Feeding approaches for biogas production from animal wastes and industrial effluents

Different feeding approaches were applied to a 5 l anaerobic digester in order to improve the biogas production. During operation, the reactor was fed with a mixture (9.7% w/v total solids (TS) and 7.6% w/v volatile solids (VS) in average) of pig manure with fish oil waste and waste from bentonite of edible oil filtration process, at different intervals of 24, 12 and 4 h at 15 days of hydraulic retention time. Production and quality of the biogas were practically constant at 183.7 ml (average) of biogas per gram of volatile solids available in the reactor per day, and the best biogas composition was 73.6% v/v CH₄ and 26.4% v/v CO₂.     

Detection of neutralizing antibody to Egtved virus in rainbow trout (Salmo gairdneri) by plaque neutralization test with complement addition

The humoral immune response of trout to Egtved virus (VHS) was examined by means of a 50 % plaque neutralization test with complement addition. The test, wich has been adapted for use in microtitre plates, is documented with regard to specificity and sensitivity. Eight weeks after VHS infection by cohabitation at 13 °C neutralizing antibody could be detected in 100% of individually tagged experimental trout. Maximal litres of 10240 were found six weeks after infection. In 36% of the trout antibody was still detectable one year after infection. Neutralizing antibody could be detected also in trout infected with VHS under trout farm conditions. The percentage of positive sera ranged from 4 to 56.