Thirty different isolates of actinomycetes collected from different localities in Gharbia Governorate, Egypt were tested for melanin pigment production. Only one isolate produced melanin and identified as Streptomyces torulosus. The selected actinomycete isolate was grown under different cultural conditions and it was found that starch-nitrate medium was the optimum for the growth of selected i...

Three strains among 20 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and Streptomyces isolation agar. They also showed the positive reaction towards L-tyrosine substrates. The pigment has been referred to be dark brown water soluble pigment, as melanin. The present study reports antioxidant activity of melanin pigment from Actinomycete (Strepto...

An actinomycete strain, Streptomyces hygroscopicus subsp. ossamyceticus (strain D10) was isolated from Thar Desert soil, Rajasthan during the year 2006 and found to produce a yellow color pigment with antibiotic activity. Crude pigment was produced from strain D10 by solid state fermentation using wheat bran medium followed by extraction with ethyl acetate. The antimicrobial activity of the cru...

This study aimed to identify the causative of the mass mortality observed in zoeal to post-larval shrimp raised in hatcheries in south Iran. For three consecutive months, samples of nauplii and zoea of Litopenaeus vannamei were collected from an affected hatchery located in the province of Bushehr. Upon culture on marine agar, bacterial colonies that produced white, orange, yellow and red pigme...

Pigment was produced in stab cultures by 97% of 297 group B streptococci isolated from human clinical specimens. The pigment, which was associated with a membranous cell fraction, showed a four-banded absorption spectrum similar to that of a carotenoid, with maxima at 435, 566, 485, and 525 nm. Addition of glucose to the growth medium suppressed pigment production in most strains. Only 37% of s...

The influence of polymeric dispersants containing different functional groups on TiO2 pigment particle suspension was investigated at pH 6.0 and 9.5, using rheology and particle size data. The dispersants chosen were polyacrylic acid and modified polyacrylamides including homo and copolymers modified with carboxylate and/or hydroxyl groups. The pigment suspension was strongly affected by both p...

A selection of exopolysaccharide (EPS)--producing bacterial strains was conducted in groundwater adjacent to an old controlled landfill in the City of São Carlos (São Paulo, Brazil). The strains were isolated in P and E media under aerobic and microacrophilic conditions at 25 degrees C. A total of 26 strains were isolated and based on the mucoid mode of the colonies, 6 were selected and their m...

Many systems are modulated by unknown slow processes. This hinders analysis in highly nonlinear systems, such as excitable systems. We show that for such systems, if the input matches the sparse “spiky” nature of the output, the spiking input-output relation can be derived. We use this relation to reproduce and interpret the irregular and complex 1/f response observed in isolated neurons stimul...