Search results for "Microbio"

Quorum Sensing effects on Pseudomonas corrugata plant interaction and antagonistic activity

2010

Numerical Taxonomy of Pseudomonads Isolated from Water, Sediment and Eels

1992

Summary A numerical taxonomic study was performed on 129 pseudomonad isolates from aquatic environments. 67 out of 98 field strains were isolated from water and sediment samples from Albufera lake, a hypereutrophic lake near Valencia, and 31 strains came from an eel hatchery. 10 clusters were formed at 84% similarity level when the Sokal-Michener similarity coefficient was used. Five clusters were designated as Pseudomonas putida (16 strains), P. fluorescens biotype I (9 strains), P. pseudoalcaligenes (11 strains), P. stutzen (4 strains) and Shewanella putrefaciens (3 strains). A subcluster of 7 strains (out of 15) was ascribed to the species Xanthomonas maltophilia , while the other strain…

Growth increase of birch seedlings under the influence of earthworms—a laboratory study

1992

The effects of the earthworm Lumbricus rubellus (Hoffm.) on net production and nitrogen content of birch seedlings were studied in laboratory microcosms. Coniferous forest floors with litter, humus and mineral horizons were simulated in transparent plastic cylinders. The materials were partially sterilized by microwaving, and re-inoculated with microflora and -fauna. A young (9 cm) birch seedling (Betula pendula Roth) was planted in each container. Earthworms were added to half of the replicates. The microcosms, through which a constant air flow was maintained, were incubated in a climate chamber. After two growth periods, leaf and stem biomasses of birch in treatments with earthworms incre…

Effects of endogeic earthworms on soil processes and plant growth in coniferous forest soil

1992

The effects of the endogeic earthworm, Aporrectodea caliginosa tuberculata (Eisen) on decomposition processes in moist coniferous forest soil were studied in the laboratory. The pH preference of this species and its effects on microbial activity, N and P mineralization, and the growth of birch seedlings were determined in separate pot experiments. Homogenized humus from a spruce stand was shown to be too acid for A. c. tuberculata. After liming, the earthworms thrived in the humus and their biomass increased (at pH above 4.8). In later experiments in which the humus was limed, the earthworms positively influenced the biological activity in humus and also increased the rate of N mineralizati…

A new species ofPythiumisolated from burgundian vineyards and its antagonism towardsBotrytis cinerea, the causative agent of the grey mould disease

2004

During the course of an investigation on the pythiaceous fungi occurring in burgundian vineyards, three isolates of Pythium were found, all of which were characterised by spherical to lemoniform, proliferating sporangia. Only one out of these three isolates produced sexual characters (S-12) after prolonged incubation, but their asexual structures, temperature growth relationship and molecular characteristics were identical. Saprolegnia-type internal proliferation of the sporangia, and Phytophthora-type lemoniform, papillate sporangia were characteristic of all the three isolates. The type specimen is S-12 which is a medium slow growing saprophyte. The sequence of its ITS region of the rDNA …

�pfels�urestoffwechsel bei Saccharomyces

1973

1. Aus Saccharomyces cerevisiae St. 79 konnte durch Protamin-und Ammoniumsulfatfallung sowie durch Chromatographie an DEAE-Cellulose ein Malatenzym [l-Malat: NAD(P) Oxidoreduktase, decarboxylierend, E.C. 1.1.1.38 oder 40] angereichert und von Malat-Dehydrogenase (l-Malat: NAD Oxidoreduktase, E.C. 1.1.1.37) weitgehend abgetrennt werden. 2. Neben Mn++-Ionen benotigt das Malatenzym der Hefe NAD oder NADP, bei einem optimalen pH-Wert von 7,5. Es ist spezifisch fur l-Malat, d-Malat wird nicht umgesetzt. Die Enzympraparate decarboxylierten Oxalessigsaure bei Abwesenheit von NAD. 3. Die Km Werte von Malatenzym sind fur l-Malat 5 · 10-2 M, fur NAD 5 · 10-4 M und fur Mangan 1,4 · 10-4 M. 4. Ein Zusa…

4-Hydroxy-5-methyl-3(2H)-furanone and 4-Hydroxy-2,5-dimethyl-3(2H)-furanone, Two Components of the Male Sex Pheromone ofEurycotis floridana(Walker) (…

1993

In Eurycotis floridana, male calling behavior is associated with the sex pheromone released by the anterior part of tergites. 2, 7, and 8. Glandular extracts of tergite 7 revealed a characteristic odor of caramel which is attractive at a distance for the females. We identified the two compounds responsible for this odor, 4-hydroxy-5-methyl-3(2H)-furanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone. These compounds are known to be very important as flavor components of foods, but this is the first time that they have been. identified as natural insect products. Various amounts of the identified compounds were tested, and their biological function is discussed.

Application of MALDI-TOF-MS and nested SAPD-PCR for discrimination ofOenococcus oeniisolates at the strain level

2015

Oenococcus oeni is the most important lactic acid bacterium during vinification and is frequently used as a commercial starter culture for malolactic fermentation. Since different strains exhibit a high heterogeneity concerning wine-related physiological characteristics, reliable methods for their differentiation at the strain level are needed, especially for the development of starter cultures. Microbial identification by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has increased over the last few years. In the present study, we used MALDI-TOF-MS for the differentiation of 11 O. oeni isolates originating from 5 different wine-growing reg…

Epimerization, oxidation and reduction of bile acids by Eubacterium lentum

1984

Summary Twenty-eight strains of Eubacterium lentum were divided into five groups on the basis of their ability to metabolize cholic acid and dehydrocholic acid: (I) Strains with 3α- and 3/β-dehydrogenating activities (1 strain), (II) strains with 12α-dehydrogenating activity (5 strains), (III) strains with 3α-, 3β-, 7α-, and 12α-dehydrogenating activities (8 isolates), (IV) transition stages between group II and III (1 strain), (V) strains devoid of any measurable bile acid metabolizing activities or with only trace activities (11 isolates). Using appropriate bile acids it was demonstrated that hydroxyl or keto groups at positions C 3 , C 7 , and C 12 did not influence bile acid transformat…

Virulent and nonvirulent Flavobacterium columnare colony morphologies: characterization of chondroitin AC lyase activity and adhesion to polystyrene

2011

Aims:  Colony morphology variants of fish pathogenic Flavobacterium columnare were studied to clarify the role of colony morphology change in the virulence of the bacterium. Typical rhizoid colony (Rz) variants are virulent and moderately adherent, nonrhizoid rough (R) colony variants are nonvirulent and highly adherent, and soft colony (S) variants are nonvirulent and poorly adherent. Methods and Results:  Chondroitin AC lyase activity, adhesion to polystyrene at different temperatures and after modification of bacterial surface, and lipopolysaccharide (LPS) profiles of the variants were studied. The chondroitinase activity was significantly higher in the virulent, rhizoid variants than in…