background
Spoilage of food products is frequently caused by bacterial spores and lactic acid bacteria. Identification of these organisms by classic cultivation methods is limited by their ability to form colonies on nutrient agar plates. In this study, we adapted and optimized 16S rRNA amplicon

Marine microorganisms as potential biofactories for synthesis of metallic nanoparticles.

Science.gov (United States)

Manivasagan, Panchanathan; Nam, Seung Yun; Oh, Junghwan

2016-11-01

The use of marine microorganisms as potential biofactories for green synthesis of metallic nanoparticles is a relatively new field of research with considerable prospects. This method is eco-friendly, time saving, and inexpensive and can be easily scaled up for large-scale synthesis. The increasing need to develop simple, nontoxic, clean, and environmentally safe production methods for nanoparticles and to decrease environmental impact, minimize waste, and increase energy productivity has become important in this field. Marine microorganisms are tiny organisms that live in marine ecosystems and account for >98% of biomass of the world's ocean. Marine microorganisms synthesize metallic nanoparticles either intracellularly or extracellularly. Marine microbially-produced metallic nanoparticles have received considerable attention in recent years because of their expected impact on various applications such as medicine, energy, electronic, and space industries. The present review discusses marine microorganisms as potential biofactories for the green synthesis of metallic nanoparticles and their potential applications.

Spoilage potential of brettanomyces bruxellensis strains isolated from Italian wines.

Science.gov (United States)

Guzzon, Raffaele; Larcher, Roberto; Guarcello, Rosa; Francesca, Nicola; Settanni, Luca; Moschetti, Giancarlo

2018-03-01

Brettanomyces bruxellensis is an important wine spoilage agent. In this study a population of Brettanomyces strains isolated from Italian wines was thoroughly investigated to evaluate adaptability to wine conditions and spoilage potential. The presumptive isolates of Brettanomyces were identified at species level with 26S rRNA gene sequencing and species-specific PCR, and subsequently subjected to analysis of intra-species variability through the study of intron splice sites (ISS-PCR). Although, some strains were tracked in wines from different regions, extensive genetic biodiversity was observed within the B. bruxellensis population investigated. All strains were evaluated for their growth ability in the presence of ethanol, high sugar content, low pH, different temperatures and sulphur dioxide, using optical density and flow cytometry measurement. The ability of yeasts to produce ethyl phenols in red wines with different chemical compositions was evaluated by means of high performance liquid chromatography with electrochemical detection (HPLC-ECD). The results highlighted wide variability in B. bruxellensis in response to wine limiting factors and in terms of the accumulation of ethyl phenols. As regards this last aspect, the differences found among strains were closely related to chemical composition of wine and strain resistance to environmental stress factors, making a priori evaluation of risk of wine alteration quite difficult. These results suggest that strategies for the control of Brettanomyces should be tailored on the basis of strain distribution and wine characteristics. Copyright © 2017. Published by Elsevier Ltd.

Sen char nsory, acteris pequ physi stics o i (Cary coche of Gree ...

African Journals Online (AJOL)

SAM

Campus - GO, with 2.91% protein, 3.47% fat, 3.99% lactose,. 11.35% total ... and spoilage microorganisms, it was possible to use milk without any risk to the final ... variety of pathogenic microorganisms present in the raw material. (Fai et al.

Microbial spoilage and formation of biogenic amines in fresh and thawed modified atmosphere-packed salmon ( Salmo salar ) at 2 degrees C

DEFF Research Database (Denmark)

Emborg, Jette; Laursen, B.G.; Rathjen, T.

2002-01-01

series of storage trials with naturally contaminated fresh and thawed modified atmosphere-packed (MAP) salmon at 2 degrees C. Photobacterium phosphoreum dominated the spoilage microflora of fresh MAP salmon at more than 106 cfu g-1 and the activity of this specific spoilage organism (SSO) limited...... small amounts of biogenic amines in this product. The elimination of P. phosphoreum by freezing allowed this bacteria to be identified as the SSO in fresh MAP salmon.Significance and Impact of the Study: The identification of P. phosphoreum as the SSO in fresh MAP salmon facilitates the development...

Mapping microbial ecosystems and spoilage-gene flow in breweries highlights patterns of contamination and resistance.

Science.gov (United States)

Bokulich, Nicholas A; Bergsveinson, Jordyn; Ziola, Barry; Mills, David A

2015-03-10

Distinct microbial ecosystems have evolved to meet the challenges of indoor environments, shaping the microbial communities that interact most with modern human activities. Microbial transmission in food-processing facilities has an enormous impact on the qualities and healthfulness of foods, beneficially or detrimentally interacting with food products. To explore modes of microbial transmission and spoilage-gene frequency in a commercial food-production scenario, we profiled hop-resistance gene frequencies and bacterial and fungal communities in a brewery. We employed a Bayesian approach for predicting routes of contamination, revealing critical control points for microbial management. Physically mapping microbial populations over time illustrates patterns of dispersal and identifies potential contaminant reservoirs within this environment. Habitual exposure to beer is associated with increased abundance of spoilage genes, predicting greater contamination risk. Elucidating the genetic landscapes of indoor environments poses important practical implications for food-production systems and these concepts are translatable to other built environments.

Characterisation and detection of spoilage mould responsible for black spot in dry-cured fermented sausages.

Science.gov (United States)

Lozano-Ojalvo, Daniel; Rodríguez, Alicia; Cordero, Mirian; Bernáldez, Victoria; Reyes-Prieto, Mariana; Córdoba, Juan J

2015-02-01

Moulds responsible for black spot spoilage of dry-cured fermented sausages were characterised. For this purpose, samples were taken from those dry-cured fermented sausages which showed black spot alteration. Most of the mould strains were first tentatively identified as Penicillium spp. due to their morphological characteristics in different culture conditions, with one strain as Cladosporium sp. The Cladosporium strain was the only one which provoked blackening in culture media. This strain was further characterised by sequencing of ITS1-5.8S-ITS2 rRNA and β-tubulin genes. This mould strain was able to reproduce black spot formation in dry-cured fermented sausage 'salchichón' throughout the ripening process. In addition, a specific and sensitive real-time PCR method was also developed to detect Cladosporium oxysporum responsible for the black spot formation in sausages. This method could be of great interest for the meat industry to detect samples contaminated with this mould before spoilage of product avoiding economic losses for this sector.

The plastic-associated microorganisms of the North Pacific Gyre

International Nuclear Information System (INIS)

Carson, Henry S.; Nerheim, Magnus S.; Carroll, Katherine A.; Eriksen, Marcus

2013-01-01

Highlights: • Microorganisms mediate processes affecting the fate and impacts of marine plastic. • North Pacific Gyre (NPG) plastics were examined with scanning-electron microscopy. • Bacillus bacteria and pennate diatoms dominated the NPG plastic fouling community. • Bacterial abundance was patchily distributed but increased on foamed polystyrene. • Diatom abundance increased on rough surfaces and at sites with high plastic density. -- Abstract: Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm −2 ) and pennate diatoms (1097 ± 154 mm −2 ) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution

The principles of ultra high pressure technology and its application ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-18

Aug 18, 2008 ... such as spoilage microorganisms, food pathogens, enzymes and food ... heavily preserved (e.g. less acid, salt, sugar) and less ... concerned with the mechanism and kinetics of pressure- .... training, food plant personnel can learn to safely operate ..... Milk was found to provide the microorganisms protection.

Probing the onset of structural instabilities as a tool for detection of staling of dairy milk: A permittivity and conductivity study

Science.gov (United States)

Madhurima, V.; Harindran, Aswini

2018-05-01

Dairy milk is a worldwide drink and a versatile raw material for food industries too. The major issue regarding dairy milk is their contamination by micro-organisms and subsequent spoiling. Pasteurization and sealed packing are used to minimize this contamination. The presence of pathogenic micro-organisms like psychrotrophs, reduces the pH of fresh milk by fermenting the lactose into lactic acid leading to the spoiling of milk. While there are various tests to check the spoilage of milk, there is no unique test to detect the onset of the complex dynamics of spoilage. There have been some studies on the dielectric properties of dairy milk but the primary method of identification of freshness of milk is through the measurement of pH. In this study, broadband dielectric spectroscopy is used as a tool to probe the spoiling of milk and that provides the information about the structural changes of milk during spoilage. The gamma dispersion explains the influence of free water content which is found to be a sensitive tool to probe the onset of milk spoilage process. The observations here are further backed by studies on the particle size and zeta potential.

Absence of surface-associated microorganisms in adult oysters (Crassostrea gigas).

OpenAIRE

Garland, C D; Nash, G V; McMeekin, T A

1982-01-01

Healthy, actively feeding intertidal oysters were removed from an estuarine environment (Pipeclay Lagoon, Tasmania). The epithelial surfaces of various organs of the mantle cavity and alimentary tract were explored by scanning and transmission electron microscopy. All epithelial tissues examined were ciliated, and nearly all were partly covered with secreted mucus. However, microorganisms were seen rarely in the adhesive mucus and never attached to the epithelium. Electron microscopy also fai...

Control of Salmonella and other pathogenic and spoilage microorganisms in poultry by gamma and electron irradiation

International Nuclear Information System (INIS)

Singh, H.

1992-07-01

Salmonella contamination of chicken is a major public health concern, causing sickness and loss of productivity. Modern, concentrated production methods increase the difficulty of Salmonella control. The current and suggested treatments with chlorinated water or heat pasteurization are unsatisfactory. In pasteurization, the end product is partially cooked, and in the chlorine water wash the poultry skin gets bleached if too much chlorine is used. There is also a risk of formation of toxic chloro-organic compounds. Further, the chlorine water wash does not completely eliminate salmonella. Low-dose radiation treatment is much more effective for the control of Salmonella and has the additional benefit of preserving the freshness of the product. Irradiation of fresh chicken carcasses, pieces or deboned chicken meat with a dose of 2.5 kGy appears to be sufficient to eliminate naturally occurring Salmonella contamination, which is generally present in extremely low numbers on this continent (1 to 30 cells/100 g). For elimination of Salmonella in frozen chicken, doses higher than 2.5 kGy are required. There is a large range of D 10 - values for the different Salmonella serotypes that have been tested, with the highest being 0.72 kGy for S. oranienberg at 22 degrees C. Thus the 2.5-kGy dose would reduce the most radio-resistant Salmonella serotype by four orders of magnitude, and the most common serotypes (with D 10 - values of 0.3 to 0.4 kGy) by greater than six orders of magnitude. The 2.5-kGy dose also appears to be sufficient to eliminate other bacterial pathogens, such as Campylobactor jejuni and Yersinia enterocolitica. The microbiological shelf life of fresh chicken carcass or deboned chicken meat (6 to 11 d) is extended by a factor of 2 to 3 with irradiation to a dose of 2.5 kGy followed by storage between 1 and 4 degrees C. In radappertization (at a dose of ≥ 45 kGy at -30 degrees C), the shelf life of enzyme-inactivated chicken meat is extended to years, on storage at ambient temperatures (∼ 20 degrees C)

A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

Science.gov (United States)

Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

2014-04-01

This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Use of Microorganism for Biological Control of Anthracnose in Nam Dok Mai Mango for Export

International Nuclear Information System (INIS)

Piadiang, Nattaya

2006-09-01

Antagonist were tested inhibition of mycelial growth of Collectorichum gloeosporioides, a causal agent of anthracnose on potato dextrose agar (PDA) revealed that 46 isolated that 46 isolate inhibited the growth of mycelia by 40.01-60.00 5. The selected four isolates inhibit the growth of fungal nycelia by 47.01-50.00 % including YFm1, YFm2, Y18 and AC2-1 were test for the potential reduce anthracnose lesion development on detected Nam Dok Mai mango by application of antagonistic microorganism before inoculation of C. gloeosporioides. This result slow that four isolate antagonistic reduced sized of lesion on Nam Dok Mai mango by 89.23, 75.38, 58.46 and 33.85 %, respectively as compare the control. Five isolate of antagonist including YFm1, YFm2, Y18, CLY35 and CLY23 could inhibited the growth of mycelia on PDA by 44.01-50.00 % were test the potential reduce anthracnose lesion development on detected Nam Dok Mai mango by application of antagonistic microorganism after inoculation of C. gloeosporioides. It was found that this application could not inhibit anthracnose on fruit mango as compare to the control. YFm1 were test for the potential inhibition anthracnose disease under field condition. It was found that YFm1 could control of C. gloeosporioides within 7 and 14 day after spraying antagonistic suspension. The efficiency test of YFm1 for anthracnose controlling on mango was followed by export treatment Azoxystrobin, ET-fon and showed 55.55%, 77.77 % and 88.88 % anthracnose infection and/or spoilage respectively

Application of Electronic Noses for Disease Diagnosis and Food Spoilage Detection

OpenAIRE

Casalinuovo, Ida A.; Di Pierro, Donato; Coletta, Massimiliano; Di Francesco, Paolo

2006-01-01

Over the last twenty years, newly developed chemical sensor systems (so-called “electronic noses”) have odour analyses made possible. This paper describes the applications of these systems for microbial detection in different fields such as medicine and the food industry, where fast detection methods are essential for appropriate management of health care. Several groups have employed different electronic noses for classification and quantification of bacteria and fungi to obtain accurate med...

Identification of food spoilage in the smart home based on neural and fuzzy processing of odour sensor responses.

Science.gov (United States)

Green, Geoffrey C; Chan, Adrian D C; Goubran, Rafik A

2009-01-01

Adopting the use of real-time odour monitoring in the smart home has the potential to alert the occupant of unsafe or unsanitary conditions. In this paper, we measured (with a commercial metal-oxide sensor-based electronic nose) the odours of five household foods that had been left out at room temperature for a week to spoil. A multilayer perceptron (MLP) neural network was trained to recognize the age of the samples (a quantity related to the degree of spoilage). For four of these foods, median correlation coefficients (between target values and MLP outputs) of R > 0.97 were observed. Fuzzy C-means clustering (FCM) was applied to the evolving odour patterns of spoiling milk, which had been sampled more frequently (4h intervals for 7 days). The FCM results showed that both the freshest and oldest milk samples had a high degree of membership in "fresh" and "spoiled" clusters, respectively. In the future, as advancements in electronic nose development remove the present barriers to acceptance, signal processing methods like those explored in this paper can be incorporated into odour monitoring systems used in the smart home.

Fossil Microorganisms in Archaean deposits of Northern Karelia

Science.gov (United States)

Astafieva, M. M.; Hoover, R. B.; Rozanov, A. Y.; Vrevskiy, A. B.

2005-01-01

Newly found biomorphic microstructures from the Upper Archaean (lopian) rocks from Northern Karelia are described. The presence of various microorganisms of bacterial nature and even cyanobacteria (and possibly eukaryotic forms) is suggested. The necessity of employing methods of electron microscopy, as well as traditional methods, while studying the very early manifestations of life in Archaean and Early Proterozoic is noted.

ANALYTICAL MICROBIOLOGY LABORATORY

Data.gov (United States)

Federal Laboratory Consortium — This laboratory contains equipment that performs a broad array of microbiological analyses for pathogenic and spoilage microorganisms. It performs challenge studies...

Spoilage of Microfiltered and Pasteurized Extended Shelf Life Milk Is Mainly Induced by Psychrotolerant Spore-Forming Bacteria that often Originate from Recontamination.

Science.gov (United States)

Doll, Etienne V; Scherer, Siegfried; Wenning, Mareike

2017-01-01

Premature spoilage and varying product quality due to microbial contamination still constitute major problems in the production of microfiltered and pasteurized extended shelf life (ESL) milk. Spoilage-associated bacteria may enter the product either as part of the raw milk microbiota or as recontaminants in the dairy plant. To identify spoilage-inducing bacteria and their routes of entry, we analyzed end products for their predominant microbiota as well as the prevalence and biodiversity of psychrotolerant spores in bulk tank milk. Process analyses were performed to determine the removal of psychrotolerant spores at each production step. To detect transmission and recontamination events, strain typing was conducted with isolates obtained from all process stages. Microbial counts in 287 ESL milk packages at the end of shelf life were highly diverse ranging from shelf life is influenced only to a minor extent by raw-milk-associated factors. In contrast, recontamination with spores, particularly from the B. cereus complex, seems to occur. To enhance milk quality throughout the entire shelf life, improved plant sanitation and disinfection that target the elimination of spores are necessary.

Effects of aqueous extract of Cinnamomum verum on growth of bread spoilage fungi

OpenAIRE

Monir Doudi; Mahbubeh Setorki; Zahra Rezayatmand

2016-01-01

Food waste has been identified as a considerable problem and bread is the most wasted food. This study aimed to evaluate In-vitro anti-fungal activity of cinnamon extract on bread spoilage fungi and to determine its anti-fungal effect in the bread slices. At first, the MIC and MFC values of the extract were determined against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium chrysogenum, Penicillium notatum and Rhizopus oryzae. Then, Aspergillus sp was sele...

Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

OpenAIRE

I. A. Adesina; A. O. Ojokoh; D. J. Arotupin

2017-01-01

Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products. Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid...

Complete genome sequences of two strains of the meat spoilage bacterium Brochothrix thermosphacta isolated from ground chicken

Science.gov (United States)

Brochothrix thermosphacta is an important meat spoilage bacterium. Here we report the genome sequences of two strains of B. thermosphacta isolated from ground chicken. The genome sequences were determined using long-read PacBio single-molecule real-time (SMRT©) technology and are the first complete ...

Silicification of wood adopted for barrel production using pure silicon alkoxides in gas phase to avoid microbial colonisation.

Science.gov (United States)

Guzzon, Raffaele; Widmann, Giacomo; Bertoldi, Daniela; Nardin, Tiziana; Callone, Emanuela; Nicolini, Giorgio; Larcher, Roberto

2015-02-01

The paper presents a new approach, covering wood with silica-based material in order to protect it from spoilage due to microbial colonisation and avoiding the loss of the natural features of the wood. Wood specimens derived from wine barrels were treated with methyltriethoxysilane in gas phase, leading to the deposition of a silica nanofilm on the surface. (29)Si and (13)C solid state Nuclear Magnetic Resonance and Scanning Electron Microscope-Energy Dispersive X-ray analysis observations showed the formation of a silica polymeric film on the wood samples, directly bonding with the wood constituents. Inductively Coupled Plasma-Mass Spectroscopy quantification of Si showed a direct correlation between the treatment time and silica deposition on the surface of the wood. The silica-coated wood counteracted colonisation by the main wine spoilage microorganisms, without altering the migration from wood to wine of 21 simple phenols measured using a HPLC-Electrochemical Coulometric Detection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Application of a Predictive Growth Model of Pseudomonas spp. for Estimating Shelf Life of Fresh Agaricus bisporus.

Science.gov (United States)

Wang, Jianming; Chen, Junran; Hu, Yunfeng; Hu, Hanyan; Liu, Guohua; Yan, Ruixiang

2017-10-01

For prediction of the shelf life of the mushroom Agaricus bisporus, the growth curve of the main spoilage microorganisms was studied under isothermal conditions at 2 to 22°C with a modified Gompertz model. The effect of temperature on the growth parameters for the main spoilage microorganisms was quantified and modeled using the square root model. Pseudomonas spp. were the main microorganisms causing A. bisporus decay, and the modified Gompertz model was useful for modelling the growth curve of Pseudomonas spp. All the bias factors values of the model were close to 1. By combining the modified Gompertz model with the square root model, a prediction model to estimate the shelf life of A. bisporus as a function of storage temperature was developed. The model was validated for A. bisporus stored at 6, 12, and 18°C, and adequate agreement was found between the experimental and predicted data.

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

Directory of Open Access Journals (Sweden)

Esko Petäjä

1993-09-01

Full Text Available This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C. The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

Natural Diversity in Heat Resistance of Bacteria and Bacterial Spores: Impact on Food Safety and Quality.

Science.gov (United States)

den Besten, Heidy M W; Wells-Bennik, Marjon H J; Zwietering, Marcel H

2018-03-25

Heat treatments are widely used in food processing often with the aim of reducing or eliminating spoilage microorganisms and pathogens in food products. The efficacy of applying heat to control microorganisms is challenged by the natural diversity of microorganisms with respect to their heat robustness. This review gives an overview of the variations in heat resistances of various species and strains, describes modeling approaches to quantify heat robustness, and addresses the relevance and impact of the natural diversity of microorganisms when assessing heat inactivation. This comparison of heat resistances of microorganisms facilitates the evaluation of which (groups of) organisms might be troublesome in a production process in which heat treatment is critical to reducing the microbial contaminants, and also allows fine-tuning of the process parameters. Various sources of microbiological variability are discussed and compared for a range of species, including spore-forming and non-spore-forming pathogens and spoilage organisms. This benchmarking of variability factors gives crucial information about the most important factors that should be included in risk assessments to realistically predict heat inactivation of bacteria and spores as part of the measures for controlling shelf life and safety of food products.

Spoilage potential of Pseudomonas species isolated from goat milk.

Science.gov (United States)

Scatamburlo, T M; Yamazi, A K; Cavicchioli, V Q; Pieri, F A; Nero, L A

2015-02-01

Pseudomonas spp. are usually associated with spoilage microflora of dairy products due to their proteolytic potential. This is of particular concern for protein-based products, such as goat milk cheeses and fermented milks. Therefore, the goal of the present study was to characterize the proteolytic activity of Pseudomonas spp. isolated from goat milk. Goat milk samples (n=61) were obtained directly from bulk tanks on dairy goat farms (n=12), and subjected to a modified International Organization for Standardization (ISO) protocol to determine the number and proteolytic activity of Pseudomonas spp. Isolates (n=82) were obtained, identified by PCR, and subjected to pulsed-field gel electrophoresis with XbaI macro-restriction. Then, the isolates were subjected to PCR to detect the alkaline protease gene (apr), and phenotypic tests were performed to check proteolytic activity at 7°C, 25°C, and 35°C. Mean Pseudomonas spp. counts ranged from 2.9 to 4.8 log cfu/mL, and proteolytic Pseudomonas spp. counts ranged from 1.9 to 4.6 log cfu/mL. All isolates were confirmed to be Pseudomonas spp., and 41 were identified as Pseudomonas fluorescens, which clustered into 5 groups sharing approximately 82% similarity. Thirty-six isolates (46.9%) were positive for the apr gene; and 57 (69.5%) isolates presented proteolytic activity at 7°C, 82 (100%) at 25°C, and 64 (78%) at 35°C. The isolates were distributed ubiquitously in the goat farms, and no relationship among isolates was observed when the goat farms, presence of apr, pulsotypes, and proteolytic activity were taken into account. We demonstrated proteolytic activity of Pseudomonas spp. present in goat milk by phenotypic and genotypic tests and indicated their spoilage potential at distinct temperatures. Based on these findings and the ubiquity of Pseudomonas spp. in goat farm environments, proper monitoring and control of Pseudomonas spp. during production are critical. Copyright © 2015 American Dairy Science Association

Effects of water activity on the performance of potassium sorbate and natamycin as preservatives against cheese spoilage moulds

Directory of Open Access Journals (Sweden)

Marín P.

2017-10-01

Full Text Available This work investigated the effects of the food preservatives potassium sorbate and natamycin, combined with different levels of ionic (sodium chloride and non-ioinic (glycerol water activity (aw, on growth of fungi involved in cheese spoilage. In general, the combined effect of water stress and presence of preservatives enhanced fungal inhibition. However, some doses of potassium sorbate (0.02% and natamycin (1, 5 and 10 ppm were able to stimulate growth of Aspergillus varians, Mucor racemosus, Penicillium chrysogenum and P. roqueforti at aw values in the range of 0.93–0.97. P. solitum was the only species whose growth was consistently reduced by any doses of preservative. The results also showed that sodium chloride and glycerol differentially affected the efficacy of preservatives. This study indicates that aw of cheese is a critical parameter to be considered in the formulation of preservative coatings used against fungal spoilage.

671-nm microsystem diode laser based on portable Raman sensor device for in-situ identification of meat spoilage

Science.gov (United States)

Sowoidnich, Kay; Schmidt, Heinar; Schwägele, Fredi; Kronfeldt, Heinz-Detlef

2011-05-01

Based on a miniaturized optical bench with attached 671 nm microsystem diode laser we present a portable Raman system for the rapid in-situ characterization of meat spoilage. It consists of a handheld sensor head (dimensions: 210 x 240 x 60 mm3) for Raman signal excitation and collection including the Raman optical bench, a laser driver, and a battery pack. The backscattered Raman radiation from the sample is analyzed by means of a custom-designed miniature spectrometer (dimensions: 200 x 190 x 70 mm3) with a resolution of 8 cm-1 which is fiber-optically coupled to the sensor head. A netbook is used to control the detector and for data recording. Selected cuts from pork (musculus longissimus dorsi and ham) stored refrigerated at 5 °C were investigated in timedependent measurement series up to three weeks to assess the suitability of the system for the rapid detection of meat spoilage. Using a laser power of 100 mW at the sample meat spectra can be obtained with typical integration times of 5 - 10 seconds. The complex spectra were analyzed by the multivariate statistical tool PCA (principal components analysis) to determine the spectral changes occurring during the storage period. Additionally, the Raman data were correlated with reference analyses performed in parallel. In that way, a distinction between fresh and spoiled meat can be found in the time slot of 7 - 8 days after slaughter. The applicability of the system for the rapid spoilage detection of meat and other food products will be discussed.

Exocellular electron transfer in anaerobic microbial communities.

Science.gov (United States)

Stams, Alfons J M; de Bok, Frank A M; Plugge, Caroline M; van Eekert, Miriam H A; Dolfing, Jan; Schraa, Gosse

2006-03-01

Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory syntrophic consortia of proton-reducing acetogenic bacteria and hydrogen-consuming methanogenic archaea. Anaerobic microorganisms that use insoluble electron acceptors for growth, such as iron- and manganese-oxide as well as inert graphite electrodes in microbial fuel cells, also transfer electrons exocellularly. Soluble compounds, like humic substances, quinones, phenazines and riboflavin, can function as exocellular electron mediators enhancing this type of anaerobic respiration. However, direct electron transfer by cell-cell contact is important as well. This review addresses the mechanisms of exocellular electron transfer in anaerobic microbial communities. There are fundamental differences but also similarities between electron transfer to another microorganism or to an insoluble electron acceptor. The physical separation of the electron donor and electron acceptor metabolism allows energy conservation in compounds as methane and hydrogen or as electricity. Furthermore, this separation is essential in the donation or acceptance of electrons in some environmental technological processes, e.g. soil remediation, wastewater purification and corrosion.

Effects of Atrazine on Soil Microorganisms

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Ljiljana Radivojević

2006-01-01

Full Text Available Effects of the herbicide atrazine on soil microorganisms was investigated. Trials were set up in laboratory, on a clay loam soil. Atrazine was applied at 8.0, 40.0 and 80.0 mg/kg soil rates. The abundance of total microorganisms, fungi, actinomycetes, cellulolytic microorganisms and amino-heterotrophs was recorded. Soil samples were collected 1, 7, 14, 21, 30 and 60 days after atrazine treatment for microbiological analyses.The results showed that the intensity of atrazine effect on soil microorganisms depended on treatment rate, exposure time and group of microorganisms. Atrazine had an inhibiting effect on cellulolytic microorganisms and amino-heterotrophs. Initially, it inhibited fungiand actinomycetes but its effect turned into a stimulating one once a population recovered. Atrazine had a stimulating effect on total abundance of microorganisms.

Identification of lactic acid bacteria from spoilage associations of cooked and brined shrimps stored under modified atmosphere between 0 degrees C and 25 degrees C

DEFF Research Database (Denmark)

Dalgaard, Paw; Vancanneyt, M.; Vilalta, N.E.

2003-01-01

MAP shrimps were characterized by phenotypic tests and identified as lactic acid bacteria (78 isolates), other Gram-positive bacteria (13 isolates) and Gram-negative bacteria (11 isolates). A selection of 48 LAB isolates were further characterized and identified by phenotypic tests and SDS-PAGE...... the dominant parts of spoilage associations of cooked and brined MAP shrimps stored at high and low temperatures, respectively. Significance and Impact of the Study: The SDS-PAGE technique and simple biochemical keys allowed the majority of LAB isolates from spoilage associations of cooked and brined MAP...

Antibacterial and Antifungal Activities of Spices

Science.gov (United States)

Liu, Qing; Meng, Xiao; Li, Ya; Zhao, Cai-Ning; Tang, Guo-Yi; Li, Hua-Bin

2017-01-01

Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices—such as clove, oregano, thyme, cinnamon, and cumin—possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives. PMID:28621716

Treatment of foods with 'soft-electrons' (low-energy electrons)

International Nuclear Information System (INIS)

Hayashi, Toru; Todoriki, Setsuko

2003-01-01

Electrons with energies of 300 keV or lower were defined as soft-electrons'. Soft-electrons can eradicate microorganisms residing on the surface of grains, pulses, spices, dehydrated vegetables, tea leaves and seeds, and reduce their microbial loads to levels lower than 10 CFU/g with little quality deterioration. Soft-electrons can inactivate insect pests infesting grains and pulses and inhibit sprouting of potatoes. (author)

Descriptive Sensory Analysis of Omashikwa, a traditional fermented ...

African Journals Online (AJOL)

UNAM002

2014-04-02

Apr 2, 2014 ... treatment of milk prior to fermentation and Hazard Analysis Critical ... spoilage microorganisms, reduce lactose intolerance to sensitive .... to good manufacturing practices on unit operations, particularly heat treatment on k-.

'WARA' A WEST AFRICAN SOFT CHEESE

African Journals Online (AJOL)

Babalobi

2011-12-07

Dec 7, 2011 ... Cymbopogon citratus (Amazon Herbs, Wonglaan, 10, Paramaribo, Suriname). The .... provided an ideal environment for the microorganisms. ... reduce the risk of microbial spoilage of food and possibility of food poisoning.

The prevalence and control of Bacillus and related spore-forming bacteria in the dairy industry

Directory of Open Access Journals (Sweden)

Nidhi eGopal

2015-12-01

Full Text Available Milk produced in udder cells is sterile but due to its high nutrient content, it can be a good growth substrate for contaminating bacteria. The quality of milk is monitored via somatic cell counts and total bacterial counts, with prescribed regulatory limits to ensure quality and safety. Bacterial contaminants can cause disease, or spoilage of milk and its secondary products. Aerobic spore-forming bacteria, such as those from the genera Sporosarcina, Paenisporosarcina, Brevibacillus, Paenibacillus, Geobacillus and Bacillus, are a particular concern in this regard as they are able to survive industrial pasteurisation and form biofilms within pipes and stainless steel equipment. These single or multiple-species biofilms become a reservoir of spoilage microorganisms and a cycle of contamination can be initiated. Indeed, previous studies have highlighted that these microorganisms are highly prevalent in dead ends, corners, cracks, crevices, gaskets, valves and the joints of stainless steel equipment used in the dairy manufacturing plants. Hence, adequate monitoring and control measures are essential to prevent spoilage and ensure consumer safety. Common controlling approaches include specific cleaning-in-place processes, chemical and biological biocides and other novel methods. In this review, we highlight the problems caused by these microorganisms, and discuss issues relating to their prevalence, monitoring thereof and control with respect to the dairy industry.

Microorganisms in food technology

Energy Technology Data Exchange (ETDEWEB)

Rose, A H

1981-11-01

Man has been using microorganisms for thousands of years to make bread, cheese, beer, wine, etc. Today, microorganisms can be specially grown or genetically manipulated so as to synthesize high-quality proteins even from low-grade basic materials.

Fossil Microorganisms in Archaean

Science.gov (United States)

Astafleva, Marina; Hoover, Richard; Rozanov, Alexei; Vrevskiy, A.

2006-01-01

Ancient Archean and Proterozoic rocks are the model objects for investigation of rocks comprising astromaterials. The first of Archean fossil microorganisms from Baltic shield have been reported at the last SPIE Conference in 2005. Since this confeence biomorphic structures have been revealed in Archean rocks of Karelia. It was determined that there are 3 types of such bion structures: 1. structures found in situ, in other words microorganisms even-aged with rock matrix, that is real Archean fossils biomorphic structures, that is to say forms inhabited early formed rocks, and 3. younger than Archean-Protherozoic minerali microorganisms, that is later contamination. We made attempt to differentiate these 3 types of findings and tried to understand of burial of microorganisms. The structures belongs (from our point of view) to the first type, or real Archean, forms were under examination. Practical investigation of ancient microorganisms from Green-Stone-Belt of Northern Karelia turns to be very perspective. It shows that even in such ancient time as Archean ancient diverse world existed. Moreover probably such relatively highly organized cyanobacteria and perhaps eukaryotic formes existed in Archean world.

Risk assessment of fungal spoilage: A case study of Aspergillus niger on yogurt.

Science.gov (United States)

Gougouli, Maria; Koutsoumanis, Konstantinos P

2017-08-01

A quantitative risk assessment model of yogurt spoilage by Aspergillus niger was developed based on a stochastic modeling approach for mycelium growth by taking into account the important sources of variability such as time-temperature conditions during the different stages of chill chain and individual spore behavior. Input parameters were fitted to the appropriate distributions and A. niger colony's diameter at each stage of the chill chain was estimated using Monte Carlo simulation. By combining the output of the growth model with the fungus prevalence, that can be estimated by the industry using challenge tests, the risk of spoilage translated to number of yogurt cups in which a visible mycelium of A. niger is being formed at the time of consumption was assessed. The risk assessment output showed that for a batch of 100,000 cups in which the percentage of contaminated cups with A. niger was 1% the predicted numbers (median (5 th , 95 th percentiles)) of the cups with a visible mycelium at consumption time were 8 (5, 14). For higher percentages of 3, 5 and 10 the predicted numbers (median (5 th , 95 th percentiles)) of the spoiled cups at consumption time were estimated to be 24 (16, 35), 39 (29, 52) and 80 (64, 94), respectively. The developed model can lead to a more effective risk-based quality management of yogurt and support the decision making in yogurt production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosurfactants from marine microorganisms

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Suppasil Maneerat

2005-11-01

Full Text Available Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, the determination of biosurfactant activity as well as the recovery of marine surfactant. The uses of marine biosurfactants for bioremediation are also discussed.

Combination treatment of gamma radiation and paraben in controlling spoilage of poultry meat

International Nuclear Information System (INIS)

Shiralkar, N.D.; Rege, D.V.

1977-01-01

With a view of controlling spoilage, combination treatment of poultry meat with gamma radiation and a chemical preservative has been investigated. Raw poultry pieces of about 25 g. weight were dipped in 0.1% propyl-paraben solution for two hours and were given a 0.1 Mrad dose from 60 Co gamma radiation. It was found that paraben was not affected by irradiation. The flavour evaluation scores indicated the shelf-life of poultry meat was prolonged by a couple of days as compared to untreated controls in refrigerated storage. (M.G.B.)

Isolation of phyllosilicate-iron redox cycling microorganisms from an illite-smectite rich hydromorphic soil.

Science.gov (United States)

Shelobolina, Evgenya; Konishi, Hiromi; Xu, Huifang; Benzine, Jason; Xiong, Mai Yia; Wu, Tao; Blöthe, Marco; Roden, Eric

2012-01-01

The biogeochemistry of phyllosilicate-Fe redox cycling was studied in a Phalaris arundinacea (reed canary grass) dominated redoximorphic soil from Shovelers Sink, a small glacial depression near Madison, WI. The clay size fraction of Shovelers Sink soil accounts for 16% of the dry weight of the soil, yet contributes 74% of total Fe. The dominant mineral in the clay size fraction is mixed layer illite-smectite, and in contrast to many other soils and sediments, Fe(III) oxides are present in low abundance. We examined the Fe biogeochemistry of Shovelers Sink soils, estimated the abundance of Fe redox cycling microorganisms, and isolated in pure culture representative phyllosilicate-Fe oxidizing and reducing organisms. The abundance of phyllosilicate-Fe reducing and oxidizing organisms was low compared to culturable aerobic heterotrophs. Both direct isolation and dilution-to-extinction approaches using structural Fe(II) in Bancroft biotite as a Fe(II) source, and O(2) as the electron acceptor, resulted in recovery of common rhizosphere organisms including Bradyrhizobium spp. and strains of Cupriavidus necator and Ralstonia solanacearum. In addition to oxidizing biotite and soluble Fe(II) with O(2), each of these isolates was able to oxidize Fe(II) in reduced NAu-2 smectite with [Formula: see text] as the electron acceptor. Oxidized NAu-2 smectite or amorphous Fe(III) oxide served as electron acceptors for enrichment and isolation of Fe(III)-reducing microorganisms, resulting in recovery of a strain related to Geobacter toluenoxydans. The ability of the recovered microorganisms to cycle phyllosilicate-Fe was verified in an experiment with native Shovelers Sink clay. This study confirms that Fe in the native Shovelers Sink clay is readily available for microbial redox transformation and can be cycled by the Fe(III)-reducing and Fe(II)-oxidizing microorganisms recovered from the soil.

Isolation of Phyllosilicate–Iron Redox Cycling Microorganisms from an Illite–Smectite Rich Hydromorphic Soil

Science.gov (United States)

Shelobolina, Evgenya; Konishi, Hiromi; Xu, Huifang; Benzine, Jason; Xiong, Mai Yia; Wu, Tao; Blöthe, Marco; Roden, Eric

2012-01-01

The biogeochemistry of phyllosilicate–Fe redox cycling was studied in a Phalaris arundinacea (reed canary grass) dominated redoximorphic soil from Shovelers Sink, a small glacial depression near Madison, WI. The clay size fraction of Shovelers Sink soil accounts for 16% of the dry weight of the soil, yet contributes 74% of total Fe. The dominant mineral in the clay size fraction is mixed layer illite–smectite, and in contrast to many other soils and sediments, Fe(III) oxides are present in low abundance. We examined the Fe biogeochemistry of Shovelers Sink soils, estimated the abundance of Fe redox cycling microorganisms, and isolated in pure culture representative phyllosilicate–Fe oxidizing and reducing organisms. The abundance of phyllosilicate–Fe reducing and oxidizing organisms was low compared to culturable aerobic heterotrophs. Both direct isolation and dilution-to-extinction approaches using structural Fe(II) in Bancroft biotite as a Fe(II) source, and O2 as the electron acceptor, resulted in recovery of common rhizosphere organisms including Bradyrhizobium spp. and strains of Cupriavidus necator and Ralstonia solanacearum. In addition to oxidizing biotite and soluble Fe(II) with O2, each of these isolates was able to oxidize Fe(II) in reduced NAu-2 smectite with NO3- as the electron acceptor. Oxidized NAu-2 smectite or amorphous Fe(III) oxide served as electron acceptors for enrichment and isolation of Fe(III)-reducing microorganisms, resulting in recovery of a strain related to Geobacter toluenoxydans. The ability of the recovered microorganisms to cycle phyllosilicate–Fe was verified in an experiment with native Shovelers Sink clay. This study confirms that Fe in the native Shovelers Sink clay is readily available for microbial redox transformation and can be cycled by the Fe(III)-reducing and Fe(II)-oxidizing microorganisms recovered from the soil. PMID:22493596

Effect of copper and lead on two consortia of phototrophic microorganisms and their capacity to sequester metals

Energy Technology Data Exchange (ETDEWEB)

Burgos, A. [Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Edifici C, Campus de UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona (Spain); Departamento de Recursos Hidrobiológicos, Universidad de Nariño, Pasto (N) (Colombia); Maldonado, J. [Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Edifici C, Campus de UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona (Spain); De los Rios, A. [Museo Nacional de Ciencias Naturales(CSIC), Serrano 115 dpdo, 28006 Madrid (Spain); Solé, A. [Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Edifici C, Campus de UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona (Spain); Esteve, I., E-mail: isabel.esteve@uab.cat [Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Edifici C, Campus de UAB, Bellaterra (Cerdanyola del Vallès), 08193 Barcelona (Spain); Departamento de Recursos Hidrobiológicos, Universidad de Nariño, Pasto (N) (Colombia); Museo Nacional de Ciencias Naturales(CSIC), Serrano 115 dpdo, 28006 Madrid (Spain)

2013-09-15

Highlights: •We studied the tolerance-resistance of phototrophic microorganisms to copper and lead. •We determined the capacity of consortia of microorganisms to sequester copper and lead. •CLSM-λscan is a technique for evaluating in vivo effect of metals on microorganisms. •SEM-EDX and TEM-EDX determined the capacity of microorganisms to sequester metals. -- Abstract: The roles of consortia of phototrophic microorganisms have been investigated in this paper to determine their potential role to tolerate or resist metals and to capture them from polluted cultures. With this purpose, two consortia of microorganisms: on one hand, Geitlerinema sp. DE2011 (Ge) and Scenedesmus sp. DE2009 (Sc) (both identified in this paper by molecular biology methods) isolated from Ebro Delta microbial mats, and on the other, Spirulina sp. PCC 6313 (Sp) and Chroococcus sp. PCC 9106 (Ch), from Pasteur culture collection were polluted with copper and lead. In order to analyze the ability of these consortia to tolerate and capture metals, copper and lead were selected, because both have been detected in Ebro Delta microbial mats. The tolerance-resistance to copper and lead for both consortia was determined in vivo and at cellular level by Confocal Laser Scanning Microscopy (CLSM-λscan function). The results obtained demonstrate that both consortia are highly tolerant-resistant to lead and that the limits between the copper concentration having cytotoxic effect and that having an essential effect are very close in these microorganisms. The capacity of both consortia to capture extra- and intracellular copper and lead was determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) respectively, coupled to an Energy Dispersive X-ray detector (EDX). The results showed that all the microorganisms assayed were able to capture copper extracellularly in the extrapolymeric substances, and lead extra- and intracellularly in polyphosphate inclusions. Moreover

Effect of copper and lead on two consortia of phototrophic microorganisms and their capacity to sequester metals

International Nuclear Information System (INIS)

Burgos, A.; Maldonado, J.; De los Rios, A.; Solé, A.; Esteve, I.

