Laboratory studies on nitrogen and phosphorus removal from swine wastewater by iron electrolysis.

Biological process-free ("Bio-free") treatment of swine wastewater (pH 8.5 or above) for the removal of nitrogen and phosphorus was examined. In this study centrifugal separation of solids and liquids was followed by iron electrolysis, which enables removal of nitrogen and phosphorus when iron is set as the cathode and anode, respectively. The manner in which the treatment efficiency varies according to the current ratio of iron anode to iron cathode (Rac) was investigated. Nitrogen was removed to a level below 60 mg l(-1) in a 3-h treatment when Rac was above 75% and phosphorus was removed to a level below 8 mg l(-1) in the same period, irrespective of Rac. Nitrogen removal efficiency was 60 kWh kg-N(-1) , which is 6 times higher than that of the same electrolytic treatment when used after aerobic biological treatment ("Post-bio").

Serologic testing for Trypanosoma cruzi: comparison of radioimmunoprecipitation assay with commercially available indirect immunofluorescence assay, indirect hemagglutination assay, and enzyme-linked immunosorbent assay kits.

The radioimmunoprecipitation assay (RIPA) has been used as a confirmatory test in several ongoing and published studies of Trypanosoma cruzi in blood donors in the United States. Despite its use as a confirmatory test, few studies are available comparing RIPA to commercially available serologic test methods. Thus, we compared RIPA with two indirect hemagglutination assays (Biolab Diagnostica SA, São Paulo, Brazil; Hemagen Diagnostics, Inc., Waltham, Mass.) and four different enzyme-linked immunosorbent assays (Abbott Laboratories, Abbott Park, Ill.; Embrabio, São Paulo, Brazil; Organon Teknika, São Paulo, Brazil; and Gull Laboratories, Salt Lake City, Utah) using a panel of 220 serum specimens from Brazilian blood donors with a range of T. cruzi antibody titers as determined by indirect immunofluorescence assay (IFA). A titer of 1:20 was used as the baseline for seropositivity. All IFA-negative serum specimens (n = 19) were nonreactive on all tests. At a titer of 1:20 (n = 9), reactivity rates varied considerably among the tests, with only the RIPA and the Organon and Gull assays identifying reactive specimens. For specimens at a 1:40 titer (n = 35), most assays identified at least 32 of 35 (91%) specimens as reactive, but the Biolab assay only identified 24 (69%). At higher titers (1:80, n = 56; 1:160, n = 101) the assays were comparable, with the exception of the Biolab assay, demonstrating rates of agreement with IFA of >/=98%. Overall, when compared with several other test formats, RIPA demonstrated equivalent or superior rates of agreement with IFA-positive specimens across all titers examined. In particular, at titers of >1:40, the RIPA compared favorably with other test methods currently in use, supporting its application as a confirmatory test, particularly in a research setting.

Biotransformation of shiromodiol diacetate, myli-4(15)-en-9-one and myliol by Aspergillus niger.

Microbiol biotransformation of shiromodiol diacetate from Neolitsea serisea koids, and of myli-4(15)-en-9-one and myliol from the liverwort Mylia taylorii, were carried out with Aspergillus niger IFO 4407. A. niger hydroxylated the allyl position (C-2) of shiromodiol diacetate, and one of the geminal dimethyl groups of myli-4(15)-en-9-one and myliol regioselectively. The structures of these transformants were elucidated by spectral analysis and confirmed by X-ray analysis.

Purification of the 43 kDa glycoprotein from exocellular components excreted by Paracoccidioides brasiliensis in liquid culture (TOM medium).

The 43 kDa glycoprotein (gp43) antigen has been purified by affinity chromatography and Sephacryl S-200 gel filtration from concentrated and dialysed culture supernatant fluids of Paracoccidioides brasiliensis grown in a tomato juice-enriched complex medium (TOM). In the TOM medium, there was rapid and extensive growth of the fungus, with an abundant production of gp43 in relation to other exocellularly accumulated components. The purified gp43 can be used for immunochemical and structure determination studies.