A New Aquatic Bioassay Technique Using

2008 ◽  
pp. 104-104-13
Author(s):  
D Strickman
Keyword(s):  
Bioassay Technique ◽  
Aquatic Bioassay

Determination of the Viability of Toxoplasma gondii in Cured Ham Using Bioassay: Influence of Technological Processing and Food Safety Implications

2010 ◽  
Vol 73 (12) ◽  
pp. 2239-2243 ◽  
Author(s):  
SUSANA BAYARRI ◽  
MARÍA J. GRACIA ◽  
REGINA LÁZARO ◽  
CONSUELO PÉREZ-ARQUILLUÉ ◽  
MONTSERRAT BARBERÁN ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Horizontal Transmission ◽  
Meat Product ◽  
Immunofluorescence Assay ◽  
Nitrite Concentration ◽  
Bioassay Technique ◽  
Technological Processing ◽  
Undercooked Meat ◽  
Porcine Tissues

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii and distributed worldwide. Ingestion of viable cysts from infected raw or undercooked meat is an important route of horizontal transmission of the parasite to humans. Little information is available concerning the effect of commercial curing on cysts of T. gondii. This study is the first in which the influence of processing of cured ham on the viability of T. gondii has been evaluated, using bioassay to assess the risk of infection from eating this meat product. Naturally infected pigs were selected for the study, and a mouse concentration bioassay technique was used to demonstrate viable bradyzoites of T. gondii in porcine tissues and hams. No viable parasites were found in the final product (14 months of curing) based on results of the indirect immunofluorescence assay and histological and PCR analyses. Our results indicate that the consumption of hams cured as described here poses an insignificant risk of acquiring toxoplasmosis. However, additional studies are required to evaluate the safety of ham products cured under different conditions of curing time, salt, and nitrite concentration.

A STANDARDIZED BIOASSAY FOR LARVICIDAL ACTIVITY OF BACILLUS THURINGIENSIS IN SUNFLOWER MOTH HOMOEOSOMA ELECTELLUM (LEPIDOPTERA: PHYCITIDAE)

1985 ◽  
Vol 117 (1) ◽  
pp. 15-22 ◽  
Author(s):  
R. G. Lidstone ◽  
D. W. Goerzen ◽  
G. G. Khachatourians
Keyword(s):  
Bacillus Thuringiensis ◽  
Larvicidal Activity ◽  
Standard Test ◽  
Mortality Curve ◽  
Bioassay Technique ◽  
Sunflower Moth ◽  
Homoeosoma Electellum ◽  
Third Instar Larvae

AbstractA standard test for the larvicidal activity of Bacillus thuringiensis (B.t.) against the larvae of the sunflower moth Homoeosoma electellum (Hulst) has been developed. Bioassay parameters investigated include diet preparation, concentration of B.t., effect of formaldehyde, and method of pathogen incorporation in diet. The LC50 for seconded third-instar larvae is 1.24 μg of Dipel® WP ml−1 or 19.8 IU B.t. ml−1 pathogen-incorporated diet. Layering of a pathogen-suspension upon the surface of the diet was not a reliable bioassay technique for H. electellum. The addition of formaldehyde in the diet reduced the slope of the dose–mortality curve but did not change the LC50.

Development of a standard bioassay technique for the adults of Bemisia tabaci Gennadius (Homoptera, Aleyrodidae)

1976 ◽  
Vol 87 (3) ◽  
pp. 543-548
Author(s):  
M. S. El-Helaly ◽  
F. H. El-Gayar ◽  
A. Y. El-Shazli
Keyword(s):  
Bemisia Tabaci ◽  
Filter Paper ◽  
Exposure Period ◽  
Bioassay Technique

SummaryA standardized impregnated filter-paper bioassay technique was specially developed for screening insecticides against adults of the whitefly Bemisia tabaci Genn. (Homoptera, Aleyrodidae). It was found that the most suitable exposure period, after which mortality counts should be made, was 11·7 ± 2·1 h. Two different techniques for applying the insecticide solutions to the filter paper disks were tested and verified.

The influence of chemical structure on the anaerobic catabolism of refractory compounds: a case study of instant coffee wastes

1994 ◽  
Vol 30 (12) ◽  
pp. 223-232 ◽  
Author(s):  
N. G. Azhar ◽  
D. C. Stuckey
Keyword(s):  
Industrial Effluent ◽  
Anaerobic Treatment ◽  
Instant Coffee ◽  
Waste Sample ◽  
Coffee Waste ◽  
Refractory Compounds ◽  
Methane Potential ◽  
Bioassay Technique ◽  
High Concentrations

Due to concerns about meeting the strict legislation currently in force, anaerobic treatment is being investigated for the treatment of a variety of waste streams. Instant coffee wastes are one type of industrial effluent that appears to be amenable to anaerobic digestion, and this paper presents some results on the biodegradation of this effluent. The method used was a batch bioassay technique known as the Biochemical Methane Potential assay (BMP), which gave 84% degradation of a composite coffee waste sample. Various fractions of the coffee waste revealed mixed degradation results mostly attributed to structural differences, with the liquid fractions being almost 60% degradable, and the solids filter cake fraction, containing most of the lignocellulosic material being only 9% degradable. Volatile fatty acid (VFA) analysis revealed high concentrations of formate being formed and subsequently degraded in the bioconversion process, and a possible role for formate production was postulated. Variations in structure did not appear to affect the route by which VFAs were produced. Bioconversion of 5-6 major classes of pure organic compounds thought to be potentially recalcitrant in coffee effluent was investigated to determine possible mechanisms of degradation, and the extent to which structural variation affected degradability. The phenolics and chlorogenic acids gave the highest degradation of 70% and 60% respectively, and the cyclic volatiles the least degradation at 40%.

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