Factors Affecting the Growth of Micro-Organisms in Foods

Micro-facts ◽  
2010 ◽  
pp. 1-7
Author(s):  
Peter Wareing
Keyword(s):  
Factors Affecting ◽  
Micro Organisms

Factors affecting the adhesion of micro-organisms to the surfaces of plant-parasitic nematodes

Parasitology ◽  
1989 ◽  
Vol 98 (1) ◽  
pp. 155-164 ◽  
Author(s):  
A. F. Bird ◽  
Ingrid Bonig ◽  
A. Bacic
Keyword(s):  
Meloidogyne Javanica ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Pasteuria Penetrans ◽  
Con A ◽  
Factors Affecting ◽  
Pas Staining ◽  
Pre Treatment ◽  
Micro Organisms ◽  
Dauer Larvae

SummaryThe influence of various agents on the adhesion of endospores of Pasteuria penetrans to the nematode Meloidogyne javanica was studied. Similarly, but to a lesser degree, we have also studied the adhesion of conidia of the fungus Dilophospora alopecuri and the coryneform bacterium Clavibacter sp. (syn. Corynebacterium rathayi) to the nematode Anguina agrostis (syn. A. funesta). Reduction in the degree of both spore and conidial attachment following their pre-treatment with periodate and the presence of PAS staining material on spores, conidia and bacteria implicated carbohydrate in these interactions. Tests involving both unbound and FITC-bound lectins demonstrated that wheat germ agglutinin (WGA) can inhibit the degree of attachment of P. penetrans to M. javanica and that this inhibition can be overcome by pre-treatment of the lectin with N, N′-diacetyl chitobiose. Endospores of P. penetrans, amphid and buccal secretions of 2nd-stage larvae of M. javanica and the cuticle and excretory pore secretions of 2nd-stage dauer larvae of A. agrostis bound WGA, indicating that accessible N-acetyl-D-glucosamine residues are present on these structures. Endospores of P. penetrans also bound Con A, indicating the presence of accessible α-D-glucose/α-D-mannose residues on their surface.

Nanoantimicrobials

2020 ◽  
pp. 146-165 ◽  
Author(s):  
Navneet Kaur
Keyword(s):  
Antimicrobial Agents ◽  
Food Preservation ◽  
Quality And Safety ◽  
Human Beings ◽  
Food Spoilage ◽  
Food Preservatives ◽  
Resistance Development ◽  
Microbial Resistance ◽  
Factors Affecting ◽  
Micro Organisms

One of the major issues food technologists deal with is food preservation and safety. Growth of micro-organisms in food poses risk to its quality and safety. Moreover, resistance of food spoilage micro-organisms against various chemical food preservatives has led to an emergence of novel antimicrobial agents with improved action and low rates of microbial resistance. Development in nanotechnology has led to the production of nanoparticles that are not only safe but also effective to resolve the problem of microbial resistance. Nanoantimicrobials have shown improved bioactive performances and controlled toxicity to human beings. They are steadily gaining popularity and the trend will continue in coming years. The chapter gives a comprehensive view of nanoantimicrobials of organic and inorganic origin, various mechanisms adopted by these nanoparticles for the destruction of micro-organisms, factors affecting anti-microbial activities of these particles along with their applications in various fields of food technology.

Factors affecting nitrogen removal from domestic wastewater using immobilized bacteria

1998 ◽  
Vol 38 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Vasanthadevi Aravinthan ◽  
Satoshi Takizawa ◽  
Kenji Fujita ◽  
Kazuya Komatsu
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Nitrate Nitrogen ◽  
Domestic Wastewater ◽  
Nitrification Rate ◽  
Factors Affecting ◽  
Immobilized Bacteria ◽  
Bulk Oxygen ◽  
Micro Organisms ◽  
Nitrogen Loadings

