Search results for "spore"

Clostridium perfringens (Holland) as an indicator of human effluent in the sediment of Lake Tuomiojärvi, central Finland

1983

The horizontal and vertical distribution of the gram-positive, non-motile, spore-forming and rod-shaped bacterium Clostridium perfringens Holland was studied. The aim of the study was to estimate the quantity of C. perfringens at different depths of the sediment and evaluate the effect of human effluent which the lake received between 1940 and 1956. C. perfringens lives in the colon of man. Because it is spore forming and cannot multiply under a temperature of 20 °C and, according to the studies of Seppanen et al. (1979) it can be at least 300 years old, it may be a suitable paleolimnological indicator of pollution by human effluent.

Early in vitro development of isolated microspores of four Sicilian olive cultivars.

2015

Nowadays there is a great interest in the advancement of the studies on gametic embryogenesis in olive, as a method for obtaining homozygous material, due to the enormous effort and relevance in its genome sequencing and gene mapping. In this study, in vitro isolated microspore culture of four Sicilian olive cultivars (‘Biancolilla napoletana’, ‘Nocellara del Belice’, ‘Tonda Iblea’ and ‘Verdello’) has been carried out, investigating the influence of two polyamines (putrescine and spermidine) and of two medium compositions on pollen embryogenesis induction. During in vitro development, different structural features have been observed: uninucleated microspores, with no development, binucleate…

Drimane Sesquiterpenoids from Marasmius sp. Inhibiting the Conidial Germination of Plant-Pathogenic Fungi

2012

From the basidiomycete Marasmius sp., strain IBWF 96046, three new sesquiterpenoids based on the drimane skeleton were isolated and named marasmene B and marasmals B and C. In this study, their isolation, structure elucidation, and biological evaluation are described. The compounds have a pronounced inhibitory effect on the conidial germination of several plant-pathogenic fungi.

Mould germination: data treatment and modelling.

2006

Abstract The objectives of this study were i/ to examine germination data sets over a range of environmental conditions (water activity, temperature) for eight food spoilage moulds, ii/ to compare the ability of the Gompertz equation and logistic function to fit the experimental plots, iii/ to simulate germination by assessing various distributions of the latent period for germination amongst a population of spores. Data sets (percentage germination, P (%), versus time, t) of Aspergillus carbonarius, Aspergillus ochraceus, Fusarium verticillioides, Fusarium proliferatum, Gibberella zeae, Mucor racemosus, Penicillium chrysogenum and Penicillium verrucosum were analysed. No correlation, or re…

TrpM, a Small Protein Modulating Tryptophan Biosynthesis and Morpho-Physiological Differentiation in Streptomyces coelicolor A3(2).

2016

In the model actinomycete Streptomyces coelicolor A3(2), small open reading frames encoding proteins with unknown functions were identified in several amino acid biosynthetic gene operons, such as SCO2038 (trpX) in the tryptophan trpCXBA locus. In this study, the role of the corresponding protein in tryptophan biosynthesis was investigated by combining phenotypic and molecular analyses. The 2038KO mutant strain was characterized by delayed growth, smaller aerial hyphae and reduced production of spores and actinorhodin antibiotic, with respect to the WT strain. The capability of this mutant to grow on minimal medium was rescued by tryptophan and tryptophan precursor (serine and/or indole) su…

Physiological and genomic characterisation of Saccharomyces cerevisiae hybrids with improved fermentation performance and mannoprotein release capaci…

2015

Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating lactic-acid bacteria growth. The selection of a yeast strain that simultaneously overproduces mannoproteins and presents good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae × S. cerevisiae hybrid bearing the two oenologically relevant features was constructed. According to the genomic characterisation of the hybrids, different copy numbers of some genes probably related with these physiological features were detected. The hybrid shared not only a similar copy number of genes SPR1…

Performance of industrial strains of Saccharomyces cerevisae during wine fermentation is affected by manipulation strategies based on sporulation.

2002

Genetic manipulation of industrial wine yeast strains has become an essential tool for both the study of the molecular mechanisms underlaying their physiology and the improvement of their fermentative properties. The construction of null mutants for any gene in these usually diploid strains, by using a procedure based on sporulation of a heterozygote lacking one copy of the gene of interest, has been tested as an alternative to the tedious work of sequential disruption of the complete set of copies. Our results indicate that most of the homozygotes resulting from sporulation of wine yeast strains are defective in glucose consumption under microvinification conditions in synthetic must and p…

Melampsora allii-fragilis f. sp. galanthi-fragilis reported for first time to cause rust on Galanthus plicatus in Latvia

2010

In Europe, Melampsora allii-fragilis f. sp. galanthi-fragilis (syn. Melampsora galanthi-fragilis) has been reported on leaves of snowdrop (Galanthus nivalis) in Romania (Savulescu, 1953; Bagyanarayana, 2005) and on Galanthus plicatus in Ukraine (Gutsevich, 1952). The GBIF Database has additional records of this fungus on G. nivalis from Austria, Czech Republic and France but the USDA SMML Specimens Database has also records from Hungary and Poland. According to this database, the established distribution area of M. allii-fragilis f. sp. galanthi-fragilis is ‘Central Europe’. Melampsora allii-fragilis f. sp. galanthi-fragilis belongs to the heteroecious rust fungi that require two hosts to c…

Advancement on isolated microspore culture in Citrus clementina Hort. ex Tan., cvs. Monreal Rosso and Nules.

2013

Coltura in vitro di microspore isolate per il miglioramento genetico di Olea europaea L.

2013

Gli aploidi (piante con un numero gametofitico di cromosomi nello sporofito: n invece di 2n) ed i doppio-aploidi (aploidi che hanno raddoppiato il numero di cromosomi spontaneamente o in maniera indotta) trovano numerose applicazioni nel miglioramento genetico vegetale, ed in particolare, nella mutagenesi, nella selezione in vitro, nella trasformazione, nell’utilizzo della variabilità gametoclonale ed anche nel sequenziamento del genoma e negli studi di genomica funzionale. Pertanto, essi costituiscono uno strumento biotecnologico particolarmente interessante nel miglioramento genetico delle piante. Ai fini dell’ottenimento dell’omozigosi nell’olivo, come in tutte le piante arboree, caratte…