2013-01-01

Highlights: •We studied the tolerance-resistance of phototrophic microorganisms to copper and lead. •We determined the capacity of consortia of microorganisms to sequester copper and lead. •CLSM-λscan is a technique for evaluating in vivo effect of metals on microorganisms. •SEM-EDX and TEM-EDX determined the capacity of microorganisms to sequester metals. -- Abstract: The roles of consortia of phototrophic microorganisms have been investigated in this paper to determine their potential role to tolerate or resist metals and to capture them from polluted cultures. With this purpose, two consortia of microorganisms: on one hand, Geitlerinema sp. DE2011 (Ge) and Scenedesmus sp. DE2009 (Sc) (both identified in this paper by molecular biology methods) isolated from Ebro Delta microbial mats, and on the other, Spirulina sp. PCC 6313 (Sp) and Chroococcus sp. PCC 9106 (Ch), from Pasteur culture collection were polluted with copper and lead. In order to analyze the ability of these consortia to tolerate and capture metals, copper and lead were selected, because both have been detected in Ebro Delta microbial mats. The tolerance-resistance to copper and lead for both consortia was determined in vivo and at cellular level by Confocal Laser Scanning Microscopy (CLSM-λscan function). The results obtained demonstrate that both consortia are highly tolerant-resistant to lead and that the limits between the copper concentration having cytotoxic effect and that having an essential effect are very close in these microorganisms. The capacity of both consortia to capture extra- and intracellular copper and lead was determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) respectively, coupled to an Energy Dispersive X-ray detector (EDX). The results showed that all the microorganisms assayed were able to capture copper extracellularly in the extrapolymeric substances, and lead extra- and intracellularly in polyphosphate inclusions. Moreover

VAREGUS FWETEGNAL ETHKOPKAN SAU€ES

African Journals Online (AJOL)

also considered as sources of spoilage microorganisms to food products (Julseth ... The sauces are basically legume-based, vegetable-based or meat-based. ..... The dominant role in the microbiology of spices is played by aerobic spore.

Treatment of foods with 'soft-electrons' (low-energy electrons)

Energy Technology Data Exchange (ETDEWEB)

Hayashi, Toru [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan); Todoriki, Setsuko [National Food Research Institute (NFRI), Tsukuba, Ibaraki (Japan)

2003-02-01

Electrons with energies of 300 keV or lower were defined as soft-electrons'. Soft-electrons can eradicate microorganisms residing on the surface of grains, pulses, spices, dehydrated vegetables, tea leaves and seeds, and reduce their microbial loads to levels lower than 10 CFU/g with little quality deterioration. Soft-electrons can inactivate insect pests infesting grains and pulses and inhibit sprouting of potatoes. (author)

Mesophilic and psychrotrophic bacteria from meat and their spoilage potential in vitro and in beef.

Science.gov (United States)

Ercolini, Danilo; Russo, Federica; Nasi, Antonella; Ferranti, Pasquale; Villani, Francesco

2009-04-01

Mesophilic and psychrotrophic populations from refrigerated meat were identified in this study, and the spoilage potential of microbial isolates in packaged beef was evaluated by analyzing the release of volatile organic compounds (VOC) by gas chromatography-mass spectrometry (GC/MS). Fifty mesophilic and twenty-nine psychrotrophic isolates were analyzed by random amplified polymorphic DNA-PCR, and representative strains were identified by 16S rRNA gene sequencing. Carnobacterium maltaromaticum and C. divergens were the species most frequently found in both mesophilic and psychrotrophic populations. Acinetobacter baumannii, Buttiauxella spp. and Serratia spp. were identified among the mesophilic isolates, while Pseudomonas spp. were commonly identified among the psychrotrophs. The isolates were further characterized for their growth at different temperatures and their proteolytic activity in vitro on meat proteins extracts at 7 degrees C. Selected proteolytic strains of Serratia proteamaculans, Pseudomonas fragi, and C. maltaromaticum were used to examine their spoilage potential in situ. Single strains of these species and mixtures of these strains were used to contaminate beef chops that were packed and stored at 7 degrees C. At time intervals up to 1 month, viable counts were determined, and VOC were identified by GC/MS. Generally, the VOC concentrations went to increase during the storage of the contaminated meats, and the profiles of the analyzed meat changed dramatically depending on the contaminating microbial species. About 100 volatiles were identified in the different contaminated samples. Among the detected volatiles, some specific molecules were identified only when the meat was contaminated by a specific microbial species. Compounds such as 2-ethyl-1-hexanol, 2-buten-1-ol, 2-hexyl-1-octanol, 2-nonanone, and 2-ethylhexanal were detectable only for C. maltaromaticum, which also produced the highest number of aldehydes, lactones, and sulfur compounds. The

Radioresistant microorganisms and food irradiation

Energy Technology Data Exchange (ETDEWEB)

Ito, H [Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment

1976-01-01

This paper deals with Micrococcus radiodurans, Arthrobacter radiotolerance, etc., which were isolated and discovered as radioresistant microorganisms. As for the explanation of the mechanism of radioresistance of these microorganisms, the consideration that these organisms have marked repair power of the damaged DNA and have many opportunity to repair the damaged DNA because of their long fission term were cited. The relationship between the radioresistance of microorganisms and food irradiation was also mentioned.

Evaluation of Bacteriological Stability of Minced Canned Meat ...

African Journals Online (AJOL)

Evaluation of Bacteriological Stability of Minced Canned Meat Stored Under Simulated ... Thermal inactivation of spoilage microorganisms is one of the widely used ... of the aforesaid strains at 104-106 spores/g prior to the heat treatment.

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African Journals Online (AJOL)

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Abstract: The risk of milk contamination with spoilage and pathogenic microorganisms is high for ... marketed raw cow milk across the milk supply chain in eastern Ethiopia. A total of 360 ..... management practices performed by milk producers.

Involvement of formate as an interspecies electron carrier in a syntrophic acetate-oxidizing anaerobic microorganism in coculture with methanogens.

Science.gov (United States)

Hattori, S; Luo, H; Shoun, H; Kamagata, Y

2001-01-01

To determine whether formate is involved in interspecies electron transfer between substrate-oxidizing bacteria and hydrogenotrophic microorganisms under anaerobic conditions, a syntrophic acetate-oxidizing bacterium Thermacetogenium phaeum strain PB was cocultured either with a formate /H2-utilizing methanogen strain TM (designated as PB/TM coculture), or an H2-utilizing methanogen strain deltaH (designated as PB/deltaH coculture). Acetate oxidation and subsequent methanogenesis in PB/TM coculture were found to be significantly faster than in PB/deltaH coculture. Formate dehydrogenase and hydrogenase were both detected in strains PB and TM. H2 partial pressures in the PB/TM coculture were kept lower (20 to 40 Pa) than those of the PB/deltaH coculture (40 to 60 Pa) during the exponential growth phase. Formate was also detected in both PB/TM and PB/deltaH cocultures, and the concentration of formate was maintained at a lower level in the PB/TM coculture (5 to 9 microM) than in the PB/deltaH coculture. Thermodynamic calculations revealed that the concentrations of both H2 and formate severely affect the syntrophic oxidation of acetate. These results strongly indicate that not only H2 but also formate may be involved in interspecies electron transfer.

Evidence for a role of biosurfactants produced by Pseudomonas fluorescens in the spoilage of fresh aerobically stored chicken meat.

Science.gov (United States)

Mellor, Glen E; Bentley, Jessica A; Dykes, Gary A

2011-08-01

Fresh chicken meat is a fat-rich environment and we therefore hypothesised that production of biosurfactants to increase bioavailability of fats may represent one way in which spoilage bacteria might enhance the availability of nutrients. Numbers of Pseudomonas were determined on a total of 20 fresh and 20 spoiled chicken thighs with skin. A total of 400 randomly isolated Pseudomonas colonies from fresh (200) and spoiled (200) chicken were screened for the presence of biosurfactant production. Biosurfactant producing strains represented 5% and 72% of the Pseudomonas spp. isolates from fresh (mean count 2.3 log(10) cfu g(-1)) and spoiled (mean count 7.4 log(10) cfu g(-1)) chicken skin, respectively. Partially-purified biosurfactants derived from a subgroup of four Pseudomonasfluorescens strains obtained through the screening process were subsequently used to investigate the role that the addition of these compounds plays in the spoilage of aerobically stored chicken. Emulsification potential of the four selected biosurfactants was measured against a range of hydrocarbons and oils. All four biosurfactants displayed a greater ability to emulsify rendered chicken fat than hydrocarbons (paraffin liquid, toluene and hexane) and oils (canola, olive, sunflower and vegetable). Storage trials (4 °C) of chicken meat treated with the four selected biosurfactants revealed a significantly greater (P increase in total aerobic count (1.3-1.7 log(10) cfu g(-1)) occurred following one day of incubation. These results indicate that biosurfactants produced by Pseudomonas spp. may play an important role in the spoilage of aerobically stored chicken meat by making nutrients more freely available and providing strains producing them with a competitive advantage. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of autochthonous bacteriocin-producing Lactococcus lactis on bacterial population dynamics and growth of halotolerant bacteria in Brazilian charqui.

Science.gov (United States)

Biscola, Vanessa; Abriouel, Hikmate; Todorov, Svetoslav Dimitrov; Capuano, Verena Sant'Anna Cabral; Gálvez, Antonio; Franco, Bernadette Dora Gombossy de Melo

2014-12-01

Charqui is a fermented, salted and sun-dried meat product, widely consumed in Brazil and exported to several countries. Growth of microorganisms in this product is unlikely due to reduced Aw, but halophilic and halotolerant bacteria may grow and cause spoilage. Charqui is a good source of lactic acid bacteria able to produce antimicrobial bacteriocins. In this study, an autochthonous bacteriocinogenic strain (Lactococcus lactis subsp. lactis 69), isolated from charqui, was added to the meat used for charqui manufacture and evaluated for its capability to prevent the growth of spoilage bacteria during storage up to 45 days. The influence of L. lactis 69 on the bacterial diversity during the manufacturing of the product was also studied, using denaturing gradient gel electrophoresis (DGGE). L. lactis 69 did not affect the counts and diversity of lactic acid bacteria during manufacturing and storage, but influenced negatively the populations of halotolerant microorganisms, reducing the spoilage potential. The majority of tested virulence genes was absent, evidencing the safety and potential technological application of this strain as an additional hurdle to inhibit undesirable microbial growth in this and similar fermented meat products. Copyright © 2014 Elsevier Ltd. All rights reserved.

40 CFR 725.85 - Microorganism identity.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Microorganism identity. 725.85 Section... to Information § 725.85 Microorganism identity. (a) Claims applicable to the period prior to... specific microorganism identity at the time of submission of the information. This claim will apply only to...

Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat.

Science.gov (United States)

Schirmer, Bjørn Christian; Langsrud, Solveig

2010-03-01

The aim of this study was to investigate the inhibitory effect of natural antimicrobials on the growth of typical spoilage bacteria from marinated pork. Minimum inhibitory concentrations (MIC) of thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, a rosemary extract, and a grapefruit seed extract against Lactobacillus algidus, Leuconostoc mesenteroides, Leuconostoc carnosum, Carnobacterium maltaromaticum, Carnobacterium divergens, Brochothrix thermosphacta, and Serratia proteamaculans were determined in a microplate assay. Combinations of antimicrobials were tested and several combinations showed synergistic effects in inhibiting bacterial growth. Single and combined antimicrobials were added to vacuum-packed pork meat to evaluate preserving effects. Antimicrobial concentrations of up to 10 times the MIC values showed no effect on total bacterial growth in vacuum packed pork meaning that although most antimicrobials inhibited the growth of spoilage bacteria in vitro, results from the microplate assay could not be transferred to the meat system. Most natural antimicrobials possess strong odor and flavor that limit their use as a food preservative. In conclusion, this study showed that the use of natural antimicrobials in meat products is limited and that bacterial quality and shelf life was not enhanced under the chosen conditions.

Relation between microbiological quality, metabolite production and sensory quality of equilibrium modified atmosphere packaged fresh-cut produce.

Science.gov (United States)

Jacxsens, L; Devlieghere, F; Ragaert, P; Vanneste, E; Debevere, J

2003-06-25

The quality of four types of fresh-cut produce, packaged in consumer-sized packages under an equilibrium modified atmosphere and stored at 7 degrees C, was assessed by establishing the relation between the microbial outgrowth and the corresponding production of nonvolatile compounds and related sensory disorders. In vitro experiments, performed on a lettuce-juice-agar, demonstrated the production of nonvolatile compounds by spoilage causing lactic acid bacteria and Enterobacteriaceae. Pseudomonas fluorescens and yeasts, however, were not able to produce detectable amounts of nonvolatile metabolites. The type of spoilage and quality deterioration in vivo depended on the type of vegetable. Mixed lettuce and chicory endives, leafy tissues, containing naturally low concentrations of sugars, showed a spoilage dominated by Gram-negative microorganisms, which are not producing nonvolatile compounds. Sensory problems were associated with visual properties and the metabolic activity of the plant tissue. Mixed bell peppers and grated celeriac, on the other hand, demonstrated a fast and intense growth of spoilage microorganisms, dominated by lactic acid bacteria and yeasts. This proliferation resulted in detectable levels of organic acids and the rejection by the trained sensory panel was based on the negative perception of the organoleptical properties (off-flavour, odour and taste). The applied microbiological criteria corresponded well with detectable changes in sensory properties and measurable concentrations of nonvolatile compounds, surely in the cases where lactic acid bacteria and yeasts were provoking spoilage. Consequently, the freshness of minimally processed vegetables, sensitive for outgrowth of lactic acid bacteria and yeasts (e.g., carrots, celeriac, bell peppers, mixtures with non-leafy vegetables) can be evaluated via analysis of the produced nonvolatile compounds.

Rapid monitoring of the spoilage of minced beef stored under conventionally and active packaging conditions using Fourier transform infrared spectroscopy in tandem with chemometrics.

Science.gov (United States)

Ammor, Mohammed Salim; Argyri, Anthoula; Nychas, George-John E

2009-03-01

Fourier transform infrared (FTIR) spectroscopy was exploited to measure biochemical changes within fresh minced beef in an attempt to rapidly monitor beef spoilage. Minced beef packaged either aerobically, under modified atmosphere and using an active packaging were held from freshness to spoilage at 0, 5, 10, and 15°C. Frequent FTIR measurements were collected directly from the sample surface using attenuated total reflectance, in parallel the total viable counts of bacteria, the sensory quality and the pH were also determined. Principal components analysis allowed illuminating the wavenumbers potentially correlated with the spoilage process. Qualitative interpretation of spectral data was carried out using discriminant factorial analysis and used to corroborate sensory data and to accurately determine samples freshness and packaging. Partial least-squares regressions permitted estimates of bacterial loads and pH values from the spectral data with a fit of R(2)=0.80 for total viable counts and fit of R(2)=0.92 for the pH. Obtained results demonstrated that a FTIR spectrum may be considered as a metabolic fingerprint and that the method in tandem with chemometrics represents a powerful, rapid, economical and non-invasive method for monitoring minced beef freshness regardless the storage conditions (e.g. packaging and temperature).

The plastic-associated microorganisms of the North Pacific Gyre.

Science.gov (United States)

Carson, Henry S; Nerheim, Magnus S; Carroll, Katherine A; Eriksen, Marcus

2013-10-15

Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm(-2)) and pennate diatoms (1097 ± 154 mm(-2)) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

High pressure inactivation of relevant target microorganisms in poultry meat products and the evaluation of pressure-induced protein denaturation of marinated poultry under different high pressure treatments

Science.gov (United States)

Schmidgall, Johanna; Hertel, Christian; Bindrich, Ute; Heinz, Volker; Toepfl, Stefan

2011-03-01

In this study, the possibility of extending shelf life of marinated poultry meat products by high pressure processing was evaluated. Relevant spoilage and pathogenic strains were selected and used as target microorganisms (MOs) for challenge experiments. Meat and brine were inoculated with MOs and treated at 450 MPa, 4 °C for 3 min. The results of inactivation show a decreasing pressure tolerance in the series Lactobacillus > Arcobacter > Carnobacterium > Bacillus cereus > Brochothrix thermosphacta > Listeria monocytogenes. Leuconostoc gelidum exhibited the highest pressure tolerance in meat. A protective effect of poultry meat was found for L. sakei and L. gelidum. In parallel, the influence of different marinade formulations (pH, carbonates, citrates) on protein structure changes during a pressure treatment was investigated. Addition of sodium carbonate shows a protection against denaturation of myofibrillar proteins and provides a maximum water-holding capacity. Caustic marinades allowed a higher retention of product characteristics than low-pH marinades.

Antimicrobial Edible Films and Coatings for Meat and Meat Products Preservation

Directory of Open Access Journals (Sweden)

Irais Sánchez-Ortega

2014-01-01

Full Text Available Animal origin foods are widely distributed and consumed around the world due to their high nutrients availability but may also provide a suitable environment for growth of pathogenic and spoilage microorganisms. Nowadays consumers demand high quality food with an extended shelf life without chemical additives. Edible films and coatings (EFC added with natural antimicrobials are a promising preservation technology for raw and processed meats because they provide good barrier against spoilage and pathogenic microorganisms. This review gathers updated research reported over the last ten years related to antimicrobial EFC applied to meat and meat products. In addition, the films gas barrier properties contribute to extended shelf life because physicochemical changes, such as color, texture, and moisture, may be significantly minimized. The effectiveness showed by different types of antimicrobial EFC depends on meat source, polymer used, film barrier properties, target microorganism, antimicrobial substance properties, and storage conditions. The perspective of this technology includes tailoring of coating procedures to meet industry requirements and shelf life increase of meat and meat products to ensure quality and safety without changes in sensory characteristics.

Species-Level Discrimination of Psychrotrophic Pathogenic and Spoilage Gram-Negative Raw Milk Isolates Using a Combined MALDI-TOF MS Proteomics-Bioinformatics-based Approach.

Science.gov (United States)

Vithanage, Nuwan R; Bhongir, Jeevana; Jadhav, Snehal R; Ranadheera, Chaminda S; Palombo, Enzo A; Yeager, Thomas R; Datta, Nivedita

2017-06-02

Identification of psychrotrophic pathogenic and spoilage Gram-negative bacteria using rapid and reliable techniques is important in commercial milk processing, as these bacteria can produce heat-resistant proteases and act as postprocessing contaminants in pasteurized milk. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a proven technology for identification of bacteria in food, however, may require optimization for identification of pathogenic and spoilage bacteria in milk and dairy products. The current study evaluated the effects of various culture conditions and sample preparation methods on assigning of raw milk isolates to the species level by MALDI-TOF MS. The results indicated that culture media, incubation conditions (temperature and time), and sample preparation significantly affected the identification rates of bacteria to the species level. Nevertheless, the development of spectral libraries of isolates grown on different media using a web tool for hierarchical clustering of peptide mass spectra (SPECLUST) followed by a ribosomal protein based bioinformatics approach significantly enhanced the assigning of bacteria, with at least one unique candidate biomarker peak identified for each species. Phyloproteomic relationships based on spectral profiles were compared to phylogenetic analysis using 16S rRNA gene sequences and demonstrated similar clustering patterns with significant discriminatory power. Thus, with appropriate optimization, MALDI-TOF MS is a valuable tool for species-level discrimination of pathogenic and milk spoilage bacteria.

Differentiation of Lactobacillus brevis strains using Matrix-Assisted-Laser-Desorption-Ionization-Time-of-Flight Mass Spectrometry with respect to their beer spoilage potential.

Science.gov (United States)

Kern, Carola C; Vogel, Rudi F; Behr, Jürgen

2014-06-01

Lactobacillus (L.) brevis is one of the most frequently encountered bacteria in beer-spoilage incidents. As the species Lactobacillus brevis comprises strains showing varying ability to grow in beer, ranging from growth in low hopped wheat to highly hopped pilsner beer, differentiation and classification of L. brevis with regard to their beer-spoiling ability is of vital interest for the brewing industry. Matrix-Assisted-Laser-Desorption-Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown as a powerful tool for species and sub-species differentiation of bacterial isolates and is increasingly used for strain-level differentiation. Seventeen L. brevis strains, representative of different spoilage types, were characterized according to their tolerance to iso-alpha-acids and their growth in wheat-, lager- and pilsner beer. MALDI-TOF MS spectra were acquired to perform strain-level identification, cluster analysis and biomarker detection. Strain-level identification was achieved in 90% out of 204 spectra. Misidentification occurred nearly exclusively among strains belonging to the same spoilage type. Though spectra of strongly beer-spoiling strains showed remarkable similarity, no decisive single markers were detected to be present in all strains of one group. However, MALDI-TOF MS spectra can be reliably assigned to the corresponding strain and thus allow to track single strains and connect them to their physiological properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antimicrobial Effect of Filipendula ulmaria Plant Extract Against Selected Foodborne Pathogenic and Spoilage Bacteria in Laboratory Media, Fish Flesh and Fish Roe Product

Directory of Open Access Journals (Sweden)

Charalampos Proestos

2011-01-01

Full Text Available Water-methanol extract from Filipendula ulmaria contains a variety of phenolic compounds, such as caffeic, p-coumaric and vanillic acid, myricetin, etc, which demonstrate antibacterial activity. Monitoring this activity in the broth using absorbance measurements showed that species of the Enterobacteriaceae family were more resistant than other Gram-negative and Gram-positive bacteria tested. Acidic environment enhanced the antibacterial activity of Filipendula ulmaria extract when it was tested against Salmonella Enteritidis PT4 and Listeria monocytogenes Scott A. The efficacy of Filipendula ulmaria extract against selected foodborne psychrotrophic bacteria was also tested using solid laboratory media and low incubation temperatures for better simulation of food preservation conditions. Higher concentrations of the extract, compared to minimum inhibitory concentration determined in the broth, were needed for satisfactory inhibition of spoilage bacteria. Potential use of Filipendula ulmaria extract as natural food preservative was also examined against natural spoilage flora and inoculated pathogenic bacteria on fish flesh and fish roe product (tarama salad. No significant differences of viable populations of spoilage or pathogenic bacteria were found between the treated samples and controls. Further trials of Filipendula ulmaria extract should be carried out in acidic foods with low fat and protein content, supplemented with additional adjuncts, in order to explore its potential as effective natural food antimicrobial agent.

Biotransformation of Spanish coals by microorganisms; Biotransformacion de Carbones Espanoles por Microorganismos

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

some newly isolated microorganisms could solubilized different kinds of Spanish coals (hard coal, subbituminous coal and lignite). Certain fungi and bacteria could solubilized lignite when growing in a mineral medium. However, to solubilized higher rank coals (hard coal and subbituminous coal) microorganisms require a complete medium. Microorganisms, which showed higher capacity to solubilized coal, were incubated in the presence of coal (hard coal, subbituminous coal and lignite) at the optimal conditions to get coal liquefaction/solubilization. The resultant products were analysed by IR and UV/visible spectrometry. No major differences among the original coal, solubilized/liquefied coal and residual coal were detected. However, an increase in metallic carboxylate and a decrease in OH'- carboxylic groups were observed in the liquefied lignite. Humic acids derived from original lignite residual lignite and liquefied/solubilized lignite by microorganisms were analysed. Several differences were observed in the humic acids extracted from the liquefied lignite, such as an increase in the total acidity and in the proportion of the phenolic groups. Differences on the humic acid molecular weight were observed too. Several fungal and bacterial strains were able to grow using humic acids as sole carbon source. Microorganisms growing in humic acid were observed by Scanning Electron Microscopy. Besides, the coal solubilization capacity of several fungal strains (M2, m$ and AGI) growing in different culture media was assayed. In order to get some insight into the mechanisms of the liquefaction/solubilization of Spanish coals (hard coal, subbituminous coal and lignite) by these microorganisms, some features in the culture supernatants were studied: pH values; extracellular specific proteins; enzyme activities possibly related with coal solubilization and the presence of oxalate. M2 and M4 fungal strains grown in the presence of coal produced some specific extracellular proteins

Biotransformation of Spanish coals by microorganisms; Biotransformacion de Carbones Espanoles por Microorganismos

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

some newly isolated microorganisms could solubilized different kinds of Spanish coals (hard coal, subbituminous coal and lignite). Certain fungi and bacteria could solubilized lignite when growing in a mineral medium. However, to solubilized higher rank coals (hard coal and subbituminous coal) microorganisms require a complete medium. Microorganisms, which showed higher capacity to solubilized coal, were incubated in the presence of coal (hard coal, subbituminous coal and lignite) at the optimal conditions to get coal liquefaction/solubilization. The resultant products were analysed by IR and UV/visible spectrometry. No major differences among the original coal, solubilized/liquefied coal and residual coal were detected. However, an increase in metallic carboxylate and a decrease in OH'- carboxylic groups were observed in the liquefied lignite. Humic acids derived from original lignite residual lignite and liquefied/solubilized lignite by microorganisms were analysed. Several differences were observed in the humic acids extracted from the liquefied lignite, such as an increase in the total acidity and in the proportion of the phenolic groups. Differences on the humic acid molecular weight were observed too. Several fungal and bacterial strains were able to grow using humic acids as sole carbon source. Microorganisms growing in humic acid were observed by Scanning Electron Microscopy. Besides, the coal solubilization capacity of several fungal strains (M2, m$ and AGI) growing in different culture media was assayed. In order to get some insight into the mechanisms of the liquefaction/solubilization of Spanish coals (hard coal, subbituminous coal and lignite) by these microorganisms, some features in the culture supernatants were studied: pH values; extracellular specific proteins; enzyme activities possibly related with coal solubilization and the presence of oxalate. M2 and M4 fungal strains grown in the presence of coal produced some specific extracellular

IPMP 2013 - A comprehensive data analysis tool for predictive microbiology

Science.gov (United States)

Predictive microbiology is an area of applied research in food science that uses mathematical models to predict the changes in the population of pathogenic or spoilage microorganisms in foods undergoing complex environmental changes during processing, transportation, distribution, and storage. It f...

Antimicrobial activity of Xylopia aethiopica, Aframomum melegueta ...

African Journals Online (AJOL)

poisoning and/or food spoilage. The microorganisms were Bacillus subtilis IAM1069, Bacillus cereus IFO 13494, Staphylococcus aureus FDA 209p, Escherichia coli NRIC 1023, Salmonella typhimurium IFO12529, Lactobacillus plantarum IAM 1041, Pediococcus acidilactici-M, Leuconostoc mesenteroides- M, Lactobacillus ...

Genomic and Transcriptomic Evidence for Carbohydrate Consumption Among Microorganisms in a Cold Seep Brine Pool

Directory of Open Access Journals (Sweden)

Weipeng Zhang

2016-11-01

Full Text Available The detailed lifestyle of microorganisms in deep-sea brine environments remains largely unexplored. Using a carefully calibrated genome binning approach, we reconstructed partial to nearly-complete genomes of 51 microorganisms in biofilms from the Thuwal cold seep brine pool of the Red Sea. The recovered metagenome-assembled genomes (MAGs belong to six different phyla: Actinobacteria, Proteobacteria, Candidatus Cloacimonetes, Candidatus Marinimicrobia, Bathyarchaeota and Thaumarchaeota. By comparison with close relatives of these microorganisms, we identified a number of unique genes associated with organic carbon metabolism and energy generation. These genes included various glycoside hydrolases, nitrate and sulfate reductases, putative bacterial microcompartment biosynthetic clusters (BMC, and F420H2 dehydrogenases. Phylogenetic analysis suggested that the acquisition of these genes probably occurred through horizontal gene transfer (HGT. Metatranscriptomics illustrated that glycoside hydrolases are among the most highly expressed genes. Our results suggest that the microbial inhabitants are well adapted to this brine environment, and anaerobic carbohydrate consumption mediated by glycoside hydrolases and electron transport systems (ETSs is a dominant process performed by microorganisms from various phyla within this ecosystem.

Genomic and Transcriptomic Evidence for Carbohydrate Consumption among Microorganisms in a Cold Seep Brine Pool

KAUST Repository

Zhang, Weipeng

2016-11-15

The detailed lifestyle of microorganisms in deep-sea brine environments remains largely unexplored. Using a carefully calibrated genome binning approach, we reconstructed partial to nearly-complete genomes of 51 microorganisms in biofilms from the Thuwal cold seep brine pool of the Red Sea. The recovered metagenome-assembled genomes (MAGs) belong to six different phyla: Actinobacteria, Proteobacteria, Candidatus Cloacimonetes, Candidatus Marinimicrobia, Bathyarchaeota, and Thaumarchaeota. By comparison with close relatives of these microorganisms, we identified a number of unique genes associated with organic carbon metabolism and energy generation. These genes included various glycoside hydrolases, nitrate and sulfate reductases, putative bacterial microcompartment biosynthetic clusters (BMC), and F420H2 dehydrogenases. Phylogenetic analysis suggested that the acquisition of these genes probably occurred through horizontal gene transfer (HGT). Metatranscriptomics illustrated that glycoside hydrolases are among the most highly expressed genes. Our results suggest that the microbial inhabitants are well adapted to this brine environment, and anaerobic carbohydrate consumption mediated by glycoside hydrolases and electron transport systems (ETSs) is a dominant process performed by microorganisms from various phyla within this ecosystem.

Necromass as a source of energy to microorganisms in marine sediments.

Science.gov (United States)

Bradley, J.; Amend, J.; LaRowe, D.

2017-12-01

Marine sediments constitute one of the largest, most energy-limited biospheres on Earth. Despite increasing exploration and interest characterizing microbial communities in marine sediments, the production and role of microbial dead-matter (necromass) has largely been overlooked. Necromass is produced on a global scale, yet its significance as a power source to heterotrophic microorganisms remains unknown. We developed a physical, bio-energetic and geochemical model to quantify the total power supply from necromass oxidation and the total power demand of living microorganisms in marine sediments. This model is first applied to sediments from the oligotrophic South Pacific Gyre (SPG), where organic carbon and biomass concentrations are extremely low, yet microorganisms persist for millions of years in some of the lowest energy states on Earth. We show that necromass does not supply sufficient power to support the total demands of the living community (maintenance demands of microorganisms in marine sediments for up to 60,000 years following burial. Our model assumes that all counted cells are viable. Yet, if only a fraction of counted cells are alive, the role of necromass as an electron donor in fueling microbial metabolisms is even greater. This new insight requires a reassessment of carbon fluxes in the deep biosphere. By extension, we also demonstrate a mechanism for microbial communities to persist by oxidizing necromass over geological timescales, and thereby endure unfavorable, low-energy settings that might be analogous to conditions on early Earth and on other planetary bodies.

Control of Microbiological Spoilage of Food by Irradiation

Energy Technology Data Exchange (ETDEWEB)

Farkas, J. [Central Food Research Institute, Budapest (Hungary)

1978-04-15

Papers published from 1973 to 1977 in the field of radiation control of microbiological spoilage are reviewed, grouping the subjects according to the type of process and food treated. Various laboratories from 33 countries have recently published data on the subject, radurization of dates, prepackaged vegetables, wet grains, bread, various meats and meat products being reported. The most widespread research activities could be observed in the field of radurization of fish and marine products (shellfish, shrimps). Radiation decontamination of dry food ingredients (enzyme preparates, protein preparates, starch, spices) and cork stoppers was studied in various laboratories. Radappertization research of several animal-protein foods has made remarkable progress and the minimal dose requirements are well established. Combination of radiation treatment with other antimicrobial agents (salt, preservatives, heat, etc.) has been investigated by many laboratories. Foods involved in these investigations were bread, several tropical and subtropical fruits, apple juice, groundnuts, fish fillets and shrimps, but a considerable part of the data relate to model systems. A better understanding of the synergistic effect will require additional knowledge and the continuation of long-range research and development in the field of combined treatments is recommended. (author)

Control of microbiological spoilage of food by irradiation

International Nuclear Information System (INIS)

Farkas, J.

1978-01-01

Papers published from 1973 to 1977 in the field of radiation control of microbiological spoilage are reviewed, grouping the subjects according to the type of process and food treated. Various laboratories from 33 countries have recently published data on the subject, radurization of dates, prepackaged vegetables, wet grains, bread, various meats and meat products being reported. The most widespread research activities could be observed in the field of radurization of fish and marine products (shellfish, shrimps). Radiation decontamination of dry food ingredients (enzyme preparates, protein preparates, starch, spices) and cork stoppers was studied in various laboratories. Radappertization research of several animal-protein foods has made remarkable progress and the minimal dose requirements are well established. Combination of radiation treatment with other antimicrobial agents (salt, preservatives, heat, etc.) has been investigated by many laboratories. Foods involved in these investigations were bread, several tropical and subtropical fruits, apple juice, groundnuts, fish fillets and shrimps, but a considerable part of the data relate to model systems. A better understanding of the synergistic effect will require additional knowledge and the continuation of long-range research and development in the field of combined treatments is recommended. (author)

Bioplastics from microorganisms.

Science.gov (United States)

Luengo, José M; García, Belén; Sandoval, Angel; Naharro, Germán; Olivera, Elías R

2003-06-01

The term 'biomaterials' includes chemically unrelated products that are synthesised by microorganisms (or part of them) under different environmental conditions. One important family of biomaterials is bioplastics. These are polyesters that are widely distributed in nature and accumulate intracellularly in microorganisms in the form of storage granules, with physico-chemical properties resembling petrochemical plastics. These polymers are usually built from hydroxy-acyl-CoA derivatives via different metabolic pathways. Depending on their microbial origin, bioplastics differ in their monomer composition, macromolecular structure and physical properties. Most of them are biodegradable and biocompatible, which makes them extremely interesting from the biotechnological point of view.

Microorganism identification technique using radioactive and fluorescent agent

International Nuclear Information System (INIS)

Silman, R.E.

1983-01-01

A method for identifying microorganisms is claimed. An emissive agent is added to a specimen of microorganisms to produce a mix of emissive products. These products are detected and characteristic pattern functioning as an identifier for the microorganisms is derived. The identifier is then compared with identifiers representing known microorganisms

Effect of the antimicrobial photodynamic therapy on microorganism reduction in deep caries lesions: a systematic review and meta-analysis

Science.gov (United States)

Ornellas, Pâmela Oliveira; Antunes, Leonardo Santos; Fontes, Karla Bianca Fernandes da Costa; Póvoa, Helvécio Cardoso Corrêa; Küchler, Erika Calvano; Iorio, Natalia Lopes Pontes; Antunes, Lívia Azeredo Alves

2016-09-01

This study aimed to perform a systematic review to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) in the reduction of microorganisms in deep carious lesions. An electronic search was conducted in Pubmed, Web of Science, Scopus, Lilacs, and Cochrane Library, followed by a manual search. The MeSH terms, MeSH synonyms, related terms, and free terms were used in the search. As eligibility criteria, only clinical studies were included. Initially, 227 articles were identified in the electronic search, and 152 studies remained after analysis and exclusion of the duplicated studies; 6 remained after application of the eligibility criteria; and 3 additional studies were found in the manual search. After access to the full articles, three were excluded, leaving six for evaluation by the criteria of the Cochrane Collaboration's tool for assessing risk of bias. Of these, five had some risk of punctuated bias. All results from the selected studies showed a significant reduction of microorganisms in deep carious lesions for both primary and permanent teeth. The meta-analysis demonstrated a significant reduction in microorganism counts in all analyses (p<0.00001). Based on these findings, there is scientific evidence emphasizing the effectiveness of aPDT in reducing microorganisms in deep carious lesions.

Prediction of Mold Spoilage for Soy/Polyethylene Composite Fibers

Directory of Open Access Journals (Sweden)

Chinmay Naphade

2015-01-01

Full Text Available Mold spoilage was determined over 109 days on soy/PE fibers held under controlled temperatures (T ranging from 10°C to 40°C and water activities (aw from 0.11 to 0.98. Water activities were created in sealed containers using saturated salt solutions and placed in temperature-controlled incubators. Soy/PE fibers that were held at 0.823 aw or higher exhibited mold growth at all temperatures. As postulated, increased water activity (greater than 0.89 and temperature (higher than 25°C accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87 aw and 10°C. A Weibull model was employed to fit the observed logarithmic values of T, aw, and an interaction term log⁡T×log⁡aw and was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

Culture-dependent and culture-independent assessment of spoilage community growth on VP lamb meat from packaging to past end of shelf-life.

Science.gov (United States)

Kaur, Mandeep; Shang, Hongshan; Tamplin, Mark; Ross, Tom; Bowman, John P

2017-12-01

Packaging and storage temperature are important factors that influence the shelf-life of vacuum packed (VP) meat. In this study the shelf-life of VP bone-in lamb hind shanks stored at 8 °C and -1.2 °C was determined in parallel to analyses of starting and eventual spoilage bacterial communities via Illumina MiSeq based 16S rRNA amplicon sequencing. The mean total viable counts (TVC) and lactic acid bacterial viable counts (LAB) were observed to increase to log 7.5 CFU/cm 2 and 7 CFU/cm 2 after 6 and 42 days at 8 °C and -1.2 °C and stayed stable until shelf-life termination after 13 and 124 days, respectively. The sequence data showed initial communities were patchily distributed and were mainly derived from skin microbiome taxa likely prevalent within the abattoir. A broad diversity of VP meat associated specific spoilage organisms (SSO) were comparatively abundant in this initial population. Overtime meat spoilage communities developed a distinctive and stable microbiome. At -1.2 °C SSO included mainly Carnobacterium, Yersinia and Clostridium spp. while at 8 °C SSO expanded to include Hafnia, Lactococcus, Providencia spp. Growth curves inferred from the sequence data after taking into account rRNA copy number suggested that SSO growth rates were consistent with overall growth rates determined from TVC and LAB data and are predictable. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Inactivation of Listeria monocytogenes on ham and bologna using pectin-based apple, carrot, and hibiscus edible films containing Carvacrol and Cinnamaldehyde

Science.gov (United States)

Edible films can be used as wrapping material on food products to reduce surface contamination. The incorporation of antimicrobials into edible films could serve as an additional barrier against pathogenic and spoilage microorganisms that contaminate food surfaces. The objective of this study was ...

Volatile sulfur compounds in foods as a result of ionizing radiation

Science.gov (United States)

Ionizing radiation improves food safety and extends shelf life by inactivating food-borne pathogens and spoilage microorganisms. However, irradiation may induce the development of an off-odor, particularly at high doses. The off-odor has been called “irradiation odor”. Substantial evidence suggests ...

Trends in antimicrobial food packaging systems: Emitting sachets and absorbent pads

Science.gov (United States)

Active antimicrobial packaging interacts with packaged food and headspace to reduce, retard, or even inhibit the growth of spoilage and pathogenic microorganisms. Sachets and pads are one of the most successful applications of active food packaging. This review discusses recent developments of antim...

Listeria monocytogenes contamination of the environment and surfaces of the equipment in the meat processing facilities in republic of Macedonia

OpenAIRE

Dean Jankuloski; Pavle Sekulovski; Risto Prodanov; Zehra Hajrulai Musliu; Biljana Stojanovska Dimzovska

2007-01-01

Listeria monocytogenes contamination of the environment and surfaces of the equipment was examined in seven meat processing facilities. Up to date prevalence of this foodborn pathogen in meat processing facilities facilities in Republic of Macedonia was unknown. Biofilms are composed from food spoilage microorganisms and food born pathogens. They are located on the surfaces of the equipment that come in contact with food and in facilities environment. Microorganisms in biofilm presenting micr...

Development of electrochemical biosensor for detection of pathogenic microorganism in Asian dust events.

