Immunochemical studies of opsonic epitopes of the lipopolysaccharide of Leptospira interrogans serovar hardjo

Abstract Leptospiral lipopolysaccharides (LPS) are the main antigens responsible for immunity in leptospirosis. In this investigation we studied the nature of the antigenic determinants of LPS extracted from Leptospira interrogans serovar hardjo (reference strain Hardjoprajitno). The reactions of anti-LPS monoclonal antibodies (mAbs) MUM/F1-4/ hardjo (IgM) and MUM/F1-6/ hardjo (IgG) with whole cell lysates in Western immunoblotting analysis were unaffected by proteinase K treatment. Periodate treatment of the LPS destroyed the binding of MUM/F1-6/ hardjo but preserved that of MUM/F1-4/ hardjo . Alkaline phosphatase decreased significantly the binding of MUM/F1-4/ hardjo to the LPS but only slightly that of MUM/F1-6/ hardjo . On the other hand, phosphodiesterase totally destroyed the binding capacity of both monoclonal antibodies in enzyme immunoassays (EIA). A number of mono- and oligosaccharides was used in EIA inhibition studies. Mannose-6-phosphate and galactose-6-phosphate inhibited the binding of MUM/F1-4/ hardjo (50% inhibition at a concentration of 5 mM) to the antigen, but glucose-6-phosphate did not. Galactosamine and mannosamine inhibited the binding of MUM/F1-6/ hardjo (50% inhibition at a concentration of 3–4 mM), whereas only a weak inhibition was observed with glucosamine. In contrast, N -acetylated amino sugars did not show any inhibition. An O -acetyl group also appears to be involved in the antigen-antibody binding process.     

Heavy metal uptake during anaerobic digestion of combined electroplating and brewery wastewaters

Batch and continuous culture laboratory-scale experiments were conducted to quantify the effect of combining chrome and nickel electroplating effluent (EE) and brewery effluent as substrate for established anaerobic digester granules. EE at a 1:12 ratio in brewery effluent was inhibitory to anaerobic digestion but acclimation at a 1:24 ratio occurred during continuous culture experiments. At least 90% of the chromium and nickel was absorbed by the granules with nickel attaching to granule perimeters while chromium penetrated into deeper recesses. © Rapid Science Ltd. 1998