Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
7.
Meat Sci ; 73(1): 82-9, 2006 May.
Article in English | MEDLINE | ID: mdl-22062057

ABSTRACT

In the Region of "Castilla y León" (Spain), as in other Mediterranean areas, fresh suckling lamb meat is regarded as having a high edible quality. The EU granted this product a Protected Geographical Indication (PGI) "Lechazo de Castilla y León" in 1999. In this study, several carcass characteristics of suckling lambs protected by this PGI were determined, while the effects of breed, sex, and carcass weight were studied. Some differences in carcass characteristics within the three PGI authorized breeds have been detected. Neither carcass weight nor conformation measurements were good predictors of the composition of the PGI protected suckling lamb carcasses. The best predictors were fatness and composition of the leg and loin tissues, although dissection of these joints is not feasible on a daily basis. Lastly, some differences, due to sex and weight were identified in conformation, fat percentage, jointing and joint composition. Differences were, however, rather small, due to the lambs' young age and low variation in carcass weight.

8.
FEMS Microbiol Lett ; 194(2): 181-5, 2001 Jan 15.
Article in English | MEDLINE | ID: mdl-11164305

ABSTRACT

Streptomyces brasiliensis ATCC 23727 showed extensive sporulation when cultured in a liquid medium containing galactose and glutamic acid as carbon and nitrogen sources. Under such conditions, glycogen and trehalose are accumulated in the hyphae coinciding with spore formation. The results reported here suggest that glycogen accumulated in sporogenic hyphae is converted into trehalose during the final period of spore maturation. Glycogen is also accumulated in the hyphae when S. brasiliensis is cultured under conditions which did not support sporulation. Under such conditions, however, glycogen degradation is not accompanied by accumulation of trehalose. This suggest that the conversion of glycogen into trehalose might be a sporulation-specific event in streptomycetes.


Subject(s)
Glycogen/metabolism , Streptomyces/physiology , Trehalose/metabolism , Spores, Bacterial , Streptomyces/cytology , Streptomyces/metabolism
9.
Can J Microbiol ; 47(11): 1042-7, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11766053

ABSTRACT

Streptomyces brasiliensis ATCC 23727 showed extensive sporulation when cultured in a liquid medium containing galactose and glutamic acid as carbon and nitrogen sources. Sporogenic hyphae formed under these conditions were morphologically similar and developmentally equivalent to aerial hyphae and metamorphosed into chains of spores by following a sequence of ultrastructural changes similar to that observed during growth on solid media. In addition, our electron microscopy study revealed two previously unrecognized aspects of hyphal development in streptomycetes: the formation of sporogenic hyphae was always preceded by changes in the structure of the nucleoid, and the sheath that characteristically covered these hyphae was not deposited coincidently with wall formation in the apical growing portion of the hypha.


Subject(s)
Mycelium/growth & development , Streptomyces/growth & development , Culture Media , Hyphae/growth & development , Hyphae/ultrastructure , Microscopy, Electron , Spores/growth & development , Spores/ultrastructure , Streptomyces/ultrastructure
10.
Int Microbiol ; 3(3): 153-8, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11032307

ABSTRACT

Colonies of streptomycetes are now viewed as multicellular entities containing morphologically and biochemically differentiated cell types which have specific functions and precise spatial relationships to one another. Like multicellular organisms, colony development in streptomycetes is also maintained by a tight balance between cell proliferation and cell death processes. This review describes the current state of knowledge concerning cell death in streptomycetes.


Subject(s)
Cell Death , Models, Biological , Streptomyces/cytology , Biological Evolution , Cell Division , Energy Metabolism , Eukaryotic Cells/cytology , Species Specificity , Spores, Bacterial , Streptomyces/growth & development , Streptomyces/physiology
11.
J Cell Biol ; 145(3): 515-25, 1999 May 03.
Article in English | MEDLINE | ID: mdl-10225953

ABSTRACT

During the life cycle of the streptomycetes, large numbers of hyphae die; the surviving ones undergo cellular differentiation and appear as chains of spores in the mature colony. Here we report that the hyphae of Streptomyces antibioticus die through an orderly process of internal cell dismantling that permits the doomed hyphae to be eliminated with minimum disruption of the colony architecture. Morphological and biochemical approaches revealed progressive disorganization of the nucleoid substructure, followed by degradation of DNA and cytoplasmic constituents with transient maintenance of plasma membrane integrity. Then the hyphae collapsed and appeared empty of cellular contents but retained an apparently intact cell wall. In addition, hyphal death occurred at specific regions and times during colony development. Analysis of DNA degradation carried out by gel electrophoresis and studies on the presence of dying hyphae within the mycelium carried out by electron microscopy revealed two rounds of hyphal death: in the substrate mycelium during emergence of the aerial hyphae, and in the aerial mycelium during formation of the spores. This suggests that hyphal death in S. antibioticus is somehow included in the developmental program of the organism.


