Proof Of Purity Research Articles

Bioformulado de Beauveria bassiana (ATCC MYA-4886) y Trichoderma lignorum (ATCC-8751) como biocontrolador de Atta cephalotes

I. La hormiga arriera está asociada a pérdidas en el sector agrícola, debido a su actividad defoliadora. El control de la especie se ha venido realizado artesanal, química y biológicamente, esta última con beneficios ambientales y de bajo riesgo para la salud humana. El objetivo de esta investigación fue desarrollar una formulación biológica para el control de la hormiga arriera (Atta cephalotes) utilizando una mezcla de esporas de dos hongos filamentosos (Beauveria bassiana y Trichoderma lignorum). M. Se desarrollaron 5 formulaciones empleando las relaciones: 1:1,6:4,4:6,3:7,2:8, de cepas de B. bassiana (ATCC MYA-4886) y T. lignorum (ATCC 8751), realizándoles prueba de viabilidad, patogenicidad y pureza. La colonización de las esporas en tejidos, se evaluó mediante la exposición de ratas Wistar a la formulación y sus componentes, realizando diagnóstico veterinario (disección) y cultivo microbiológico. R. Las formulaciones presentaron viabilidad a 24 h del 95+2 %, el 100% de las formulaciones no se contaminaron después de 10 días, las formulaciones 6.4, 1:1, 2:8 infectaron la totalidad de los individuos en 6 días, las formulaciones 4:6 y 3:7 a los 8 días, no se observó colonización de las cepas en la formulación, ni en tejidos de los biomodelos. C. Las formulaciones 6.4, 1:1, 2:8 de Beauveria bassiana y Trichoderma lignorum, poseen mayor actividad infecciosa sobre la hormiga arriera (Atta cephalotes).

Purification of cytochrome b6. A tightly bound protein in chloroplast membranes.

Abstract Purification of cytochrome b6 was pursued to further develop rational technology for purification, proof of purity, and study of properties of membrane proteins. Cytochrome b6 was purified—the first time from any source—from spinach chloroplast membranes; yield of pure cytochrome b6 was 30% of that found in ethanol-extracted particles. The three-step procedure (pH 8) employed: (I) extraction in Triton X-100-4 M (optionally 2 M) urea, (II) chromatography in a Bio-Gel A-1.5m Column (Triton X-100-4 M urea). Without this step, subsequent electrophoresis failed. (III) Preparative disc gel electrophoresis. Properties of cytochrome b6: Cytochrome b6 migrated in undenatured form as a single band in disc electrophoresis (pH 8, 7 or 8.9). None of the limited, accepted properties of the cytochrome in particles was altered by the purification procedure: Reduced b6 has absorption maxima (22 °C) at 434, 536, and 563 nm; at −199 °C the a absorption region shows two peaks of equal intensity at 561 and 557 nm. Cytochrome b6 is reduced by dithionite (not by ascorbate) and is autoxidizable. The prosthetic group of b6 is protohaemin and is fully extractable by acid-acetone. No non-haem iron is present. The millimolar extinction coefficient of reduced b6 (563–600nm) per mole of haem is 21. The protein equivalent weight is 40000 g per mole of haem. Cytochrome b4 is an intrinsically aggregatable molecule. The reduced cytochrome does not react with CO except when Triton X-100 is present.

Fractionation of Lignin by Chromatography

THE most striking characteristic of the collection of lignin ‘structures’ listed by Brauns1 is the extent of their dissimilarity. This state of affairs arises from the lack of an established criterion of purity for lignin. Purification of lignin preparations has usually been carried out according to the choice of the worker, and structural investigation undertaken without any proof of purity. Brauns's1 admirable survey on the isolation of lignin should convince any interested reader of these facts.