Science.gov (United States)

Yoo, Min-Sang; Shin, Minguk; Kim, Younghun; Jang, Min; Choi, Yoon-E; Park, Si Jae; Choi, Jonghoon; Lee, Jinyoung; Park, Chulhwan

2017-05-01

We developed a single-walled carbon nanotubes (SWCNTs)-based electrochemical biosensor for the detection of Bacillus subtilis, one of the microorganisms observed in Asian dust events, which causes respiratory diseases such as asthma and pneumonia. SWCNTs plays the role of a transducer in biological antigen/antibody reaction for the electrical signal while 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) and ant-B. subtilis were performed as a chemical linker and an acceptor, respectively, for the adhesion of target microorganism in the developed biosensor. The detection range (10 2 -10 10  CFU/mL) and the detection limit (10 2  CFU/mL) of the developed biosensor were identified while the response time was 10 min. The amount of target B. subtilis was the highest in the specificity test of the developed biosensor, compared with the other tested microorganisms (Staphylococcus aureus, Flavobacterium psychrolimnae, and Aquabacterium commune). In addition, target B. subtilis detected by the developed biosensor was observed by scanning electron microscope (SEM) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of copper and lead on two consortia of phototrophic microorganisms and their capacity to sequester metals.

Science.gov (United States)

Burgos, A; Maldonado, J; De Los Rios, A; Solé, A; Esteve, I

2013-09-15

The roles of consortia of phototrophic microorganisms have been investigated in this paper to determine their potential role to tolerate or resist metals and to capture them from polluted cultures. With this purpose, two consortia of microorganisms: on one hand, Geitlerinema sp. DE2011 (Ge) and Scenedesmus sp. DE2009 (Sc) (both identified in this paper by molecular biology methods) isolated from Ebro Delta microbial mats, and on the other, Spirulina sp. PCC 6313 (Sp) and Chroococcus sp. PCC 9106 (Ch), from Pasteur culture collection were polluted with copper and lead. In order to analyze the ability of these consortia to tolerate and capture metals, copper and lead were selected, because both have been detected in Ebro Delta microbial mats. The tolerance-resistance to copper and lead for both consortia was determined in vivo and at cellular level by Confocal Laser Scanning Microscopy (CLSM-λscan function). The results obtained demonstrate that both consortia are highly tolerant-resistant to lead and that the limits between the copper concentration having cytotoxic effect and that having an essential effect are very close in these microorganisms. The capacity of both consortia to capture extra- and intracellular copper and lead was determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) respectively, coupled to an Energy Dispersive X-ray detector (EDX). The results showed that all the microorganisms assayed were able to capture copper extracellularly in the extrapolymeric substances, and lead extra- and intracellularly in polyphosphate inclusions. Moreover, the studied micro-organisms did not exert any inhibitory effect on each other's metal binding capacity. From the results obtained in this paper, it can be concluded that consortia of phototrophic microorganisms could play a very important role in biorepairing sediments polluted by metals, as a result of their ability to tolerate or resist high concentrations of metals and to

Recent Advances in Physical Post-Harvest Treatments for Shelf-Life Extension of Cereal Crops

Science.gov (United States)

Schmidt, Marcus; Zannini, Emanuele; Arendt, Elke K.

2018-01-01

As a result of the rapidly growing global population and limited agricultural area, sufficient supply of cereals for food and animal feed has become increasingly challenging. Consequently, it is essential to reduce pre- and post-harvest crop losses. Extensive research, featuring several physical treatments, has been conducted to improve cereal post-harvest preservation, leading to increased food safety and sustainability. Various pests can lead to post-harvest losses and grain quality deterioration. Microbial spoilage due to filamentous fungi and bacteria is one of the main reasons for post-harvest crop losses and mycotoxins can induce additional consumer health hazards. In particular, physical treatments have gained popularity making chemical additives unnecessary. Therefore, this review focuses on recent advances in physical treatments with potential applications for microbial post-harvest decontamination of cereals. The treatments discussed in this article were evaluated for their ability to inhibit spoilage microorganisms and degrade mycotoxins without compromising the grain quality. All treatments evaluated in this review have the potential to inhibit grain spoilage microorganisms. However, each method has some drawbacks, making industrial application difficult. Even under optimal processing conditions, it is unlikely that cereals can be decontaminated of all naturally occurring spoilage organisms with a single treatment. Therefore, future research should aim for the development of a combination of treatments to harness their synergistic properties and avoid grain quality deterioration. For the degradation of mycotoxins the same conclusion can be drawn. In addition, future research must investigate the fate of degraded toxins, to assess the toxicity of their respective degradation products. PMID:29565832

Effects of a spoilage yeast from silage on in vitro ruminal fermentation.

Science.gov (United States)

Santos, M C; Lock, A L; Mechor, G D; Kung, L

2015-04-01

Feeding silages with high concentrations of yeasts from aerobic spoilage is often implicated as a cause of poor animal performance on dairies. Our objective was to determine if a commonly found spoilage yeast, isolated from silage, had the potential to alter in vitro ruminal fermentations. A single colony of Issatchenkia orientalis, isolated from high-moisture corn, was grown in selective medium. The yeast culture was purified and added to in vitro culture tubes containing a total mixed ration (43% concentrate, 43% corn silage, 11% alfalfa haylage, and 3% alfalfa hay on a dry matter basis), buffer, and ruminal fluid to achieve added theoretical final concentrations of 0 (CTR), 4.40 (low yeast; LY), 6.40 (medium yeast; MY), and 8.40 (high yeast; HY) log10 cfu of yeast/mL of in vitro fluid. Seven separate tubes were prepared for each treatment and each time point and incubated for 12 and 24h at 39 °C. At the end of the incubation period, samples were analyzed for pH, yeast number, neutral detergent fiber (NDF) digestibility, volatile fatty acids (VFA), and fatty acids (FA). We found that total viable yeast counts decreased for all treatments in in vitro incubations but were still relatively high (5.3 log10 cfu of yeasts/mL) for HY after 24h of incubation. Addition of HY resulted in a lower pH and higher concentration of total VFA in culture fluid compared with other treatments. Moreover, additions of MY and HY decreased in vitro NDF digestibility compared with CTR, and the effect was greatest for HY. Overall, the biohydrogenation of dietary unsaturated FA was not altered by addition of I. orientalis and decreased over time with an increase in the accumulation of saturated FA, especially palmitic and stearic acids. We conclude that addition of I. orientalis, especially at high levels, has the potential to reduce in vitro NDF digestion and alter other aspects of ruminal fermentations. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All

Lipidomics as an important key for the identification of beer-spoilage bacteria.

Science.gov (United States)

Řezanka, T; Matoulková, D; Benada, O; Sigler, K

2015-06-01

Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) was used for characterizing intact plasmalogen phospholipid molecules in beer-spoilage bacteria. Identification of intact plasmalogens was carried out using collision-induced dissociation and the presence of suitable marker molecular species, both qualitative and quantitative, was determined in samples containing the anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method had a limit of detection at 1 pg for the standard, i.e. 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and be linear in the range of four orders of magnitude from 2 pg to 20 ng. This technique was applied to intact plasmalogen extracts from the samples of contaminated and uncontaminated beer without derivatization and resulted in the identification of contamination of beer by Megasphaera and Pectinatus bacteria. The limit of detection was about 830 cells of anaerobic bacteria, i.e. bacteria containing natural cyclopropane plasmalogenes (c-p-19:0/15:0), which is the majority plasmalogen located in both Megasphaera and Pectinatus. The SIM ESI-MS method has been shown to be useful for the analysis of low concentration of plasmalogens in all biological samples, which were contaminated with anaerobic bacteria, e.g. juice, not only in beer. Significance and impact of the study: Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) using collision-induced dissociation was used to characterize intact plasmalogen phospholipid molecules in beer-spoilage anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method has a detection limit of 1 pg for the standard 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and is linear within four orders of magnitude (2 pg to 20 ng). The limit of detection was about 830 cells of bacteria containing natural cyclopropane plasmalogen (c-p-19:0/15:0). SIM ESI-MS method is useful for analyzing low

Development of a novel colorimetric sensor based on alginate beads for monitoring rainbow trout spoilage.

Science.gov (United States)

Majdinasab, Marjan; Hosseini, Seyed Mohammad Hashem; Sepidname, Marziyeh; Negahdarifar, Manizheh; Li, Peiwu

2018-05-01

Alginate is a non-toxic, renewable, and linear copolymer obtained from the brown algae Laminaria digitata that can be easily shaped into beads. Its good gel forming properties have made it useful for entrapping food and pharmaceutical ingredients. In this study, alginate beads were used in a novel application as a colorimetric sensor in food intelligent packaging. Colorimetric sensor was developed through entrapping red cabbage extract as a pH indicator in alginate beads. The pH indicator beads were used in rainbow trout packaging for monitoring fillets spoilage. Color change of beads during fish storage was measured using the CIELab method. The alginate bead colorimetric sensor is validated by measuring total volatile basic nitrogen (TVB-N) levels and microbial populations in fish samples. Moreover, peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were evaluated during storage. Results indicated that increasing the bacterial population during storage and production of proteolytic enzymes resulted in protein degradation, accumulation of volatile amine compounds, increase in the pH and finally color change of alginate beads. The values of TVB-N, pH, PV and TBARS increased with time of storage. The results of TVB-N and microbial growth were in accordance with color change of beads and CIELab data. Therefore, the proposed system enjoys a high sensitivity to pH variations and is capable of monitoring the spoilage of fish or other protein-rich products through its wide range of color changes. The alginate beads containing the red cabbage extract can, thus, be used as a low-cost colorimetric sensor for intelligent packaging applications.

Airborne microorganisms from waste containers.

Science.gov (United States)

Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

2012-01-01

In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

Doppler speedometer for micro-organisms

International Nuclear Information System (INIS)

Penkov, F.; Tuleushev, A.; Lisitsyn, V.; Kim, S.; Tuleushev, Yu.

1996-01-01

Objective of Investigations: Development and creation of the Doppler speedometer for micro-organisms which allows to evaluate, in a real temporal scale, variations in the state of water suspension of micro-organisms under the effect of chemical, physical and other external actions. Statement of the Problem The main problem is absence of reliable, accessible for users and simple, in view of application, Doppler speedometers for micro-organisms. Nevertheless, correlation Doppler spectrometry in the regime of heterodyning the supporting and cell-scattered laser radiation is welt known. The main idea is that the correlation function of photo-current pulses bears an information on the averages over the assembly of cell velocities. For solving the biological problems, construction of auto-correlation function in the real-time regime with the delay time values comprising, function in the real-time regime with the delay time values comprising, nearly, 100 me (10 khz) or higher is needed. Computers of high class manage this problem using but the program software. Due to this, one can simplify applications of the proposed techniques provided he creates the Doppler speedometer for micro-organism on a base of the P entium . Expected Result Manufactured operable mock-up of the Doppler speedometer for micro-organisms in a form of the auxiliary computer block which allows to receive an information, in the real time scale, on the results of external effects of various nature on the cell assembly in transparent medium with a small volume of the studied cell suspension

Growth of Thermophilic and Hyperthermophilic Fe(III)-Reducing Microorganisms on a Ferruginous Smectite as the Sole Electron Acceptor▿

Science.gov (United States)

Kashefi, Kazem; Shelobolina, Evgenya S.; Elliott, W. Crawford; Lovley, Derek R.

2008-01-01

Recent studies have suggested that the structural Fe(III) within phyllosilicate minerals, including smectite and illite, is an important electron acceptor for Fe(III)-reducing microorganisms in sedimentary environments at moderate temperatures. The reduction of structural Fe(III) by thermophiles, however, has not previously been described. A wide range of thermophilic and hyperthermophilic Archaea and Bacteria from marine and freshwater environments that are known to reduce poorly crystalline Fe(III) oxides were tested for their ability to reduce structural (octahedrally coordinated) Fe(III) in smectite (SWa-1) as the sole electron acceptor. Two out of the 10 organisms tested, Geoglobus ahangari and Geothermobacterium ferrireducens, were not able to conserve energy to support growth by reduction of Fe(III) in SWa-1 despite the fact that both organisms were originally isolated with solid-phase Fe(III) as the electron acceptor. The other organisms tested were able to grow on SWa-1 and reduced 6.3 to 15.1% of the Fe(III). This is 20 to 50% less than the reported amounts of Fe(III) reduced in the same smectite (SWa-1) by mesophilic Fe(III) reducers. Two organisms, Geothermobacter ehrlichii and archaeal strain 140, produced copious amounts of an exopolysaccharide material, which may have played an active role in the dissolution of the structural iron in SWa-1 smectite. The reduction of structural Fe(III) in SWa-1 by archaeal strain 140 was studied in detail. Microbial Fe(III) reduction was accompanied by an increase in interlayer and octahedral charges and some incorporation of potassium and magnesium into the smectite structure. However, these changes in the major element chemistry of SWa-1 smectite did not result in the formation of an illite-like structure, as reported for a mesophilic Fe(III) reducer. These results suggest that thermophilic Fe(III)-reducing organisms differ in their ability to reduce and solubilize structural Fe(III) in SWa-1 smectite and that SWa-1

Inactivation of Microorganisms

Science.gov (United States)

Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

Influence of cultural conditions on the production of bacteriocin by ...

African Journals Online (AJOL)

Bacteriocin produced by Lactobacillus brevis OG1 has large spectrum of inhibition against pathogenic, food spoilage microorganisms and various Lactic acid bacteria employed as test strains. The bacteriocin inhibited E coli NCTC 10418 and Enterococcus faecalis, but did not inhibit Candida albicans ATCC 10231 and ...

Cultivation, Isolation and Characterization of Bacteriocin from Fresh ...

African Journals Online (AJOL)

ADOWIE PERE

agar diffusion method on culture plates seeded with Staphylococcus and E.coli. Bacteriocinogenic ... Bacilliocins (FCM6 and FMS1) and Micrococin FMS2 are thermal and pressure stable. BLPs that are ... medium that support broad spectrum of spoilage and benefious ..... inactivation of microorganisms in milk. Innovative ...

The Antimicrobial Activity of the Essential Oil of Pistacia lentiscus var. Chia

NARCIS (Netherlands)

Gkogka, E.; Hazeleger, W.C.; Posthumus, M.A.; Beumer, R.R.

2013-01-01

The essential oil of the resin of Pistacia lentiscus var. Chia (mastic oil) was studied in vitro against a wide range of foodborne pathogenic and spoilage microorganisms with a diffusion and a dilution method. Furthermore its chemical composition was analyzed by means of Gas Chromatography-Mass

Knowledge and practices of food hygiene and safety among camel ...

African Journals Online (AJOL)

The respondents showed low knowledge in answering questions regarding spoilage microorganisms and effective cleaning of containers. About 53% of women retailers used rejected/spoiled milk for household consumption. This could result in a high food safety risk. Therefore, training of actors along the camel milk value ...

Microbiological Safety Assessment of Fermented Cassava Flour “Lafun” Available in Ogun and Oyo States of Nigeria

Directory of Open Access Journals (Sweden)

A. O. Adebayo-Oyetoro

2013-01-01

Full Text Available The microorganisms involved in the fermentation and spoilage of fermented cassava flour were investigated. The water samples used at the different processing sites were also investigated to determine their safety status. There was predominance of Staphylococcus aureus, Aspergillus spp., and Escherichia coli in all samples. Coliforms were observed to be present in all of the processing water. In the fermented cassava flour, the total bacterial count ranged between 4.9×106 cfu/mL from Eleso, Bakatari, and Oja Odan processing sites and 8.10×106 cfu/mL in Eruku processing site. The majority of the microorganisms involved in the spoilage of “lafun” were found to be Aspergillus niger which ranged between 4.6×105 cfu/mL in Eleso and 8.1×105 cfu/mL in Kila. The control sample prepared in the laboratory had a low microbial load compared to samples collected from various sites and markets.

Radiation resistance of microorganisms on unsterilized infusion sets

DEFF Research Database (Denmark)

Christensen, E. Ahrensburg; Kristensen, H.; Hoborn, J.

1991-01-01

Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor in a steriliza......Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor...

Advances of electronic nose and its application in fresh foods: A review.

Science.gov (United States)

Shi, Hao; Zhang, Min; Adhikari, Benu

2017-06-30

The science and technology aspects of electronic nose (E-nose) has been developed rapidly in last decade (2006-2016). This paper reviews of the publications that that cover the developments in science and technological aspects of electronic nose together with its application in fresh foods. The first part of this review covers the sensing and pattern recognition system (PR) of E-nose. The second part covers the application of E-nose in classification, flavor detection, and evaluation of spoilage in fresh foods area. With more new sensor materials to be found and more combination between E-nose and other analysis technologies, the usages of E-nose in fresh foods will have wider prospects.

Purification of leucocin A for use on wieners to inhibit Listeria monocytogenes in the presence of spoilage organisms.

Science.gov (United States)

Balay, Danielle R; Dangeti, Ramana V; Kaur, Kamaljit; McMullen, Lynn M

2017-08-16

The aims of this study were to improve the method for purification of leucocin A to increase yield of peptide and to evaluate the efficacy of leucocin A and an analogue of leucocin A (leucocin N17L) to inhibit the growth of Listeria monocytogenes on wieners in the presence of spoilage organisms. Leucocin A was produced by Leuconostoc gelidum UAL187 and purified with a five-fold increase in yield; leucocin N17L was synthesized replacing asparagine at residue 17 with leucine. Five strains of L. monocytogenes associated with foodborne illness were used to assess bacteriocin efficacy in vitro and in situ. Minimum inhibitory concentrations could not be determined in broth; however, on agar the minimum inhibitory concentrations ranged from 11.7-62.5μM and 62.5->500μM for leucocin A and leucocin N17L, respectively. Leucocin N17L was less effective than the native bacteriocin at controlling the growth of L. monocytogenes. The inactivation profiles of L. monocytogenes in broth in the presence of leucocin A suggested each isolate had different levels of resistance to the bacteriocin as determined by the initial bactericidal effect. The formation of spontaneously resistance subpopulations were also observed for each strain of L. monocytogenes. In situ, wieners were inoculated with the spoilage organisms, Carnobacterium divergens and Brochothrix thermosphacta, followed by surface application of purified leucocin A, and inoculated with a cocktail of L. monocytogenes. Wieners were vacuum packaged and stored at 7°C for 16d. Leucocin A reduced the counts L. monocytogenes on wieners during storage, regardless of the presence of C. divergens. B. thermosphacta was unaffected by the presence of leucocin A on wieners over the duration of storage. This study suggests that leucocin A may be beneficial to industry as a surface application on wieners to help reduce L. monocytogenes counts due to post-processing contamination even in the presence of spoilage organisms. However, further

Spoilage-related activity of Carnobacterium maltaromaticum strains in air-stored and vacuum-packed meat.

Science.gov (United States)

Casaburi, Annalisa; Nasi, Antonella; Ferrocino, Ilario; Di Monaco, Rossella; Mauriello, Gianluigi; Villani, Francesco; Ercolini, Danilo

2011-10-01

One hundred three isolates of Carnobacterium spp. from raw meat were analyzed by random amplification of polymorphic DNA (RAPD) and PCR and were identified by 16S rRNA gene sequencing. Forty-five strains of Carnobacterium maltaromaticum were characterized for their growth capabilities at different temperatures, NaCl concentrations, and pH values and for in vitro lipolytic and proteolytic activities. Moreover, their spoilage potential in meat was investigated by analyzing the release of volatile organic compounds (VOCs) in meat stored in air or vacuum packs. Almost all the strains were able to grow at 4, 10, and 20°C, at pH values of 6 to 9, and in the presence of 2.5% NaCl. The release of VOCs by each strain in beef stored at 4°C in air and vacuum packs was evaluated by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) analysis. All the meat samples inoculated and stored in air showed higher numbers of VOCs than the vacuum-packed meat samples. Acetoin, 1-octen-3-ol, and butanoic acid were the compounds most frequently found under both storage conditions. The contaminated meat samples were evaluated by a sensory panel; the results indicated that for all sensory odors, no effect of strain was significant (P > 0.05). The storage conditions significantly affected (P meat, and mozzarella cheese odors, which were more intense in meat stored in air than in vacuum packs but were never very intense. In conclusion, different strains of C. maltaromaticum can grow efficiently in meat stored at low temperatures both in air and in vacuum packs, producing volatile molecules with low sensory impacts, with a negligible contribution to meat spoilage overall.

Isolation and characterization of Arctic microorganisms decomposing bioplastics.

Science.gov (United States)

Urbanek, Aneta K; Rymowicz, Waldemar; Strzelecki, Mateusz C; Kociuba, Waldemar; Franczak, Łukasz; Mirończuk, Aleksandra M

2017-12-01

The increasing amount of plastic waste causes significant environmental pollution. In this study, screening of Arctic microorganisms which are able to degrade bioplastics was performed. In total, 313 microorganisms were isolated from 52 soil samples from the Arctic region (Spitsbergen). Among the isolated microorganisms, 121 (38.66%) showed biodegradation activity. The ability of clear zone formation on emulsified poly(butylene succinate-co-adipate) (PBSA) was observed for 116 microorganisms (95.87%), on poly(butylene succinate) (PBS) for 73 microorganisms (60.33%), and on poly(ɛ-caprolactone) (PCL) for 102 microorganisms (84.3%). Moreover, the growth of microorganisms on poly(lactic acid) (PLA) agar plates was observed for 56 microorganisms (46.28%). Based on the 16S rRNA sequence, 10 bacterial strains which showed the highest ability for biodegradation were identified as species belonging to Pseudomonas sp. and Rhodococcus sp. The isolated fungal strains were tested for polycaprolactone films and commercial corn and potato starch bags degradation under laboratory conditions. Strains 16G (based on the analysis of a partial 18S rRNA sequence, identified as Clonostachys rosea) and 16H (identified as Trichoderma sp.) showed the highest capability for biodegradation. A particularly high capability for biodegradation was observed for the strain Clonostachys rosea, which showed 100% degradation of starch films and 52.91% degradation of PCL films in a 30-day shake flask experiment. The main advantage of the microorganisms isolated from Arctic environment is the ability to grow at low temperature and efficient biodegradation under this condition. The data suggest that C. rosea can be used in natural and laboratory conditions for degradations of bioplastics.

Anti-microorganism contamination measures for crude drugs utilizing radiation sterilization

International Nuclear Information System (INIS)

Kimura, Syojiro

1998-01-01

Crude drugs are manufactured by simple processing of natural mineral, animal or plant part materials, and are used in Chinese medicine. Because these components are originated by nature, they tend to have a much higher level of contaminating microorganisms than chemically synthesized compound. Many plant-derived crude drugs contain bacteria; 10 3 -10 5 cells/g and fungi; 10 2 -10 4 spores/g. Some animal-derived crude drugs contain bacteria levels of up to 10 8 cells/g, including dangerous varieties like E. coli or Salmonella. The survival rate and the required dose can be quantified as follows: N/No=e -kD and SD=D 10 x log (No/SAL), respectively. Where, k is the sterilization constant of microorganism, No is the initial count of bacteria, D is the absorbed dose, D 10 is the dose required to decrease the count to 1/10 and SAL is the count limit or sterilization assurance. The D 10 value for general microorganism is approximately 2 kGy for bacteria, 1 kGy for fungi, and 3-4 kGy for spore-forming bacteria. The results of our past studies have shown that the dose of 5-7 kGy is necessary to sterilize general microorganism that are attached to crude drugs. Besides, the D 10 value of specific bacteria ranges from 0.1 to 0.8 kGy, so the above dose should be sufficient for sterilizing the specific microorganism (SAL; 10 -6 ). The stability of crude drugs can be quantified be the following formula, C/Co=e -k'D . Where, C/Co is the residual rate of drug components, and k' is the loss coefficient. The value of k is 1-2, but that of k' is three to four figures smaller. The C/Co ratio of most drug components is more than 0.99 with a dose of 5-7 kGy. Furthermore, radiolysis materials that are decomposed by radiation are similar to compounds that are decomposed by ultraviolet rays or sunlight. 60 Co ray are suitable for sterilizing raw materials. On the other hand, electron beams are used to sterilize a thin layer of pulverized specimens, and can be incorporated into the

Functional microorganisms for functional food quality.

Science.gov (United States)

Gobbetti, M; Cagno, R Di; De Angelis, M

2010-09-01

Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.

Evaluation of five essential oils from aromatic plants of Cameroon for controlling food spoilage and mycotoxin producing fungi.

Science.gov (United States)

Nguefack, J; Leth, V; Amvam Zollo, P H; Mathur, S B

2004-08-01

Five essential oils (EO) extracted from Cymbopogon citratus, Monodora myristica, Ocimum gratissimum, Thymus vulgaris and Zingiber officinale were investigated for their inhibitory effect against three food spoilage and mycotoxin producing fungi, Fusarium moniliforme, Aspergillus flavus and Aspergillus fumigatus. Five strains of each fungus were tested. The agar dilution technique was used to determine the inhibitory effect of each EO on the radial growth of the fungus, and a dose response was recorded. The EO from O. gratissimum, T. vulgaris and C. citratus were the most effective and prevented conidial germination and the growth of all three fungi on corn meal agar at 800, 1000 and 1200 ppm, respectively. Moderate activity was observed for the EO from Z. officinale between 800 and 2500 ppm, while the EO from M. myristica was less inhibitory. These effects against food spoilage and mycotoxin producing fungi indicated the possible ability of each essential oil as a food preservative. A comparative test on the preservative ability of the EO from O. gratissimum and potassium sorbate against A. flavus at pH 3.0 and 4.5 showed that the EO remained stable at both pH, whereas the efficacy of potassium sorbate was reduced at higher pH. We concluded that the EO from O. gratissimum is a potential food preservative with a pH dependent superiority against potassium sorbate, and these are novel scientific information.

Isolation of microorganisms involved in reduction of crystalline iron(III) oxides in natural environments.

Science.gov (United States)

Hori, Tomoyuki; Aoyagi, Tomo; Itoh, Hideomi; Narihiro, Takashi; Oikawa, Azusa; Suzuki, Kiyofumi; Ogata, Atsushi; Friedrich, Michael W; Conrad, Ralf; Kamagata, Yoichi

2015-01-01

Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing microorganisms in soils and sediments. Firstly, iron reducers were enriched and other untargeted eutrophs were depleted by 2-years successive culture on a crystalline ferric iron oxide (i.e., goethite, lepidocrocite, hematite, or magnetite) as electron acceptor. Fifty-eight out of 136 incubation conditions allowed the continued existence of microorganisms as confirmed by PCR amplification. High-throughput Illumina sequencing and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures on each of the ferric iron oxides contained bacteria belonging to the Deltaproteobacteria (mainly Geobacteraceae), followed by Firmicutes and Chloroflexi, which also comprised most of the operational taxonomic units (OTUs) identified. Venn diagrams indicated that the core OTUs enriched with all of the iron oxides were dominant in the Geobacteraceae while each type of iron oxides supplemented selectively enriched specific OTUs in the other phylogenetic groups. Secondly, 38 enrichment cultures including novel microorganisms were transferred to soluble-iron(III) containing media in order to stimulate the proliferation of the enriched iron reducers. Through extinction dilution-culture and single colony isolation, six strains within the Deltaproteobacteria were finally obtained; five strains belonged to the genus Geobacter and one strain to Pelobacter. The 16S rRNA genes of these isolates were 94.8-98.1% identical in sequence to cultured relatives. All the isolates were able to grow on acetate and ferric iron but their physiological characteristics differed considerably in

[Characteristics of proteins synthesized by hydrogen-oxidizing microorganisms].

Science.gov (United States)

Volova, T G; Barashkov, V A

2010-01-01

The study was conducted to determine the biological value of proteins synthesized by hydrogen-oxidizing microorganisms--the hydrogen bacteria Alcaligenes eutrophus Z1 and Ralstonia eutropha B5786 and the CO-resistant strain of carboxydobacterium Seliberia carboxydohydrogena Z1062. Based on a number of significant parameters characterizing the biological value of a product, the proteins of hydrogen-oxidizing microorganisms have been found to occupy an intermediate position between traditional animal and plant proteins. The high total protein in biomass of these microorganisms, their complete amino acid content, and availability to proteolytic enzymes allow for us to consider these microorganisms as potential protein producers.

Mechanisms of nickel toxicity in microorganisms

Science.gov (United States)

Macomber, Lee

2014-01-01

Summary Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological concern. To date, the mechanisms of nickel toxicity in microorganisms and higher eukaryotes are poorly understood. In this review, we summarize nickel homeostasis processes used by microorganisms and highlight in vivo and in vitro effects of exposure to elevated concentrations of nickel. On the basis of this evidence we propose four mechanisms of nickel toxicity: 1) nickel replaces the essential metal of metalloproteins, 2) nickel binds to catalytic residues of non-metalloenzymes; 3) nickel binds outside the catalytic site of an enzyme to inhibit allosterically, and 4) nickel indirectly causes oxidative stress. PMID:21799955

Irradiation of meats and poultry

International Nuclear Information System (INIS)

Urbain, W.M.

1978-01-01

A number of beneficial effects can be achieved by irradiating meats and poultry under different conditions. It is possible, for example, to extend the market life of both fresh and processed meats by applying radiation doses sufficient to reduce the microbial population, thereby delaying onset of spoilage; higher doses aimed at destroying both spoilage and pathogenic microorganisms can also be applied to meats, packaged to prevent recontamination, resulting in a shelf-stable product; the objective may also be to inactivate pathogenic bacteria, parasites and viruses in order to obtain a product which is acceptable from the point of view of public health. (orig.) [de

Effects of packaging and irradiation on cut vegetables

International Nuclear Information System (INIS)

Langerak, D.I.

1980-01-01

A disadvantage of packaging cut vegetables is that it accelerates microbial spoilage in the product, resulting in an unfavourable gas composition (too low O 2 content) in the packaging, which promotes fermentation. For this reason perforations in the packaging material are necessary in practise to increase the O 2 content in the packaging by which the favourable effect on the quality is partly lost. Application of ionizing rays offers, however, the possibility of using a packaging without perforations, because radiation inactivates microorganisms, so that spoilage and other undesirable conversions (e.g. Nitrate → Nitrite) are reduced. Optimal maintenance of the quality is achieved by the combination of packaging and irradiation. (orig.)

Specific inhibition of Photobacterium phosphoreum extends the shelf life of modified-atmosphere-packed cod fillets

DEFF Research Database (Denmark)

Dalgaard, Paw; Munoz, L.G.; Mejlholm, Ole

1998-01-01

rather than the development of a new product. In naturally contaminated modified-atmosphere-packed cod fillets, 500 ppm Na(2)CaEDTA reduced the growth rate of P. phosphoreum by 40% and shelf life was increased proportionally by 40%, from 15 to 17 days to 21 to 23 days at 0 degrees C. In aerobically...... stored cod fillets other microorganisms were responsible for spoilage and Na2CaEDTA had no effect on shelf Life. The extension of the shelf life of modified-atmosphere-packed cod therefore was a result of the reduced growth of P. phosphoreum and no other microbial or nonmicrobial spoilage reactions...

Decomposition of diesel oil by various microorganisms

Energy Technology Data Exchange (ETDEWEB)

Suess, A; Netzsch-Lehner, A

1969-01-01

Previous experiments demonstrated the decomposition of diesel oil in different soils. In this experiment the decomposition of /sup 14/C-n-Hexadecane labelled diesel oil by special microorganisms was studied. The results were as follows: (1) In the experimental soils the microorganisms Mycoccus ruber, Mycobacterium luteum and Trichoderma hamatum are responsible for the diesel oil decomposition. (2) By adding microorganisms to the soil an increase of the decomposition rate was found only in the beginning of the experiments. (3) Maximum decomposition of diesel oil was reached 2-3 weeks after incubation.

Antimicrobial Compounds from Marine Invertebrates-Derived Microorganisms.

Science.gov (United States)

Liu, Juan; Jung, Jee H; Liu, Yonghong

2016-01-01

It is known that marine invertebrates, including sponges, tunicates, cnidaria or mollusks, host affluent and various communities of symbiotic microorganisms. The microorganisms associated with the invertebrates metabolized various biologically active compounds, which could be an important resource for the discovery and development of potentially novel drugs. In this review, the new compounds with antimicrobial activity isolated from marine invertebrate-derived microorganisms in the last decade (2004-2014) will be presented, with focus on the relevant antimicrobial activities, origin of isolation, and information of strain species. New compounds without antimicrobial activity were not revealed.

Transformation of the insecticide teflubenzuron by microorganisms

NARCIS (Netherlands)

Finkelstein, Z.I.; Baskunov, B.P.; Rietjens, I.M.C.M.; Boersma, M.G.; Vervoort, J.; Golovleva, L.A.

2001-01-01

Transformation of teflubenzuron, the active component in the insecticide commercialized as Nomolt, by soil microorganisms was studied. It was shown that microorganisms, belonging to Bacillus, Alcaligenes, Pseudomonas and Acinetobacter genera are capable to perform the hydrolytic cleavage of the

Inactivation of the Radiation-Resistant Spoilage Bacterium Micrococcus radiodurans

Science.gov (United States)

Duggan, D. E.; Anderson, A. W.; Elliker, P. R.

1963-01-01

A simplified technique permitting the pipetting of raw puréed meats for quantitative bacteriological study is described for use in determining survival of these non-sporing bacteria, which are exceptionally resistant to radiation. Survival curves, using gamma radiation as the sterilizing agent, were determined in raw beef with four strains of Micrococcus radiodurans. Survival curves of the R1 strain in other meat substrates showed that survival was significantly greater in raw beef and raw chicken than in raw fish or in cooked beef. Resistance was lowest in the buffer. Cells grown in broth (an artificial growth medium) and resuspended in beef did not differ in resistance from cells that had been grown and irradiated in beef. Survival rate was statistically independent of the initial cell concentration, even though there appeared to be a correlation between lower death rate and lower initial cell concentrations. The initial viable count of this culture of the domesticated R1 strain in beef was reduced by a factor of about 10-5 by 3.0 megarad, and 4.0 megarad reduced the initial count by a factor of more than 10-9. Data suggest that M. radiodurans R1 is more resistant to radiation than spore-forming spoilage bacteria for which inactivation rates have been published. PMID:14063780

Fate of indicator microorganisms under nutrient management plan conditions.

Science.gov (United States)

Bradford, Scott A; Segal, Eran

2009-01-01

Nutrient management plans (NMPs) for application of wastewater from concentrated animal feeding operations are designed to meet crop water and nutrient requirements, but implicitly assume that pathogenic microorganisms in the wastewater will be retained and die-off in the root zone. A NMP was implemented on a field plot to test this assumption by monitoring the fate of several fecal indicator microorganisms (Enterococcus, fecal coliforms, somatic coliphage, and total Escherichia coli). When well-water and wastewater were applied to meet measured evapotranspiration (ET), little advective transport of the indicator microorganisms occurred below the root zone and the remaining microorganisms rapidly died-off (within 1 mo). Additional experiments were conducted in the laboratory to better quantify microorganism transport and survival in the field soil. Batch survival experiments revealed much more rapid die-off rates for the bacterial indicator microorganisms in native than in sterilized soil, suggesting that biotic factors controlled survival. Saturated column experiments with packed field soil, demonstrated much greater transport potential for somatic coliphage than bacterial indicators (Enterococcus and total E. coli) and that the retention rates for the indicator microorganisms were not log-linear with depth. A worst case transport scenario of ponded infiltration on a large undistributed soil column from the field was also initiated and indicator microorganisms were not detected in the column outflow or in the soil at a depth of 65 cm. All of these observations support the hypothesis that a NMP at this site will protect groundwater supplies from microorganism contamination, especially when applied water and wastewater meet ET.

Toxigenic genes, spoilage potential, and antimicrobial resistance of Bacillus cereus group strains from ice cream.

Science.gov (United States)

Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa

2014-02-01

Bacillus spp. can be recovered from almost every environment. It is also found readily in foods, where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature, and extracellular enzymes. In this study, 29 Bacillus cereus group strains from ice cream were examined for the presence of following virulence genes hblC, nheA, cytK and ces genes, and tested for a range of the extracellular enzymes, and antimicrobial susceptibility. The strains were found to produce extracellular enzymes: proteolytic and lipolytic activity, gelatin hydrolysis and lecithinase production (100%), DNase production (93.1%) and amylase activity (93.1%). Of 29 strains examined, 24 (82.8%) showed hemolytic activity on blood agar. Beta-lactamase enzyme was only produced by 20.7% of B. cereus group. Among 29 B. cereus group from ice cream, nheA was the most common virulence gene detected in 44.8% of the strains, followed by hblC gene with 17.2%. Four (13.8%) of the 29 strains were positive for both hblC gene and nheA gene. Contrarily, cytK and ces genes were not detected in any of the strains. Antimicrobial susceptibility of ice cream isolates was tested to 14 different antimicrobial agents using the disc diffusion method. We detected resistance to penicillin and ampicillin with the same rate of 89.7%. Thirty-one percent of the strains were multiresistant to three or more antibiotics. This study emphasizes that the presence of natural isolates of Bacillus spp. harboring one or more enterotoxin genes, producing extracellular enzymes which may cause spoilage and acquiring antibiotic resistance might hold crucial importance in the food safety and quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

Directory of Open Access Journals (Sweden)

Fernando Rodrigues

Full Text Available Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2, C(3 and C(4. The incorporation of [U-(14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

Electron microscopy study of antioxidant interaction with bacterial cells

Science.gov (United States)

Plotnikov, Oleg P.; Novikova, Olga V.; Konnov, Nikolai P.; Korsukov, Vladimir N.; Gunkin, Ivan F.; Volkov, Uryi P.

2000-10-01

To maintain native microorganisms genotype and phenotype features a lyophylization technique is widely used. However in this case cells are affected by influences of vacuum and low temperature that cause a part of the cells population to be destruction. Another factor reduced microorganisms vitality is formation of reactive oxygen forms that damage certain biological targets (such as DNA, membranes etc.) Recently to raise microorganism's resistance against adverse condition natural and synthetic antioxidants are used. Antioxidant- are antagonists of free radicals. Introduction of antioxidants in protective medium for lyophylization increase bacteria storage life about 2,0-4,8 fold in comparison with reference samples. In the article the main results of our investigation of antioxidants interaction with microorganism cells is described. As bacteria cells we use vaccine strain yersinia pestis EV, that were grown for 48 h at 28 degree(s)C on the Hottinger agar (pH 7,2). Antioxidants are inserted on the agar surface in specimen under test. To investigate a localization of antioxidants for electron microscopy investigation, thallium organic antioxidants were used. The thallium organic compounds have an antioxidant features if thallium is in low concentration (about 1(mu) g/ml). The localization of the thallium organic antioxidants on bacteria Y. pestis EV is visible in electron microscopy images, thallium being heavy metal with high electron density. The negatively stained bacteria and bacteria thin sections with thallium organic compounds were investigated by means of transmission electron microscopy. The localization of the thallium organic compounds is clearly visible in electron micrographs as small dark spots with size about 10-80nm. Probably mechanisms of interaction of antioxidants with bacteria cells are discussed.

Modelling and application of the inactivation of microorganism

International Nuclear Information System (INIS)

Oğuzhan, P.; Yangılar, F.

2013-01-01

Prevention of consuming contaminated food with toxic microorganisms causing infections and consideration of food protection and new microbial inactivation methods are obligatory situations. Food microbiology is mainly related with unwanted microorganisms spoiling foods during processing and transporting stages and causing diseases. Determination of pathogen microorganisms is important for human health to define and prevent dangers and elongate shelf life. Inactivation of pathogen microorganisms can provide food security and reduce nutrient losses. Microbial inactivation which is using methods of food protection such as food safety and fresh. With this aim, various methods are used such as classical thermal processes (pasteurisation, sterilisation), pressured electrical field (PEF), ionised radiation, high pressure, ultrasonic waves and plasma sterilisation. Microbial inactivation modelling is a secure and effective method in food production. A new microbiological application can give useful results for risk assessment in food, inactivation of microorganisms and improvement of shelf life. Application and control methods should be developed and supported by scientific research and industrial applications

Artifical Microorganism Infection in Aviation Kerosene

Directory of Open Access Journals (Sweden)

Dušan Vallo

2004-12-01

Full Text Available The fuel used in the aviation engineering has to be clean and dry, it may not contain mechanical impurities and water. Water inaviation kerosene may occur in soluble and insoluble form. The danger inheres in the insoluble form, which may drop out in the crystallineform and cause various failures, such as those caused by mechanical impurities. The water assists in the biological matter formation createdby various species of microorganisms (bacteria, mould fungi and yeast. The microorganisms, present in water phase occurring on thebottom of tanks or on the interface water phase – kerosene, grow and reproduce and subsequently may pollute (impair the fuel by thebiomass or by the products of their metabolism. There is a possibility to infect the fuel artificially by a selected reference microorganismstrain, which usually occur in contaminated fuel, or by microorganisms which cause a biological contamination of aviation kerosene.Out of the selected reference strains used in the experiments, the reference strains of Proteus vulgaris, Sacharamyces cerevisiae andClostridium perfringens were not cultivated in the sterile aviation kerosene and the propagating nutrient medium. The aviation kerosene actsas a biocide medium for the presented reference microorganism strains.

Control of Native Spoilage Yeast on Dealcoholized Red Wine by Preservatives Alone and in Binary Mixtures.