Subject(s)
Streptomyces antibioticus , Cell Membrane/physiology , Colony Count, Microbial , Cytoplasm/physiology , DNA Fragmentation , DNA, Bacterial/metabolism , Image Processing, Computer-Assisted , Microbiological Techniques , Microscopy, Electron , Microscopy, Electron, Scanning , Streptomyces antibioticus/cytology , Streptomyces antibioticus/growth & development , Streptomyces antibioticus/ultrastructure
12.
Rev Esp Anestesiol Reanim ; 46(2): 85-7, 1999 Feb.
Article in Spanish | MEDLINE | ID: mdl-10100444

ABSTRACT

Atrioventricular canal defects are a class of malformation attributable to anomalies in embryonic development of the anterior and posterior endocardial cushions. In the absence of surgical correction, death usually ensues in the first few years of life. Defects as severe as those observed in our patient are rare in adults. We describe the anesthetic management (epidural anesthesia with spontaneous ventilation by laryngeal mask) for a 46-year-old woman with this malformation who underwent emergency laparotomy.


Subject(s)
Abdomen, Acute/surgery , Anesthesia, Epidural , Carcinoma, Endometrioid/surgery , Endocardial Cushion Defects/complications , Heart Failure/complications , Laparotomy , Laryngeal Masks , Ovarian Neoplasms/surgery , Abdomen, Acute/etiology , Anesthetics, Local/pharmacology , Carcinoma, Endometrioid/complications , Diagnostic Errors , Emergencies , Endocardial Cushion Defects/physiopathology , Female , Heart Failure/physiopathology , Hemoperitoneum/etiology , Hemoperitoneum/surgery , Humans , Hysterectomy , Middle Aged , Ovarian Cysts/diagnosis , Ovarian Neoplasms/complications , Ovariectomy , Vascular Resistance/drug effects
13.
J Bacteriol ; 176(7): 2105-7, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8144478

ABSTRACT

The pattern of growth of aerial mycelium in Streptomyces species was investigated by autoradiography. Colonies of Streptomyces antibiotics were labeled with N-acetyl-D-[1-3H] glucosamine to localize the sites of hyphal growth during the development of aerial mycelium. Autoradiographs obtained with sections of the colonies revealed that hyphal growth occurs not only at the top of the colony but also in the inner zones of the aerial mycelium.


Subject(s)
Streptomyces antibioticus/growth & development , Acetylglucosamine/metabolism , Aerobiosis , Autoradiography , Morphogenesis , Streptomyces antibioticus/metabolism
14.
FEMS Microbiol Lett ; 109(2-3): 123-9, 1993 May 15.
Article in English | MEDLINE | ID: mdl-8339904

ABSTRACT

We have devised a method for obtaining synchronous and dispersed growth of Streptomyces antibioticus in liquid cultures. After ultrasonic treatment, most of the spores germinated at the same time, yielding hyphae very similar in length. Dispersed growth was achieved in media without Ca2+ and in which the levels of Fe2+ and Mg2+ were carefully controlled. Studies on the kinetics of growth carried out with synchronous cultures of young hyphae revealed a multiphasic pattern of hyphal elongation, with successive periods of linear growth and changes in growth rate at defined intervals.


Subject(s)
Streptomyces antibioticus/growth & development , Culture Media , Kinetics , Spores, Bacterial , Streptomyces antibioticus/physiology , Ultrasonics
15.
FEMS Microbiol Lett ; 100(1-3): 351-9, 1992 Dec 15.
Article in English | MEDLINE | ID: mdl-1478470

ABSTRACT

In this report we propose a model of apical growth for streptomycetes. The apical tip is considered as a multilayered wall that expands by an inside-to-outside mechanism of growth. It is also assumed that each layer is made up of peptidoglycan blocks, each of them being the result of the biosynthetic activity of a wall-synthesizing unit or membrane-associated growth zone. According to our model, apical growth occurs as follows: as a consequence of the hydrostatic pressure and the cleavage of some bonds, the layers are pushed and forced to slide (one with respect to the other), migrating from the center of the tip (at the inside of the wall) towards a peripheral location (at the outside of the wall). The model also incorporates a mechanism by which apical growth can be regulated and coordinated with the replication of the chromosome.


Subject(s)
Streptomyces/growth & development , Cell Wall/metabolism , DNA, Bacterial/biosynthesis , Models, Biological , Peptidoglycan/biosynthesis , Streptomyces/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...