scholarly journals Efficacy of the nematode-trapping fungusDuddingtonia flagransagainst infections byHaemonchusandTrichostrongylusspecies in lambs at pasture

2007 ◽  
Vol 81 (4) ◽  
pp. 387-392 ◽  
Author(s):  
R.A. Rocha ◽  
J.V. Araújo ◽  
A.F.T. Amarante

AbstractThe efficacy of the nematode-trapping fungusDuddingtonia flagransagainst infections by trichostrongyle nematodes in sheep was assessed throughout 6 months. Twenty Ile de France lambs were divided into two groups (control and treated groups), which were kept in separate pastures. Animals of the treated group were fed withD. flagranstwice a week (Tuesdays and Fridays). Pellets were prepared with the fungus mycelia in liquid culture medium and contained approximately 20% fungus. They were mixed with the animals' diet at a concentration of 1 g pellet per 10 kg live weight. Faecal egg counts (FEC), packed cell volume (PCV), total serum protein and the animals' body weight were determined fortnightly from 7 October 2005 to 24 March 2006. Comparison of such parameters between groups showed no significant differences (P> 0.05), except on 10 February 2006, when the control group presented a higher mean FEC than the treated group (P<  0.05). Feeding sheep with pellets containingD. flagranshad no benefit to the prophylaxis of nematode infections under the experimental conditions used in the present study.

2005 ◽  
Vol 79 (2) ◽  
pp. 151-157 ◽  
Author(s):  
N.F. Ojeda-Robertos ◽  
P. Mendoza-de Gives ◽  
J.F.J. Torres-Acosta ◽  
R.I. Rodríguez-Vivas ◽  
A.J. Aguilar-Caballero

AbstractThe use ofDuddingtonia flagransin the control of goat nematodes was investigated. Initially, the time of passage of chlamydospores through the digestive tract of goats was evaluated. Two groups of seven parasite-free kids were formed. Group A received a single dose of 3.5×106D. flagranschlamydospores (FTHO-8 strain) per kg of live weight. Group B did not receive any chlamydospores. Faeces were obtained from each kid daily from day 4 prior to inoculation until day 5 post-inoculation (PI) and were placed in Petri dishes containing water agar. Gastrointestinal nematode infective larvae were added to each Petri dish and incubated at 25°C for 7 days. Petri dishes were examined to detect the fungus and trapped nematodes. A second trial evaluated the effect ofD. flagranson the number of gastrointestinal nematode larvae harvested from goat faecal cultures in naturally infected goats. Two groups of seven goats were formed. The treated group received a single dose of 3.5×106D. flagranschlamydospores per kg of liveweight. The control group did not receive any chlamydospores. Faeces were obtained twice daily from each kid. Two faecal cultures were made for each kid. One was incubated for 7 days and the other for 14 days. Gastrointestinal nematode larvae were recovered from each culture and counted. Percentage of larval development reduction was determined using a ratio of larvae/eggs deposited in the control and treated groups.Duddingtonia flagranssurvived the digestive process of goats, and maintained its predatory activity, being observed from 21 to 81 h PI (3 to 4 days). A reduction in the infective larvae population in the treated group compared to the non-treated group was observed in both incubation periods (7 days: 5.3–36.0%; 14 days: 0–52.8%,P>0.05). Although a single inoculation ofD. flagranscan induce a reduction of infective larvae collected from faeces, a different scheme of dosing may be needed to enhance the efficacy ofD. flagransin goats.


1967 ◽  
Vol 24 (11) ◽  
pp. 2339-2354 ◽  
Author(s):  
James E. Stewart ◽  
John W. Cornick ◽  
Diane M. Foley ◽  
M. F. Li ◽  
C. M. Bishop

Total serum protein values, hemocyte numbers, and muscle weights were determined for 216 intermolt lobsters immediately after their capture, and for 230 others held captive under a variety of dietary and environmental conditions. Average muscle values ranged from approximately 13% to the more normal 20–25% of the live animals' weight, depending upon experimental conditions. The total serum protein up to a level of 55 mg/ml was shown to be a reliable indicator of muscle weights, although the relationship was not identical for all lobster groups. It appeared to be modified chiefly by the areas from which the different groups were taken. Diet was more important than the temperatures (5 to 14 C) in affecting changes in muscle and serum protein values. Starvation caused a greater reduction (50 to 70%) in the size of the hepatopancreas than in the muscle. Histological examination of the hepatopancreatic tissue showed that the lipid content was markedly reduced upon starvation and that a degeneration of this organ was apparent for lobsters fed a beef liver and herring diet. Measurement of serum proteins would appear to be a useful technique in experiments on lobster nutrition and have value, within specified limits, for assessing the physiological condition of wild lobsters.