The parameters affecting the nitrogen removal process by the immobilized bacteria in the anoxic-oxic process have been studied by investigating two bench scale Runs A and B. The hollow polypropylene pellets have been dosed into the anoxic reactor in Run A and into the oxic reactors of both Runs up to 24% of volume. Run B was operated with no pellets in the anoxic reactor as a control. The maximum nitrification rate of 0.4 kg NH4-N/m3d was achieved in sufficient DO (6.5 mg/l) at 15°C in the reactor with both activated sludge and immobilized micro-organisms. The volumetric nitrification rate was found to be greatly dependent on bulk oxygen concentration especially when the DO was maintained below 4 mg/l. A mathematical model developed successfully simulated the experimental results showing the variation of nitrification rate with DO. In the case of denitrification, the contribution of immobilized bacteria was prominent when lesser concentration of MLSS was present in the activated sludge in the combined immobilized and activated sludge system. The presence of immobilized bacteria in the anoxic reactor will be effective when higher nitrate nitrogen loadings are expected and the maintenance of higher MLSS than 2 g/l in an activated sludge facility is not feasible.

scholarly journals Studies of the loss of viability of bacterial aerosols: III. Factors affecting death rates of certain non-pathogens

1958 ◽  
Vol 56 (3) ◽  
pp. 389-403 ◽  
Author(s):  
Ronald M. Ferry ◽  
William F. Brown ◽  
Edwin B. Damon
Keyword(s):  
Petroleum Ether ◽  
Chemical Structure ◽  
Ambient Medium ◽  
Death Rates ◽  
Factors Affecting ◽  
Lipid Material ◽  
Quantitative Studies ◽  
Bacterial Aerosols ◽  
Micro Organisms ◽  
Physical And Chemical

1. Additional quantitative studies of the survival of micro-organisms in aerosols are reported.2. Substitution of nitrogen for oxygen in the ambient medium decreases k′2, the rate of secondary loss of viability ofM. candidus, Esch. coliandS. marcescens, by 30–50%.3. The rate of primary decay (k′1) ofEsch. colidoes not appear to be affected by a similar change of atmosphere.4. The rate of secondary decay, k′2, ofM. candidusappears to increase two-to three-fold for 10°C. increments in temperature.5. Treatment of suspensions ofEsch. coliwith petroleum ether alone or containing lipid material increases k′1in aerosols generated from such suspensions.6. Treatment ofMyco. phleiwith petroleum ether appears to lower resistance to subsequent sonic irradiation.These observations are consistent with the hypothesis that differences in the physical and chemical structure of micro-organisms are reflected in constants k′1, k′2and b.We gratefully acknowledge the effective interest of two former assistants, T. Grant Maple and Eugene Mills, as well as the careful, effective, and conscientious work of our technical assistants, Ann Barr, Nora Galins, Cynthia Hartwig, Grace C. Leigh, Elizabeth Neidhardt, Paulette Slaney and Martha Szerslip, who have at different times helped secure the data presented here. Mrs Joseph J. Ecker deserves special thanks for care in the preparation of the manuscript.

scholarly journals Factors affecting the inactivation of micro-organisms by intense light pulses

2005 ◽  
Vol 99 (3) ◽  
pp. 460-470 ◽  
Author(s):  
V.M. Gomez-Lopez ◽  
F. Devlieghere ◽  
V. Bonduelle ◽  
J. Debevere
Keyword(s):  
Factors Affecting ◽  
Light Pulses ◽  
Intense Light ◽  
Micro Organisms ◽  
Intense Light Pulses

scholarly journals Factors restricting the abundance of wasp colonies of the European hornet Vespa crabro and the Saxon wasp Dolichovespula saxonica (Hymenoptera: Vespidae) in an urban area in Poland

