1. Complement fixation is obtained in every antigen-antibody reaction involving the presence or formation of a heterogeneous phase (red cells, bacteria, precipitate). 2. The physical constants of fixation (temperature coefficient, velocity, quantitative relationships between the reactants) are those commonly associated with adsorption processes, and are the same in the three types of fixation s...

Microbiologist, Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Riverside, Calif. Abstract: Presently available data indicate that biological dinitrogen fixation is responsible for the greatest proportion of nitrogen entering chaparral ecosystems. Dinitrogen fixation by the Rhizobium-legume symbioses is relatively unimportant in chaparral w...

Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation ((14)C-SOC) in CT soils was significantly hig...

Full blood count and erythrocyte sedimentation rate, antistreptolysin titre, albumin/ globulin ratio, blood sugar estimation, gonococcal complement-fixation test, Wassermann and Treponema pallidum immobilization tests, Waaler-Rose latex-fixation test, Toxoplasma complement-fixation test, Tine test, histoplasmosis complement-fixation test. Urine and stool examination for parasites and bacteria. ...

Biological N2 fixation (BNF) by associative diazotrophic bacteria is a spontaneous process where soil N is limited and adequate C sources are available. Yet the ability of these bacteria to contribute to yields in crops is only partly a result of BNF. A range of diazotrophic plant growth-promoting rhizobacteria participate in interactions with C3 and C4 crop plants (e.g. rice, wheat, maize, sug...

Sheep and guinea pigs were immunized with cellular and extracellular antigen from Legionella pneumophila bacteria. After immunization, the animals developed immunoglobulin G titers against the immunizing agent. The same sera were also tested in a Mycoplasma pneumoniae complement fixation test. All the preimmunization sera from sheep showed positive M. pneumoniae complement fixation tests of var...

The use of synthetic nitrogen fertilizers to grow biofuel crops adds the economic and environmental costs biomass production. Biological fixation provides an alternative, eco-friendly source for leguminous plants some nonlegumes. With objective characterizing eventually harnessing nitrogen-fixing bacteria in switchgrass roots, we assayed nitrogenase activity surveyed nifH-expressing roots grown...

It has been established that maize/soybean intercropping can improve nitrogen use efficiency. However, few studies have addressed how affects nitrogen-fixing bacterial diversity and N fixation efficiency of intercropped soybean. In this study, communities, efficiency, their relationships with soil properties under three fertilization application rates (N0 0 kg/ha, N1 40 N2 80 kg/ha) were explor...

Access to fixed or available forms of nitrogen limits the productivity of crop plants and thus food production. Nitrogenous fertilizer production currently represents a significant expense for the efficient growth of various crops in the developed world. There are significant potential gains to be had from reducing dependence on nitrogenous fertilizers in agriculture in the developed world and ...