2011 ◽  
Vol 84 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Nikki Kenters ◽  
Gemma Henderson ◽  
Jeyamalar Jeyanathan ◽  
Sandra Kittelmann ◽  
Peter H. Janssen

1938 ◽  
Vol 21 (5) ◽  
pp. 601-620 ◽  
Author(s):  
M. Kunitz

1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2. The concentration of kinase in the medium is increased gradually during the growth of the mold organism and continues to increase for some time even after the mold has ceased growing. 3. Mold kinase transforms trypsinogen to trypsin only in an acid medium. It differs thus from enterokinase and trypsin which activate trypsinogen best in a slightly alkaline medium. 4. The action of the mold kinase in the process of transformation of trypsinogen is that of a typical enzyme. The process follows the course of a catalytic unimolecular reaction, the rate of formation of a definite amount of trypsin being proportional to the concentration of kinase added. The ultimate amount of trypsin formed, however, is independent of the concentration of kinase used. 5. The formation of trypsin from trypsinogen by mold kinase is not accompanied by any measurable loss of protein. 6. The temperature coefficient of formation of trypsin from trypsinogen by mold kinase varies from Q5–15 = 1.70 to Q25–30 = 1.25 with a corresponding variation in the value of µ from 8100 to 4250. 7. Trypsin formed from trypsinogen by means of mold kinase is identical in crystalline form with the crystalline trypsin obtained by spontaneous autocatalytic activation of trypsinogen at pH 8.0. The two products have within the experimental error the same solubility and specific activity. A solution saturated with the crystals of either one of the trypsin preparations does not show any increase in protein concentration or activity when crystals of the other trypsin preparation are added. 8. The Penicillium mold kinase has a slight activating effect on chymo-trypsinogen the rate being only 1–2 per cent of that of trypsinogen. The activation, as in the case of trypsinogen, takes place only in an acid medium. 9. Mold kinase is rapidly destroyed when brought to pH 6.5 or higher, and also when heated to 70°C. In the temperature range of 50–60°C. the inactivation of kinase follows a unimolecular course with a temperature coefficient of Q10 = 12.1 and µ = 53,500. The molecular weight of mold kinase, as determined by diffusion, is 40,000.


1989 ◽  
Vol 52 (2) ◽  
pp. 105-108 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
STEVE L. TAYLOR

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected by the formation of crystal violet from the leuco base in the presence of horseradish peroxidase. Liquid culture medium containing bacteria that produce greater than 1200 nmole histamine per ml will develop a positive purple color. Cultures containing bacteria that produce little or no histamine will not develop a purple color. Other amines often found in cheese, such as tyramine, cadaverine, or putrescine, will not interfere with the color formation.


1971 ◽  
Vol 34 (3) ◽  
pp. 119-123 ◽  
Author(s):  
C. N. Shih ◽  
E. H. Marth

A rapid and efficient method has been developed to recover aflatoxin from cheese and other foods. The procedure involves: (a) blending the sample with a mixture of chloroform, methanol, and water (solvents are used in such proportions that a miscible (monophasic) system is formed, (b) adding more chloroform and water so the mixture becomes biphasic, (c) filtering to remove the food residue, (d) separating the lower chloroform layer which contains virtually all of the aflatoxin, and (e) purification, if necessary, of the material in step (d) after it has been concentrated. Purification is achieved by sequential addition of methanol, water, and hexane; recovery of tho methanol-water fraction; and extraction of aflatoxins from it with chloroform. Purification can be eliminated if the substrate contains little or no lipid or pigment which, if present, interfere with thin-layer chromaographic analysis. Extraction can be done in approximately 35 min and purification in approximately 20 min. When aflatoxins were added to various substrates, the method recovered 92–98% B1 and 96–100% G1 from rice; 95–96% B1 and 90–95% G1 from peanut butter; 93–94% B1 and 92–98% G1 from Cheddar cheese; 100% B1 and G1 from corn meal; 91–100% B1, 91–100% B2, 90–96% G1, and 92–100% G2 from brick cheese; and 97–100% B1, 95–100% B2, 92–100% G1, and 98–100% G2 from a liquid culture medium.


2020 ◽  
Vol 39 (11) ◽  
pp. 1415-1424
Author(s):  
Yuhya Wakasa ◽  
Atsushi Kasai ◽  
Muneo Yamazaki ◽  
Yutaka Tabei ◽  
Mutsuo Tsuyama ◽  
...  

2003 ◽  
Vol 68 (9) ◽  
pp. 1636-1646
Author(s):  
Domenica Tonelli ◽  
Barbara Ballarin ◽  
Mario Berrettoni ◽  
Marcello Trevisani

The electrocatalytic oxidation of mannitol at a nickel oxide electrode was investigated. The experimental conditions for determining mannitol concentrations have been optimised taking into account the involved electrochemistry. Unlike what previously reported in the literature, our findings lead to the conclusion that both the electrochemical reaction involving the Ni(II)/Ni(III) couple and the chemical reaction between mannitol and Ni(III) are effective in determining the overall kinetics of the electrocatalytic process. The calibration line for mannitol was linear up to 20.0 mmol l-1. Mannitol determination with the nickel oxide electrode was performed in a liquid culture medium selective for Staphylococcus aureus in order to make an indirect calibration of bacterial viable cells, but the results were not satisfactory.


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