the aim of this study was to find the optimal conditions of a newly isolated streptomyces strain jrs 19. screening for keratinase producing bacteria and their keratinase production were investigated. the keratinase produced by the isolate was purified by chromatographic techniques and the optimum ph maintained was 7.0 and maintained at different temperatures viz., 20ºc, 25ºc, 30ºc, 35ºc and 40º...

In the framework of study on wood inhabiting Hyphomycetes in Gilan province, Iran, during 2002- 2003 eighteen taxa belonging to different genera were identified as follows: Chloridium botryoideum, Dendryphiopsis atra, Epicoccum nigrum, Periconia minutissima, Periconia byssoides, Periconia sp., Phaeoisaria clematidis, Pseudospiropes simplex, Sporidesmium adscendens, Sporidesmium brachypus, Spori...

Calcium (Ca)-containing fixation solutions applied to slices of electric organ of the electric ray, Narcine brasiliensis, have been shown to have three distinct ultrastructural effects on cholinergic synaptic vesicles of the nerve terminals. (a) An electron-dense particle (EDS) is observed within the vesicle; the particle is seen in unosmicated, unstained tissues and can be removed from thin se...

Antibodies were raised in rabbits to synaptic vesicles purified to homogeneity from the electric organ of Narcine brasiliensis, a marine electric ray. These antibodies were shown by indirect immunofluorescence techniques to bind a wide variety of nerve terminals in the mammalian nervous system, both peripheral and central. The shared antigenic determinants are found in cholinergic terminals, in...

Narcine brasiliensis electric organ was stimulated to fatigue in vivo. Electrical display of organ output and biochemical assay of bound acetylcholine (ACh) and ATP in isolated vesicles were used to assess the state of fatigue relative to denervated control organs of the same fish. A morphometric analysis of the fate of the synaptic vesicle populations in the nerve terminals was carried out. St...

Unlike most batoid fishes, electric rays neither oscillate nor undulate their body disc to generate thrust. Instead they use body-caudal-fin (BCF) locomotion. In addition, these negatively buoyant rays perform unpowered glides as they sink in the water column. In combination, BCF swimming and unpowered gliding are opposite ends on a spectrum of swimming, and electric rays provide an appropriate...

In this study, acetylcholine receptor-rich postsynaptic membranes from electric tissues of the electric rays Narcine brasiliensis and Torpedo californica are negatively contrasted for thin-section electron microscopy through the use of tannic acid. Both outer (extracellular) and inner (cytoplasmic) membrane surfaces are negatively contrasted, and can be studied together in transverse sections. ...