Science.gov (United States)

Sánchez-Rubio, Marta; Guerrouj, Kamal; Taboada-Rodríguez, Amaury; López-Gómez, Antonio; Marín-Iniesta, Fulgencio

2017-09-01

In order to preserve a commercial dealcoholized red wine (DRW), a study with 4 preservatives and binary mixtures of them were performed against 2 native spoilage yeasts: Rhodotorula mucilaginosa and Saccharomyces cerevisiae. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) for potassium sorbate, sodium benzoate, sodium metabisulfite and dimethyl dicarbonate (DMDC) were evaluated in DRW stored at 25 °C. MICs of potassium sorbate and sodium metabisulfite were 250 and 60 mg/kg, respectively for both target strains. However for sodium benzoate, differences between yeasts were found; R. mucilaginosa was inhibited at 125 mg/kg, while S. cerevisiae at 250 mg/kg. Regarding MFC, differences between strains were only found for sodium metabisulfite obtaining a MFC of 500 mg/kg for R. mucilaginosa and a MFC of 250 mg/kg for S. cerevisiae. Potassium sorbate and sodium benzoate showed the MFC at 1000 mg/kg and DMDC at 200 mg/kg. Regarding the effect of binary mixtures the Fractional Fungicidal Concentration Index (FFC i ) methodology showed that binary mixtures of 100 mg/kg DMDC/200 mg/kg potassium sorbate (FFC i = 0.7) and 50 mg/kg DMDC / 400 mg/kg sodium benzoate (FFC i = 0.65) have both synergistic effect against the 2 target strains. These binary mixtures can control the growth of spoilage yeasts in DRW without metabisulfite addition. The results of this work may be important in preserving the health of DRW consumers by eliminating the use of metabisulfite and reducing the risk of growth of R. mucilagosa, recently recognized as an emerging pathogen. © 2017 Institute of Food Technologists®.

Synthesis of ZnWO{sub 4} Electrode with tailored facets: Deactivating the Microorganisms through Photoelectrocatalytic methods

Energy Technology Data Exchange (ETDEWEB)

Zhan, Su [Department of Materials Science and Engineering, Dalian Maritime University, Dalian 116026 (China); Zhou, Feng, E-mail: zhoufeng99@mails.tsinghua.edu.cn [Department of Materials Science and Engineering, Dalian Maritime University, Dalian 116026 (China); Huang, Naibao; Liu, Yujun; He, Qiuchen; Tian, Yu; Yang, Yifan [Department of Materials Science and Engineering, Dalian Maritime University, Dalian 116026 (China); Ye, Fei [Department of Materials Science and Engineering, Dalian University of Technology, Dalian 116026 (China)

2017-01-01

Highlights: • ZnWO{sub 4} with different exposed facets was synthesized by the hydrothermal method. • The reactive facets were tailored by varying the solution pH. • The photoelectrocatalysis was more efficient in deactivating the microorganism. - Abstract: The exotic invasive species from the ballast water in the ship will bring about serious damages to ecosystem. Photocatalyst films have been widely studied for sterilization. In this study, ZnWO{sub 4} with different exposed facets was synthesized by hydrothermal method, and ZnWO{sub 4} film electrodes have been applied in ballast water treatment through the electro-assisted photocatalytic system. Then the samples were investigated by X-ray diffraction (XRD), X-ray photo-electron spectroscopy (XPS), Field emission on scanning electron microcopy (FE-SEM), Transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS), BET specific surface area analysis, Fourier transform infrared (FT-IR) and Electrochemical impedance spectra (EIS). ZnWO{sub 4} with an appropriate exposure of (0 1 1) facets ratio exhibited the best photocatalytic and photoelectrocatalytic activities. The microorganisms deactivated completely in 10 min by ZnWO{sub 4} films with 3 V bias. The mechanisms of (0 1 1) facets enhanced the photocatalytic and photoelectrocatalytic activities which were deduced based on the calculated result from the first principles. Simultaneously, appropriate exposed facets and applied bias could reduce the recombination of the photogenerated electron-hole pairs, and improve the photocatalytic activities of ZnWO{sub 4}.

Metal-microorganism interactions

International Nuclear Information System (INIS)

Andres, Y.; Thouand, G.; Redercher, S.; Boualam, M.; Texier, A.Cl.; Hoeffer, R.

1997-01-01

The physico-chemical procedures of treating the metalliferous effluents are not always adapted to de polluting the slightly concentrated industrial wastes. An alternative idea was advanced, implying the ability of some microorganisms to fix in considerable amounts the metal ions present in aqueous solutions, possibly in a selective way. This approach has been investigated thoroughly during the last 30 years, particularly from a mechanistic point of view. The advantage of the microorganisms lies mainly in the large diversity of bacteria and in their chemical state dependent interaction with metals, as well as, in the possibilities of developing their selective and quantitative separation properties. A biomass from Mycobacterium smegmatis, an acidic alcoholic resistant bacteria, has been used to prepare a bio-sorption support allowing the preferential sorption of thorium as compared to uranium and lanthanum. These studies have been extended to biological polymers such as chitosan and to studies related to bioaccumulation mechanisms and/or to the microbial resistances towards metals

Esterase screening using whole cells of Brazilian soil microorganisms

Energy Technology Data Exchange (ETDEWEB)

Mantovani, Simone M.; Oliveira, Luciana G. de; Marsaioli, Anita J., E-mail: anita@iqm.unicamp.b [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

2010-07-01

A miniaturized enzymatic assay using fluorescent probes to reveal esterase producing microorganisms was optimized and applied to screen 64 soil bacterial strains. The best results were validated using traditional non-fluorogenic assays with acetyl and propanoyl phenylethanol to confirm the miniaturized results. The most active microorganisms belong to the genus Bacillus showing esterase activity and good enantiomeric ratios for the resolution of phenylethanol derivatives (E > 30). Part of the microorganisms are kept in our laboratory in glycerol or freezedried and the best microorganisms will be deposited in the CBMAI/CPQBA/UNICAMP culture collection. (author)

Pathogenic and opportunistic microorganisms in caves

Directory of Open Access Journals (Sweden)

Sanchez-Moral Sergio

2010-01-01

Full Text Available With today’s leisure tourism, the frequency of visits to many caves makes it necessary to know about possible potentially pathogenic microorganisms in caves, determine their reservoirs, and inform the public about the consequences of such visits. Our data reveal that caves could be a potential danger to visitors because of the presence of opportunistic microorganisms, whose existence and possible development in humans is currently unknown.

PROBIOTICS BASED ON TRANSGENIC MICROORGANISMS

Directory of Open Access Journals (Sweden)

S. А. Starovoitova

2012-02-01

Full Text Available Modern tendencies of recombinant microorganisms creation for obtaining on their basis a new effective biopreparations (probiotics with wider spectrum of biological and therapeutic properties were considered. A lot of attention was focused on the main genera of perspective bacteria for creation of recombinant probiotics particularly: Lactococcus, Bifidobac terium,Bacillus, Escherichia. The main created Ukrainian and foreign gene-modified strains, that are widely used today in creation of effective recombinant biopreparations were characterized. Some fundamental directions and methods of gene-modified strains obtaining, which are used in getting effective biopreparations that used for therapy and prophylactic illness were reported, under which this group of pharmaceutical drugs were not used earlier. The safety matters of probiotics using on basis of genemodified strains were examined. Medical and veterinary biopreparations on basis of recombinant microorganisms could be used directly and effectively for therapy and prophylaxis of different illness, beginning from disbacteriosis up to cardiovascular diseases. It is related with some probiotic microorganisms ability for lowering of serum cholesterol at the host organism.

Secondary metabolites from marine microorganisms.

Science.gov (United States)

Kelecom, Alphonse

2002-03-01

After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

Secondary metabolites from marine microorganisms

Directory of Open Access Journals (Sweden)

KELECOM ALPHONSE

2002-01-01

Full Text Available After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

Microorganisms as sources of oils

Directory of Open Access Journals (Sweden)

Thevenieau France

2013-11-01

Full Text Available A number of microorganism belonging to the genera of yeast, fungi, bacteria and microalgae have ability to accumulate substantial amounts of oil, sometimes up to an even in excess of 70% of their biomass weight under specific cultivation conditions. For nearly 100 years, the commercial opportunities of using microorganisms as sources of oils have been continuously examined. Although it was evident that microbial oils could never compete commercially with the major commodity plant oils, there were commercially opportunities for the production of some of the higher valued oils. Today, with the great progress of metabolic and genetic engineering, the developments are focus on the high value oils containing important polyunsaturated or specific fatty acids. Such oils have the potential to be used in different applications area as food, feed and oleochemistry. This review is covering the related researches about different oleaginous microorganisms for lipids production and microbial oils biosynthesis process. In add, the lipid metabolism, metabolic engineering strategies to increase lipid production and the economics of microbial oils production are introduced.

Attachment of Asaia bogorensis Originating in Fruit-Flavored Water to Packaging Materials

Directory of Open Access Journals (Sweden)

Dorota Kregiel

2014-01-01

Full Text Available The objective of this study was to investigate the adhesion of isolated spoilage bacteria to packaging materials used in the food industry. Microorganisms were isolated from commercial fruit-flavored mineral water in plastic bottles with flocks as a visual defect. The Gram-negative rods were identified using the molecular method through the amplification of a partial region of the 16S rRNA gene. Based on the sequence identity (99.6% between the spoilage organism and a reference strain deposited in GenBank, the spoilage isolate was identified as Asaia bgorensis. Experiments on bacterial adhesion were conducted using plates made of glass and polystyrene (packaging materials commonly used in the beverage industry. Cell adhesion ability was determined using luminometry, plate count, and the microscopic method. The strain of A. bogorensis was characterized by strong adhesion properties which were dependent on the surface type, with the highest cell adhesion detected on polystyrene.

Attachment of Asaia bogorensis Originating in Fruit-Flavored Water to Packaging Materials

Science.gov (United States)

Otlewska, Anna; Antolak, Hubert

2014-01-01

The objective of this study was to investigate the adhesion of isolated spoilage bacteria to packaging materials used in the food industry. Microorganisms were isolated from commercial fruit-flavored mineral water in plastic bottles with flocks as a visual defect. The Gram-negative rods were identified using the molecular method through the amplification of a partial region of the 16S rRNA gene. Based on the sequence identity (99.6%) between the spoilage organism and a reference strain deposited in GenBank, the spoilage isolate was identified as Asaia bgorensis. Experiments on bacterial adhesion were conducted using plates made of glass and polystyrene (packaging materials commonly used in the beverage industry). Cell adhesion ability was determined using luminometry, plate count, and the microscopic method. The strain of A. bogorensis was characterized by strong adhesion properties which were dependent on the surface type, with the highest cell adhesion detected on polystyrene. PMID:25295262

Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications.

Science.gov (United States)

Gudiña, Eduardo J; Teixeira, José A; Rodrigues, Lígia R

2016-02-18

Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.

Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications

Directory of Open Access Journals (Sweden)

Eduardo J. Gudiña

2016-02-01

Full Text Available Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens, and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.

Microorganisms and methods for producing pyruvate, ethanol, and other compounds

Energy Technology Data Exchange (ETDEWEB)

Reed, Jennifer L.; Zhang, Xiaolin

2017-12-26

Microorganisms comprising modifications for producing pyruvate, ethanol, and other compounds. The microorganisms comprise modifications that reduce or ablate activity of one or more of pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase, phosphate acetyltransferase, acetate kinase, pyruvate oxidase, lactate dehydrogenase, cytochrome terminal oxidase, succinate dehydrogenase, 6-phosphogluconate dehydrogenase, glutamate dehydrogenase, pyruvate formate lyase, pyruvate formate lyase activating enzyme, and isocitrate lyase. The microorganisms optionally comprise modifications that enhance expression or activity of pyruvate decarboxylase and alcohol dehydrogenase. The microorganisms are optionally evolved in defined media to enhance specific production of one or more compounds. Methods of producing compounds with the microorganisms are provided.

Evolution of the Microbiological Profile of Vacuum-Packed Ricotta Salata Cheese During Shelf-Life.

Science.gov (United States)

Casti, Daniele; Scarano, Christian; Pala, Carlo; Cossu, Francesca; Lamon, Sonia; Spanu, Vincenzo; Ibba, Michela; Mocci, Anna Maria; Tedde, Francesco; Nieddu, Gavino; Spanu, Carlo; De Santis, Enrico Pietro Luigi

2016-04-19

Ricotta salata cheese is a salted variety of ricotta traditionally made in Sardinia (Italy) from the whey remaining after the production of Pecorino Romano protected designation of origin or other sheep milk cheeses. Ricotta salata cheese is very critical for the possible growth of pathogenic and spoilage microorganisms. Sporadic cases of listeriosis associated with ricotta salata cheese have been reported over recent years. The objective of the present study was to assess the evolution of spoilage and pathogen microorganism of vacuum-packed ricotta salata cheese during the entire product shelf-life. The durability study was conducted on 18 vacuum-packed ricotta salata cheese samples analysed at the beginning of the shelf-life and after 60 and 90 days of refrigerated storage. Pathogens as Listeria monocytogenes and Bacillus cereus were never detected. During shelf-life total bacterial counts ranged between 7.90±0.64 and 9.19±0.58 CFU g -1 on the rind and between 2.95±0.68 and 4.27±1.10 CFU g -1 in the inner paste, while Enterobacteriaceae ranged between 4.22±0.66 and 5.30±0.73 CFU g -1 on the rind and 3.13±1.80 and 2.80±0.88 CFU g -1 in the inner paste. By considering the technology used, the intrinsic properties and the almost total absence of competing microflora, ricotta salata cheese can support the growth of spoilage and pathogen microorganisms originating from the processing environment. The high level of total bacterial counts and Enterobacteriaceae observed both on the rind and in the inner paste suggests contamination of the product from the processing environment. Therefore, a strict implementation of hygiene during processing is essential in order to reduce the load of environmental contaminants that may grow during refrigerated storage.

System for identification of microorganism and detection of infectious disorder

DEFF Research Database (Denmark)

2013-01-01

Methods for the identification of microorganisms or infectious disorders are disclosed, comprising obtaining a suitable sample from sources such as persons, animals, plants, food, water or soil. The methods also comprise providing tailored nucleic acid substrate(s) designed to react with a type 1...... topoisomerase from one or more microorganism(s) or infectious agent(s), and incubating said substrate with said sample, or extracts or preparations from the sample, so that the substrate is processed by said topoisomerase if said microorganism(s) or infectious agent(s) is present in the sample. Finally......, processed substrates are identified and potentially quantified by one or more of a range of standard molecular biology methods and read-out systems. The identification and potential quantification of microorganisms and infectious agents, including but not limited to Plasmodium falciparum and Mycobacterium...

[DIFFERENTIAL SENSITIVITY OF MICROORGANISMS TO POLYHEXAMETHYLENEGUANIDINE].

Science.gov (United States)

Lysytsya, A V; Mandygra, Y M; Bojko, O P; Romanishyna, O O; Mandygra, M S

2015-01-01

Factors identified that affect the sensitivity of microorganisms to polyhexamethyleneguanidine (PHMG). Salts of PHMG chloride, valerate, maleate, succinate was to use. Test strains of Esherichia coli, Staphylococcus aureus, Bacillus cereus, Leptospira interrogans, Paenibacillus larvae, Mycobacterium bovis, M. avium, M. fortuitum, Aspergillus niger and some strains of viruses are taken as objects of research. We have determined that the cytoplasm membrane phospholipids is main "target" for the polycation molecules of PHMG. A differential sensitivity of the microorganisms to this drug is primarily determined by relative amount of lipids in membrane and their accessibility. Such trends exist: increase the relative contents of anionic lipids and more negative surface electric potential of membrane, and reduction of the sizes fat acid remainder of lipids bring to increase of microorganism sensitivity. Types of anion salt PHMG just have a certain value. Biocide activity of PHMG chloride is more, than its salts with organic acid. Feasibility of combining PHMG with other biocides in the multicomponent disinfectants studied and analyzed. This combination does not lead to a significant increase in the sensitivity of microorganisms tested in most cases. Most species of pathogenic bacteria can be quickly neutralized by aqueous solutions of PHMG in less than 1% concentrations.

Methods for preservation and extension of shelf life.

Science.gov (United States)

Gould, G W

1996-11-01

There is potential for spoilage of all foods at some rate or other following harvest, slaughter or manufacture and spoilage may occur at any of the stages between the acquisition of raw materials and the eventual consumption of a food product. These stages include processing, packaging, distribution, retail display, transport, storage and use by the consumer. They are under varying degrees of control that aim to deliver a satisfactory shelf life, to ensure that the finally-consumed product is of high quality and to ensure that it is safe. Spoilage may be caused by a wide range of reactions including some that are essentially physical, some that are chemical, some enzymic and some microbiological. The various forms of microbiological spoilage are preventable to a large degree by a wide range of preservation techniques, most of which act by preventing or inhibiting microbial growth (e.g., chilling, freezing, drying, curing, conserving, vacuum packing, modified atmosphere packing, acidifying, fermenting and adding preservatives). A smaller number of techniques act by inactivating microorganisms (e.g., pasteurization, sterilization and irradiation). Additional techniques restrict the access of microorganisms to products (e.g., aseptic processing and packaging. A major trend is that new and emerging preservation techniques which are coming into use or are under development include more that act by inactivation (e.g., ultrahigh pressure, electroporation, manothermosonication and addition of bacteriolytic enzymes). A further trend is towards the use of procedures that deliver products that are less heavily preserved, have higher quality, are more natural, freer from additives and nutritionally healthier. Less severe preservation procedures are therefore being developed that make use of preservative factors in combinations to deliver (a) less damage to product quality (hurdle technologies); (b) new methods of heating that are better controlled and therefore deliver milder

Elimination of the risk resulting from pathogenic microorganisms in dried and smoked fish by gamma irradiation

International Nuclear Information System (INIS)

Gonzalez, O.N.

1981-01-01

The usefulness of irradiation in improving the microbiological quality and storage life of agricultural and fishery products was tried in a special study which had the following objectives: to determine the incidence of pathogenic organisms in dried, smoked and steamed fish; to determine the physico-chemical properties of these fish products; to determine the radiation dose necessary to eliminate the said pathogens at various levels of infections under practical conditions prevailing in the Philippines; to determine the organoleptic properties of the irradiated products. Staphylococcus aureus seemed to be the most radiation resistant among the test organisms used. For the purpose of the study the fish products were subjected to a radiation dose of 500 Kr. No significant difference of organoleptic properties at 0.05% level of significance existed between the irradiated and unirradiated counterparts. It was concluded that the use of low dose irradiation could be advantageously applied in combination with salting, drying and smoking and steaming not only to prolong the storage life of the fishery product but to eliminate the risk resulting from Salmonella, E. coli and Staphylococcus aureus pathogens - it appears that radiation could be most promising in smoked and steamed fish products where the low salt and high moisture contents provide less protection relative to dried fish against the growth of these microorganisms. Further the process would destroy much of the spoilage agents like the bacteria, insects, parasites, molds and yeasts which are known to be the main causes of losses in dried and smoked fishery products being experienced in developing countries like the Philippines

Microorganisms of Grape Berries

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Kántor Attila

2017-12-01

Full Text Available Grape surface is an unstable habitat that changes greatly according to the stage of grape ripening. Different bacteria and yeasts can colonise the surface of grape berry and the diversity of microorganisms depends on the stage of ripening, pesticide application and health condition. The aim of this study was to study the microflora of the surface of grape berries. Altogether, 19 grape samples from Slovakia were collected. The spread plate method was applied and a 100 μL inoculum of each dilution (10−2, 10−3 was plated on TSA, MEA, and MRS agar for isolation of microorganisms from grapes. Proteins were extracted from cells by ethanol/formic acid extraction procedure. MALDI-TOF Mass Spectrometry was used for identification of microorganisms. In total, 11 genera of Gram-negative bacteria, 11 of Gram-positive bacteria and nine of yeasts were identified. Among 200 isolates, Gram-negative, Gram-positive bacteria and yeasts represented 11%, 27% and 62% of the total number of isolates studied. The most common genera of isolated yeasts were Hanseniaspora (37%, Metschnikowia (31%, and Rhodotorula (10%. The most frequently isolated among Gram-negative bacteria were Acinetobacter (22%, Pseudomonas (22% and Sphingomonas (13%. The most common genera of Gram-positive bacteria were Bacillus (20%, Lactobacillus (19%, Leuconostoc and Staphylococcus (11%, respectively.

Irradiation of carabao mangoes for decay control

International Nuclear Information System (INIS)

Alabastro, E.F.; Pineda, A.S.; Pangan, A.C.; Valle, M.J. del.

Control of postharvest diseases of carabao mangoes by gamma radiation has been the subject of several local studies, notably that of Herrera and Valencia (1964) and Pablo et al (1971) which showed dose levels of 16.6 Kr. and 60 Kr. respectively, to be effective in extending the market life. The wide range of resorted effective dose levels for mangoes prompted this investigation which aimed to establish the pre-dominant spoilage-causing micro-organisms and the effectivity of irradiation in controlling or delaying the growth of these micro-organisms. (author)

Establishing Drug Resistance in Microorganisms by Mass Spectrometry

Science.gov (United States)

Demirev, Plamen A.; Hagan, Nathan S.; Antoine, Miquel D.; Lin, Jeffrey S.; Feldman, Andrew B.

2013-08-01

A rapid method to determine drug resistance in bacteria based on mass spectrometry is presented. In it, a mass spectrum of an intact microorganism grown in drug-containing stable isotope-labeled media is compared with a mass spectrum of the intact microorganism grown in non-labeled media without the drug present. Drug resistance is determined by predicting characteristic mass shifts of one or more microorganism biomarkers using bioinformatics algorithms. Observing such characteristic mass shifts indicates that the microorganism is viable even in the presence of the drug, thus incorporating the isotopic label into characteristic biomarker molecules. The performance of the method is illustrated on the example of intact E. coli, grown in control (unlabeled) and 13C-labeled media, and analyzed by MALDI TOF MS. Algorithms for data analysis are presented as well.

Effect of gamma-irradiation to prevent the spoilage of 'retainer type Kamaboko'

International Nuclear Information System (INIS)

Ito, Hitoshi; Iizuka, Hiroshi.

1978-01-01

The species of main microorganisms which can grow in retainer-Kamaboko a kind of fish meat jelly products were Bacillus subtilis and B. pumilus at 20 0 C, and B. pumilus, B. megaterium, b. cereus, Pseudomonas and yeasts at 10 0 C. When Kamaboko was stored at 5 0 C, microorganisms capable to grow were the species of Pseudomonas, Brevibacterium, Aeromonas and yeasts. Irradiation of Kamaboko at 300 krad and 450 krad reduced the aforementioned flora to the Bacillus and yeasts, and the storage life of Kamaboko was extended about 2 times at 10 0 C. The growth of Bacillus strains at 10 0 C was suppressed for 3 days or more after destruction to about 95% of the total viable cells by irradiation at 300 krad. The putrefaction in retainer-Kamaboko was brought mainly by Bacillus, which seemed to be originated mainly from starch at a manufacturing process. The number of microorganisms in Potato starch was 200 per gram, and they were consisted mainly of Bacillus. These bacteria in starch could be almost eliminated by means of 500 krad irradiation. (auth.)

Biogenic amine formation and microbial spoilage in chilled garfish ( Belone belone belone ) - effect of modified atmosphere packaging and previous frozen storage

DEFF Research Database (Denmark)

Dalgaard, Paw; Madsen, H.L.; Samieian, N.

2006-01-01

Abstract Aims: To evaluate biogenic amine formation and microbial spoilage in fresh and thawed chilled garfish. Methods and Results: Storage trials were carried out with fresh and thawed garfish fillets at 0 or 5oC in air or in modified atmosphere packaging (MAP: 40% CO2 and 60% N2). During storage...... 1000 ppm of histamine was formed in garfish; thus even when it is chilled this product represents a histamine fish-poisoning risk....

Biotechnological exploitation of Tetrapisispora phaffii killer toxin: heterologous production in Komagataella phaffii (Pichia pastoris).

Science.gov (United States)

Chessa, Rossella; Landolfo, Sara; Ciani, Maurizio; Budroni, Marilena; Zara, Severino; Ustun, Murat; Cakar, Zeynep Petek; Mannazzu, Ilaria

2017-04-01

The use of natural antimicrobials from plants, animals and microorganisms to inhibit the growth of pathogenic and spoilage microorganisms is becoming more frequent. This parallels the increased consumer interest towards consumption of minimally processed food and 'greener' food and beverage additives. Among the natural antimicrobials of microbial origin, the killer toxin produced by the yeast Tetrapisispora phaffii, known as Kpkt, appears to be a promising natural antimicrobial agent. Kpkt is a glycoprotein with β-1,3-glucanase and killer activity, which induces ultrastructural modifications to the cell wall of yeast of the genera Kloeckera/Hanseniaspora and Zygosaccharomyces. Moreover, Kpkt maintains its killer activity in grape must for at least 14 days under winemaking conditions, thus suggesting its use against spoilage yeast in wine making and the sweet beverage industry. Here, the aim was to explore the possibility of high production of Kpkt for biotechnological exploitation. Molecular tools for heterologous production of Kpkt in Komagataella phaffii GS115 were developed, and two recombinant clones that produce up to 23 mg/L recombinant Kpkt (rKpkt) were obtained. Similar to native Kpkt, rKpkt has β-glucanase and killer activities. Moreover, it shows a wider spectrum of action with respect to native Kpkt. This includes effects on Dekkera bruxellensis, a spoilage yeast of interest not only in wine making, but also for the biofuel industry, thus widening the potential applications of this rKpkt.

Spoilage-Related Activity of Carnobacterium maltaromaticum Strains in Air-Stored and Vacuum-Packed Meat ▿ †

Science.gov (United States)

Casaburi, Annalisa; Nasi, Antonella; Ferrocino, Ilario; Di Monaco, Rossella; Mauriello, Gianluigi; Villani, Francesco; Ercolini, Danilo

2011-01-01

One hundred three isolates of Carnobacterium spp. from raw meat were analyzed by random amplification of polymorphic DNA (RAPD) and PCR and were identified by 16S rRNA gene sequencing. Forty-five strains of Carnobacterium maltaromaticum were characterized for their growth capabilities at different temperatures, NaCl concentrations, and pH values and for in vitro lipolytic and proteolytic activities. Moreover, their spoilage potential in meat was investigated by analyzing the release of volatile organic compounds (VOCs) in meat stored in air or vacuum packs. Almost all the strains were able to grow at 4, 10, and 20°C, at pH values of 6 to 9, and in the presence of 2.5% NaCl. The release of VOCs by each strain in beef stored at 4°C in air and vacuum packs was evaluated by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) analysis. All the meat samples inoculated and stored in air showed higher numbers of VOCs than the vacuum-packed meat samples. Acetoin, 1-octen-3-ol, and butanoic acid were the compounds most frequently found under both storage conditions. The contaminated meat samples were evaluated by a sensory panel; the results indicated that for all sensory odors, no effect of strain was significant (P > 0.05). The storage conditions significantly affected (P meat, and mozzarella cheese odors, which were more intense in meat stored in air than in vacuum packs but were never very intense. In conclusion, different strains of C. maltaromaticum can grow efficiently in meat stored at low temperatures both in air and in vacuum packs, producing volatile molecules with low sensory impacts, with a negligible contribution to meat spoilage overall. PMID:21784913

Biodiesel production by various oleaginous microorganisms from organic wastes.

Science.gov (United States)

Cho, Hyun Uk; Park, Jong Moon

2018-05-01

Biodiesel is a biodegradable and renewable fuel. A large amount of research has considered microbial oil production using oleaginous microorganisms, but the commercialization of microbial lipids produced in this way remains uncertain due to the high cost of feedstock or low lipid yield. Microbial lipids can be typically produced by microalgae, yeasts, and bacteria; the lipid yields of these microorganisms can be improved by using sufficient concentrations of organic carbon sources. Therefore, combining low-cost organic compounds contained in organic wastes with cultivation of oleaginous microorganisms can be a promising approach to obtain commercial viability. However, to achieve effective bioconversion of low-cost substrates to microbial lipids, the characteristics of each microorganism and each substrate should be considered simultaneously. This article discusses recent approaches to developing cost-effective microbial lipid production processes that use various oleaginous microorganisms and organic wastes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Glyphosate-Degrading Microorganisms from Industrial Activated Sludge

OpenAIRE

Balthazor, Terry M.; Hallas, Laurence E.

1986-01-01

A plating medium was developed to isolate N-phosphonomethylglycine (glyphosate)-degrading microorganisms, with glyphosate as the sole phosphorus source. Two industrial biosystems treating glyphosate wastes contained elevated microbial counts on the medium. One purified isolate metabolized glyphosate to aminomethylphosphonic acid, mineralizing this accumulating intermediate during log growth. This microorganism has been identified as a Flavobacterium species.

Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

Science.gov (United States)

Sivaperumal, P; Kamala, K; Rajaram, R

Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes. © 2017 Elsevier Inc. All rights reserved.

SELECTION OF MICROORGANISMS FOR FERMENTATION OF MEAT MATERIALS

Directory of Open Access Journals (Sweden)

Danylenko S. G.

2014-08-01

Full Text Available Principal criteria for the selection of microorganisms with a wide range of biological and technological properties for fermentation of raw meats are considered. Attention is paid to the main groups of microorganisms such as Micrococсus, Staphylococcus, Lactobacillus, Bifidobacterium and Propionibacterium which are promising for creation of bacterial preparations. To create bacterial preparations, the basic criteria of selection for microorganisms were determined as follows: the ability of microorganisms to be developed within the specific ecological niche (raw meat materials and their influence on flavor characteristics of the final product under the conditions of intensification of production technologies of meat products. Methods used for search and retrieval of technologically promising strains from different natural sources (fresh meats, minced meats, meat, dairy and sour-milk products, vegetables, fruit, brines and mixtures for salting are considered.

Modified atmosphere packaging for prevention of mold spoilage of bakery products with different pH and water activity levels.

Science.gov (United States)

Guynot, M E; Marín, S; Sanchis, V; Ramos, A J

2003-10-01

A sponge cake analog was used to study the influence of pH, water activity (aw), and carbon dioxide (CO2) levels on the growth of seven fungal species commonly causing bakery product spoilage (Eurotium amstelodami, Eurotium herbariorum, Eurotium repens, Eurotium rubrum, Aspergillus niger, Aspergillus flavus, and Penicillium corylophilum). A full factorial design was used. Water activity, CO2, and their interaction were the main factors significantly affecting fungal growth. Water activity at levels of 0.80 to 0.90 had a significant influence on fungal growth and determined the concentration of CO2 needed to prevent cake analog spoilage. At an aw level of 0.85, lag phases increased twofold when the level of CO2 in the headspace increased from 0 to 70%. In general, no fungal growth was observed for up to 28 days of incubation at 25 degrees C when samples were packaged with 100% CO2, regardless of the aw level. Partial least squares projection to latent structures regression was used to build a polynomial model to predict sponge cake shelf life on the basis of the lag phases of all seven species tested. The model developed explained quite well (R2 = 79%) the growth of almost all species, which responded similarly to changes in tested factors. The results of this study emphasize the importance of combining several hurdles, such as modified atmosphere packaging, aw, and pH, that have synergistic or additive effects on the inhibition of mold growth.

Application of thermotolerant microorganisms for biofertilizer preparation.

Science.gov (United States)

Chen, Kuo-Shu; Lin, Yann-Shying; Yang, Shang-Shyng

2007-12-01

Intensive agriculture is practised in Taiwan, and compost application is very popular as a means of improving the soil physical properties and supplying plant nutrition. We tested the potential of inoculation with thermotolerant microorganisms to shorten the maturity and improve the quality of biofertilizer prepared by composting. Thermotolerant microorganisms were isolated from compost and reinoculated for the preparation of biofertilizer. The physical, chemical and biological properties of the biofertilizer were determined during composting. The effects of biofertilizer application on the growth and yield of rape were also studied. Among 3823 colonies of thermotolerant microorganisms, Streptomyces thermonitrificans NTU-88, Streptococcus sp. NTU-130 and Aspergillus fumigatus NTU-132 exhibited high growth rates and cellulolytic and proteolytic activities. When a mixture of rice straw and swine manure were inoculated with these isolates and composted for 61 days, substrate temperature increased initially and then decreased gradually during composting. Substrate pH increased from 7.3 to 8.5. Microbial inoculation enhanced the rate of maturity, and increased the content of ash and total and immobilized nitrogen, improved the germination rate of alfalfa seed, and decreased the content of total organic carbon and the carbon/nitrogen ratio. Biofertilizer application increased the growth and yield of rape. Inoculation of thermotolerant and thermophilic microorganisms to agricultural waste for biofertilizer preparation enhances the rate of maturity and improves the quality of the resulting biofertilizer. Inoculation of appropriate microorganisms in biofertilizer preparation might be usefully applied to agricultural situations.

Nitrogen acquisition by plants and microorganisms in a temperate grassland.

Science.gov (United States)

Liu, Qianyuan; Qiao, Na; Xu, Xingliang; Xin, Xiaoping; Han, Jessie Yc; Tian, Yuqiang; Ouyang, Hua; Kuzyakov, Yakov

2016-03-10

Nitrogen (N) limitation is common in most terrestrial ecosystems, often leading to strong competition between microorganisms and plants. The mechanisms of niche differentiation to reduce this competition remain unclear. Short-term (15)N experiments with NH4(+), NO3(-), and glycine were conducted in July, August and September in a temperate grassland to evaluate the chemical, spatial and temporal niche differentiation by competition between plants and microorganisms for N. Microorganisms preferred NH4(+) and NO3(-), while plants preferred NO3(-). Both plants and microorganisms acquired more N in August and September than in July. The soil depth had no significant effects on microbial uptake, but significantly affected plant N uptake. Plants acquired 67% of their N from the 0-5 cm soil layer and 33% from the 5-15 cm layer. The amount of N taken up by microorganisms was at least seven times than plants. Although microorganisms efficiently compete for N with plants, the competition is alleviated through chemical partitioning mainly in deeper soil layer. In the upper soil layer, neither chemical nor temporal niche separation is realized leading to strong competition between plants and microorganisms that modifies N dynamics in grasslands.

Influence of temperature on the fixation and penetration of silver during the chalcopyrite leaching using moderate thermophilic microorganisms

International Nuclear Information System (INIS)

Cancho, L.; Blazquez, M. L.; Munoz, J. A.; Gonzalez, F.; Ballester, A.

2004-01-01

Bio leaching of chalcopyrite using mesophilic microorganisms considerable improves in the presence of silver. However, the studies carried out with moderate thermophilic microorganisms do not show a significant improvement with regard to the use of mesophilic bacteria. The main objective of the present work has been to study the silver fixation on chalcopyrite ar 35 and 45 degree centigree and its influence on the microbiological attack. Different observations using SEM, EDS microanalysis and concentration profiles using electron microprobe have been carried out. The study of the different samples showed that silver fixation was more favourable at 35 degree centigree than at 45 degree centigree. In addition, bacterial action improved silver penetration through attack cracks. (Author)

Mechanisms of nickel toxicity in microorganisms

OpenAIRE

Macomber, Lee; Hausinger, Robert P.

2011-01-01

Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological co...

Properties of thermophilic microorganisms

International Nuclear Information System (INIS)

Ljungdahl, L.G.

1984-01-01

Microorganisms are called thermophilic or extreme thermophilic (caldo-active) if they grow and reproduce over 47 0 C and 70 0 C, respectively. A survey of growth characteristics of thermophiles is presented and it includes those which also live at extreme pH. The prevalent but not completely emcompassing theory of the ability of thermophiles to grow at high temperatures is that they have macromolecules and cell organelles with high thermostability. Work on some proteins and cell organelles from thermophiles is reviewed. The thermostabilities of these components are compared with those of the living cells, and factors which may govern optimum as well as minimum growth temperatures of microorganisms are discussed. Examples are from the literature but also include enzymes involved in tetrahydrofolate metabolism and other proteins of acetogenic therhmophilic bacteria which are presently studied in the author's laboratory

the economic importance of microorganism in food processing

African Journals Online (AJOL)

BSN

This paper attempts to highlight the Economic Importance of microorganisms in food processing and manufacturing; it goes further to differentiate between the desirable ... Desirable importance are those cost saving and revenue generating activities ... Microorganism (yeast) play very useful role in the Bakery industries.

Contamination of cell phones by pathogenic microorganisms: Comparison between hospital staff and college students

OpenAIRE

PURNIMA R. CHITLANGE

2014-01-01

Chitlange PR. 2014. Contamination of cell phones by pathogenic microorganisms: Comparison between hospital staff and college students. Nusantara Bioscience 6: 203-206. Cell phone (CP) is a long range portable electronic device. The cell phone is constantly exposed to arrays of micro organisms, making it a harbour and breeding ground for microbes especially those associated with skin. The adult human is covered with approximately 2m2 of skin with area supporting about 106 bacteria. To check wh...

Influence of microorganisms on the alteration of glasses

International Nuclear Information System (INIS)

Besnainou, B.; Libert, M.F.

1997-01-01

Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

[Relationships between air conditioning, airborne microorganisms and health].

Science.gov (United States)

Parat, S; Perdrix, A; Baconnier, P

1999-01-01

Concurrently with the increase of air-conditioning, potentially severe or frequent new diseases have emerged, giving rise to social and economical consequences. The first part of this work is a state of the art review of the relationships between air-conditioning, airborne microorganisms and health, through a technical, metrological and medical approach. The second part presents four studies performed in this field. Two of them deal with the relationship between airborne microorganisms and technical features of air-conditioning. Measurements performed on actual sites demonstrated the benefit of using high efficiency filters and low risk components in air-conditioning systems. The third study was aimed to look for a relationship between airborne microorganisms and sick building syndrome symptoms. Statistical analyses of individual data revealed significant associations between airborne bacteria or fungi and symptoms. These results may be the first step in determining a dose-response relationship, in order to define threshold limit values in this field. In the fourth study, the contribution of particle counting in assessing exposure to airborne microorganisms was explored by monitoring simultaneous variations of microbial and particle concentrations. The results showed that associating particle counting may allow to detect microbial variations instantaneously, and therefore improve the assessment of exposure to airborne microorganisms.

African fermented dairy products - Overview of predominant technologically important microorganisms focusing on African Streptococcus infantarius variants and potential future applications for enhanced food safety and security.

Science.gov (United States)

Jans, Christoph; Meile, Leo; Kaindi, Dasel Wambua Mulwa; Kogi-Makau, Wambui; Lamuka, Peter; Renault, Pierre; Kreikemeyer, Bernd; Lacroix, Christophe; Hattendorf, Jan; Zinsstag, Jakob; Schelling, Esther; Fokou, Gilbert; Bonfoh, Bassirou

2017-06-05

Milk is a major source of nutrients, but can also be a vehicle for zoonotic foodborne diseases, especially when raw milk is consumed. In Africa, poor processing and storage conditions contribute to contamination, outgrowth and transmission of pathogens, which lead to spoilage, reduced food safety and security. Fermentation helps mitigate the impact of poor handling and storage conditions by enhancing shelf life and food safety. Traditionally-fermented sour milk products are culturally accepted and widely distributed in Africa, and rely on product-specific microbiota responsible for aroma, flavor and texture. Knowledge of microbiota and predominant, technologically important microorganisms is critical in developing products with enhanced quality and safety, as well as sustainable interventions for these products, including Africa-specific starter culture development. This narrative review summarizes current knowledge of technologically-important microorganisms of African fermented dairy products (FDP) and raw milk, taking into consideration novel findings and taxonomy when re-analyzing data of 29 publications covering 25 products from 17 African countries. Technologically-important lactic acid bacteria such as Lactococcus lactis and Streptococcus infantarius subsp. infantarius (Sii), Lactobacillus spp. and yeasts predominated in raw milk and FDP across Africa. Re-analysis of data also suggests a much wider distribution of Sii and thus a potentially longer history of use than previously expected. Therefore, evaluating the role and safety of African Sii lineages is important when developing interventions and starter cultures for FDP in Africa to enhance food safety and food security. In-depth functional genomics, epidemiologic investigations and latest identification approaches coupled with stakeholder involvement will be required to evaluate the possibility of African Sii lineages as novel food-grade Streptococcus lineage. Copyright © 2017 The Authors. Published by

Atmospheric Sampling of Microorganisms with UAS

Science.gov (United States)

Schmale, D. G., III

2017-12-01

Many microorganisms relevant to crops, domestic animals, and humans are transported over long distances through the atmosphere. Some of these atmospheric microbes catalyze the freezing of water at higher temperatures and facilitate the onset of precipitation. A few have crossed continents. New technologies are needed to study the movement of microorganisms in the atmosphere. We have used unmanned aircraft systems (UAS) to study the transport of microorganisms tens to hundreds of meters above the ground. These UAS are equipped with unique devices for collecting microbes in the atmosphere during flight. Autonomous systems enable teams of UAS to perform complex atmospheric sampling tasks, and coordinate flight missions with one another. Data collected with UAS can be used to validate and improve disease forecasting models along highways in the sky, connecting transport scales across farms, states, and continents. Though terrestrial environments are often considered a major contributor to atmospheric microbial aerosols, little is known about aquatic sources of microbial aerosols. Droplets containing microorganisms can aerosolize from the water surface, liberating them into the atmosphere. We are using teams of unmanned surface vehicles (USVs) and UAS to study the aerosolization of microbes from aquatic environments. Controlled flume studies using highspeed video have allowed us to observe unique aerosolization phenomena that can launch microbes out of the water and into the air. Unmanned systems may be used to excite the next generation of biologists and engineers, and raise important ethical considerations about the future of human-robot interactions.

