Chromatophore material from the bacterium Rhodopseudomonas spheroides was freed of ribosomes by centrifugation in 27 per cent RbCl and then separated into "heavy" and "light" fractions by centrifugation through a sucrose gradient. The fractions differed from one another in the following ways. (a) The isopycnic density of the heavy fraction was between 1.15 and 1.18 gm/ml and that of the light f...

Abstract This review covers the current situation of use Spirulina in poultry diets and discusses its benefits challenges with particular emphasis on effect supplementation production performances meat quality. Feed enriched influences broilers’ health by improving their immune response gut function increasing PUFA pigment content meat. However, despite numerous studies, broiler performance rem...

BACKGROUND Age-related macular degeneration (AMD) is a disease with multiple risk factors, many of which appear to involve oxidative stress. Macular pigment, with its antioxidant and light-screening properties, is thought to be protective against AMD. A result has been the appearance of dietary supplements containing the macular carotenoids, lutein and zeaxanthin. More recently, a supplement ha...

Gillam & Heilbron (1935) in a study of the effects of feeding maize and grass on the composition of yolk pigment have shown that xanthophyll is the principal pigment of egg yolk, although cryptoxanthin and B-carotene are also present, the former sometimes in amounts that contribute appreciably to the total vitamin A activity of the yolk. In view of this, the extent of the variations in the cryp...

The aim of this study is to evaluate the  effects of water deficit stress on chlorophyll fluorescence (CF) characteristics of photosystem II (PSII) and pigment contents in two rootstock seedlings (Pistacia atlantica L. and P. khinjuk L.). Three levels of soil water potential (Ψs) was used, including WWD (-0.05 MPa), MWD (-0.7 MPa) and SWD (-1.5 MPa). It was found that water stress increased the...

Grape phylloxera is a root-feeding pest of grapevines. In Australia, phylloxera infested vineyards are subjected to quarantine restrictions and early detection remains vital for the timely implementation of post-outbreak quarantine protocols. Current detection methods rely on time-consuming ground surveying which involves detailed examination of grapevine (Vitis vinifera L.) root systems. Leaf ...

background and objective: pigment production by microorganisms is important due to more rapid growth, higher efficiency, easier extraction, and antimicrobial effects compared to other methods. the aim of the present study is to isolate and identify antibiotic pigment-producing actinomycetes from the soil of the persian gulf and to evaluate the antibiotic activity of their pigments in the second...

Leaf chlorophyll content provides valuable information about physiological status of plants. Reflectance measurement makes it possible to quickly and non-destructively assess, in situ, the chlorophyll content in leaves. Our objective was to investigate the spectral behavior of the relationship between reflectance and chlorophyll content and to develop a technique for non-destructive chlorophyll...