A new method for determining the metabolic activity of specific bacterial populations in soil using tritiated leucine and immunomagnetic separation

2000 ◽  
Vol 32 (3) ◽  
pp. 202-208 ◽  
Author(s):  
Gitte Sengeløv ◽  
Søren J. Sørensen ◽  
Lone Frette ◽  
N. Kroer
2017 ◽  
Vol 9 (36) ◽  
pp. 5293-5300 ◽  
Author(s):  
Jian-Hui Wang ◽  
Hai-Yan Li ◽  
Jin-Song Guo ◽  
Peng Yan ◽  
Yu Shen ◽  
...  

A new method has been developed for estimating relative oxygen metabolic activity microdistribution in biofilms based on catastrophe points during oxygen-infusion processes.


Author(s):  
KATIA ELISA SAATKAMP LAZARETTI ◽  
MARCIA REGINA BEUX ◽  
IDA CHAPAVAL PIMENTEL ◽  
ANELISE TALAMINI ◽  
JUAREZ GABARDO

A contagem de bolores e leveduras é uma das análises realizadas no controle de qualidade de alimentos com intuito de estimar a vida útil de determinado produto alimentício. Embora considerada indicadora de contaminação, quantificar estes fungos é fundamental na avaliação da qualidade de produtos armazenados, principalmente cereais e preparados para infusões, em virtude do potencial micotoxigênico de algumas espécies de bolores. O presente trabalho teve por objetivo comparar o número de unidades formadoras de colônias (UFC) de fungos, obtidas a partir de três marcas de ervamate, semeadas em quintuplicata em ágar batata dextrosado, ágar dicloran rosa de bengala cloranfenicol e meio para bolores e leveduras ­ SIMPLATE. O ágar batata dextrosado e o ágar dicloran rosa de bengala cloranfenicol são rotineiramente empregados em laboratórios de análise, necessitando após inoculação, de cinco dias para leitura dos resultados. O meio para bolores e leveduras ­SIMPLATE é um método novo, baseado na atividade metabólica, que permite efetuar a leitura em dois dias após a inoculação, reduzindo significativamente o prazo analítico. Os resultados obtidos foram avaliados estatisticamente por meio da análise de variância e Teste de Tukey. Na prática laboratorial o melhor método é aquele que recupera maior número de unidades formadoras de colônias (UFC). Na amostra que apresentou contagem de até 10.000 UFC/g não se constatou diferença significativa entre os meios de cultura testados, porém nas amostras com contagens superiores a 10.000 UFC/g o ágar dicloran rosa de bengala cloranfenicol e o meio para bolores e leveduras ­SIMPLATE revelaramse estatisticamente mais eficazes que o ágar batata dextrosado. Abstract The mould and yeasts counting is one of the analyses accomplished in the control of quality of foods with an aim to estimate the useful life of certain nutritious product. Although considered indicative of contamination, to quantify these fungi is fundamental in the evaluation of the quality of stored products, mainly cereals and prepared for infusions, by virtue of the toxicant potential of some mould species. The present work had for objective to compare the number of forming colonies units (FCU) of fungi, obtained from three “mate” marks, sowed five fold in potato dextrose agar, dichloranrosebengal medium and medium for mould and yeasts ­ SIMPLATE. The potato dextrose agar and the dichloranrosebengal medium are routinely employed in analysis laboratories, needing after inoculation, of five days for reading of the results. The medium for mould and yeasts ­SIMPLATE is a new method, based on the metabolic activity, that allows to make the reading in two days after the inoculation, reducing the analytic period significantly. The obtained results were appraised statistically by means of the variance analysis and Test of Tukey. In the laboratory practical the best method is that which recovers larger number of forming colonies units (FCU). In the sample that presented counting of up to 10.000 UFC/g significant difference was not verified among the tested culture mediums, even so in the samples with superior counting to 10.000 UFC/g the dichloranrosebengal medium and the medium SIMPLATE were revealed statistically more effective than the potato dextrose agar.