Irradiation effect on bulgogi sauce for making commercial Korean traditional meat product, bulgogi[Bulgogi; Traditional meat products; Irradiation; Safety; Quality

Energy Technology Data Exchange (ETDEWEB)

Jo, C.; Kim, D.H.; Shin, M.G.; Kang, I.J.; Byun, M.W. E-mail: mwbyun@kaeri.re.kr

2003-12-01

Gamma-irradiated sauce of bulogogi, Korean traditional meat products, was compared with heat-pasteurized one to enhance its safety, quality, and commercial availability. The sauce is usually sold in refrigerated state with 2-7 days of self-life or heat-sterilized and sold in room temperature for a year. Raw vegetables, fruits and soy sauce for sauce making were highly contaminated by thermophillic microorganisms (totally 2.13x10{sup 6} CFU/g) and coliform bacteria (totally 5.90x10{sup 4} CFU/g) at the initial stage. Heat treatment (100 deg. C for 30 min) was effective to control coliform and microbes counted from Salmonella-Shigella selective agar in the sauce but not on thermophillic microorganisms, resulting in a rapid spoilage after 2 weeks at 20 deg. C. Gamma irradiation reduced the level of thermophillic microorganisms and the spoilage was prevented during storage for 4 weeks at 20 deg. C. Protease activity of the sauce was significantly reduced by heat treatment while was not changed by irradiation at 2.5, 5.0, and 10 kGy. Sensory evaluation showed that the irradiation was better in color than nonirradiated control or heat-treated sample. Results indicate that low dose irradiation (2.5-5.0 kGy) is effective to ensure safety of bulgogi sauce with acceptable sensory quality.

Irradiation effect on bulgogi sauce for making commercial Korean traditional meat product, bulgogi

International Nuclear Information System (INIS)

Jo, C.; Kim, D.H.; Shin, M.G.; Kang, I.J.; Byun, M.W.

2003-01-01

Gamma-irradiated sauce of bulogogi, Korean traditional meat products, was compared with heat-pasteurized one to enhance its safety, quality, and commercial availability. The sauce is usually sold in refrigerated state with 2-7 days of self-life or heat-sterilized and sold in room temperature for a year. Raw vegetables, fruits and soy sauce for sauce making were highly contaminated by thermophillic microorganisms (totally 2.13x10 6 CFU/g) and coliform bacteria (totally 5.90x10 4 CFU/g) at the initial stage. Heat treatment (100 deg. C for 30 min) was effective to control coliform and microbes counted from Salmonella-Shigella selective agar in the sauce but not on thermophillic microorganisms, resulting in a rapid spoilage after 2 weeks at 20 deg. C. Gamma irradiation reduced the level of thermophillic microorganisms and the spoilage was prevented during storage for 4 weeks at 20 deg. C. Protease activity of the sauce was significantly reduced by heat treatment while was not changed by irradiation at 2.5, 5.0, and 10 kGy. Sensory evaluation showed that the irradiation was better in color than nonirradiated control or heat-treated sample. Results indicate that low dose irradiation (2.5-5.0 kGy) is effective to ensure safety of bulgogi sauce with acceptable sensory quality

Effect of kaolin silver complex on the control of populations of Brettanomyces and acetic acid bacteria in wine.

Science.gov (United States)

Izquierdo-Cañas, P M; López-Martín, R; García-Romero, E; González-Arenzana, L; Mínguez-Sanz, S; Chatonnet, P; Palacios-García, A; Puig-Pujol, A

2018-05-01

In this work, the effects of kaolin silver complex (KAgC) have been evaluated to replace the use of SO 2 for the control of spoilage microorganisms in the winemaking process. The results showed that KAgC at a dose of 1 g/L provided effective control against the development of B. bruxellensis and acetic acid bacteria. In wines artificially contaminated with an initial population of B. bruxellensis at 10 4 CFU/mL, a concentration proven to produce off flavors in wine, only residual populations of the contaminating yeast remained after 24 days of contact with the additive. Populations of acetic bacteria inoculated into wine at concentrations of 10 2 and 10 4  CFU/mL were reduced to negligible levels after 72 h of treatment with KAgC. The antimicrobial effect of KAgC against B. bruxellensis and acetic bacteria was also demonstrated in a wine naturally contaminated by these microorganisms, decreasing their population in a similar way to a chitosan treatment. Related to this effect, wines with KAgC showed lower concentrations of acetic acid and 4-ethyl phenol than wines without KAgC. The silver concentration from KAgC that remained in the finished wines was below the legal limits. These results demonstrated the effectiveness of KAgC to reduce spoilage microorganisms in winemaking.

[Ants as carriers of microorganisms in hospital environments].

Science.gov (United States)

Pereira, Rogério Dos Santos; Ueno, Mariko

2008-01-01

Concern exists regarding the real possibility of public health threats caused by pathogenic agents that are carried by urban ants. The present study had the objective of isolating and identifying the microorganisms that are associated with ants in hospital environments. One hundred and twenty-five ants of the same species were collected from different units of a university hospital. Each ant was collected using a swab soaked with physiological solution and was transferred to a tube containing brain heart infusion broth and incubated at 35 degrees C for 24 hours. From each tube, with growth, inoculations were made into specific culturing media, to isolate any microorganisms. The ants presented a high capacity for carrying microorganism groups: spore-producing Gram-positive bacilli 63.5%, Gram-negative bacilli 6.3%, Gram-positive cocci 23.1%, filamentous fungi 6.7% and yeast 0.5%. Thus, it can be inferred that ants may be one of the agents responsible for disseminating microorganisms in hospital environments.

Multiorganismal insects: diversity and function of resident microorganisms.

Science.gov (United States)

Douglas, Angela E

2015-01-07

All insects are colonized by microorganisms on the insect exoskeleton, in the gut and hemocoel, and within insect cells. The insect microbiota is generally different from microorganisms in the external environment, including ingested food. Specifically, certain microbial taxa are favored by the conditions and resources in the insect habitat, by their tolerance of insect immunity, and by specific mechanisms for their transmission. The resident microorganisms can promote insect fitness by contributing to nutrition, especially by providing essential amino acids, B vitamins, and, for fungal partners, sterols. Some microorganisms protect their insect hosts against pathogens, parasitoids, and other parasites by synthesizing specific toxins or modifying the insect immune system. Priorities for future research include elucidation of microbial contributions to detoxification, especially of plant allelochemicals in phytophagous insects, and resistance to pathogens; as well as their role in among-insect communication; and the potential value of manipulation of the microbiota to control insect pests.

Food fermentations: Microorganisms with technological beneficial use

DEFF Research Database (Denmark)

Bourdichon, François; Casaregola, Serge; Farrokh, Choreh

2012-01-01

Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on “the history of use”, “traditional food”, or “general recognition of safety”. Authoritative lists of microorganism......, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature....... cultures in practical use. However, as the focus mainly was on commercially available dairy cultures, there was an unmet need for a list with a wider scope. We present an updated inventory of microorganisms used in food fermentations covering a wide range of food matrices (dairy, meat, fish, vegetables...

PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

Science.gov (United States)

Prevost, S; Andre, S; Remize, F

2010-12-01

Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

Lateral gene exchanges shape the genomes of amoeba-resisting microorganisms

Directory of Open Access Journals (Sweden)

Claire eBertelli

2012-08-01

Full Text Available Based on Darwin’s concept of the tree of life, vertical inheritance was thought to be dominant, and mutations, deletions and duplication were streaming the genomes of living organisms. In the current genomic era, increasing data indicated that both vertical and lateral gene inheritance interact in space and time to trigger genome evolution, particularly among microorganisms sharing a given ecological niche. As a paradigm to their diversity and their survival in a variety of cell types, intracellular microorganisms, and notably intracellular bacteria, were considered as less prone to lateral genetic exchanges. Such specialized microorganisms generally have a smaller gene repertoire because they do rely on their host’s factors for some basic regulatory and metabolic functions. Here we review events of lateral gene transfer (LGT that illustrate the genetic exchanges among intra-amoebal microorganisms or between the microorganism and its amoebal host. We tentatively investigate the functions of laterally transferred genes in the light of the interaction with their host as they should confer a selective advantage and success to the amoeba-resisting microorganisms.

Producing Biosurfactants from Purified Microorganisms Obtained from Oil-contaminated Soil

Directory of Open Access Journals (Sweden)

Nader Mokhtarian

2010-09-01

Full Text Available Contamination of soil by crude oil can pose serious problems to ecosystems. Soil washing by solutions containing biosurfactants is one of the most efficient methods for the remediation of contaminated soil by crude oil because it removes not only the crude oil but also heavy metals. In this study, five soil samples were taken from fields exposed to oil compounds over the years in order to produce biosurfactants from microorganisms that were capable of degrading oil compounds. Sixteen such microorganisms were isolated. After cultivation, their emulsification strength was examined using E24 test. From among the experimental microorganisms, a gram-negative and rod-shape microorganism called A-12 showed the greatest value of the E24 test index (36%. For each liter of the culture medium containing 365 mg of microorganisms, 3 gr of the biosurfactant compound was produced and separated as dried powder. The purified biosurfactant was used in the soil washing process. Also, the insulated microorganisms were capable of degrading crude oil floating on wastewaters.

Study of benzoate, propionate, and sorbate salts as mould spoilage inhibitors on intermediate moisture bakery products of low pH (4.5-5.5).

Science.gov (United States)

Guynot, M E; Ramos, A J; Sanchis, V; Marín, S

2005-05-25

A hurdle technology approach has been applied to control common mold species causing spoilage of intermediate moisture bakery products (Eurotium spp., Aspergillus spp., and Penicillium corylophilum), growing on a fermented bakery product analogue (FBPA). The factors studied included a combination of different levels of weak acid preservatives (potassium sorbate, calcium propionate, and sodium benzoate; 0-0.3%), pH (4.5-5.5), and water activity (a(w); 0.80-0.90). Potassium sorbate was found to be the most effective in preventing fungal spoilage of this kind of products at the maximum concentration tested (0.3%) regardless of a(w). The same concentration of calcium propionate and sodium benzoate was effective only at low a(w) levels. On the other hand, potassium sorbate activity was slightly reduced at pH 5.5, the 0.3% being only effective at 0.80 a(w). These findings indicate that potassium sorbate may be a suitable preserving agent to inhibit deterioration of a FBPA of slightly acidic pH (near 4.5) by xerophilic fungi. Further studies have to be done in order to adjust the minimal inhibitory concentration necessary to obtain a product with the required shelf life.

Long distance electron transmission in marine sediment

DEFF Research Database (Denmark)

Risgaard-Petersen, Nils; Nielsen, Lars Peter

processes leads to formation of electrical fields, which modifies ion transport. The local proton producing and proton consuming half reactions induces pH extremes that accelerate dissolution of iron sul-phides and calcium carbonates in anoxic layers and promotes the formation of Mg-calcite and iron oxides......Geochemical observations in marine sediment have recently shown that electric currents may intimately couple spatially separated biogeochemical processes like oxygen reduction at the sediment surface and hydrogen sul-phide oxidation in anoxic layers centimeters below 1. Further experimental studies...... suggest that the electron conductance is mediated by microorgan-isms. The spatial separation of electron and proton donors and acceptors has major impacts on element cycling by redox processes, pH balances, mineral dissolution/precipitations, and electromigration of ions. The sepa-ration of redox...

Recall costs balanced against spoilage control in Dutch custard.

Science.gov (United States)

Velthuis, A G J; Reij, M W; Baritakis, K; Dang, M; van Wagenberg, C P A

2010-06-01

The relation between the moment at which a recall of Dutch custard is initiated and the direct costs of this recall was investigated. A simulation model of the custard supply chain was developed to compare scenarios with and without a quarantine of 48 h at the storage of the production plant. The model consists of 3 parts: 1) the distribution of a 24,000-L batch of custard over the supply chain over time is simulated; 2) the time to detect spoilage bacteria with a recontamination test procedure is simulated; and 3) the direct recall costs of custard over the different parts of the supply chain are calculated. Direct recall costs increase from about 25,000 euros/batch to 36,171 euros/batch from 57 to 135 h in the situation without quarantine and from 25,000 euros/batch to 36,648 euros/batch from 123 h to 163 h for the situation with quarantine. Then costs decrease because more and more custard is at the consumer level and only 0.13% of the consumers will ask for a refund. With low true contamination probabilities quarantine is not profitable, but at later detection moments with high probabilities it is. We conclude that a simulation model is a helpful tool to evaluate the efficiency of risk management strategies like end product testing and a quarantine situation. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ancient Item Spoilage Ritual Used in Nomadic Burial Rite

Directory of Open Access Journals (Sweden)

Beisenov Arman Z.

2017-07-01

Full Text Available The article considers the findings of items in ancient burials which were intentionally spoiled prior to deposition in graves. This tradition was widely spread both in terms of chronology and geography, and therefore cannot be attributed to any individual cultures or regions. The authors present new information on the ritual obtained during an investigation of Borsyk burial mound of the Middle Sarmatian period located in West Kazakhstan. The central grave of barrow 6 contained a heavily damaged bronze cauldron. The grave was looted in antiquity. Individual scattered bones of a human skeleton and minor gold foil adornments from the ceremonial dress of a nobleman were discovered in the grave. The authors suggest that the cauldron was intentionally deformed by the participants of an ancient mortuary and memorial ritual. According to the principal hypothesis concerning the essence of this ritual, spoilage of the items was related to the idea of assign the items with “different” and “transcendent” properties, which resulted from the necessity of burying the owner. Cauldrons played an important role in the life of steppe leaders. The authors assume a sacral nature of the use of cauldrons in the culture of steppe peoples associated with feasts, battles, and sacred hunting. Perhaps, there was a tradition of burying cauldrons together with their owners after spoiling the items in view of the concept of the other world and the role of a heroic leader therein.

Method to treat a product infested with microorganisms with ionizing radiation and heat

International Nuclear Information System (INIS)

Gruenewald, T.

1977-01-01

The method applies to the reduction of the number of germs in infected products by combined treatment of the microorganisms with ionizing radiation and raised temperatures. In this process, at least part of the energy lost in the irradiation unit (e.g. electron linear accelerator or X-ray unit), which is not converted into ionizing radiation is used to heat the product. The invention can be used in the field of food and animal food treatment, for the sterilisation of medical equipment, or for the pasteurisation of waste water and fertilizers. (VJ) [de

Food irradiation: An update

International Nuclear Information System (INIS)

Morrison, Rosanna M.

1984-01-01

Recent regulatory and commercial activity regarding food irradiation is highlighted. The effects of irradiation, used to kill insects and microorganisms which cause food spoilage, are discussed. Special attention is given to the current regulatory status of food irradiation in the USA; proposed FDA regulation regarding the use of irradiation; pending irradiation legislation in the US Congress; and industrial applications of irradiation

Method and apparatus for detecting micro-organisms

International Nuclear Information System (INIS)

Mirsky, J.

1976-01-01

A method and apparatus is described for determining the presence and quantity of microorganisms, such as bacteria, fungi and yeast, in a given sample. The apparatus includes two sealed containers, a portion of which may be penetrated by a sharp instrument, as for example, glass vials with flexible septum tops. One container includes a radioactive nutrient medium which is capable of supporting the life process of the microorganism whose presence is being tested. The second container includes a liquid scintillation solution which absorbs the product of metabolism of the organisms. The sample is introduced into the first sealed container, for example, by means of a standard syringe. Any microorganisms present will consume the radioactive nutrient and as a result produce radioactive waste. Means are then applied to penetrate the containers and allow the flow of the radioactive metabolic product from the first container to the second container while preventing any contamination from the ambient. The liquid scintillation solution will emit light in proportion to the amount of the product of metabolism collected from the first container. This light may be detected by standard liquid scintillation counters, thus providing a qualitative and quantitative measure of the microorganism in the tested sample

In vitro evaluation of the antimicrobial effect of a raw bacteriocin extract in combination with chemical preservatives employed in meat industry

Directory of Open Access Journals (Sweden)

Luis A. Aguado Bautista

2010-12-01

Full Text Available Biopreservation can be defined as the foods shelf life extension employing antibacterial products like bacteriocins. The objective of this work was to determinate the efficacy of E. faecium MXVK29 bacteriocin in combination with chemical preservatives against spoilage and pathogens microorganisms. Bacteriocin raw extrac antimicrobial activity was 46.34 UA/g of protein. Growth of Pseudomonas putida was not affected by the preservatives employed at the conditions employed. Antimicrobial response was different for other microorganisms since a synergetic effect of the preservatives combination inhibited Brochothrix thermosphacta and Escherichia coli growth. Sodium lactate had additive effect only against Listeria innocua.

Pesticides in Soil: Effects on Microorganisms

Directory of Open Access Journals (Sweden)

Ljiljana Radivojević

2007-01-01

Full Text Available Since their discovery to the present day, pesticides have been an inevitable segment of agricultural production and efforts have been made to synthesize compounds that would share a required efficacy along with selectivity, sufficient persistence on the object of protection and favourable toxicological and ecotoxicological characteristics so as to minimize their effect on the environment.When a pesticide gets into soil after application, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors as well, such as: physical, chemical and biological characteristics of soil; climatic factors, equipment used, method of application, method of storage, handling and disposal of waste, site characteristics (proximity of ground and underground waters, biodiversity and sensitivity of the environment. Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on populations of microorganisms and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity.The article discusses complex interactions between pesticides and microorganisms in soil immediately after application and over the ensuing period. Data on changes in the abundance of some systematic and physiological groups of microorganisms, their microbial biomass and enzymatic activity caused under pesticide activity are discussed as indicators of these processes.

Dynamic size spectrometry of airborne microorganisms: Laboratory evaluation and calibration

Science.gov (United States)

Qian, Yinge; Willeke, Klaus; Ulevicius, Vidmantas; Grinshpun, Sergey A.; Donnelly, Jean

Bioaerosol samplers need to be calibrated for the microorganisms of interest. The Aerosizer, a relatively new aerodynamic size spectrometer, is shown to be a suitable dynamic instrument for the evaluation and calibration of such samplers in the laboratory, prior to their use in the field. It provides the necessary reference count against which the microbiological response of the sampler can be compared. It measures the health-significant aerodynamic diameters of microorganisms down to 0.5 μm, thus including most of the bacteria, fungi and pollen found in outdoor and indoor air environments. Comparison tests with a laser size spectrometer indicate that the suspension of microorganisms needs to be washed several times before aerosolization to avoid coating of the airborne microorganisms with nutrients and microbial slime from the suspension, and to reduce the residue particles to sizes below the lowest size of the aerosolized microorganisms.

Millimeter-sized marine plastics: a new pelagic habitat for microorganisms and invertebrates.

Directory of Open Access Journals (Sweden)

Julia Reisser

Full Text Available Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7-24.3 mm, median = 3.2 mm from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded 'epiplastic' coccolithophores (7 genera, bryozoans, barnacles (Lepas spp., a dinoflagellate (Ceratium, an isopod (Asellota, a marine worm, marine insect eggs (Halobates sp., as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated.

Risk Assessment of Genetically Modified Microorganisms

DEFF Research Database (Denmark)

Jacobsen, B. L.; Wilcks, Andrea

2001-01-01

the industry, national administration and research institutions were gathered to discuss which elements should be considered in a risk assessment of genetically modified microorganisms used as food or food ingredients. The existing EU and national regulations were presented, together with the experiences......The rapid development of recombinant DNA techniques for food organisms urges for an ongoing discussion on the risk assessment of both new as traditional use of microorganisms in food production. This report, supported by the Nordic Council of Ministers, is the result of a workshop where people from...... with risk assessment of these organisms in each Nordic country....

Use of electron beam irradiation to improve the microbiological safety of Hippophae rhamnoides

Energy Technology Data Exchange (ETDEWEB)

Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Electron Accelerators Department, 409 Atomistilor St., Bucharest-Magurele 077125 (Romania); Nemtanu, M.R. [National Institute for Lasers, Plasma and Radiation Physics, Electron Accelerators Department, 409 Atomistilor St., Bucharest-Magurele 077125 (Romania)], E-mail: monica.nemtanu@inflpr.ro; Manea, S.; Mazilu, E. [S.C. Hofigal Export-Import S.A., 2A Intrarea Serelor St., 75669, Bucharest 4 (Romania)

2007-09-21

Sea buckthorn (Hippophae rhamnoides) is increasingly used in food supplements due to its dietary and medicinal compounds with a beneficial role in human diet and health. As many other medicinal plants, sea buckthorn can be contaminated with microorganisms which exerts an important impact on the overall quality of the products. Irradiation is an effective method for food preservation because it is able to destroy pathogenic microorganisms keeping the organoleptic and nutritional characteristics of the foods. The objective of the present study was to investigate the application of electron beam irradiation in order to improve the microbiological safety of sea buckthorn. The experimental results indicated that the electron beam treatment might be a good method to remove undesirable microorganisms from sea buckthorn without significant changes in its active principles.

Compost supplementation with nutrients and microorganisms in composting process.

Science.gov (United States)

Sánchez, Óscar J; Ospina, Diego A; Montoya, Sandra

2017-11-01

The composting is an aerobic, microorganism-mediated, solid-state fermentation process by which different organic materials are transformed into more stable compounds. The product obtained is the compost, which contributes to the improvement of physical, chemical and microbiological properties of the soil. However, the compost usage in agriculture is constrained because of its long-time action and reduced supply of nutrients to the crops. To enhance the content of nutrients assimilable by the plants in the compost, its supplementation with nutrients and inoculation with microorganisms have been proposed. The objective of this work was to review the state of the art on compost supplementation with nutrients and the role played by the microorganisms involved (or added) in their transformation during the composting process. The phases of composting are briefly compiled and different strategies for supplementation are analyzed. The utilization of nitrogenous materials and addition of microorganisms fixing nitrogen from the atmosphere or oxidizing ammonia into more assimilable for plants nitrogenous forms are analyzed. Several strategies for nitrogen conservation during composting are presented as well. The supplementation with phosphorus and utilization of microorganisms solubilizing phosphorus and potassium are also discussed. Main groups of microorganisms relevant during the composting process are described as well as most important strategies to identify them. In general, the development of this type of nutrient-enriched bio-inputs requires research and development not only in the supplementation of compost itself, but also in the isolation and identification of microorganisms and genes allowing the degradation and conversion of nitrogenous substances and materials containing potassium and phosphorus present in the feedstocks undergoing the composting process. In this sense, most important research trends and strategies to increase nutrient content in the compost

Volatilization of Po by microorganisms at laboratory culture experiments

International Nuclear Information System (INIS)

Momoshima, N.; Ishida, A.; Yoshinaga, C.; Fukuda, A.

2005-01-01

The previous experiments proved the volatility of polonium form culture medium in which microorganisms were propagated from seed of seawater, river water or pond water, therefore we did not know what kind of species are responsible to Po volatility. To search microorganisms, which concerned with Po emission we carried out culture experiments using known microorganisms. Three microorganisms were examined; Escherichia coli K-12, Bacillus subtilis and Chromobacterium violaceum. The microorganisms were pre-cultured in LB medium at 30 degree C and a small portion of the pre-cultured was transferred to a culture bottle in which LB medium and 208 Po tracer were contained. The culture was done at 30 degree C with shaking the culture bottle and air passed through a filter was introduced. The Po volatilized was transferred into the trap vials in which scintillator for liquid scintillation counting (LSC) was contained. The Po activity was measured by LSC. All of the microorganisms examined volatilized Po but their ability was quite different each other. Highest ability was observed on Chromobacterium violaceum and then Escherichia coli K-12 followed by Bacillus subtilis, the relative magnitude of the ability was 10 2 , 10, 1, respectively. Chromobacterium violaceum and Escherichia coli K-12 showed high volatility for the first 24 h but Escherichia coli K-12 showed a decrease thereafter. However high volatility was continued on Chromobacterium violaceum during the culture. The low culture temperature suppressed Po volatility, supporting biologically mediated Po emission from the culture.

Exocellular electron transfer in anaerobic microbial communities

NARCIS (Netherlands)

Stams, A.J.M.; Bok, de F.A.M.; Plugge, C.M.; Eekert, van M.H.A.; Dolfing, J.; Schraa, G.

2006-01-01

Exocellular electron transfer plays an important role in anaerobic microbial communities that degrade organic matter. Interspecies hydrogen transfer between microorganisms is the driving force for complete biodegradation in methanogenic environments. Many organic compounds are degraded by obligatory

Microscale interactions between earthworms and microorganisms: a review

Directory of Open Access Journals (Sweden)

Zirbes, L.

2012-01-01

Full Text Available Microorganisms are well adapted to their soil microhabitat where they live together in consortia, interacting with other living members, including earthworms. This literature review consists of four sections that focus on microscale interactions between earthworms and microorganisms. The first part is devoted to nephridia symbiosis. Recent discoveries show that Verminephrobacter spp. is present as a symbiont in earthworm nephridia. The second section deals with earthworm food preference and focuses on the major hypotheses of foraging strategies. The third section presents evidence of gut symbionts and highlights the need for additional studies in this field. The last section of this review explains why microorganism activities are enhanced in burrows and casts of earthworms.

Microbial genome-enabled insights into plant-microorganism interactions.

Science.gov (United States)

Guttman, David S; McHardy, Alice C; Schulze-Lefert, Paul

2014-12-01

Advances in genome-based studies on plant-associated microorganisms have transformed our understanding of many plant pathogens and are beginning to greatly widen our knowledge of plant interactions with mutualistic and commensal microorganisms. Pathogenomics has revealed how pathogenic microorganisms adapt to particular hosts, subvert innate immune responses and change host range, as well as how new pathogen species emerge. Similarly, culture-independent community profiling methods, coupled with metagenomic and metatranscriptomic studies, have provided the first insights into the emerging field of research on plant-associated microbial communities. Together, these approaches have the potential to bridge the gap between plant microbial ecology and plant pathology, which have traditionally been two distinct research fields.

Color-Removal by Microorganisms Isolated from Human Hands

Directory of Open Access Journals (Sweden)

Tsukasa Ito

2013-08-01

Full Text Available Microorganisms are essential for human life. Microorganisms decompose the carbon compounds in dead animals and plants and convert them into carbon dioxide. Intestinal bacteria assist in food digestion. Some vitamins are produced by bacteria that live in the intestines. Sewage and industrial wastewater are treated by activated sludge composed of microbial communities. All of these are due to the ability of microbes to produce many enzymes that can degrade chemicals. How do teachers make students understand that microorganisms are always associated with humans, and that microorganisms have the ability to degrade chemicals? The presence of microorganisms on humans can be shown by incubating agar plates after they are touched by the hands of students. The ability of microorganisms to degrade chemicals can be shown by an analytical measurement of the degradation of chemicals. When the chemicals are dyes (colorants in water, microbial activity on degradation of dyes can be demonstrated by observing a decreasing degree of color as a result of the enzymatic activity (e.g., azoreductase. Dyes are widely used in the textile, food, and cosmetic industries. They are generally resistant to conventional biological wastewater treatment systems such as the activated sludge process (4. The discharge of wastewater containing dye pollutes surface water. The ability of microorganisms to decolorize and degrade dyes has been widely investigated to use for bioremediation purposes (5. The goal of this tip is to understand the presence of bacteria on human skin and the ability of bacteria to degrade colorant chemicals (decolorization. In this tip, students first cultivate and isolate bacteria on their hands, and then examine potential decolorization activity of each bacterium by observing the degree of color of the liquid in tubes in which bacteria isolated from students’ hands were inoculated. Decolorization activity of bacterial isolates from human skin has been

Ecology and resistance of Moraxella-Acinetobacter

International Nuclear Information System (INIS)

Gulistani, A.W.

1977-01-01

The diverse microenvironments of foods, changing with processing and preservation, might provide conditions that would enhance the growth of microorganisms which are the principal cause of spoilage, off-odor and unpleasant flavor in foods. Radiation is a potential process which may provide a product with far superior microbial quality for food preservation, by reduction of microbial population; elimination of food-borne pathogens; extension of shelf-life; and reduction of spoilage. The aim of irradiation at low dose level is to eliminate certain microorganisms, especially spoilage types and those of public health significance. But, the radurization dose allows the outgrowth of radioresistant bacteria. Certain strains of Moraxella-Acinetobacter (M-A) groups have been recognized as radioresistant bacteria (Welch and Maxcy, 1975), which may have gone unnoticed by food microbiologists, since these bacteria have not been associated with problems and are present in relatively small numbers. However, irrradiation with radurization doses reduces the number of organisms and brings the M-A group into prominence, which may cause problems in irradiated foods. When M-A isolate No. 4 was grown in PCB and TSB media at 32 0 C and on PCA at ambient temperature and ambient RH, as well as when its resistance was observed in a film of various soiling materials on stainless steel surfaces at ambient temperature and room RH, it was concluded that these bacteria were resistant under various conditions for long periods of time. Other tests in which M-A isolates were observed were salt tolerance, various pH levels, quats, chlorine, antibiotic sensitivity, effects of dyes and hydrogen peroxide

Emerging Preservation Techniques for Controlling Spoilage and Pathogenic Microorganisms in Fruit Juices

OpenAIRE

Aneja, Kamal Rai; Dhiman, Romika; Aggarwal, Neeraj Kumar; Aneja, Ashish

2014-01-01

Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Therma...

Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages.

Science.gov (United States)

Hultman, Jenni; Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K Johanna

2015-10-01

Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2%±5%), as well as on the processing plant surfaces (food safety concerns related to their resilient existence on surfaces. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Cybernetic modeling of adaptive prediction of environmental changes by microorganisms.

Science.gov (United States)

Mandli, Aravinda R; Modak, Jayant M

2014-02-01

Microorganisms exhibit varied regulatory strategies such as direct regulation, symmetric anticipatory regulation, asymmetric anticipatory regulation, etc. Current mathematical modeling frameworks for the growth of microorganisms either do not incorporate regulation or assume that the microorganisms utilize the direct regulation strategy. In the present study, we extend the cybernetic modeling framework to account for asymmetric anticipatory regulation strategy. The extended model accurately captures various experimental observations. We use the developed model to explore the fitness advantage provided by the asymmetric anticipatory regulation strategy and observe that the optimal extent of asymmetric regulation depends on the selective pressure that the microorganisms experience. We also explore the importance of timing the response in anticipatory regulation and find that there is an optimal time, dependent on the extent of asymmetric regulation, at which microorganisms should respond anticipatorily to maximize their fitness. We then discuss the advantages offered by the cybernetic modeling framework over other modeling frameworks in modeling the asymmetric anticipatory regulation strategy. Copyright © 2013. Published by Elsevier Inc.

Microorganism Utilization for Synthetic Milk

Science.gov (United States)

Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

2014-01-01

A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required

DMPD: Signaling pathways activated by microorganisms. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17303405 Signaling pathways activated by microorganisms. Takeuchi O, Akira S. Curr ...Opin Cell Biol. 2007 Apr;19(2):185-91. Epub 2007 Feb 15. (.png) (.svg) (.html) (.csml) Show Signaling pathways activated by microorg...anisms. PubmedID 17303405 Title Signaling pathways activated by microorganisms. Auth

Mini-review: Inhibition of biofouling by marine microorganisms.

Science.gov (United States)

Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

2013-01-01

Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

Reductive Dehalogenation of Brominated Phenolic Compounds by Microorganisms Associated with the Marine Sponge Aplysina aerophoba

Science.gov (United States)

Ahn, Young-Beom; Rhee, Sung-Keun; Fennell, Donna E.; Kerkhof, Lee J.; Hentschel, Ute; Häggblom, Max M.

2003-01-01

Marine sponges are natural sources of brominated organic compounds, including bromoindoles, bromophenols, and bromopyrroles, that may comprise up to 12% of the sponge dry weight. Aplysina aerophoba sponges harbor large numbers of bacteria that can amount to 40% of the biomass of the animal. We postulated that there might be mechanisms for microbially mediated degradation of these halogenated chemicals within the sponges. The capability of anaerobic microorganisms associated with the marine sponge to transform haloaromatic compounds was tested under different electron-accepting conditions (i.e., denitrifying, sulfidogenic, and methanogenic). We observed dehalogenation activity of sponge-associated microorganisms with various haloaromatics. 2-Bromo-, 3-bromo-, 4-bromo-, 2,6-dibromo-, and 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzoate were reductively debrominated under methanogenic and sulfidogenic conditions with no activity observed in the presence of nitrate. Monochlorinated phenols were not transformed over a period of 1 year. Debromination of 2,4,6-tribromophenol, and 2,6-dibromophenol to 2-bromophenol was more rapid than the debromination of the monobrominated phenols. Ampicillin and chloramphenicol inhibited activity, suggesting that dehalogenation was mediated by bacteria. Characterization of the debrominating methanogenic consortia by using terminal restriction fragment length polymorphism (TRFLP) and denaturing gradient gel electrophoresis analysis indicated that different 16S ribosomal DNA (rDNA) phylotypes were enriched on the different halogenated substrates. Sponge-associated microorganisms enriched on organobromine compounds had distinct 16S rDNA TRFLP patterns and were most closely related to the δ subgroup of the proteobacteria. The presence of homologous reductive dehalogenase gene motifs in the sponge-associated microorganisms suggested that reductive dehalogenation might be coupled to dehalorespiration. PMID:12839794

Complete Reductive Dehalogenation of Brominated Biphenyls by Anaerobic Microorganisms in Sediment

Science.gov (United States)

Bedard, Donna L.; Van Dort, Heidi M.

1998-01-01

We sought to determine whether microorganisms from the polychlorinated biphenyl (PCB)-contaminated sediment in Woods Pond (Lenox, Mass.) could dehalogenate brominated biphenyls. The PCB dechlorination specificities for the microorganisms in this sediment have been well characterized. This allowed us to compare the dehalogenation specificities for brominated biphenyls and chlorinated biphenyls within a single sediment. Anaerobic sediment microcosms were incubated separately at 25°C with 16 different mono- to tetrabrominated biphenyls (350 μM) and disodium malate (10 mM). Samples were extracted and analyzed by gas chromatography with an electron capture detector and a mass spectrometer detector at various times for up to 54 weeks. All of the tested brominated biphenyls were dehalogenated. For most congeners, including 2,6-dibromobiphenyl (26-BB) and 24-25-BB, the dehalogenation began within 1 to 2 weeks. However, for 246-BB and 2-2-BB, debromination was first observed at 7 and 14 weeks, respectively. Most intermediate products did not persist, but when 2-2-BB was produced as a dehalogenation product, it persisted for at least 15 weeks before it was dehalogenated to 2-BB and then to biphenyl. The dehalogenation specificities for brominated and chlorinated biphenyls were similar: meta and para substituents were generally removed first, and ortho substituents were more recalcitrant. However, the brominated biphenyls were better dehalogenation substrates than the chlorinated biphenyls. All of the tested bromobiphenyls, including those with ortho and unflanked meta and para substituents, were ultimately dehalogenated to biphenyl, whereas their chlorinated counterparts either were not dehalogenation substrates or were only partially dehalogenated. Our data suggest that PCB-dechlorinating microorganisms may be able to dehalogenate brominated biphenyls and may exhibit a relaxed specificity for these substrates. PMID:16349530

Nucleic acid-based approaches to investigate microbial-related cheese quality defects

Directory of Open Access Journals (Sweden)

Daniel eO Sullivan

2013-01-01

Full Text Available AbstractThe microbial profile of cheese is a primary determinant of cheese quality. Microorganisms can contribute to aroma and taste defects, form biogenic amines, cause gas and secondary fermentation defects, and can contribute to cheese pinking and mineral deposition issues. These defects may be as a result of seasonality and the variability in the composition of the milk supplied, variations in cheese processing parameters, as well as the nature and number of the non-starter microorganisms which come from the milk or other environmental sources. Such defects can be responsible for production and product recall costs and thus represent a significant economic burden for the dairy industry worldwide. Traditional non-molecular approaches are often considered biased and have inherently slow turnaround times. Molecular techniques can provide early and rapid detection of defects that result from the presence of specific spoilage microbes and, ultimately, assist in enhancing cheese quality and reducing costs. Here we review the DNA-based methods that are available to detect/quantify spoilage bacteria, and relevant metabolic pathways, in cheeses and, in the process, highlight how these strategies can be employed to improve cheese quality and reduce the associated economic burden on cheese processors.

Unraveling microbial biofilms of importance for food microbiology.

Science.gov (United States)

Winkelströter, Lizziane Kretli; Teixeira, Fernanda Barbosa dos Reis; Silva, Eliane Pereira; Alves, Virgínia Farias; De Martinis, Elaine Cristina Pereira

2014-07-01

The presence of biofilms is a relevant risk factors in the food industry due to the potential contamination of food products with pathogenic and spoilage microorganisms. The majority of bacteria are able to adhere and to form biofilms, where they can persist and survive for days to weeks or even longer, depending on the microorganism and the environmental conditions. The biological cycle of biofilms includes several developmental phases such as: initial attachment, maturation, maintenance, and dispersal. Bacteria in biofilms are generally well protected against environmental stress, consequently, extremely difficult to eradicate and detect in food industry. In the present manuscript, some techniques and compounds used to control and to prevent the biofilm formation are presented and discussed. Moreover, a number of novel techniques have been recently employed to detect and evaluate bacteria attached to surfaces, including real-time polymerase chain reaction (PCR), DNA microarray and confocal laser scanning microscopy. Better knowledge on the architecture, physiology and molecular signaling in biofilms can contribute for preventing and controlling food-related spoilage and pathogenic bacteria. The present study highlights basic and applied concepts important for understanding the role of biofilms in bacterial survival, persistence and dissemination in food processing environments.

Competition between roots and microorganisms for nitrogen: mechanisms and ecological relevance

Science.gov (United States)

Kuzyakov, Yakov; Xu, Xingliang

2014-05-01

Demand of all living organisms on the same nutrients forms the basis for interspecific competition between plants and microorganisms in soils. This competition is especially strong in the rhizosphere. To evaluate competitive and mutualistic interactions between plants and microorganisms and to analyse ecological consequences of these interactions, we analysed 424 data pairs from 41 15N-labelling studies that investigated 15N redistribution between roots and microorganisms. Calculated Michaelis-Menten kinetics based on Km (Michaelis constant) and Vmax (maximum uptake capacity) values from 77 studies on the uptake of nitrate, ammonia, and amino acids by roots and microorganisms clearly showed that, shortly after nitrogen (N) mobilization from soil organic matter and litter, microorganisms take up most N. Lower Km values of microorganisms suggest that they are especially efficient at low N concentrations, but can also acquire more N at higher N concentrations (Vmax) compared with roots. Because of the unidirectional flow of nutrients from soil to roots, plants are the winners for N acquisition in the long run. Therefore, despite strong competition between roots and microorganisms for N, a temporal niche differentiation reflecting their generation times leads to mutualistic relationships in the rhizosphere. This temporal niche differentiation is highly relevant ecologically because it: protects ecosystems from N losses by leaching during periods of slow or no root uptake; continuously provides roots with available N according to plant demand; and contributes to the evolutionary development of mutualistic interactions between roots and microorganisms.

The application of powerful promoters to enhance gene expression in industrial microorganisms.

Science.gov (United States)

Zhou, Shenghu; Du, Guocheng; Kang, Zhen; Li, Jianghua; Chen, Jian; Li, Huazhong; Zhou, Jingwen

2017-02-01

Production of useful chemicals by industrial microorganisms has been attracting more and more attention. Microorganisms screened from their natural environment usually suffer from low productivity, low stress resistance, and accumulation of by-products. In order to overcome these disadvantages, rational engineering of microorganisms to achieve specific industrial goals has become routine. Rapid development of metabolic engineering and synthetic biology strategies provide novel methods to improve the performance of industrial microorganisms. Rational regulation of gene expression by specific promoters is essential to engineer industrial microorganisms for high-efficiency production of target chemicals. Identification, modification, and application of suitable promoters could provide powerful switches at the transcriptional level for fine-tuning of a single gene or a group of genes, which are essential for the reconstruction of pathways. In this review, the characteristics of promoters from eukaryotic, prokaryotic, and archaea microorganisms are briefly introduced. Identification of promoters based on both traditional biochemical and systems biology routes are summarized. Besides rational modification, de novo design of promoters to achieve gradient, dynamic, and logic gate regulation are also introduced. Furthermore, flexible application of static and dynamic promoters for the rational engineering of industrial microorganisms is highlighted. From the perspective of powerful promoters in industrial microorganisms, this review will provide an extensive description of how to regulate gene expression in industrial microorganisms to achieve more useful goals.