2013 ◽  
Vol 24 (4) ◽  
pp. 204-215 ◽  
Author(s):  
Jerzy Nadolski
Keyword(s):  
Abundant Species ◽  
Considerable Decrease ◽  
Wasp Species ◽  
Factors Affecting ◽  
Vespa Crabro ◽  
Or Groups ◽  
Wasp Nests ◽  
Micro Organisms ◽  
The City ◽  
Aphomia Sociella

Various factors affecting the reproductive success of Vespacrabro and Dolichovespula saxonica (Vespinae), including their parasitoids, parasites, pathogens and other micro organisms accompanying their nests in the city of LódzŸ in Poland were investigated. Sphecophaga vesparum, Aphomia sociella and especially Quedius brevicornis, whose larvae cause destruction of wasp nests, were recorded. Totally 19 species or groups of bacteria, including pathogens like Pseudomon aeruginosa, Enterobacter cloacae, Staphylococcus aureus and Enterococcus faecalis, and 5 species of fungi were identified. Cities create very good conditions for wasp societies. Unfortunately, their presence can cause specific but important risks to humans, which lead to massive destruction of wasp nests. However, this does not cause considerable decrease in the number of colonies of common wasp species but less abundant species may be endangered in cities by this practice. It is thus recommended to limit the number of all wasp nests destroyed and to discriminate between the species.

Biogenesis of Conjugated Linoleic Acids

2017 ◽  
pp. 1-28
Author(s):  
Sailas Benjamin ◽  
Kizhakepowathil Nair Unni ◽  
Prakasan Priji ◽  
Andre-Denis Girard Wright
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Unsaturated Fatty Acids ◽  
Vaccenic Acid ◽  
Meat Products ◽  
Animal Husbandry ◽  
Conjugated Linoleic Acids ◽  
Factors Affecting ◽  
Micro Organisms ◽  
Relationship Of

One of the key areas in animal husbandry is to improve the quality (nutritional value) of dairy and meat products by enriching them with Conjugated Linoleic Acids (CLAs) like (cis-9, trans-11)- and (trans-10, cis-12)-octadecadienicacids; the former (rumenic acid) predominates all the CLAs. Though Vaccenic Acid (VA) is the immediate precursor of rumenic acid, dietary unsaturated fatty acids like Oleic Acid (OA), Linoleic Acid (LA) and a-Linolenic Acid (ALA) are the distant precursors of CLAs; and that CLA and VA are formed as intermediates during the biohydrogenation of the dietary OA, LA and ALA into fully saturated stearic acid. The mutual inter-relationship of rumen microbiota encompassing bacteria, protozoa and fungi facilitates the biohydrogenation process. Thus, this chapter critically evaluates the knowledge accumulated during the past four decades on the precursor of CLAs, micro-organisms involved in the production of CLA, the mechanism of biohydrogenation, and chemical synthesis of CLA, coupled with the rationale for biohydrogenation and factors affecting the production of CLA.

SOME FACTORS AFFECTING THE SURVIVAL OF RHIZOBIUM TRIFOLII ON WHITE CLOVER

1976 ◽  
pp. 182-186 ◽  
Author(s):  
C.N. Hale
Keyword(s):  
Seed Coat ◽  
White Clover ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Rhizobium Trifolii ◽  
Factors Affecting ◽  
Naturally Occurring ◽  
Clover Seed ◽  
Micro Organisms ◽  
Selection Of

Survival of Rhizobium trifolii on white clover seed before sowing is adversely affected by both drying and a water-soluble toxin which diffuses from the seed coat during the inoculation process. Survival of rhizobia is increased by removal of the toxin by seed washing or the suppression of its inhibitory effect by treatment of seed with phenolic adsorbents. Survival of rhizobia introduced into tbe soil on seed before the rhizosphere is capable of supporting growth and multiplication may be affected by the toxic diffusate and competition and/or antagonism from naturally occurring populations of soil micro-organisms, Selection of effective strains of rhizobia on criteria such as survival and competition abilities, as well as on the ability to nodulate and fix nitrogen, is considered to be extremely important.

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