2012 ◽  
Vol 39 (3) ◽  
pp. 429-436 ◽  
Author(s):  
Petr Szturz ◽  
Zdeněk Řehák ◽  
Renata Koukalová ◽  
Zdeněk Adam ◽  
Marta Krejčí ◽  
...  

Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 106-111 ◽  
Author(s):  
R. R. Walcott ◽  
R. D. Gitaitis ◽  
A. C. Castro ◽  
F. H. Sanders ◽  
J. C. Diaz-Perez

An immunomagnetic separation and polymerase chain reaction (IMS-PCR) assay was used to detect Pantoea ananatis in naturally infested onion seeds. Using species-specific PCR primers and polyclonal antibodies, IMS-PCR consistently demonstrated detection thresholds of 101 to 103 CFU/ml. There was no significant difference between the numbers of CFU recovered from onion seed wash by IMS (after repeated rinses) and by direct plating, indicating that IMS effectively captured P. ananatis cells from heterogeneous bacterial populations. Using IMS-PCR and IMS followed by plating on nutrient agar, P. ananatis was detected in 19.7% of onion seed samples harvested from two onion fields in which center rot developed naturally in 2000. When planted in germination boxes, 53% of the seed samples that tested positive for P. ananatis produced seedlings with symptoms of center rot. There was no significant difference in germination between infested and noninfested seed samples. This is the first report of natural infestation and transmission of P. ananatis in onion seed.


2009 ◽  
Vol 76 (5) ◽  
pp. 1674-1678 ◽  
Author(s):  
Claude Saint-Ruf ◽  
Corinne Cordier ◽  
J�rome M�gret ◽  
Ivan Matic

ABSTRACT We have developed a new method for accurate quantification of dead microbial cells. This technique employs the simultaneous use of fluorescent hydrazides and nucleic acid dyes. Fluorescent hydrazides allow detection of cells that cannot be detected with currently used high-affinity nucleic acid dyes. This is particularly important for nongrowing bacterial populations and for multicellular communities containing physiologically heterogeneous cell populations, such as colonies and biofilms.


2003 ◽  
Vol 69 (11) ◽  
pp. 6758-6761 ◽  
Author(s):  
Jaime Massanet-Nicolau

ABSTRACT A new method for the isolation of Cryptosporidium parvum oocysts and Giardia lamblia cysts from biosolid samples has been developed that utilizes sedimentation and immunomagnetic separation. The method was used to recover stained cysts and oocysts (spike organisms) from primary settled sewage sludge, anaerobically digested sewage sludge, and bovine manure. Recovery efficiencies associated with this method were approximately 40 to 60% and were significantly greater than those associated with similar methods based on sucrose flotation (P < 0.001). The recovery efficiency of the sedimentation-based method showed no significant reduction as a result of sample storage for up to 21 days (P > 0.05). Recovery efficiencies were determined by spiking samples with prestained cysts and oocysts, allowing them to be differentiated from those naturally present in the biosolid samples. The prestained cysts and oocysts had been fixed in 5% formalin, and the recovery efficiencies associated with this method may be different from recovery efficiencies for fresh cysts or oocysts.


2016 ◽  
Vol 93 (2) ◽  
pp. fiw233 ◽  
Author(s):  
Roberta Grimaldi ◽  
Drinalda Cela ◽  
Jonathan R. Swann ◽  
Jelena Vulevic ◽  
Glenn R. Gibson ◽  
...  

Author(s):  
W. Kuenzig ◽  
M. Boublik ◽  
J.J. Kamm ◽  
J.J. Burns

Unlike a variety of other animal species, such as the rabbit, mouse or rat, the guinea pig has a relatively long gestation period and is a more fully developed animal at birth. Kuenzig et al. reported that drug metabolic activity which increases very slowly during fetal life, increases rapidly after birth. Hepatocytes of a 3-day old neonate metabolize drugs and reduce cytochrome P-450 at a rate comparable to that observed in the adult animal. Moreover the administration of drugs like phenobarbital to pregnant guinea pigs increases the microsomal mixed function oxidase activity already in the fetus.Drug metabolic activity is, generally, localized within the smooth endoplasmic reticulum (SER) of the hepatocyte.


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