Effects of heat-activated persulfate oxidation on soil microorganisms

DEFF Research Database (Denmark)

Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

2008-01-01

/L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

Classification of photobacteria associated with spoilage of fish products by numerical taxanomy and pyrolysis mass spectrometry

DEFF Research Database (Denmark)

Dalgaard, Paw; Manfio, G.P.; Goodfellow, M.

1997-01-01

, from spoiled products and by using a specific detection method. The data were analysed using the similarity coefficient and the unweighted pair-group with arithmetic averages algorithm. In addition twenty-six of the fish isolates and five reference strains were analysed by Curie-point pyrolysis mass...... sub-groups. One sub-group of psychrotolerant P. phosphoreum strains, which was selected in modified atmosphere packed fish stored at low temperature, was also highlighted using each of the methods. The importance of classifying food spoilage bacteria has been shown and a simple key generated......Forty strains of luminous and non-luminous Photobacterium phosphoreum isolates from cod (Gadus morhua) and seven reference strains of psychrotolerant and mesophilic photobacteria were examined for 156 unit characters in a numerical taxonomic study. The fish strains were isolated from the intestines...

Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms.

Science.gov (United States)

Satpute, Surekha K; Banat, Ibrahim M; Dhakephalkar, Prashant K; Banpurkar, Arun G; Chopade, Balu A

2010-01-01

Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications.

Introduction to the Microbiological Spoilage of Foods and Beverages

Science.gov (United States)

Sperber, William H.

Though direct evidence of ancient food-handling practices is difficult to obtain and examine, it seems safe to assume that over the span of several million years, prehistoric humans struggled to maintain an adequate food supply. Their daily food needed to be hunted or harvested and consumed before it spoiled and became unfit to eat. Freshly killed animals, for example, could not have been kept for very long periods of time. Moreover, many early humans were nomadic, continually searching for food. We can imagine that, with an unreliable food supply, their lives must have often been literally "feast or famine." Yet, our ancestors gradually learned by accident, or by trial and error, simple techniques that could extend the storage time of their food (Block, 1991). Their brain capacity was similar to that of modern humans; therefore, some of them were likely early scientists and technologists. They would have learned that primitive cereal grains, nuts and berries, etc. could be stored in covered vessels to keep them dry and safer from mold spoilage. Animal products could be kept in cool places or dried and smoked over a fire, as the controlled use of fire by humans is thought to have begun about 400,000 years ago. Quite likely, naturally desiccated or fermented foods were also noticed and produced routinely to provide a more stable supply of edible food. Along with the development of agricultural practices for crop and animal production, the "simple" food-handling practices developed during the relatively countless millennia of prehistory paved the way for human civilizations.

Food irradiation - A new way to process food

International Nuclear Information System (INIS)

1987-01-01

The film shows how irradiation of food by ionizing energy (gamma rays or beams of electrons) can help cut down post-harvest losses of food such as cereals, meat, fish and shellfish and fresh or dried fruits and vegetables. One quarter to one third of the total world food production is lost due to sprouting, destruction by insects and parasites, spoilage by micro-organisms such as bacteria and funghi, and premature ripening. Food contamination not only leads to economic problems but can also cause diseases such as trichinosis, toxoplasmosis, etc. The new technique of food irradiation has been studied by independent groups of experts whose evaluations without exception have been favourable. One of the main advantages is that there are no chemical residues. On the long run, food irradiation will help to assure world-wide food security

78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms

Science.gov (United States)

2013-07-16

.... FDA-2013-N-0253] Animal Feeds Contaminated With Salmonella Microorganisms AGENCY: Food and Drug... revoking an advisory opinion on animal feeds contaminated with Salmonella microorganisms. This action is... articulated in a final compliance policy guide (CPG) on Salmonella in food for animals. DATES: This rule is...

Competition between roots and microorganisms for nitrogen: mechanisms and ecological relevance.

Science.gov (United States)

Kuzyakov, Yakov; Xu, Xingliang

2013-05-01

Demand of all living organisms on the same nutrients forms the basis for interspecific competition between plants and microorganisms in soils. This competition is especially strong in the rhizosphere. To evaluate competitive and mutualistic interactions between plants and microorganisms and to analyse ecological consequences of these interactions, we analysed 424 data pairs from 41 (15)N-labelling studies that investigated (15)N redistribution between roots and microorganisms. Calculated Michaelis-Menten kinetics based on K(m) (Michaelis constant) and V(max) (maximum uptake capacity) values from 77 studies on the uptake of nitrate, ammonia, and amino acids by roots and microorganisms clearly showed that, shortly after nitrogen (N) mobilization from soil organic matter and litter, microorganisms take up most N. Lower K(m) values of microorganisms suggest that they are especially efficient at low N concentrations, but can also acquire more N at higher N concentrations (V(max)) compared with roots. Because of the unidirectional flow of nutrients from soil to roots, plants are the winners for N acquisition in the long run. Therefore, despite strong competition between roots and microorganisms for N, a temporal niche differentiation reflecting their generation times leads to mutualistic relationships in the rhizosphere. This temporal niche differentiation is highly relevant ecologically because it: protects ecosystems from N losses by leaching during periods of slow or no root uptake; continuously provides roots with available N according to plant demand; and contributes to the evolutionary development of mutualistic interactions between roots and microorganisms. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Functional Properties of Microorganisms in Fermented Foods

Directory of Open Access Journals (Sweden)

Jyoti Prakash Tamang

2016-04-01

Full Text Available Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

Potential spoilage yeasts in winery environments: Characterization and proteomic analysis of Trigonopsis cantarellii.

Science.gov (United States)

Portugal, Cauré; Pinto, Luís; Ribeiro, Miguel; Tenorio, Carmen; Igrejas, Gilberto; Ruiz-Larrea, Fernanda

2015-10-01

Wine microbiota is complex and includes a wide diversity of yeast species. Few of them are able to survive under the restrictive conditions of dry red wines. In our study we detected and identified seven yeast species of the order Saccharomycetales that can be considered potential spoilers of wines due to physiological traits such as acidogenic metabolism and off-odor generation: Arthroascus schoenii, Candida ishiwadae, Meyerozyma guilliermondii, Pichia holstii, Pichia manshurica, Trigonopsis cantarellii, and Trigonopsis variabilis. Based on the prevalence of T. cantarellii isolates in the wine samples of our study, we further characterized this species, determined molecular and phenotypic features, and performed a proteomic analysis to identify differentially expressed proteins at mid-exponential growth phase in the presence of ethanol in the culture broth. This yeast species is shown to be able to grow in the presence of ethanol by expressing heat shock proteins (Hsp70, Hsp71) and a DNA damage-related protein (Rad24), and to be able to confer spoilage characteristics on wine. Copyright © 2015 Elsevier B.V. All rights reserved.

Role of Microorganisms in the Removal of Radionuclides from Soil

International Nuclear Information System (INIS)

Bashandy, A.S.

2007-01-01

Resistance to radio nuclides and their accumulation by bacteria is a wide spread phenomenon that can be explored for the improvement of the environment. Metal resistant bacteria have developed very efficient and varying mechanisms for tolerating high levels of. toxic metals and thus hold potential for controlling heavy metal pollution. This property has been successfully applied for metal removal from soil. A total of 59 microorganisms were isolated from 5 locations in Sinai Desert. The microorganisms were examined for resistance to strontium, cobalt and cesium by spot technique on two kinds of media containing metals, Nutrient agar and King B agar. The resistant microorganisms were identified morphologically by Gram stain. The microorganisms were resistant to Sr and Cs at concentrations up to 200 mg/I and while Co proved to be toxic at a concentration of 100 mg/ I. The mechanisms of metal resistance to high concentrations were studied. Evidence show that the isolated microorganisms can uptake high concentrations of the studied elements. The results also, indicated that no binding proteins are released in the environment of the studied isolate

Biodegradation of oil palm empty fruit bunch by composite micro-organisms

International Nuclear Information System (INIS)

Yusri Atan; Mat Rasol Awang; Mohammed Omar; Azizah Hashim; Tamikazu Kume; Shoji Hashimoto

1998-01-01

A comparison study on the comparative biodegradation ability on EFB by five groups of composite micro-organisms [Organomine, Thomas, Ohres C, Ohres II and micro-organisms from POME (palm oil mill effluent)] has been performed with the aim of producing a compost at a faster rate than that by natural biodegradation. The experiment was carried out by mixing 50 gram EFB (dry weight basis) with 3% ammonium sulphate to which was added 1% composite micro-organisms and water to produce a composting media of moisture content about 60%. Respiration of composite micro-organisms as well as from decomposition of EFB releasing CO sub 2. The choice of useful micro-organisms was based on its ability to degrade EFB as reflected by higher evolution rate of CO sub 2 released and retaining higher percentage of nitrogen in the final product

Biofuel production by recombinant microorganisms

Science.gov (United States)

Liao, James C.; Atsumi, Shota; Cann, Anthony F.

2017-07-04

Provided herein are metabolically-modified microorganisms useful for producing biofuels. More specifically, provided herein are methods of producing high alcohols including isobutanol, 1-butanol, 1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol from a suitable substrate.

Physiologically anaerobic microorganisms of the deep subsurface

Energy Technology Data Exchange (ETDEWEB)

Stevens, S.E. Jr.; Chung, K.T.

1991-06-01

This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

Combined effects of thermosonication and slightly acidic electrolyzed water on the microbial quality and shelf life extension of fresh-cut kale during refrigeration storage.

Science.gov (United States)

Mansur, Ahmad Rois; Oh, Deog-Hwan

2015-10-01

This study evaluated the efficacy of thermosonication combined with slightly acidic electrolyzed water (SAcEW) on the shelf life extension of fresh-cut kale during storage at 4 and 7 °C. Each kale (10 ± 0.2 g) was inoculated to contain approximately 6 log CFU/g of Listeria monocytogenes. Each inoculated or uninoculated samples was dip treated at 40 °C for 3 min with deionized water, thermosonication (400 W/L), SAcEW (5 mg/L), sodium chlorite (SC; 100 mg/L), sodium hypochlorite (SH; 100 mg/L), and thermosonication combined with SAcEW, SC, and SH (TS + SAcEW, TS + SC, and TS + SH, respectively). Growths of L. monocytogenes and spoilage microorganisms and changes in sensory (overall visual quality, browning, and off-odour) were evaluated. The results show that lag time and specific growth rate of each microorganism were not significantly (P > 0.05) affected by treatment and storage temperature. Exceeding the unacceptable counts of spoilage microorganisms did not always result in adverse effects on sensory attributes. This study suggests that TS + SAcEW was the most effective method to prolong the shelf life of kale with an extension of around 4 and 6 days at 4 and 7 °C, respectively, and seems to be a promising method for the shelf life extension of fresh produce. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic Nose for Microbiological Quality Control of Food Products

Directory of Open Access Journals (Sweden)

M. Falasconi

2012-01-01

Full Text Available Electronic noses (ENs have recently emerged as valuable candidates in various areas of food quality control and traceability, including microbial contamination diagnosis. In this paper, the EN technology for microbiological screening of food products is reviewed. Four paradigmatic and diverse case studies are presented: (a Alicyclobacillus spp. spoilage of fruit juices, (b early detection of microbial contamination in processed tomatoes, (c screening of fungal and fumonisin contamination of maize grains, and (d fungal contamination on green coffee beans. Despite many successful results, the high intrinsic variability of food samples together with persisting limits of the sensor technology still impairs ENs trustful applications at the industrial scale. Both advantages and drawbacks of sensor technology in food quality control are discussed. Finally, recent trends and future directions are illustrated.

Magnetotaxy in microorganisms of Rio de Janeiro region: an overview

International Nuclear Information System (INIS)

Barros, H.G. de P.L. de; Esquivel, D.M.S.

1983-01-01

Some characteristics of several magnetotactic microorganisms found in sediments collected in Rio de Janeiro region are presented. The study of magnetic characteristics of these microorganisms indicate some general properties of the magnetotaxy phenomenons. (L.C.) [pt

Millimeter-Sized Marine Plastics: A New Pelagic Habitat for Microorganisms and Invertebrates

Science.gov (United States)

Reisser, Julia; Shaw, Jeremy; Hallegraeff, Gustaaf; Proietti, Maira; Barnes, David K. A.; Thums, Michele; Wilcox, Chris; Hardesty, Britta Denise; Pattiaratchi, Charitha

2014-01-01

Millimeter-sized plastics are abundant in most marine surface waters, and known to carry fouling organisms that potentially play key roles in the fate and ecological impacts of plastic pollution. In this study we used scanning electron microscopy to characterize biodiversity of organisms on the surface of 68 small floating plastics (length range = 1.7–24.3 mm, median = 3.2 mm) from Australia-wide coastal and oceanic, tropical to temperate sample collections. Diatoms were the most diverse group of plastic colonizers, represented by 14 genera. We also recorded ‘epiplastic’ coccolithophores (7 genera), bryozoans, barnacles (Lepas spp.), a dinoflagellate (Ceratium), an isopod (Asellota), a marine worm, marine insect eggs (Halobates sp.), as well as rounded, elongated, and spiral cells putatively identified as bacteria, cyanobacteria, and fungi. Furthermore, we observed a variety of plastic surface microtextures, including pits and grooves conforming to the shape of microorganisms, suggesting that biota may play an important role in plastic degradation. This study highlights how anthropogenic millimeter-sized polymers have created a new pelagic habitat for microorganisms and invertebrates. The ecological ramifications of this phenomenon for marine organism dispersal, ocean productivity, and biotransfer of plastic-associated pollutants, remains to be elucidated. PMID:24941218

Hydrosols of orange blossom (Citrus aurantium), and rose flower (Rosa damascena and Rosa centifolia) support the growth of a heterogeneous spoilage microbiota.

Science.gov (United States)

Labadie, Cécile; Ginies, Christian; Guinebretiere, Marie-Hélène; Renard, Catherine M G C; Cerutti, Céline; Carlin, Frédéric

2015-10-01

Hydrosols are hydrodistillation products of aromatic plants. They contain less than 1g/L of dispersed essential oils giving organoleptic properties. Hydrosols are subjected to microbial proliferation. Reasons for spoilage have to be found in the nature of substrates supporting growth and of microbiological contaminants. The composition in essential oils and the microbiota of 22 hydrosol samples of Citrus aurantium L. ssp. amara L. (orange blossom), Rosa damascena Miller (rose D.), and Rosa centifolia L. (rose C.) flowers were analyzed to determine the factors responsible for decay. The median concentrations in essential oils were 677mg/L for orange blossom hydrosols, 205mg/L for rose D. hydrosols, and 116mg/L for rose C. hydrosols. The dry matter content of these hydrosols varied between 4.0mg/L and 702mg/L, and the carbohydrate content varied between 0.21mg/L and 0.38mg/L. These non-volatile compounds were likely carried over during distillation by a priming and foaming effect, and could be used as nutrients by microorganisms. A microbial proliferation at ambient temperature and also at 5°C has been observed in all studied hydrosols when stored in a non-sterile container. In contaminated hydrosols, maximal counts were about 7log 10 CFU/mL, while the French pharmacopeia recommends a maximal total bacterial count of 2log 10 CFU/mL. Neither yeast nor mold was detected. The isolated microbial population was composed of environmental Gram-negative bacteria, arranged in four major genera: Pseudomonas sp., Burkholderia cepacia complex, and presumably two new genera belonging to Acetobacteraceae and Rhodospirillaceae. Among those bacteria, Burkholderia vietnamiensis and Novosphingobium capsulatum were able to metabolize volatile compounds, such as geraniol to produce 6-methyl-5-hepten-2-one or geranic acid, or phenylethyl acetate to produce 2-phenylethanol. EO concentrations in hydrosols or cold storage are not sufficient to insure microbiological stability. Additional

Some estimates of the continuous cultivation of microorganisms

Directory of Open Access Journals (Sweden)

G. V. Alekseev

2017-01-01

Full Text Available The proteins, fats and carbohydrates received by the person traditionally from animal and vegetable sources don't cover all increasing needs of mankind any more today. At the same time proteins and fats of microorganisms with success can replace proteins and fats of a traditional origin. As protein producers microorganisms at the high content of protein in biomass and high growth rate of microorganisms have certain advantages. The present article is devoted to questions of numerical modeling of processes of cultivation of microorganisms. On the basis of the known model offered Mono in which saturation of growth rate of culture at increase in initial concentration of a substratum of S0 is considered the system of the differential equations describing the happening processes in that number before achievement of stationarity is written down. At the same time dependence of separate sizes, the systems entering the equations is insufficiently studied at change of parameters of process. The behavior of all system at violation of regulations is of interest or at unauthorized change of one of parameters. For studying of these questions numerical modeling is carried out and the basic picture of change of chemostate curves in these conditions is received

Is arsenic biotransformation a detoxification mechanism for microorganisms?

International Nuclear Information System (INIS)

Rahman, M. Azizur; Hassler, Christel

2014-01-01

Arsenic (As) is extremely toxic to living organisms at high concentration. In aquatic systems, As exists in different chemical forms. The two major inorganic As (iAs) species are As V , which is thermodynamically stable in oxic waters, and As III , which is predominant in anoxic conditions. Photosynthetic microorganisms (e.g., phytoplankton and cyanobacteria) take up As V , biotransform it to As III , then biomethylate it to methylarsenic (MetAs) forms. Although As III is more toxic than As V , As III is much more easily excreted from the cells than As V . Therefore, majority of researchers consider the reduction of As V to As III as a detoxification process. The biomethylation process results in the conversion of toxic iAs to the less toxic pentavalent MetAs forms (monomethylarsonate; MMA V , dimethylarsonate; DMA V , and trimethylarsenic oxide; TMAO V ) and trimethylarsine (TMAO III ). However, biomethylation by microorganisms also produces monomethylarsenite (MMA III ) and dimethylarsenite (DMA III ), which are more toxic than iAs, as a result of biomethylation by the microorganisms, demonstrates the need to reconsider to what extent As biomethylation contributes to a detoxification process. In this review, we focused on the discussion of whether the biotransformation of As species in microorganisms is really a detoxification process with recent data

40 CFR 725.67 - Applications to exempt new microorganisms from this part.

Science.gov (United States)

2010-07-01

...) The effects of the new microorganism on health and the environment. (ii) The magnitude of exposure of human beings and the environment to the new microorganism. (iii) The benefits of the new microorganism... economic consequences of granting or denying the exemption, including effects on the national economy...

Decontamination of food packaging using electron beam--status and prospects

Energy Technology Data Exchange (ETDEWEB)

Mittendorfer, J. E-mail: htcmitt@eunet.at; Bierbaumer, H.P.; Gratzl, F.; Kellauer, E

2002-03-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding.

Decontamination of food packaging using electron beam—status and prospects

Science.gov (United States)

Mittendorfer, J.; Bierbaumer, H. P.; Gratzl, F.; Kellauer, E.

2002-03-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding.

Decontamination of food packaging using electron beam--status and prospects

International Nuclear Information System (INIS)

Mittendorfer, J.; Bierbaumer, H.P.; Gratzl, F.; Kellauer, E.

2002-01-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding

Evolution, Metabolism and Biotechnological Usage of Methylotrophic Microorganisms

OpenAIRE

Oleg Mosin; Ignat Ignatov

2014-01-01

Methylotrophs – aerobic chemoheterotrophic microorganisms submitted by cocci and bacilli mobile forms, are inhabitants of reservoirs and soils of various type, where there are going on various processes of decomposition of organic substances with formation of the one-carbon С1-compounds and some С2-, and С3-compounds, capable to be assimilated by methylotrophs. These microorganisms assimilating carbon on ribuloso-5-monophospate and serine pathways, are allocated from soil ground, the sewage c...

Interactions between nitric oxide and ethylene in monomeric G-protein activation in relation to food spoilage

DEFF Research Database (Denmark)

Hall, M A; moshkov, moshkov; Novikova, G

2014-01-01

Climate change is likely to increase crop stress with negative impacts on yield and quality. Therefore, there is a need to develop our understanding of the key events which govern plant tolerance to stress. Intense research has identified key signalling cascades regulating stress tolerance...... and it is notable that many are dependent on the production of volatile signals or signals which have volatile derivatives. Ethylene (ET) has long been recognized as an important regulator of development, stress responses, senescence and food spoilage. Our work has focused on the gaseous signal nitric oxide (NO......) and how it interacts with established stress signalling pathways and in particular, those regulated by ET. Using laser photoacoustic detection (LPAD) we have established that NO production overlaps with that of ethylene during plant responses to disease. To examine the interaction of NO and ET signalling...

Screening of microorganisms for microbial enhanced oil recovery processes

Energy Technology Data Exchange (ETDEWEB)

Yonebayashi, H. [Japan National Oil Corp., Tokyo (Japan); Yoshida, S. [Japan Food Research Laboratiories, Tokyo (Japan). Div. of Microbiology; Ono, K. [Japan National Oil Corp., Chiba (Japan). Tech. Research Center; Enomoto, H. [Tohoku University, Sendai (Japan). Dept. of Geoscience and Tech.

2000-01-01

The objective of this study is to screen effective microorganisms for the Microbial Enhanced Oil Recovery process (or simply as MEOR). Samples of drilling cuttings, formation water, and soil were collected from domestic drilling sites and oil fields. Moreover, samples of activated-sludge and compost were collected from domestic sewage treatment facility and food treatment facility. At first, microorganisms in samples were investigated by incubation with different media; then they were isolated. By two stage-screening based on metabolizing ability, 4 strains (Bacillus licheniformis TRC-18-2-a, Enterobacter cloacae TRC-322, Bacillus subtilis TRC-4118, and Bacillus subtilis TRC-4126) were isolated as effective microorganisms for oil recovery. B. licheniformis TRC-18-2-a is a multifunctional microorganism possessing excellent surfactant productivity, and in addition it has gas, acid and polymer productivities. E. cloacae TRC-332 has gas and acid producing abilities. B. subtilis TRC-4118 and TRC-4126 are effective biosurfactant producers, and they reduce the interfacial tension to 0.04 and 0.12 dyne/cm, respectively. (author)

Powering microbes with electricity: direct electron transfer from electrodes to microbes.

Science.gov (United States)

Lovley, Derek R

2011-02-01

The discovery of electrotrophs, microorganisms that can directly accept electrons from electrodes for the reduction of terminal electron acceptors, has spurred the investigation of a wide range of potential applications. To date, only a handful of pure cultures have been shown to be capable of electrotrophy, but this process has also been inferred in many studies with undefined consortia. Potential electron acceptors include: carbon dioxide, nitrate, metals, chlorinated compounds, organic acids, protons and oxygen. Direct electron transfer from electrodes to cells has many advantages over indirect electrical stimulation of microbial metabolism via electron shuttles or hydrogen production. Supplying electrons with electrodes for the bioremediation of chlorinated compounds, nitrate or toxic metals may be preferable to adding organic electron donors or hydrogen to the subsurface or bioreactors. The most transformative application of electrotrophy may be microbial electrosynthesis in which carbon dioxide and water are converted to multi-carbon organic compounds that are released extracellularly. Coupling photovoltaic technology with microbial electrosynthesis represents a novel photosynthesis strategy that avoids many of the drawbacks of biomass-based strategies for the production of transportation fuels and other organic chemicals. The mechanisms for direct electron transfer from electrodes to microorganisms warrant further investigation in order to optimize envisioned applications. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Root Canal Microorganism Profiles on Upper Anterior Teeth of Apical Periodontitis

OpenAIRE

Riuwpassa, E. Irene

2013-01-01

Microorganisms are the main causative agents on the development of apical periodontitis. Microorganisms infecting the root canal system are colonized in communities as biofilm. These bacterial communities show distinct pattern related to the different forms of apical periodontitis which are determined by species richness and abundance.this study is aimed to examine the root canal microorganisms on upper anterior teeth of asymptomatic apical periodontitis and chronic apical abscess. Samples we...

Root Canal Microorganisms Profiles of Upper Anterior Teeth with Periapical Lesion

OpenAIRE

Maria Tanumiharja; Irene E. Riewpassa; Mansjur Nasir; Burhanuddin D. Pasiga

2014-01-01

Microorganisms are the main causative agents on the development of apical periodontitis. Microorganisms infecting the root canal system are colonized in communities as biofilm. These bacterial communities show distinct pattern related to the different forms of apical periodontitis which are determined by species richness and abundance. Objective: This study is aimed to examine the root canal microorganisms on upper anterior teeth of asymptomatic apical periodontitis and chronic apical abscess...

Differentiation and detection of microorganisms using Fourier transform infrared photoacoustic spectroscopy

Science.gov (United States)

Irudayaraj, Joseph; Yang, Hong; Sakhamuri, Sivakesava

2002-03-01

Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was used to differentiate and identify microorganisms on a food (apple) surface. Microorganisms considered include bacteria (Lactobacillus casei, Bacillus cereus, and Escherichia coli), yeast (Saccharomyces cerevisiae), and fungi (Aspergillus niger and Fusarium verticilliodes). Discriminant analysis was used to differentiate apples contaminated with the different microorganisms from uncontaminated apple. Mahalanobis distances were calculated to quantify the differences. The higher the value of the Mahalanobis distance metric between different microorganisms, the greater is their difference. Additionally, pathogenic (O157:H7) E. coli was successfully differentiated from non-pathogenic strains. Results demonstrate that FTIR-PAS spectroscopy has the potential to become a non-destructive analysis tool in food safety related research.

Progress in decontamination by halophilic microorganisms in saline wastewater and soil

International Nuclear Information System (INIS)

Zhuang Xuliang; Han Zhen; Bai Zhihui; Zhuang Guoqiang; Shim Hojae

2010-01-01

Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.

Progress in decontamination by halophilic microorganisms in saline wastewater and soil

Energy Technology Data Exchange (ETDEWEB)

Zhuang Xuliang, E-mail: xlzhuang@rcees.ac.c [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Bureau of Science and Technology for Resources and Environment, Chinese Academy of Sciences, Beijing 100864 (China); Han Zhen [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Bai Zhihui; Zhuang Guoqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Shim Hojae [Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau (China)

2010-05-15

Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.

Calculation of the radiative properties of photosynthetic microorganisms

International Nuclear Information System (INIS)

Dauchet, Jérémi; Blanco, Stéphane; Cornet, Jean-François; Fournier, Richard

2015-01-01

A generic methodological chain for the predictive calculation of the light-scattering and absorption properties of photosynthetic microorganisms within the visible spectrum is presented here. This methodology has been developed in order to provide the radiative properties needed for the analysis of radiative transfer within photobioreactor processes, with a view to enable their optimization for large-scale sustainable production of chemicals for energy and chemistry. It gathers an electromagnetic model of light-particle interaction along with detailed and validated protocols for the determination of input parameters: morphological and structural characteristics of the studied microorganisms as well as their photosynthetic-pigment content. The microorganisms are described as homogeneous equivalent-particles whose shape and size distribution is characterized by image analysis. The imaginary part of their refractive index is obtained thanks to a new and quite extended database of the in vivo absorption spectra of photosynthetic pigments (that is made available to the reader). The real part of the refractive index is then calculated by using the singly subtractive Kramers–Krönig approximation, for which the anchor point is determined with the Bruggeman mixing rule, based on the volume fraction of the microorganism internal-structures and their refractive indices (extracted from a database). Afterwards, the radiative properties are estimated using the Schiff approximation for spheroidal or cylindrical particles, as a first step toward the description of the complexity and diversity of the shapes encountered within the microbial world. Finally, these predictive results are confronted to experimental normal-hemispherical transmittance spectra for validation. This entire procedure is implemented for Rhodospirillum rubrum, Arthrospira platensis and Chlamydomonas reinhardtii, each representative of the main three kinds of photosynthetic microorganisms, i.e. respectively

Calculation of the radiative properties of photosynthetic microorganisms

Science.gov (United States)

Dauchet, Jérémi; Blanco, Stéphane; Cornet, Jean-François; Fournier, Richard

2015-08-01

A generic methodological chain for the predictive calculation of the light-scattering and absorption properties of photosynthetic microorganisms within the visible spectrum is presented here. This methodology has been developed in order to provide the radiative properties needed for the analysis of radiative transfer within photobioreactor processes, with a view to enable their optimization for large-scale sustainable production of chemicals for energy and chemistry. It gathers an electromagnetic model of light-particle interaction along with detailed and validated protocols for the determination of input parameters: morphological and structural characteristics of the studied microorganisms as well as their photosynthetic-pigment content. The microorganisms are described as homogeneous equivalent-particles whose shape and size distribution is characterized by image analysis. The imaginary part of their refractive index is obtained thanks to a new and quite extended database of the in vivo absorption spectra of photosynthetic pigments (that is made available to the reader). The real part of the refractive index is then calculated by using the singly subtractive Kramers-Krönig approximation, for which the anchor point is determined with the Bruggeman mixing rule, based on the volume fraction of the microorganism internal-structures and their refractive indices (extracted from a database). Afterwards, the radiative properties are estimated using the Schiff approximation for spheroidal or cylindrical particles, as a first step toward the description of the complexity and diversity of the shapes encountered within the microbial world. Finally, these predictive results are confronted to experimental normal-hemispherical transmittance spectra for validation. This entire procedure is implemented for Rhodospirillum rubrum, Arthrospira platensis and Chlamydomonas reinhardtii, each representative of the main three kinds of photosynthetic microorganisms, i.e. respectively

Microorganisms having enhanced tolerance to inhibitors and stress

Energy Technology Data Exchange (ETDEWEB)

Brown, Steven D.; Yang, Shihui

2014-07-29

The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

Genomics-Based Identifcation of Microorganisms in Human Ocular Body Fluid

DEFF Research Database (Denmark)

Kirstahler, Philipp; Solborg Bjerrum, Søren; Friis-Møller, Alice

2018-01-01

genomes and (iii) the environment. Our metagenomic read classification revealed in nearly all cases the same microorganism that was determined in cultivation- and mass spectrometry-based analyses. For some patients, we identified the sequence type of the microorganism and antibiotic resistance genes...

Organotins and microorganisms. Yuki suzu kagobutsu to biseibutsu

Energy Technology Data Exchange (ETDEWEB)

Shinoda, S.; Onogi, H. (Okayama Univ., Okayama (Japan). Faculty of Pharmaceutical Sciences)

1992-08-10

Tributyltin (TBT) and triphenyltin have higher toxicity than other organotin compounds and are used as biocides, but in recent years the pollution of water and aquatic organisms has become a social problem. This paper describes the interaction between organotin compounds and microorganisms, centering on the decomposition of TBT. Part of microalgae whose activity is promoted by light or nutritive salts within an aquatic environment play an important role in TBT decomposition. Diatoms, and dinoflagellataes are mentioned as the examples. Moreover, an example in which microorganisms promote the transformation of inorganotin compounds to dimethyltin or trimethyltin is given. However, it is pointed out in this paper that the action of microorganisms relates greatly to the continuance of existence of organotins in environments, but the degradation efficiency is considered to be very low and prevention against pollution is of primary importance. 32 refs., 2 figs., 3 tabs.

Longterm storage of post-packaged bread by controlling spoilage pathogens using Lactobacillus fermentum C14 isolated from homemade curd.

Directory of Open Access Journals (Sweden)

Soma Barman

Full Text Available One potent lactic acid bacterial strain C14 with strong antifungal activity was isolated from homemade curd. Based on morphological as well as biochemical characters and 16S rDNA sequence homology the strain was identified as Lactobacillus fermentum. It displayed a wide antimicrobial spectrum against both Gram-positive and Gram-negative pathogenic bacteria, and also against number of food spoilage, plant and human pathogenic fungi. The cell free supernatant (CFS of the strain C14 was also effective against the fungi tested. Inhibition of radial growth of Penicillium digitatum, Trichophyton rubrum and Mucor sp. was noticed in the presence of CFS of C14 even at low concentration (1%. More than 94.3 ± 1.6% and 91.5 ± 2.2% inhibition of conidial germination of P. digitatum and Mucor sp. were noticed in the presence of 10-fold-concentrated CFS of C14. Massive deformation of the fungal mycelia was observed by SEM studies, and losses of cellular proteins and DNA are also evident upon its treatment with C14. HPLC analysis revealed the presence of phenyl lactic acid, lactic acid along with some unidentified compounds in the antifungal extract. Challenge experiment showed immense potential of the strain C14 in preventing the spoilage of bread samples caused by Mucor sp. and Bacillus subtilis. The bread samples remained fresh upto 25 days even after inoculation with Mucor sp. (3.7 × 104 spores /ml and B. subtilis (4.6 × 104 CFU /ml. Along with the antifungal properties, the isolated lactic acid bacterial strain also showed very good antioxidant activities. Unchanged level of liver enzymes serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase in albino mice upon feeding with C14 also suggested non-toxic nature of the bacterial isolate.

Investigation of sea microorganisms of the genus Alteromonas by 31P-NMR of high resolution

International Nuclear Information System (INIS)

Ivanova, E.P.; Isakov, V.V.; Mikhajlov, V.V.; Sokolova, S.V.; Gorshkova, N.M.; Fedosov, Yu.V.; Kiprianova, E.A.

1993-01-01

Comparative analysis of the 31 P-NMR spectra of intact cells of bacteria belonging to the genus Alteromonas, the producers of alkaline phosphatase was carried out. Differences in the content of phosphate-containing compounds were detected in individual species of the genus Alteromonas. By comparing the data on 31 P-NMR spectra, the electron micrographs and phosphatase activities, the possibility of revealing the presence of capsules was shown. Peculiar features of the 31 P-NMR spectra of alteromonades, as compared with other taxonomic groups of microorganisms, have been discussed

Gut Microorganisms Found Necessary for Successful Cancer Therapy | Poster

Science.gov (United States)

By Nancy Parrish, Staff Writer Humans play host to trillions of microorganisms that help our bodies perform basic functions, like digestion, growth, and fighting disease. In fact, bacterial cells outnumber the human cells in our bodies by 10 to 1.1 The tens of trillions of microorganisms thriving in our intestines are known as gut microbiota, and those that are not harmful to

Is arsenic biotransformation a detoxification mechanism for microorganisms?

Energy Technology Data Exchange (ETDEWEB)

Rahman, M. Azizur, E-mail: Mohammad.Rahman@uts.edu.au [Centre for Environmental Sustainability, School of the Environment, Faculty of Science, University of Technology, P.O. Box 123, Broadway, Sydney, NSW 2007 (Australia); Hassler, Christel [Marine and Lake Biogeochemistry, Institute F. A. Forel, University of Geneva, 10 rte de Suisse, Versoix, 1290 Switzerland (Switzerland)

2014-01-15

Arsenic (As) is extremely toxic to living organisms at high concentration. In aquatic systems, As exists in different chemical forms. The two major inorganic As (iAs) species are As{sup V}, which is thermodynamically stable in oxic waters, and As{sup III}, which is predominant in anoxic conditions. Photosynthetic microorganisms (e.g., phytoplankton and cyanobacteria) take up As{sup V}, biotransform it to As{sup III}, then biomethylate it to methylarsenic (MetAs) forms. Although As{sup III} is more toxic than As{sup V}, As{sup III} is much more easily excreted from the cells than As{sup V}. Therefore, majority of researchers consider the reduction of As{sup V} to As{sup III} as a detoxification process. The biomethylation process results in the conversion of toxic iAs to the less toxic pentavalent MetAs forms (monomethylarsonate; MMA{sup V}, dimethylarsonate; DMA{sup V}, and trimethylarsenic oxide; TMAO{sup V}) and trimethylarsine (TMAO{sup III}). However, biomethylation by microorganisms also produces monomethylarsenite (MMA{sup III}) and dimethylarsenite (DMA{sup III}), which are more toxic than iAs, as a result of biomethylation by the microorganisms, demonstrates the need to reconsider to what extent As biomethylation contributes to a detoxification process. In this review, we focused on the discussion of whether the biotransformation of As species in microorganisms is really a detoxification process with recent data.

Significance of heme-based respiration in meat spoilage caused by Leuconostoc gasicomitatum.

Science.gov (United States)

Jääskeläinen, Elina; Johansson, Per; Kostiainen, Olli; Nieminen, Timo; Schmidt, Georg; Somervuo, Panu; Mohsina, Marzia; Vanninen, Paula; Auvinen, Petri; Björkroth, Johanna

2013-02-01

Leuconostoc gasicomitatum is a psychrotrophic lactic acid bacterium (LAB) which causes spoilage in cold-stored modified-atmosphere-packaged (MAP) meat products. In addition to the fermentative metabolism, L. gasicomitatum is able to respire when exogenous heme and oxygen are available. In this study, we investigated the respiration effects on growth rate, biomass, gene expression, and volatile organic compound (VOC) production in laboratory media and pork loin. The meat samples were evaluated by a sensory panel every second or third day for 29 days. We observed that functional respiration increased the growth (rate and yield) of L. gasicomitatum in laboratory media with added heme and in situ meat with endogenous heme. Respiration increased enormously (up to 2,600-fold) the accumulation of acetoin and diacetyl, which are buttery off-odor compounds in meat. Our transcriptome analyses showed that the gene expression patterns were quite similar, irrespective of whether respiration was turned off by excluding heme from the medium or mutating the cydB gene, which is essential in the respiratory chain. The respiration-based growth of L. gasicomitatum in meat was obtained in terms of population development and subsequent development of sensory characteristics. Respiration is thus a key factor explaining why L. gasicomitatum is so well adapted in high-oxygen packed meat.

Assessment of system reliability for a stochastic-flow distribution network with the spoilage property

Science.gov (United States)

Lin, Yi-Kuei; Huang, Cheng-Fu; Yeh, Cheng-Ta

2016-04-01

In supply chain management, satisfying customer demand is the most concerned for the manager. However, the goods may rot or be spoilt during delivery owing to natural disasters, inclement weather, traffic accidents, collisions, and so on, such that the intact goods may not meet market demand. This paper concentrates on a stochastic-flow distribution network (SFDN), in which a node denotes a supplier, a transfer station, or a market, while a route denotes a carrier providing the delivery service for a pair of nodes. The available capacity of the carrier is stochastic because the capacity may be partially reserved by other customers. The addressed problem is to evaluate the system reliability, the probability that the SFDN can satisfy the market demand with the spoilage rate under the budget constraint from multiple suppliers to the customer. An algorithm is developed in terms of minimal paths to evaluate the system reliability along with a numerical example to illustrate the solution procedure. A practical case of fruit distribution is presented accordingly to emphasise the management implication of the system reliability.

Antibiotic cytotoxic effects of microorganisms isolated from Jachymov uranium mines

International Nuclear Information System (INIS)

Fuska, J.; Fuskova, A.

1982-01-01

Microorganisms were isolated from old relinquished uranium mines in Jachymov; they had been growing for several decades in darkness in temperatures of 5 to 12 degC and relative humidity from 80 to 100%. The concentration of uranium salts in mine waters varied from 10 -4 to 10 -5 g.l -1 , that of Rn in the atmosphere was from 0.04 to 40 Bq.l -1 . Of 324 cultures, 18.8% inhibited the growth of Bacillus subtilis, Escherichia coli and Candida pseudotropicalis and 16.6% that of HeLa cells. The frequency of microorganisms inhibiting the growth of HeLa or Ehrlich ascites cells was markedly higher in this set of cultures than among microorganisms kept in culture collections or isolated from other natural habitats. About 10% of the isolated cultures were mycelia sterilia. The following antibiotics were isolated from microorganisms obtained from uranium mines: frequentin, vermiculin, vermicillin, vermistatin, cytostipin and duclauxin. (author)

Antibiotic cytotoxic effects of microorganisms isolated from Jachymov uranium mines

Energy Technology Data Exchange (ETDEWEB)

Fuska, J.; Fuskova, A. (Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia). Chemickotechnologicka Fakulta); Jilek, R. (Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia))

1982-01-01

Microorganisms were isolated from old relinquished uranium mines in Jachymov; they had been growing for several decades in darkness in temperatures of 5 to 12 degC and relative humidity from 80 to 100%. The concentration of uranium salts in mine waters varied from 10/sup -4/ to 10/sup -5/ g.l/sup -1/, that of Rn in the atmosphere was from 0.04 to 40 Bq.l/sup -1/. Of 324 cultures, 18.8% inhibited the growth of Bacillus subtilis, Escherichia coli and Candida pseudotropicalis and 16.6% that of HeLa cells. The frequency of microorganisms inhibiting the growth of HeLa or Ehrlich ascites cells was markedly higher in this set of cultures than among microorganisms kept in culture collections or isolated from other natural habitats. About 10% of the isolated cultures were mycelia sterilia. The following antibiotics were isolated from microorganisms obtained from uranium mines: frequentin, vermiculin, vermicillin, vermistatin, cytostipin and duclauxin.

Radiation hygienization of cattle and swine slurry with high energy electron beam

International Nuclear Information System (INIS)

Skowron, Krzysztof; Olszewska, Halina; Paluszak, Zbigniew; Zimek, Zbigniew; Kałuska, Iwona; Skowron, Karolina Jadwiga

2013-01-01

The research was carried out to assess the efficiency of radiation hygienization of cattle and swine slurry of different density using the high energy electron beam based on the inactivation rate of Salmonella ssp, Escherichia coli, Enterococcus spp and Ascaris suum eggs. The experiment was conducted with use of the linear electron accelerator Elektronika 10/10 in Institute of Nuclear Chemistry and Technology in Warsaw. The inoculated slurry samples underwent hygienization with high energy electron beam of 1, 3, 5, 7 and 10 kGy. Numbers of reisolated bacteria were determined according to the MPN method, using typical microbiological media. Theoretical lethal doses, D 90 doses and hygienization efficiency of high energy electron beam were determined. The theoretical lethal doses for all tested bacteria ranged from 3.63 to 8.84 kGy and for A. suum eggs from 4.07 to 5.83 kGy. Salmonella rods turned out to be the most sensitive and Enterococcus spp were the most resistant to electron beam hygienization. The effectiveness or radiation hygienization was lower in cattle than in swine slurry and in thick than in thin one. Also the species or even the serotype of bacteria determined the dose needed to inactivation of microorganisms. - Highlights: ► The hygienic efficiency of electron beam against slurry was researched. ► The hygienization efficiency depended on the slurry characteristics and microorganism species. ► In most of the cases 7 kGy dose was sufficient for slurry hygienization. ► Dose below 1 kGy allowed for 90% elimination of microorganism population. ► The radiation hygienization is a good alternative for typical slurry treatment methods

Use of Probiotic Microorganisms for Bio-Protective Aims

Directory of Open Access Journals (Sweden)

Filiz YANGILAR

2015-03-01

Full Text Available It was known that some diseases can be treated as the result of the use of antibiotics in certain periods and at certain dosages while inactivating and deteriorating normal microorganisms performing useful activities in human metabolism (in especially intestinal flora. It was occured that after the use of antibiotics, some defects can be seen resulting from antibiotics (such as allergy, diarrhea, gas formation etc. With this aim, nutraceutics and functional food have gained importance over the last years and consumers began to be interested in probiotics, natural antioxidants, dietary fibres, products with low calorie and cholesterol contents, especially the products containing probioticbacteria. Bacteriocins produced by probiotic bacteria can play important roles as food protective and safeguarding since they can compete with unwanted or pathogen microorganisms survive in the media and colonize in intestines. In this review, is aimed to emphasis bioprotective compounds, advantages and disadvantages of biopreservation method and the importance of the mechanisms of probiotic microorganisms.

Use of ion chromatography for monitoring microbial spoilage in the fruit juice industry.

Science.gov (United States)

Trifirò, A; Saccani, G; Gherardi, S; Vicini, E; Spotti, E; Previdi, M P; Ndagijimana, M; Cavalli, S; Reschiotto, C

1997-05-16

Fruit juices and purees are defined as fermentable, but unfermented, products obtained by mechanical processing of fresh fruits. The presence of undesired metabolites derived from microbial growth can arise from the use of unsuitable fruit or from defects in the production line or subsequent contamination. This involves a loss in the overall quality that cannot be resolved by thermal treatment following the start of fermentation. With these considerations, together with microbiological control, the analysis of different metabolites, which can be considered as microbial growth markers, such as alcohols (i.e. ethanol, etc.), acids (i.e. acetic, fumaric, lactic, etc.) is fundamental in order to achieve a better evaluation of product quality. Enzymatic determination and other single-component analytical techniques are often used for the determination of these metabolites. When the microbial spoilage is not well known, this results in a long and cumbersome procedure. A versatile technique that is capable of determining many metabolites in one analysis could be helpful in improving routine quality control. For this purpose, an ion chromatographic technique, such as ion exclusion, for separation, and diode array spectrophotometry and conductivity, for detection, were evaluated. Both different industrial samples and inoculated samples were analyzed.

Modelling the Ozone-Based Treatments for Inactivation of Microorganisms

Directory of Open Access Journals (Sweden)

Agnieszka Joanna Brodowska

2017-10-01

Full Text Available The paper presents the development of a model for ozone treatment in a dynamic bed of different microorganisms (Bacillus subtilis, B. cereus, B. pumilus, Escherichia coli, Pseudomonas fluorescens, Aspergillus niger, Eupenicillium cinnamopurpureum on a heterogeneous matrix (juniper berries, cardamom seeds initially treated with numerous ozone doses during various contact times was studied. Taking into account various microorganism susceptibility to ozone, it was of great importance to develop a sufficiently effective ozone dose to preserve food products using different strains based on the microbial model. For this purpose, we have chosen the Weibull model to describe the survival curves of different microorganisms. Based on the results of microorganism survival modelling after ozone treatment and considering the least susceptible strains to ozone, we selected the critical ones. Among tested strains, those from genus Bacillus were recognized as the most critical strains. In particular, B. subtilis and B. pumilus possessed the highest resistance to ozone treatment because the time needed to achieve the lowest level of its survival was the longest (up to 17.04 min and 16.89 min for B. pumilus reduction on juniper berry and cardamom seed matrix, respectively. Ozone treatment allow inactivate microorganisms to achieving lower survival rates by ozone dose (20.0 g O3/m3 O2, with a flow rate of 0.4 L/min and contact time (up to 20 min. The results demonstrated that a linear correlation between parameters p and k in Weibull distribution, providing an opportunity to calculate a fitted equation of the process.

Modelling the Ozone-Based Treatments for Inactivation of Microorganisms

Science.gov (United States)

Brodowska, Agnieszka Joanna; Nowak, Agnieszka; Kondratiuk-Janyska, Alina; Piątkowski, Marcin; Śmigielski, Krzysztof

2017-01-01

The paper presents the development of a model for ozone treatment in a dynamic bed of different microorganisms (Bacillus subtilis, B. cereus, B. pumilus, Escherichia coli, Pseudomonas fluorescens, Aspergillus niger, Eupenicillium cinnamopurpureum) on a heterogeneous matrix (juniper berries, cardamom seeds) initially treated with numerous ozone doses during various contact times was studied. Taking into account various microorganism susceptibility to ozone, it was of great importance to develop a sufficiently effective ozone dose to preserve food products using different strains based on the microbial model. For this purpose, we have chosen the Weibull model to describe the survival curves of different microorganisms. Based on the results of microorganism survival modelling after ozone treatment and considering the least susceptible strains to ozone, we selected the critical ones. Among tested strains, those from genus Bacillus were recognized as the most critical strains. In particular, B. subtilis and B. pumilus possessed the highest resistance to ozone treatment because the time needed to achieve the lowest level of its survival was the longest (up to 17.04 min and 16.89 min for B. pumilus reduction on juniper berry and cardamom seed matrix, respectively). Ozone treatment allow inactivate microorganisms to achieving lower survival rates by ozone dose (20.0 g O3/m3 O2, with a flow rate of 0.4 L/min) and contact time (up to 20 min). The results demonstrated that a linear correlation between parameters p and k in Weibull distribution, providing an opportunity to calculate a fitted equation of the process. PMID:28991199

Microorganisms' mediated reduction of β-ketoesters

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... Whole cells usually express a multitude of enzymatic activities; therefore an ... Each microorganism was cultivated for the biomass development on specific medium ..... Ketoester reductase for conversion of keto acid esters to ...

Threshold Dynamics of a Stochastic Chemostat Model with Two Nutrients and One Microorganism

Directory of Open Access Journals (Sweden)

Jian Zhang

2017-01-01

Full Text Available A new stochastic chemostat model with two substitutable nutrients and one microorganism is proposed and investigated. Firstly, for the corresponding deterministic model, the threshold for extinction and permanence of the microorganism is obtained by analyzing the stability of the equilibria. Then, for the stochastic model, the threshold of the stochastic chemostat for extinction and permanence of the microorganism is explored. Difference of the threshold of the deterministic model and the stochastic model shows that a large stochastic disturbance can affect the persistence of the microorganism and is harmful to the cultivation of the microorganism. To illustrate this phenomenon, we give some computer simulations with different intensity of stochastic noise disturbance.

ENHANCING FOOD SAFETY AND STABILITY THROUGH IRRADIATION: A REVIEW

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Manzoor Ahmad Shah

2014-04-01

Full Text Available Food irradiation is one of the non thermal food processing methods. It is the process of exposing food materials to the controlled amounts of ionizing radiations such as gamma rays, X-rays and accelerated electrons, to improve microbiological safety and stability. Irradiation disrupts the biological processes that lead to decay of food quality. It is an effective tool to reduce food-borne pathogens, spoilage microorganisms and parasites; to extend shelf-life and for insect disinfection. The safety and consumption of irradiated foods have been extensively studied at national levels and in international cooperations and have concluded that foods irradiated under appropriate technologies are both safe and nutritionally adequate. Specific applications of food irradiation have been approved by national legislations of more than 55 countries worldwide. This review aims to discuss the applications of irradiation in food processing with the emphasis on food safety and stability.

Selection of Suitable Microorganism for Biocatalytic Oxidation Reaction of Racemic Propranolol

Directory of Open Access Journals (Sweden)

Rahime SONGÜR

2017-12-01

Full Text Available Propranolol is one of the β-blockers which are pharmaceutically important, especially used for treatment of cardiovasculer disease. In this study, the production of enantiomerically pure propranolol was aimed via biocatalytic deracemization including tandem oxidation-reduction reactions of racemic propranolol. Within this content, firstly suitable microorganism for the oxidation of racemic propranolol was investigated. Alcohol dehydrogenase (ADH enzyme for oxidation of propranolol and NADH oxidase enzyme for cofactor regeneration were necessary for the oxidation reactions. For this reason, ADH and NADH oxidase enzymes activities of different microorganisms were measured to select the microorganism for using as enzyme source. These microorganisms are Lactobacillus kefir NRRL B-1839, Rhodotorula glutunis DSM 70398, Rhizopus oryzae CBS 111718, Rhizopus arhizus. The highest ADH and NADH oxidase activities were obtained for L. kefir.

Effect of gamma-irradiation to prevent the spoilage of fried-Kamaboko

Energy Technology Data Exchange (ETDEWEB)

Ito, H; Siagian, E G [Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment

1979-08-01

The study was done to determine the effect of irradiation on the shelf life and quality of a fish meat jelly product named as Fried-Kamaboko which is sometimes called as Satsumaage. Fresh samples were packed and sealed in cellophane coated polyvinylchloride bag with nitrogen gas, and irradiated at 0, 300 and 500 krad followed by storage at 10/sup 0/C. The results showed that irradiation of 300 krad extended the shelf life of Fried-Kamaboko to be 20 days, in contrast to unirradiated samples which were kept only 3 to 6 days at 10/sup 0/C. The species of main microorganisms which grew in unirradiated samples were Micrococcus, Moraxella-Acinetobacter, lactic acid bacteria, yeasts and molds. Irradiation of Fried-Kamaboko at 300 krad reduced the aforementioned flora to the yeasts. The most radio-resistant microorganisms of Fried-Kamaboko was brownish black Fungi identified as Spicaria, and its D/sub 10/ value was obtained to be 130 krad. No remarkable difference was observed between the irradiated Fried-Kamaboko and unirradiated ones with respect to the organoleptic evaluation. But off-odor was slightly induced with the dose of 500 krad irradiation.

Effect of gamma-irradiation to prevent the spoilage of fried-Kamaboko

International Nuclear Information System (INIS)

Ito, Hitoshi; Siagian, E.G.

1979-01-01

The study was done to determine the effect of irradiation on the shelf life and quality of a fish meat jelly product named as Fried-Kamaboko which is sometimes called as Satsumaage. Fresh samples were packed and sealed in cellophane coated polyvinylchloride bag with nitrogen gas, and irradiated at 0, 300 and 500 krad followed by storage at 10 0 C. The results showed that irradiation of 300 krad extended the shelf life of Fried-Kamaboko to be 20 days, in contrast to unirradiated samples which were kept only 3 to 6 days at 10 0 C. The species of main microorganisms which grew in unirradiated samples were Micrococcus, Moraxella-Acinetobacter, lactic acid bacteria, yeasts and molds. Irradiation of Fried-Kamaboko at 300 krad reduced the aforementioned flora to the yeasts. The most radio-resistant microorganisms of Fried-Kamaboko was brownish black Fungi identified as Spicaria, and its D 10 value was obtained to be 130 krad. No remarkable difference was observed between the irradiated Fried-Kamaboko and unirradiated ones with respect to the organoleptic evaluation. But off-odor was slightly induced with the dose of 500 krad irradiation. (author)

Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon ( Salmo salar ) analyzed by GC-MS and multivariate regression

DEFF Research Database (Denmark)

Jørgensen, Lasse Vigel; Huss, Hans Henrik; Dalgaard, Paw

2001-01-01

alcohols, which were produced by microbial activity. Partial least- squares regression of volatile compounds and sensory results allowed for a multiple compound quality index to be developed. This index was based on volatile bacterial metabolites, 1- propanol and 2-butanone, and 2-furan......, 1- penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography- olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop...

Microorganisms present on peripheral intravenous needleless connectors in the clinical environment.

Science.gov (United States)

Slater, Karen; Cooke, Marie; Whitby, Michael; Fullerton, Fiona; Douglas, Joel; Hay, Jennine; Rickard, Claire

2017-08-01

The aim of this study was to quantify culturable microorganisms on needleless connectors (NCs) attached to peripheral intravenous catheters in hospitalized adult medical patients. Half (50%) of 40 NCs were contaminated with microorganisms commonly found on the skin or mouth. Staphylococcus capitis and Staphylococcus epidermidis were most commonly isolated. Emergency department insertion and higher patient dependency were statistically associated with positive NC microorganism growth. These results reaffirm the need for NC decontamination prior to access. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Identification and Characterization of Extremophile Microorganisms with Significance to Astrobiology

Science.gov (United States)

Bej, Asim K.

2003-01-01

It is now well recognized that microorganisms thrive in extreme ecological conditions such as geothermal vents, polar region, acid and alkaline lakes, and the cold pressurized depth of the ocean floor of this planet. Morphological, physiological, biochemical and genetic adaptations to extreme environments by these extremophile microorganisms have generated immense interest amongst astrobiologists who increasingly believe in the existence of extraterrestrial life. The evidence collected by NASA's space probe Galileo suggested the presence of liquid water and volcanic activity on Mars and Jupiter's satellite Europa. Volcanic activity provides some of the heat necessary to keep the water on Europa from freezing that could provide important dissolved chemicals needed by living organisms. The possibility of the existence of hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters on Mars, and a layer of liquid water under the ice on Europa provide sufficient 'raison d'etre' to study microorganisms in similar extreme environments on Earth, which could provide us with a model that would help establish the existence of extraterrestrial life on other planetary bodies. The objectives of the summer research project were as follows: (1) application of molecular approaches to help establish new species of extremophile microorganisms isolated from a hypersaline alkaline lake; and (2) identification of a major cold-shock gene (cspA) homolog from a psychrotolerant microorganism, PmagG1.

Metabolic Profiling of Food Protective Cultures by in vitro NMR Spectroscopy

DEFF Research Database (Denmark)

Ebrahimi, Parvaneh

Food spoilage is of major concern to the food industry, because it leads to considerable economic losses, a deteriorated environmental food-print, and to possible public health hazards. In order to limit food spoilage, research on the preservation of food products has always received particular......-called protective cultures) has unexploited potential to inhibit the growth of pathogenic microorganisms and enhance the shelf life of the final food product. In order to apply biopreservation in food products effectively, detailed knowledge on the metabolism of protective cultures is required. The present Ph......D project is mainly focused on the application of in vitro NMR spectroscopy for studying the metabolism of protective cultures. As an important part of this work, an analytical protocol was developed for realtime in vitro NMR measurements of bacterial fermentation, which includes guidelines from the sample...

Microbial changes and growth of Listeria monocytogenes during chilled storage of brined shrimp ( Pandalus borealis )

DEFF Research Database (Denmark)

Mejlholm, Ole; Kjeldgaard, J.; Modberg, A.

2008-01-01

Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produced...... and lactic acids were studied. Furthermore, the effect of adding diacetate to brined shrimp was evaluated. A single batch of cooked and peeled shrimp was used to study both industrially and manually processed brined shrimp with respect to the effect of process hygiene on microbial changes and the shelf life...... of products. Concentrations of microorganisms on newly produced brined shrimp from an industrial scale processing line were 1.0-2.3 log (CFU g(-1)) higher than comparable concentrations in manually processed samples. This resulted in a substantially shorter shelf life and a more diverse spoilage microflora...

Uric acid in plants and microorganisms: Biological applications and genetics - A review.

Science.gov (United States)

Hafez, Rehab M; Abdel-Rahman, Tahany M; Naguib, Rasha M

2017-09-01

Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

Uric acid in plants and microorganisms: Biological applications and genetics - A review

Directory of Open Access Journals (Sweden)

Rehab M. Hafez

2017-09-01

Full Text Available Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

The evolution of glutathione metabolism in phototrophic microorganisms

Science.gov (United States)

Fahey, Robert C.; Buschbacher, Ralph M.; Newton, Gerald L.

1988-01-01

The low molecular weight thiol composition of a variety of phototropic microorganisms is examined in order to ascertain how evolution of glutathione (GSH) production is related to the evolution of oxygenic photosynthesis. Cells were extracted in the presence of monobromobimane (mBBr) to convert thiols (RSH) to fluorescent derivatives (RSmB) which were analyzed by high performance liquid chromatography (HPLC). Significant levels of GSH were not found in green sulfur bacteria. Substantial levels were present in purple bacteria, cyanobacteria, and eukaryotic algae. Other thiols measured included cysteine, gamma-glutamylcysteine, thiosulfate, coenzyme A, and sulfide. Many of the organisms also exhibited a marked ability to reduce mBBr to syn-(methyl,methyl)bimane, an ability which was quenched by treatment with 2-pyridyl disulfide or 5,5 prime-bisdithio - (2-nitrobenzoic acid) prior to reaction with mBBr. These observations indicate the presence of a reducing system capable of electron transfer to mBBr and reduction of reactive disulfides. The distribution of GSH in phototropic eubacteria indicates that GSH synthesis evolved at or around the time that oxygenic photosynthesis evolved.

The useful micro-organism

International Nuclear Information System (INIS)

1970-01-01

Can man survive civilization? Academician Ivan Malek, Director of the Institute of Microbiology in Prague, a member of the Agency's Scientific Advisory Committee and for many years an adviser to the Food and Agriculture Organization, the World Health Organization and UNESCO, believes he can, But he also considers that if man is to survive he must study and use all the resources at his disposal - including the micro-organisms of the planet earth. (author)

Stethoscopes as potential intrahospital carriers of pathogenic microorganisms.

Science.gov (United States)

Campos-Murguía, Alejandro; León-Lara, Ximena; Muñoz, Juan M; Macías, Alejandro E; Alvarez, José A

2014-01-01

Stethoscopes can take part in the transmission of health care-associated infections. We cultured 112 stethoscopes by direct imprint on blood agar to estimate the prevalence of potentially pathogenic microorganisms. Forty-eight (47%) produced 50 potentially pathogenic microorganisms; from these, 43 (86%) were Staphylococcus aureus, of which 18 (42%) were methicillin-resistant S. aureus. We concluded that stethoscopes should be considered as potential fomites and must be disinfected routinely before and after each patient contact. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Extremely thermophilic microorganisms and their polymer-hidrolytic enzymes

Directory of Open Access Journals (Sweden)

Andrade Carolina M.M.C.

1999-01-01

Full Text Available Thermophilic and hyperthermophilic microorganisms are found as normal inhabitants of continental and submarine volcanic areas, geothermally heated sea-sediments and hydrothermal vents and thus are considered extremophiles. Several present or potential applications of extremophilic enzymes are reviewed, especially polymer-hydrolysing enzymes, such as amylolytic and hemicellulolytic enzymes. The purpose of this review is to present the range of morphological and metabolic features among those microorganisms growing from 70oC to 100°C and to indicate potential opportunities for useful applications derived from these features.

ROOT CANAL MICROORGANISMS PROFILES O F UPPER ANTERIOR TEETH WITH APICAL PERIODONTITIS

OpenAIRE

Tanumihardja, Maria; Riewpassa, Irene E; Mansjurnasir; Burhanuddin, DP

2013-01-01

Microorganisms are the main causative agents on the development of apical periodontitis. Microorganisms infecting the root canal system are colonized in communities as biofilm. These bacterial communities show distinct pattern related to the different forms of apical periodontitis which are determined by species richness and abundance. This study is aimed to examine the root canal microorganisms on upper anterior teeth of asymptomatic apical periodontitis and ch ronic api...

Marine microorganisms. Umi no biseibutsu

Energy Technology Data Exchange (ETDEWEB)

Shimizu, U. (Hiroshima University, Hiroshima (Japan). Faculty of Applied Biological Science)

1992-11-10

This paper explains properties, interactions, and activities of marine microorganisms. Marine bacteria include bacteria of vibrio family of arteromonas genus, luminous bacteria, and aerobic photosynthetic bacteria. Majority of marine bacteria is halophilic, and many proliferate at 5[degree]C or lower. Some of them can proliferate at 20[degree]C to 30[degree]C, or as high temperature as 80[degree]C and higher. Spongiaria and tumicata have many symbiotic microorganisms, and genes equivalent to luminous bacteria genes were discovered in DNA of light emitting organs in luminous fishes. It was verified that animal groups in upwelling zones are supported by bacteria that assimilate inorganics supplied from ocean bottoms. Marine bacteria decompose almost all of organics brought in from land to sea, and those produced in sea. Marine bacteria engage in complex interrelations with other organisms for competition, antagonism, parasitism, and symbiosis. The bacteria make antibacterial substances, anti-algae bacteria, enzyme inhibitors, toxins, pharmacologically active substances, and such physiologically active substances as deposition promoting substances to undersea structures including shells and barnacles, and deposition blocking substances. 53 refs., 3 figs.

Electrical resistivity and dielectric properties of helical microorganism cells coated with silver by electroless plating

Energy Technology Data Exchange (ETDEWEB)

Cai, Jun, E-mail: jun_cai@buaa.edu.cn [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Lan, Mingming; Zhang, Deyuan; Zhang, Wenqiang [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

2012-09-01

Highlights: Black-Right-Pointing-Pointer We use the microorganism cells as forming templates to fabricate the bio-based conductive particles. Black-Right-Pointing-Pointer The microorganism cells selected as forming templates are Spirulina platens, which are of natural helical shape and high aspect ratio. Black-Right-Pointing-Pointer The sliver-coated Spirulina cells are a kind of lightweight conductive particles. Black-Right-Pointing-Pointer The composites containing sliver-coated Spirulina cells exhibit a lower percolation value. - Abstract: In this paper, microorganism cells (Spirulina platens) were used as forming templates for the fabrication of the helical functional particles by electroless silver plating process. The morphologies and ingredients of the coated Spirulina cells were analyzed with scanning electron microscopy and energy dispersive spectrometer. The crystal structures were characterized by employing the X-ray diffraction. The electrical resistivity and dielectric properties of samples containing different volume faction of sliver-coated Spirulina cells were measured and investigated by four-probe meter and vector network analyzer. The results showed that the Spirulina cells were successfully coated with a uniform silver coating and their initial helical shapes were perfectly kept. The electrical resistivity and dielectric properties of the samples had a strong dependence on the volume content of sliver-coated Spirulina cells and the samples could achieve a low percolation value owing to high aspect ratio and preferable helical shape of Spirulina cells. Furthermore, the conductive mechanism was analyzed with the classic percolation theory, and the values of {phi}{sub c} and t were obtained.

A hydrogen-oxidizing, Fe(III)-reducing microorganism from the Great Bay estuary, New Hampshire

Science.gov (United States)

Caccavo, F.; Blakemore, R.P.; Lovley, D.R.

1992-01-01

A dissimilatory Fe(III)- and Mn(IV)-reducing bacterium was isolated from bottom sediments of the Great Bay estuary, New Hampshire. The isolate was a facultatively anaerobic gram-negative rod which did not appear to fit into any previously described genus. It was temporarily designated strain BrY. BrY grew anaerobically in a defined medium with hydrogen or lactate as the electron donor and Fe(III) as the electron acceptor. BrY required citrate, fumarate, or malate as a carbon source for growth on H2 and Fe(III). With Fe(III) as the sole electron acceptor, BrY metabolized hydrogen to a minimum threshold at least 60-fold lower than the threshold reported for pure cultures of sulfate reducers. This finding supports the hypothesis that when Fe(III) is available, Fe(III) reducers can outcompete sulfate reducers for electron donors. Lactate was incompletely oxidized to acetate and carbon dioxide with Fe(III) as the electron acceptor. Lactate oxidation was also coupled to the reduction of Mn(IV), U(VI), fumarate, thiosulfate, or trimethylamine n-oxide under anaerobic conditions. BrY provides a model for how enzymatic metal reduction by respiratory metal-reducing microorganisms has the potential to contribute to the mobilization of iron and trace metals and to the immobilization of uranium in sediments of Great Bay Estuary.

Assessing the transport and fate of bioengineered microorganisms in the environment

International Nuclear Information System (INIS)

Barnthouse, L.W.; Palumbo, A.V.

1985-01-01

We review the methods currently available for quantifying the transport and fate of microbes in atmospheric and aqueous media and assess their adequacy for purposes of risk assessment. We review the literature on transport and fate of microorganisms, including studies of: (1) pathways of migration, (2) the survival of microorganisms during transport and fate. In addition, we review the transport and fate models that have been used in environmental risk assessments for radionuclides and toxic chemicals and evaluate their applicability to the problem of assessing environmental risks of bioengineered microorganisms

Inquiry-Based Laboratory Activity to Investigate Physical Growth Requirements of Microorganisms

Directory of Open Access Journals (Sweden)

Michelle Furlong

2014-08-01

Full Text Available Standard "cookbook" laboratory activities that are used to teach students the optimal physical growth conditions of microorganisms should be modified so that they more effectively foster student's higher order cognitive skills and attract student interest.  This paper describes a laboratory activity that engages students in an inquiry-based approach to studying the physical growth requirements of microorganisms.  In this activity, students design and implement an experiment to obtain pure cultures of specific microorganisms, with distinct growth properties, that are provided to them in a mixed culture.

Industrial applications or electron beams

International Nuclear Information System (INIS)

Martin, J. I.

2001-01-01

Industrial use of electron beams began in the 1950's with the crosslinking of polyethylene film and wire insulation. Today the number of electron beam Processing Systems installed for industrial applications throughout the world has grown to more than six hundred stations in over 35 countries. Total installed power is now approaching 40 megawatts (over 8 million tons of products per year). Electron beam is now utilized by many major industries including plastics, automotive, rubber goods, wire and cable, electrical insulation, semiconductor, medical, packaging, or pollution control. The principal effect of high-energy electrons is to produce ions in the materials treated, resulting in the liberation of orbital electrons. As a result, the original molecule is modified and the ree radicals combine to form new molecules with new chemical reactions or dis organisation od the DNA chains of living organisms (insects, fungus, microorganisms, etc.). (Author) 8 refs

In vivo investigations of genetically modified microorganisms using germ-free rats

DEFF Research Database (Denmark)

Lund jacobsen, Bodil

Risk evaluation of genetically modified microorganism (GMMO) in relation to human health effects brings into consideration the ability of the microorganism to survive and colonise the gastrointestinal tract and the potential gene transfer to the resident microbiota. Different biological containment...

Effects of High Hydrostatic Pressure on Escherichia coli Ultrastructure, Membrane Integrity and Molecular Composition as Assessed by FTIR Spectroscopy and Microscopic Imaging Techniques

OpenAIRE

Prieto-Calvo, María; Prieto, Miguel; López, Mercedes; Alvarez-Ordóñez, Avelino

2014-01-01

High hydrostatic pressure (HHP) is a novel food processing technology that is considered as an attractive alternative to conventional heat treatments for the preservation of foods, due to its lethal effects on pathogenic and spoilage microorganisms, while causing minor effects on food quality and sensorial attributes. This study is aimed at investigating how HHP treatments at varying intensities in the range 50–900 MPa affect the viability, membrane integrity, ultrastructure and molecular com...

Swimming of Microorganisms Viewed from String and Membrane Theories

OpenAIRE

Kawamura, Masako; Sugamoto, Akio; Nojiri, Shin'ichi

1993-01-01

Swimming of microorganisms is studied from a viewpoint of extended objects (strings and membranes) swimming in the incompressible f luid of low Reynolds number. The flagellated motion is analyzed in two dimensional fluid, by using the method developed in the ciliated motion with the Joukowski transformation. Discussion is given on the conserved charges and the algebra which are associated with the area (volume)- preserving diffeomorphisms giving the swimming motion of microorganisms. It is al...

Selection of mesophilic microorganisms with biodesulfuration capacity

International Nuclear Information System (INIS)

Madero, A; Mogollon, L. I; Mora, A.L; Osorio, L.F

1998-01-01

The development of bio desulfurization (BDS) processes for hydrocarbons requires fast and reliable methods for the screening of microorganisms. This work shows the results of the screening process for indigenous Colombian strains with a BDS potential capacity. The main criteria for the screening were the qualitative and quantitative determination of 2-hydroxybiphenyl (2-HBP) as the typical metabolite of the 4S specific pathway. Microorganisms were cultured by two methodologies, A and B, using DBT as the model compound. The quantitative determination of metabolites was made by HPLC. Thirteen strains were evaluated, including the strain Rhodococcus rhodocrous IGTS8, by methods A and B. In method A, the inoculum was exposed to DBT since the beginning of the culture. Method B, employed two stages: (i) Growth period under limiting sulfur conditions, (ii) Transforming period, in which the pre-grown inoculum was exposed to the organic sulfur substrate. The culture of mesophilic microorganisms isolated by method B, served to find a mechanism for the organic sulfur metabolism, and the evaluation of the sulfur removal capability of five indigenous strains. In the cultures of these strains, 2- hydroxybiphenyl (2-HBP) was detected as a byproduct of DBT metabolism, both qualitatively and quantitatively

[Succession of chitinolytic microorganisms in chernozem soil].

Science.gov (United States)

Manucharova, N A; Belova, E V; Vorob'ev, A V; Polianskaia, L M; Stepanov, A L

2005-01-01

The chitinolytic prokaryotic and eukaryotic microbial complex of chernozem soil has been investigated in the course of a succession initiated by the introduction of chitin and humidification. The dynamics of the cell numbers of chitinolytic microorganisms and of their biomass was assessed by fluorescent microscopy and by inoculation of selective media. Emission of carbon dioxide and nitrous oxide, as well as dinitrogen fixation, was assessed by gas chromatography. It was found that, when the succession was initiated by the introduction of both chitin and humidification, it resulted in greater cell numbers and biomass of chitinolytic microorganisms and higher levels of CO2 and N2O emission and of nitrogen fixation than when the succession was initiated by humidification alone. As compared to the control samples, a significant (twofold) increase in the prokaryote cell number and biomass was found on the fourth day of the succession initiated by humidification and introduction of chitin. One week after the initiation of succession, the fungal biomass and length of mycelium were twice as high as those in the control samples. These results led to the conclusion that chitin utilization in chernozem soil starts during the initial stages of succession and is performed by both prokaryotic and eukaryotic microorganisms.

[Application of Fourier transform infrared spectroscopy in identification of wine spoilage].

Science.gov (United States)

Zhao, Xian-De; Dong, Da-Ming; Zheng, Wen-Gang; Jiao, Lei-Zi; Lang, Yun

2014-10-01

In the present work, fresh and spoiled wine samples from three wines produced by different companies were studied u- sing Fourier transform infrared (FTIR) spectroscopy. We analyzed the physicochemical property change in the process of spoil- age, and then, gave out the attribution of some main FTIR absorption peaks. A novel determination method was explored based on the comparisons of some absorbance ratios at different wavebands although the absorbance ratios in this method were relative. Through the compare of the wine spectra before and after spoiled, the authors found that they were informative at the bands of 3,020~2,790, 1,760~1,620 and 1,550~800 cm(-1). In order to find the relation between these informative spectral bands and the wine deterioration and achieve the discriminant analysis, chemometrics methods were introduced. Principal compounds analysis (PCA) and soft independent modeling of class analogy (SIMCA) were used for classifying different-quality wines. And partial least squares discriminant analysis (PLS-DA) was applied to identify spoiled wines and good wines. Results showed that FTIR technique combined with chemometrics methods could effectively distinguish spoiled wines from fresh samples. The effect of classification at the wave band of 1 550-800 cm(-1) was the best. The recognition rate of SIMCA and PLSDA were respectively 94% and 100%. This study demonstrates that Fourier transform infrared spectroscopy is an effective tool for monitoring red wine's spoilage and provides theoretical support for developing early-warning equipments.

Preparation of microorganism free carrier for biofertilizer product

International Nuclear Information System (INIS)

Latiffah Norddin; Maizatul Akmam Mhd Nasir; Phua Choo Kwai Hoe

2007-01-01

Biofertilizer has been identified as an alternative or complementary to chemical fertilizer to increase soil fertility and crop production in sustainable farming. Biofertilizers are products containing living cells of different types of known microorganisms that may increase crop productivity through N2 fixation, phosphate solubilization or stimulation of plant growth by synthesising phytohormones. A good biofertilizer product needs a good carrier or substrate. A good carrier is free from microbial contamination and can optimise the growth of the biofertilizer microorganisms. Compost is commonly used as carrier or substrate for biofertilizer microorganisms. In the present study, compost produced by Nuclear Malaysia using the Natural Farming was used as a carrier for the biofertilizer products. Gamma irradiation has been used to produce a ?clean? or sterile carrier. The sterilization effect of the carrier was checked by using serial dilution technique. Carriers that were irradiated at 50 kGy of gamma irradiation were found to be sterile. The shelf life of the sterile carriers was also determined. After six months the compost carriers were still free from microbial contamination. (Author)

Selection of potential microorganism for sago starch fermentation

Directory of Open Access Journals (Sweden)

RUTH MELLIAWATI

2006-02-01

Full Text Available Fermentation process of sago starch for the production of bioproduct requires potential microorganism that have ability to hydrolyze sago starch. The purpose of this research was to get the potential of amylolytic microorganisms for their capability of amyloglucosidase activity and to know the sugar strains of the fermentation result. Eleven amylolytic microorganisms (9 strains of mold and 2 strains of yeast were obtained from the collection Research Centre for Biotechnology – Indonesian Institute of Sciences (LIPI, Cibinong-Bogor were used. The selection step was carried out based on their capability of starch hydrolysis to reducing sugar. The best result indicates that the production of reducing sugar reached the highest 18.485 ppm and amyloglucosidase activities was 3.583 units by KTU-1 strain. The highest total acid obtained was 5.85 mg/mL by Rhizopus IFO.R5442. The cell biomass was obtained between 0.5 to 1.74 g dry weight/100 mL and pH of the final fermentation (72 h were 3.57 to 8.38.

Lignite microorganisms

Energy Technology Data Exchange (ETDEWEB)

Bulankina, M.A.; Lysak, L.V.; Zvyagintsev, D.G. [Moscow MV Lomonosov State University, Moscow (Russian Federation). Faculty of Soil Science

2007-03-15

The first demonstration that samples of lignite at a depth of 10 m are considerably enriched in bacteria is reported. According to direct microscopy, the abundance of bacteria was about 10{sup 7} cells/g. About 70% of cells had intact cell membranes and small size, which points to their anabiotic state. The fungal mycelium length was no more than 1 m. Lignite inoculation onto solid glucose-yeast-peptone medium allowed us to isolate bacteria of the genera Bacillus, Rhodococcus, Arthrobacter, Micrococcus, Spirillum, and Cytophaga. Representatives of the genera Penicillium and Trichoderma were identified on Czapek medium. Moistening of lignite powder increased the microbial respiration rate and microbial and fungal abundance but did not increase their generic diversity. This finding suggests that the studied microorganisms are autochthonous to lignite.

A Double-Stimuli-Responsive Fluorescent Center for Monitoring of Food Spoilage based on Dye Covalently Modified EuMOFs: From Sensory Hydrogels to Logic Devices.

Science.gov (United States)

Xu, Xiao-Yu; Lian, Xiao; Hao, Ji-Na; Zhang, Chi; Yan, Bing

2017-10-01

Unsafe food is a huge threat to human health and the economy, and detecting food spoilage early is an ongoing and imperative need. Herein, a simple and effective strategy combining a fluorescence sensor and one-to-two logic operation is designed for monitoring biogenic amines, indicators of food spoilage. Sensors (methyl red@lanthanide metal-organic frameworks (MR@EuMOFs)) are created by covalently modifying MR into NH 2 -rich EuMOFs, which have a high quantum yield (48%). A double-stimuli-responsive fluorescence center is produced via energy transfer from the ligands to Eu 3+ and MR. Portable sensory hydrogels are obtained by dispersing and solidifying MR@EuMOFs in water-phase sodium salt of carboxy methyl cellulose (CMC-Na). The hydrogels exhibit a color transition upon "smelling" histamine (HI) vapor. This transition and shift in the MR-based emission peak are closely related to the HI concentration. Using the HI concentration as the input signal and the two fluorescence emissions as output signals, an advanced analytical device based on a one-to-two logic gate is constructed. The four output combinations, NOT (0, 1), YES (1, 0), PASS 1 (1, 1), and PASS 0 (0, 0), allow the direct analysis of HI levels, which can be used for real-time food-freshness evaluation. The novel strategy suggested here may be a new application for a molecular logic system in the sensing field. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia.

Science.gov (United States)

Avellaneda-Torres, Lizeth Manuela; Pulido, Claudia Patricia Guevara; Rojas, Esperanza Torres

2014-01-01

A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP), Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS) of ribosomal DNA for fungi. Multivariate statistical analysis (MVA) was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

Directory of Open Access Journals (Sweden)

Lizeth Manuela Avellaneda-Torres

2014-12-01

Full Text Available A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP, Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS of ribosomal DNA for fungi. Multivariate statistical analysis (MVA was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

IgG antibodies against microorganisms and atopic disease in Danish adults

DEFF Research Database (Denmark)

Linneberg, Allan; Ostergaard, Christian; Tvede, Michael

2003-01-01

BACKGROUND: Seropositivity to food-borne and orofecal microorganisms (hepatitis A virus, Helicobacter pylori, and Toxoplasma gondii ), which are considered to be markers of poor hygiene, has been reported to be associated with a lower prevalence of atopy. In contrast, colonization of the gut...... with Clostridium difficile, a potential intestinal bacterial pathogen, in early childhood may be associated with a higher prevalence of atopy. OBJECTIVE: The objective of this study was to investigate the association between atopy and exposure to 2 groups of food-borne and orofecal microorganisms: (1) markers...... to microorganisms was assessed as IgG seropositivity to microorganisms. RESULTS: Seropositivity to 2 or 3 markers of poor hygiene (hepatitis A virus, H pylori, and T gondii ) was associated with a lower prevalence of atopy (adjusted odds ratio, 0.5; 95% CI, 0.3 to 0.8). In contrast, seropositivity to 2 or 3...

Phytoalexins as possible controlling agents of microbial spoilage of irradiated fresh fruit and vegetables during storage

International Nuclear Information System (INIS)

El-Sayed, S.A.

1978-01-01

The decline in biogenerating capacity to form natural antibiotic compounds (phytoalexins), rishitin and lubimin in potato tubers and rishitin in tomatoes, after gamma irradiation seems to be the essence of the suppression of natural immunity exhibited by an increase in per cent of rotted tubers and fruits during storage. In vitro studies postulated that the rot-causing fungi Phytophthora infestans (Mond) De Bary, Alternaria solani (Ellis and Martin) James and Grout, Botrytis cinerea Persson., Fusarium oxysporum Syder and Hansen and Rhizopus stolonifer Ehrenberg were significantly controlled by the application of phytoalexins that had been initially formed by potato tubers (rishitin), tomato fruits (rishitin) and pepper fruits (capsidiol). In vivo studies revealed that post-irradiation treatment of potato tubers and tomato fruits with phytoalexins that had been produced by the same plant organ or by another of the same family seems to be experimentally feasible to reduce the radiation dose or increase the efficiency of irradiation in controlling microbial spoilage during storage of irradiated potatoes and tomatoes. (author)

Antifungal activity of essential oils evaluated by two different application techniques against rye bread spoilage fungi

DEFF Research Database (Denmark)

Suhr, Karin Isabel; Nielsen, Per Væggemose

2003-01-01

Aims: To study how antifungal activity of natural essential oils depends on the assay method used.Methods and Results: Oils of bay, cinnamon leaf, clove, lemongrass, mustard, orange, sage, thyme and two rosemary oils were tested by two methods: (1) a rye bread-based agar medium was supplemented...... with 100 and 250 mu l l(-1) essential oil and (2) real rye bread was exposed to 136 and 272 mu l l(-1) volatile oil in air. Rye bread spoilage fungi were used for testing. Method 1 proved thyme oil to be the overall best growth inhibitor, followed by clove and cinnamon. On the contrary, orange, sage...... and rosemary oils had very limited effects. Mustard and lemongrass were the most effective oils by the volatile method, and orange, sage and one rosemary showed some effects. Oil compositions were analysed by gas chromatography-mass spectrography.Conclusions: Antifungal effects of the essential oils depended...

Using natural biomass microorganisms for drinking water denitrification.

Science.gov (United States)

Costa, Darleila Damasceno; Gomes, Anderson Albino; Fernandes, Mylena; Lopes da Costa Bortoluzzi, Roseli; Magalhães, Maria de Lourdes Borba; Skoronski, Everton

2018-07-01

Among the methods that are studied to eliminate nitrate from drinking water, biological denitrification is an attractive strategy. Although several studies report the use of denitrifying bacteria for nitrate removal, they usually involve the use of sewage sludge as biomass to obtain the microbiota. In the present study, denitrifying bacteria was isolated from bamboo, and variable parameters were controlled focusing on optimal bacterial performance followed by physicochemical analysis of water adequacy. In this way, bamboo was used as a source of denitrifying microorganisms, using either Immobilized Microorganisms (IM) or Suspended Microorganisms (SM) for nitrate removal. Denitrification parameters optimization was carried out by analysis of denitrification at different pH values, temperature, nitrate concentrations, carbon sources as well as different C/N ratios. In addition, operational stability and denitrification kinetics were evaluated. Microorganisms present in the biomass responsible for denitrification were identified as Proteus mirabilis. The denitrified water was submitted to physicochemical treatment such as coagulation and flocculation to adjust to the parameters of color and turbidity to drinking water standards. Denitrification using IM occurred with 73% efficiency in the absence of an external carbon source. The use of SM provided superior denitrification efficiency using ethanol (96.46%), glucose (98.58%) or glycerol (98.5%) as carbon source. The evaluation of the operational stability allowed 12 cycles of biomass reuse using the IM and 9 cycles using the SM. After physical-chemical treatment, only SM denitrified water remained within drinking water standards parameters of color and turbidity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Importance of different physiological groups of iron reducing microorganisms in an acidic mining lake remediation experiment.

Science.gov (United States)

Porsch, Katharina; Meier, Jutta; Kleinsteuber, Sabine; Wendt-Potthoff, Katrin

2009-05-01

Iron- and sulfate-reducing microorganisms play an important role for alkalinity-generating processes in mining lakes with low pH. In the acidic mining lake 111 in Lusatia, Germany, a passive in situ remediation method was tested in a large scale experiment, in which microbial iron and sulfate reduction are stimulated by addition of Carbokalk (a mixture of the nonsugar compounds of sugar beets and lime) and straw. The treated surface sediment consisted of three layers of different pH and geochemical composition. The top layer was acidic and rich in Fe(III), the second and third layer both showed moderately acidic to circum-neutral pH values, but only the second was rich in organics, strongly reduced and sulfidic. Aim of the study was to elucidate the relative importance of neutrophilic heterotrophic, acidophilic heterotrophic, and acidophilic autotrophic iron-reducing microorganisms in each of the three layers. In order to distinguish between them, the effect of their respective characteristic electron donors acetate, glucose, and elemental sulfur on potential iron reduction rates was investigated. Limitation of iron reduction by the availability of Fe(III) was revealed by the addition of Fe(OH)(3). The three groups of iron-reducing microorganisms were quantified by most probable number (MPN) technique and their community composition was analyzed by cloning and sequencing of 16S rRNA genes. In the acidic surface layer, none of the three electron donors stimulated iron reduction; acetate even had an inhibiting effect. In agreement with this, no decrease of the added electron donors was observed. Iron reduction rates were low in comparison to the other layers. Iron reduction in layers 2 and 3 was enhanced by glucose and acetate, accompanied by a decrease of these electron donors. Addition of elemental sulfur did not enhance iron reduction in either layer. Layer 2 exhibited the highest iron reduction rate (4.08 mmol dm(-3) d(-1)) and the highest cell numbers in MPN

Isolation of microorganisms for biological control the moniliophthora roreri

OpenAIRE

suarez contreras, liliana yanet; Rangel Riaño, Alba Luz

2014-01-01

Moniliophlhora roreri is the causal agent of cocoa Moniliasis, which produces losses of up to 60% of the crop, as it affects only its commercial product, the cob. Biological control appears as an alternative management, using endophytic microorganisms. The reason because of this research came up was that it was aimed to isolate microorganisms with antagonist potential for biological control towards the phytopathogen M. roreri in Norte de Santander. This is done through isolation and identifica...

2.3. Global-scale atmospheric dispersion of microorganisms

Science.gov (United States)

Griffin, Dale W.; Gonzalez-Martin, Cristina; Hoose, C.; Smith, D.J.; Delort, Anne-Marie; Amato, Pierre

2018-01-01

This chapter addresses long-range dispersion and the survival of microorganisms across a wide range of altitudes in Earth's atmosphere. Topics include mechanisms of dispersion, survivability of microorganisms known to be associated with long-range transport, natural and artificial sources of bioaerosols, residence time estimation through the use of proxy aerosols, transport and emission models, and monitoring assays (both culture and molecular based). We conclude with a discussion of the known limits for Earth's biosphere boundary, relating aerobiology studies to planetary exploration given the large degree of overlapping requirements for in situ studies (including low biomass life detection and contamination control).

Screening of biosurfactants from cloud microorganisms

Science.gov (United States)

Sancelme, Martine; Canet, Isabelle; Traikia, Mounir; Uhliarikova, Yveta; Capek, Peter; Matulova, Maria; Delort, Anne-Marie; Amato, Pierre

2015-04-01

The formation of cloud droplets from aerosol particles in the atmosphere is still not well understood and a main source of uncertainties in the climate budget today. One of the principal parameters in these processes is the surface tension of atmospheric particles, which can be strongly affected by trace compounds called surfactants. Within a project devoted to bring information on atmospheric surfactants and their effects on cloud droplet formation, we focused on surfactants produced by microorganisms present in atmospheric waters. From our unique collection of microorganisms, isolated from cloud water collected at the Puy-de-Dôme (France),1 we undertook a screening of this bank for biosurfactant producers. After extraction of the supernatants of the pure cultures, surface tension of crude extracts was determined by the hanging drop technique. Results showed that a wide variety of microorganisms are able to produce biosurfactants, some of them exhibiting strong surfactant properties as the resulting tension surface decreases to values less then 35 mN.m-1. Preliminary analytical characterization of biosurfactants, obtained after isolation from overproducing cultures of Rhodococcus sp. and Pseudomonas sp., allowed us to identify them as belonging to two main classes, namely glycolipids and glycopeptides. 1. Vaïtilingom, M.; Attard, E.; Gaiani, N.; Sancelme, M.; Deguillaume, L.; Flossmann, A. I.; Amato, P.; Delort, A. M. Long-term features of cloud microbiology at the puy de Dôme (France). Atmos. Environ. 2012, 56, 88-100. Acknowledgements: This work is supported by the French-USA ANR SONATA program and the French-Slovakia programs Stefanik and CNRS exchange.

Diversity and adaptations of deep-sea microorganisms

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, C.

-tolerant enzymes, natural products of potential use in human health management and environmental bioremediation using solvent-tolerant microorganisms are some of the potential biotechnological applications of these deep-sea microbes....

Extracellular Electron Transfer Mediated by Flavins in Gram-positive Bacillus sp. WS-XY1 and Yeast Pichia stipitis

International Nuclear Information System (INIS)

Wu, Song; Xiao, Yong; Wang, Lu; Zheng, Yue; Chang, Kenlin; Zheng, Zhiyong; Yang, Zhaohui; Varcoe, John R.; Zhao, Feng

2014-01-01

Extracellular electron transfer (EET) of microorganisms represents a communicative bridge between the interior and exterior of the cells. Most prior EET studies have focused on Gram-negative bacteria. However, fungi and Gram-positive bacteria, that contain dense cellular walls, have rarely been reported. Herein, two model dense cell wall microorganisms (Bacillus sp. WS-XY1 and the yeast Pichia stipitis) were identified to be electrochemically active. Further analysis indicated that the two microorganisms were able to secrete flavins to mediate their EET. The discovery, that dense cell wall containing microorganisms can undertake mediated EET, adds to the body of knowledge towards building a comprehensive understanding of biogeochemical and bioelectrical processes

Shallow irradiation of vienna sausage by electron beams in preventation of the slime production

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Kume, Tamikazu; Ito, Hitoshi; Aoki, Shohei; Sato, Tomotaro

1975-01-01

Vienna sausages get spoiled by slime production or putrefaction due to the propagation of microorganisms when stored for 3 to 5 days at 10 deg C. The radiation pasteurization of vienna sausages has mainly been studied with gamma irradiation. The slime of sausages is believed to be microorganisms themselves growing on the surface of the sausages. Pasteurization of the surface of vienna sausages with electron irradiation was thus investigated. The results obtained are as follows: The vienna sausages irradiated with a dose of 0.8 to approximately 1.0 Mrad by 0.5 MeV electrons could be stored without slime production or putrefaction for more than a week at 11 deg C. The effect of pasteurization increased with energy and dose of electrons. However, the changes in the organoleptic qualities of vienna sausages were detected when irradiated with a dose of over 0.7 Mrad by 2.0 MeV electrons. Consequently, the irradiation with a dose of 1.0 Mrad by 1.0 MeV electrons was effectual in lengthening their shelf-life without deterioration of the organoleptic qualities. (author)

A novel screen-printed mast cell-based electrochemical sensor for detecting spoilage bacterial quorum signaling molecules (N-acyl-homoserine-lactones) in freshwater fish.

Science.gov (United States)

Jiang, Donglei; Liu, Yan; Jiang, Hui; Rao, Shengqi; Fang, Wu; Wu, Mangang; Yuan, Limin; Fang, Weiming

2018-04-15

A novel screen-printed cell-based electrochemical sensor was developed to assess bacterial quorum signaling molecules, N-acylhomoserine lactones (AHLs). Screen-printed carbon electrode (SPCE), which possesses excellent properties such as low-cost, disposable and energy-efficient, was modified with multi-walled carbon nanotubes (MWNTs) to improve electrochemical signals and enhance the sensitivity. Rat basophilic leukemia (RBL-2H3) mast cells encapsulated in alginate/graphene oxide (NaAgl/GO) hydrogel were immobilized on the MWNTs/SPCE to serve as recognition element. Electrochemical impedance spectroscopy (EIS) was employed to record the cell impedance signal as-influenced by Pseudomonas aeruginosa quorum-sensing molecule, N-3-oxododecanoyl homoserine lactone (3OC 12 -HSL). Experimental results show that 3OC 12 -HSL caused a significant decrease in cell viability in a dose dependent manner. The EIS value decreased with concentrations of 3OC 12 -HSL in the range of 0.1-1μM, and the detection limit for 3OC 12 -HSL was calculated to be 0.094μM. These results were confirmed via cell viability, SEM, TEM analysis. Next, the sensor was successfully applied to monitoring the production of AHLs by spoilage bacteria in three different freshwater fish juice samples which efficiently proved the practicability of this cell based method. Therefore, the proposed cell sensor may serve as an innovative and effective approach to the measurement of quorum signaling molecule and thus provides a new avenue for real-time monitoring the spoilage bacteria in freshwater fish production. Copyright © 2017 Elsevier B.V. All rights reserved.

DENTINE CARIES: ACID-TOLERANT MICROORGANISMS AND ASPECTS ON COLLAGEN DEGRADATION.

Science.gov (United States)

Lager, Anders Hedenbjörk

2014-01-01

Dental caries is a common disease all over the world, despite the fact that it can be both effectively prevented and treated. It is driven by acids produced by oral microorganisms as a consequence of their metabolism of dietary carbohydrates. Given enough acid challenge, eventually the tooth enamel barrier will be broken down, and the carious lesion will extend into underlying hard tissue, forming a macroscopic cavity in the dentine. In comparison to biofilm on enamel, a dentine carious lesion provides a vastly different environment for the residing microorganisms. The environment influences the types and numbers of microorganisms that can colonize the dentine caries lesion. The overall aims for this thesis are to enumerate and further study microorganisms found in established dentine caries lesions and also to illuminate how host-derived proteolytic enzymes might contribute to this degradation, not only to better understand the caries process in dentine but also to find incitements for new methods to influence the natural progression of caries lesions. In Paper I, the numbers of remaining viable microorganisms after completed excavation using two excavation methods were investigated. Samples of carious dentine tissue were collected before and after excavation and cultivated on different agar media in different atmospheres. Analysis was performed by counting the number of colony-forming units (CFUs). Key findings: The number of remaining microorganisms after excavation was low for both methods, but some microorganisms always remained in the cavity floors even when the cavities were judged as caries free using normal clinical criteria. In Paper II, the acid tolerant microbiota in established dentine caries lesions was investigated. Samples were taken as in Paper I, but on three levels (superficial, center of lesion, floor of lesion after completed excavation). The samples were cultivated in anaerobic conditions on solid pH-selective agar media of different acidity

Modelling the morphology of filamentous microorganisms

DEFF Research Database (Denmark)

Nielsen, Jens Bredal

1996-01-01

The rapid development in image analysis techniques has made it possible to study the growth kinetics of filamentous microorganisms in more detail than previously, However, owing to the many different processes that influence the morphology it is important to apply mathematical models to extract...

Engineering of microorganisms towards recovery of rare metal ions

Energy Technology Data Exchange (ETDEWEB)

Kuroda, Kouichi; Ueda, Mitsuyoshi [Kyoto Univ. (Japan). Div. of Applied Life Sciences

2010-06-15

The bioadsorption of metal ions using microorganisms is an attractive technology for the recovery of rare metal ions as well as removal of toxic heavy metal ions from aqueous solution. In initial attempts, microorganisms with the ability to accumulate metal ions were isolated from nature and intracellular accumulation was enhanced by the overproduction of metal-binding proteins in the cytoplasm. As an alternative, the cell surface design of microorganisms by cell surface engineering is an emerging strategy for bioadsorption and recovery of metal ions. Cell surface engineering was firstly applied to the construction of a bioadsorbent to adsorb heavy metal ions for bioremediation. Cell surface adsorption of metal ions is rapid and reversible. Therefore, adsorbed metal ions can be easily recovered without cell breakage, and the bioadsorbent can be reused or regenerated. These advantages are suitable for the recovery of rare metal ions. Actually, the cell surface display of a molybdate-binding protein on yeast led to the enhanced adsorption of molybdate, one of the rare metal ions. An additional advantage is that the cell surface display system allows high-throughput screening of protein/peptide libraries owing to the direct evaluation of the displayed protein/peptide without purification and concentration. Therefore, the creation of novel metal-binding protein/ peptide and engineering of microorganisms towards the recovery of rare metal ions could be simultaneously achieved. (orig.)

Tapping uncultured microorganisms through metagenomics for drug ...

African Journals Online (AJOL)

African Journal of Biotechnology ... Microorganisms are major source of bioactive natural products, and several ... This review highlights the recent methodologies, limitations, and applications of metagenomics for the discovery of new drugs.

Microbial contamination of red meat and consideration of gamma irradiation effects for increasing the shelf-life and decontamination of pathogenic microorganisms

International Nuclear Information System (INIS)

Motamedee Sadeh, F.; Majd, F.; Fathollahee, H.; Arbabi, K.; Mohammad Beygi Abhari, M.

2003-01-01

Red meat has a lot of microbial flora from different sources. Prevention of outbreak of food born diseases that are caused by pathogenic agents and prevention of microbial spoilage of meat that makes many losses to the human health and economic of society are very important. Also, different methods for decreasing the microbial flora under a standard allowance for increasing the shelf life and decontamination of microbial pathogens have been proposed. In this research, irradiation technique was used for this purposes. After drawing dose/survival curves for all kinds of meats microbial contamination, an optimum dose of 3 kGy for decreasing the contamination and specially for decontamination of salmonella was obtained. When meat is irradiated by 3 kGy gamma rays, it can be kept in a 4-7 d ig C refrigerator for 2 week without appearing any spoilage nor color changes or odor. Also, some of biochemical factors were analyzed and amounts of 16 amino acids were measured in the irradiated and controlled samples and no difference was observed between the samples

Effect of brine marination on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat shrimp (Pandalus borealis)

DEFF Research Database (Denmark)

Mejlholm, Ole; Devitt, Tina D.; Dalgaard, Paw

2012-01-01

The effect of brine marination at chill temperatures on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat cold water shrimp was studied. Survival and growth of Lactobacillus sakei, Listeria monocytogenes, Salmonella, Staphylococcus...... aureus and Vibrio parahaemolyticus were examined. The effect of brine composition and pH was determined in 12 screening experiments without addition of shrimp. Sixteen challenge tests with shrimp were then carried out to examine the effect of brine composition and storage temperature on survival...

Investigations on the Antifungal Effect of Nerol against Aspergillus flavus Causing Food Spoilage

Directory of Open Access Journals (Sweden)

Jun Tian

2013-01-01

Full Text Available The antifungal efficacy of nerol (NEL has been proved against Aspergillus flavus by using in vitro and in vivo tests. The mycelial growth of A. flavus was completely inhibited at concentrations of 0.8 μL/mL and 0.1 μL/mL NEL in the air at contact and vapor conditions, respectively. The NEL also had an evident inhibitory effect on spore germination in A. flavus along with NEL concentration as well as time-dependent kinetic inhibition. The NEL presented noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1 (AFB1 by A. flavus, totally restraining AFB1 production at 0.6 μL/mL. In real food system, the efficacy of the NEL on resistance to decay development in cherry tomatoes was investigated in vivo by exposing inoculated and control fruit groups to NEL vapor at different concentration. NEL vapors at 0.1 μL/mL air concentration significantly reduced artificially contaminated A. flavus and a broad spectrum of fungal microbiota. Results obtained from presented study showed that the NEL had a great antifungal activity and could be considered as a benefit and safe tool to control food spoilage.

Effects of aqueous extract of Cinnamomum verum on growth of bread spoilage fungi

Directory of Open Access Journals (Sweden)

Monir Doudi

2016-01-01

Full Text Available Food waste has been identified as a considerable problem and bread is the most wasted food. This study aimed to evaluate In-vitro anti-fungal activity of cinnamon extract on bread spoilage fungi and to determine its anti-fungal effect in the bread slices. At first, the MIC and MFC values of the extract were determined against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium chrysogenum, Penicillium notatum and Rhizopus oryzae. Then, Aspergillus sp was selected to assess antifungal activities of different doses of cinnamon extract in bread slices. Cinnamon extract at a dose of 64 mg/ml completely inhibited all standard and bread isolated fungi. This concentration of extract also inhibited Aspergillus growth on bread slices and delayed colony formation but adversely affected the sensory characteristics of bread. Cinnamon extract at 32 mg/ml not only delayed fungal growth, but also improved bread shelf life and delayed its staling. Moreover, 32mg/ml of extract did not adversely affect bread aroma, flavor and texture. However, sodium acetate inhibited the growth of Aspergillus sp but is not recommended for fungal control because it is considered as chemical. Therefore 32 mg/ml of extract is recommended for increasing the shelf-life of flat bread.

Detection of extracellular enzymatic activity in microorganisms ...

African Journals Online (AJOL)

Detection of extracellular enzymatic activity in microorganisms isolated from waste vegetable oil contaminated soil using plate methodologies. Eugenia G. Ortiz Lechuga, Isela Quintero Zapata, Katiushka Arévalo Niño ...

Detection of extracellular enzymatic activity in microorganisms ...

African Journals Online (AJOL)

sunny t

2015-09-18

Sep 18, 2015 ... microorganisms with all three enzymatic activities, thereby establishing these techniques as ... supplemented at 1% with vegetable oils, including olive (OLI) ..... cepacia lipase for biodiesel fuel production from soybean oil.

Bioemulsan Production by Iranian Oil Reservoirs Microorganisms

Directory of Open Access Journals (Sweden)

A Amiriyan, M Mazaheri Assadi, VA Saggadian, A Noohi

2004-10-01

Full Text Available The biosurfactants are believed to be surface active components that are shed into the surrounding medium during the growth of the microorganisms. The oil degrading microorganism Acinetobacter calcoaceticus RAG-1 produces a poly-anionic biosurfactant, hetero-polysaccharide bioemulsifier termed as emulsan which forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. In the present paper results of the possibility of biosurfactant (Emulsan production by microorganisms isolated from Iranian oil reservoirs is presented. Fourthy three gram negative and gram positive, non fermentative, rod bacilli and coccobacilli shaped baceria were isolated from the oil wells of Bibi Hakimeh, Siri, Maroon, Ilam , East Paydar and West Paydar. Out of the isolated strains, 39 bacterial strains showed beta haemolytic activity, further screening revealed the emulsifying activity and surface tension. 11 out of 43 tested emulsifiers were identified as possible biosurfactant producers and two isolates produced large surface tension reduction, indicating the high probability of biosurfactant production. Further investigation revealed that, two gram negative, oxidase negative, aerobic and coccoid rods isolates were the best producers and hence designated as IL-1, PAY-4. Whole culture broth of isolates reduced surface tension from 68 mN /m to 30 and 29.1mN/m, respectively, and were stable during exposure to high salinity (10%NaCl and elevated temperatures(120C for 15 min .

Ultra-violet radiation for the inactivation of microorganisms in hydroponics

International Nuclear Information System (INIS)

Buyanosvsky, G.; Gale, J.; Degani, N.

1981-01-01

The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm -2 h -1 ) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10 3 to 10-50 x 10 3 cells per ml. (orig.)

Ultra-violet radiation for the inactivation of microorganisms in hydroponics

Energy Technology Data Exchange (ETDEWEB)

Buyanosvsky, G; Gale, J [Ben-Gurion Univ. of the Negev, Beersheva (Israel). Jacob Blaustein Inst. for Desert Research; Degani, N [Israel Atomic Energy Commission, Beersheba. Nuclear Research Center-Negev

1981-01-01

The growth of microorganisms in the nutrient solution of a circulating hydroponic system was suppressed by ultra-violet radiation. Applied for three hours daily (572 Jm/sup -2/h/sup -1/) throughout experiments in which tomato and corn were grown, it was effective in reducing the population of microorganisms from between 500-800 x 10/sup 3/ to 10-50 x 10/sup 3/ cells per ml.

Coal Enrichment Methods by Using Microorganisms and Their Metabolites

Directory of Open Access Journals (Sweden)

Małgorzata Deska

2018-03-01

Full Text Available The aim of this study is to review the literature on the methods of low-rank coal enrichment by using microorganisms and their metabolites. Effective bio-beneficiation technologies for low-rank coals in the future are also suggested throughout this paper. An extensive literature review highlights recent advances in bio-beneficiation technologies for low rank coals. This paper presents the state of the art in the field of the bio-beneficiation technology - carbon leaching with the aid of microorganisms, especially fungi. The knowledge of the low-rank coals leaching is an important step to meet the carbon eco-requirements and improve the economics of mining companies. There are several reasons to investigate microbial activities towards coal. This paper presents the current state of knowledge concerning bioleaching of coal. Thus, in view of the increasing importance of hard coal as a raw material and energy source, it seems hopeful to study the potential of microorganisms to modify the low-rank coal structure.

Genetic fingerprint of microorganisms associated with the ...

Indian Academy of Sciences (India)

inviting range of elements which microorganisms use in their ... ization and degradation of organic binders leading to struc- tural damage (Herrera et al. 2004). Microbial solubilization of materials involves the produc- ... architectural cement.

Activation of inoculum microorganism from dairy cattle feces

Science.gov (United States)

Ayuningtyas, Widya D.; Ridwan, Roni; Joni, I. M.; Marlina, E. T.; Harlia, Ellin

2018-02-01

Coal produces Coal Bed Methane (CBM) which is formed both biogenically and thermogenically. Lignite is not utilized optimally because it has low heat content and productivity time limit that decreases CBM production. In order to utilize lignite waste, adding inoculum consortium microorganism from dairy cattle waste as starter for biogas process can be a solution. This study aimed to produce inoculum consortium microorganism as biogas starter from dairy cattle feces through in vitro activation process by Theoudorou modification method. The research used complete randomized design with 3 replications. The treatments were blank (R0), 100% concentrate (R1), 70% concentrate+30% grass (R2), 70% grass+30% concentrate (R3) and 100% grass (R4). All treatments were added by buffer solution and feces with ratio of 2:1 into 100 ml serum injection bottle with anaerobic conditions. The parameters observed were gas production, pH and gas kinetics (orskov's equation) for 2, 4, 6, 8, 10, 12, 24 and 48 hours. The results showed that the treatment had significant effect (P <0.05) on the observed parameters. The highest total gas production was for R2 and R3 treatments with total production of 91.17 ml and 101.17 ml, pH (6.62 and 6.57), maximum gas production (94.03 and 97.62 ml), speed of gas production (0.066 and 0.084 ml/hour). There is not a significant difference for both the treatments. The source of inoculum consortium microorganisms for biogas starter selected based on the observed parameters and potential availability of proteolytic and fibrocytic microorganisms is R2 (70% concentrate +30% grass).

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

Institute of Scientific and Technical Information of China (English)

Sirikamon Saengmee-anupharb; Toemsak Srikhirin; Boonyanit Thaweboon; Sroisiri Thaweboon; Taweechai Amornsakchai; Surachai Dechkunakorn; Theeralaksna Suddhasthira

2013-01-01

Objective: To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated. Methods: The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candidaalbicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials. Results: All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 µm) and more uniformly shaped than AgZ. Conclusions: Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

Antimicrobial effects of silver zeolite,silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

Institute of Scientific and Technical Information of China (English)

Sirikamon; Saengmee-anupharb; Toemsak; Srikhirin; Boonyanit; Thaweboon; Sroisiri; Thaweboon; Taweechai; Amornsakchai; Surachai; Dechkunakorn; Theeralaksna; Suddhasthira

2013-01-01

Objective:To evaluate the antimicrobial activities of silver inorganic materials,including silver zeolite(AgZ),silver zirconium phosphate silicate(AgZrPSi)and silver zirconium phosphate(AgZrp),against oral microorganisms.In line with this objective,the morphology and structure of each type of silver based powders were also investigated.Methods:The antimicrobial activities of AgZ,AgZrPSi and AgZrP were tested against Streptococcus mutans,Lactobacillus casei,Candida albicans and Staphylococcus aureus using disk diffusion assay as a screening test.The minimum inhibitory concentration(MIC)and minimum lethal concentration(MLC)were determined using the modified membrane method.Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials.Results:All forms of silver inorganic materials could inhibit the growth of all test microorganisms.The MIC of AgZ,AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L.In terms of morphology and structure.AgZrPSi and AgZrP had smaller sized particles(1.5-3.0μm)and more uniformly shaped than AgZ.Conclusions:Silver inorganic materials in the form of AgZ,AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers.These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

Antimicrobial activity of different disinfectants against cariogenic microorganisms

Directory of Open Access Journals (Sweden)

Esra UZER CELIK

Full Text Available Abstract The aim of this study was to assess the in vitro antimicrobial effects of chlorhexidine digluconate (CHX, polyhexamethylene biguanide (PHBM, and octenidine dihydrochloride (OCT on cariogenic microorganisms by using their minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC. CHX, PHBM, and OCT were diluted in distilled water to the final test concentrations. Using the in-tube dilution method, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Actinomyces viscosus were cultivated on blood agar and Mueller–Hinton broth (MHB at 37°C for 48 h. They were read using a spectrophotometer to detect MIC. To determine MBC, samples in the range of the turbidity threshold after 24 h were transferred onto blood agar and evaluated for growth after 24 h. Different MICs and MBCs were observed in all disinfectants against each microorganism. The lowest MIC and MBC against S. mutans (60 mg/L were obtained from PHBM. The lowest values against L. rhamnosus (15 mg/L, 30 mg/L, A. viscosus (30 mg/L, and L. acidophilus (15 mg/L, 30 mg/L were determined by OCT. PHBM and OCT have the potential to be replaced with CHX because they were effective against cariogenic microorganisms.

Effect of L-glucose and D-tagatose on bacterial growth in media and a cooked cured ham product.

Science.gov (United States)

Bautista, D A; Pegg, R B; Shand, P J

2000-01-01

Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, approximately 2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. L-Glucose and D-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of D-glucose. Results showed that both L-glucose and D-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, D-glucose, L-glucose, and D-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P D-tagatose than those containing L- or D-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P D-tagatose at 10 degrees C was extended by 7 to 10 days. These results indicate that D-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.

Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

International Nuclear Information System (INIS)

Gonzalez-Barreiro, O.; Rioboo, C.; Herrero, C.; Cid, A.

2006-01-01

The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides

Removal of triazine herbicides from freshwater systems using photosynthetic microorganisms

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Barreiro, O. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Rioboo, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Herrero, C. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain); Cid, A. [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n. 15071 A Coruna (Spain)]. E-mail: cid@udc.es

2006-11-15

The uptake of the triazine herbicides, atrazine and terbutryn, was determined for two freshwater photosynthetic microorganisms, the green microalga Chlorella vulgaris and the cyanobacterium Synechococcus elongatus. An extremely rapid uptake of both pesticides was recorded, although uptake rate was lower for the cyanobacterium, mainly for atrazine. Other parameters related to the herbicide bioconcentration capacity of these microorganisms were also studied. Growth rate, biomass, and cell viability in cultures containing herbicide were clearly affected by herbicide uptake. Herbicide toxicity and microalgae sensitivity were used to determine the effectiveness of the bioconcentration process and the stability of herbicide removal. C. vulgaris showed higher bioconcentration capability for these two triazine herbicides than S. elongatus, especially with regard to terbutryn. This study supports the usefulness of such microorganisms, as a bioremediation technique in freshwater systems polluted with triazine herbicides.

Collective Motion of Micro-organisms from Field Theoretical Viewpoint

OpenAIRE

Nojiri, Shin'ichi; Kawamura, Masako; Sugamoto, Akio

1995-01-01

We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro- organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide ...

THE ASPECTS OF INVESTIGATION OF MICROORGANISM ANTIBIOTIC RESISTANCE AT THE PRESENT STAGE

Directory of Open Access Journals (Sweden)

Andreeva I.A.

2015-05-01

Full Text Available Introduction. At the present stage for ensuring epidemic safety and prevention of nosocomial infections the complex of analytical study and managerial procedure to improve the epidemiological supervision over nosocomial infections through the introduction of infection control in health care practice are using. The microbiological monitoring is part of the infectious control and allows supervising circulation of microorganisms and their antimicrobial resistance by dynamic observation over structure and level of resistance to antibiotics that are used in the given particular hospital. Materials and methods. For the dynamic observation of the structure and the level of resistance of microorganisms to antimicrobial agents the computer software WHONET recommended by WHO has been used. With using WHONET in Dnepropetrovsk Children's Hospital № 3 the computer database has been created. In this database the information about each patient, hospital department, samples under test and the date of its excretion, the data about the detected microorganism and its sensitivity/resistance to antimicrobial agents have been stored. The examination and analysis of antibiotic resistance of microorganisms has been provided for 2010- 2014 years, in total the data on 6168 isolates from 3876 patients have been analyzed. Results and discussion. By the total data the isolates belong to a wide spectrum of microorganisms (more than 40 different types. By means of the analysis of isolating of clinically significant microorganisms it has been established that one of the most frequent isolated were Escherichia coli (1-20 %, Klebsiella pneumoniae (4-18 %, Staphylococcus epidermidis (1-12 %, S. aureus (1-10 %, Enterobacter cloacae (2-9 %, Pseudomonas aeruginosa (1-8 %. Detection of other microorganisms was irregular and its frequency is varied from 0 % to 10 %. As a result of examining the sensitivity of microorganisms it has been shown that tested strains of bacteria were

Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

Directory of Open Access Journals (Sweden)

Isabel Kimiko Sakamoto

2012-10-01

Full Text Available The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN method were 9.0x10(7 cells/mL at the beginning of the assay and 8.0x10(5 cells/mL after 738 hours of operation.

Studies on the radiation sensitivity of food microorganism by high dose irradiation

International Nuclear Information System (INIS)

Hwang, Han Joon; Lee, Eun Jung; Yu, Hyun Hee; Lee, Jae Ho

2010-04-01

We investigated the radio resistance of pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Methicillin resistant Staphylococcus aureus(MRSA) and Escherichia coli O157) in irradiating environments. Their radiation conditions of pathogenic microorganisms varied with pH(3-10), salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition. In addition, the effect of γ-irradiation on the inactivation of pathogenic microorganisms inoculated into food (saengsik, sliced ham, chopped beef) was investigated. The radiation dose ranged from 0 to 3 kGy. The γ--irradiated B.cereus(γ--BC) St.aureus(γ--SA), MRSA(γ--MRSA) and E.coli O157(γ--EC) were then cultured and the viable cell count on plate count agar and D10-values(dose required to inactivate 90% of a microbial population) were calculated. The number of pathogenic microorganisms at pH(3-10) and salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition decreased by 1 log CFU/ml after irradiation. The D 10 -value of γ--SA in the optimum condition was 0.152 kGy, and these of γ--MRSA and γ--EC were 0.346 and 0.240 kGy, respectively. The initial cell counts of pathogenic microorganisms in culture broth were slightly decreased as the decrease of pH and the increase of salt concentration. However, radiation resistance of pathogenic microorganisms was increased at frozen state. Moreover, D 10 -values of these is test strains in saengsik, sliced ham and chopped beef were 0.597, 0.226 , 0.398 and 0.416 kGy, respectively. These results provide the basic information for the in activation of pathogenic microorganisms in foods by irradiation

Studies on the radiation sensitivity of food microorganism by high dose irradiation

Energy Technology Data Exchange (ETDEWEB)

Hwang, Han Joon; Lee, Eun Jung; Yu, Hyun Hee; Lee, Jae Ho [Korea University, Seoul (Korea, Republic of)

2010-04-15

We investigated the radio resistance of pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Methicillin resistant Staphylococcus aureus(MRSA) and Escherichia coli O157) in irradiating environments. Their radiation conditions of pathogenic microorganisms varied with pH(3-10), salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition. In addition, the effect of {gamma}-irradiation on the inactivation of pathogenic microorganisms inoculated into food (saengsik, sliced ham, chopped beef) was investigated. The radiation dose ranged from 0 to 3 kGy. The {gamma}--irradiated B.cereus({gamma}--BC) St.aureus({gamma}--SA), MRSA({gamma}--MRSA) and E.coli O157({gamma}--EC) were then cultured and the viable cell count on plate count agar and D10-values(dose required to inactivate 90% of a microbial population) were calculated. The number of pathogenic microorganisms at pH(3-10) and salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition decreased by 1 log CFU/ml after irradiation. The D{sub 10}-value of {gamma}--SA in the optimum condition was 0.152 kGy, and these of {gamma}--MRSA and {gamma}--EC were 0.346 and 0.240 kGy, respectively. The initial cell counts of pathogenic microorganisms in culture broth were slightly decreased as the decrease of pH and the increase of salt concentration. However, radiation resistance of pathogenic microorganisms was increased at frozen state. Moreover, D{sub 10}-values of these is test strains in saengsik, sliced ham and chopped beef were 0.597, 0.226 , 0.398 and 0.416 kGy, respectively. These results provide the basic information for the in activation of pathogenic microorganisms in foods by irradiation

Growth of Pseudomonas spp. in cottage cheese

DEFF Research Database (Denmark)

Østergaard, Nina Bjerre; Dalgaard, Paw

Cottage cheese is a mixture of cheese curd with pH 4.5-4.8 and an uncultured or cultured cream dressing with a pH as high as 7.0. This results in a final product with microenvironments and a bulk pH of about 4.8 to 5.5. As for other lightly preserved foods microbial contamination and growth...... of spoilage microorganisms in cottage cheese can cause undesirable alterations in flavour, odour, appearance and texture. Contamination and growth of psychrotolerant pseudomonads including Pseudomonas fragi and Pseudomonas putida has been reported for cottage cheese but the influence of these bacteria...... on product spoilage and shelf-life remains poorly described. The present study used a quantitative microbial ecology approach to model and predict the effect of product characteristics and storage conditions on growth of psychrotolerant pseudomonads in cottage cheese. The effect of temperature (5-15˚C) and p...

Antimicrobials Treatment

Science.gov (United States)

Drosinos, Eleftherios H.; Skandamis, Panagiotis N.; Mataragas, Marios

The use of antimicrobials is a common practice for preservation of foods. Incorporation, in a food recipe, of chemical antimicrobials towards inhibition of spoilage and pathogenic micro-organisms results in the compositional modification of food. This treatment is nowadays undesirable for the consumer, who likes natural products. Scientific community reflecting consumers demand for natural antimicrobials has made efforts to investigate the possibility to use natural antimicrobials such us bacteriocins and essential oils of plant origin to inhibit microbial growth.

Use of Atmospheric Pressure Cold Plasma for Meat Industry

OpenAIRE

Lee, Juri; Lee, Cheol Woo; Yong, Hae In; Lee, Hyun Jung; Jo, Cheorun; Jung, Samooel

2017-01-01

Novel, effective methods to control and prevent spoilage and contamination by pathogenic microorganisms in meat and meat products are in constant demand. Non-thermal pasteurization is an ideal method for the preservation of meat and meat products because it does not use heat during the pasteurization process. Atmospheric pressure cold plasma (APCP) is a new technology for the non-thermal pasteurization of meat and meat products. Several recent studies have shown that APCP treatment reduces th...

Enhancement of Biodegradation of Palm Oil Mill Effluents by Local Isolated Microorganisms.

Science.gov (United States)

Soleimaninanadegani, Mohammadreza; Manshad, Soheila

2014-01-01

This study was designed to investigate the microorganisms associated with palm oil mill effluent (POME) in Johor Bahru state, Malaysia. Biodegradation of palm oil mill effluents (POME) was conducted to measure the discarded POME based on physicochemical quality. The bacteria that were isolated are Micrococcus species, Bacillus species, Pseudomonas species, and Staphylococcus aureus, while the fungi that were isolated are Aspergillus niger, Aspergillus fumigatus, Candida species, Fusarium species, Mucor species, and Penicillium species. The autoclaved and unautoclaved raw POME samples were incubated for 7 days and the activities of the microorganisms were observed each 12 hours. The supernatants of the digested POME were investigated for the removal of chemical oxygen demand (COD), color (ADMI), and biochemical oxygen demand (BOD) at the end of each digestion cycle. The results showed that the unautoclaved raw POME sample degraded better than the inoculated POME sample and this suggests that the microorganisms that are indigenous in the POME are more effective than the introduced microorganisms. This result, however, indicates the prospect of isolating indigenous microorganisms in the POME for effective biodegradation of POME. Moreover, the effective treatment of POME yields useful products such as reduction of BOD, COD, and color.

Enhancement of Biodegradation of Palm Oil Mill Effluents by Local Isolated Microorganisms

Science.gov (United States)

Soleimaninanadegani, Mohammadreza

2014-01-01

This study was designed to investigate the microorganisms associated with palm oil mill effluent (POME) in Johor Bahru state, Malaysia. Biodegradation of palm oil mill effluents (POME) was conducted to measure the discarded POME based on physicochemical quality. The bacteria that were isolated are Micrococcus species, Bacillus species, Pseudomonas species, and Staphylococcus aureus, while the fungi that were isolated are Aspergillus niger, Aspergillus fumigatus, Candida species, Fusarium species, Mucor species, and Penicillium species. The autoclaved and unautoclaved raw POME samples were incubated for 7 days and the activities of the microorganisms were observed each 12 hours. The supernatants of the digested POME were investigated for the removal of chemical oxygen demand (COD), color (ADMI), and biochemical oxygen demand (BOD) at the end of each digestion cycle. The results showed that the unautoclaved raw POME sample degraded better than the inoculated POME sample and this suggests that the microorganisms that are indigenous in the POME are more effective than the introduced microorganisms. This result, however, indicates the prospect of isolating indigenous microorganisms in the POME for effective biodegradation of POME. Moreover, the effective treatment of POME yields useful products such as reduction of BOD, COD, and color. PMID:27433516

Profiling micro-organic contaminants in groundwater using multi-level piezometers

OpenAIRE

White, Debbie; Lapworth, Dan; Stuart, Marianne; Williams, Peter

2015-01-01

The presence of micro-organic pollutants, including ‘emerging contaminants’ within groundwater is of increasing interest. Robust protocols are required to minimise the introduction of contamination during the sampling process. Below we discuss the sampling protocols used to reduce inputs of plasticisers during the sampling process, as well as the techniques used to characterise the distribution of micro-organic pollutants in the subsurface. In this study multi-level piezometers...

Method for treating wastewater using microorganisms and vascular aquatic plants

Science.gov (United States)

Wolverton, B. C. (Inventor)

1983-01-01

A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.