Celia Flores

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The ploidy levels and amounts of DNA of 23 Opuntia species from Mexico were determined by flow cytometry. Four different ploidy levels (2n = 2x, 2n = 4x, 2n = 6x, 2n = 8x) with 2C-DNA amount ranging from 4.17 pg (Opuntia incarnadilla Griffiths) to 6.53 pg (Opuntia heliabravoana Scheinvar) were determined among the samples analyzed. Polyploidy is widespread(More)
The transcription of genes involved in alginate polymerization and depolymerization, as well as the alginase activity (extracellular and intracellular) under oxygen-limited and non oxygen-limited conditions in cultures of A. vinelandii, was studied. Two levels of dissolved oxygen tension (DOT) (1% and 5%, oxygen-limited and non-oxygen-limited, respectively)(More)
AIMS To select Trichoderma strains for enhanced laccase production in Pleurotus ostreatus or Agaricus bisporus cultures. METHODS AND RESULTS Laccase production by P. ostreatus and A. bisporus was evaluated in liquid (axenic) and solid (dual cultures) malt extract medium. Oxidation of ABTS, DMP and syringaldazine was evaluated in order to assess the(More)
Fluorescence microscopy and image analysis were evaluated in order to assess the viability of Trichoderma harzianum, an economically important filamentous fungus. After the evaluation of the two most commonly used fluorochromes, acridine orange (AO) and fluorescein diacetate (FDA) as metabolic indicator stains, AO gave ambiguous results and therefore FDA(More)
Baffled 500 ml Erlenmeyer flasks were compared with conventional 2800 ml Fernbach flasks forXanthomonas campestris to produce xanthan. Bacterial growth rates were similar in both types of flask although the Fernbach flasks gave higher biomass concentrations. Xanthan production was similar in both types of flasks but different viscosities were attained. On a(More)
Brassica oleracea seeds were sterilized by gamma radiation and sodium hypochlorite washing. Xanthomonas campestris was inoculated into the seeds by incubating, under vacuum, a suspension of the bacteria with the seeds. After thorough washings with sterile distilled water, the seeds retained about 13 000 cells per seed. The seeds were maintained at 4°C(More)
In this study, the respiratory activity and carbon usage of the mutant strain of A. vinelandii AT6, impaired in poly-β-hydroxybutyrate (PHB) production, and their relationship with the synthesis of alginate were evaluated. The alginate yield and the specific oxygen uptake rate were higher (2.5-fold and 62 %, respectively) for the AT6 strain, compared to the(More)
6-Pentyl-α-pyrone (6PP) production by Trichoderma harzianum, in an extractive fermentation system, was elicitated by Rhizoctonia solani. The extent of 6PP elicitation was related to the state of Rhizoctonia and to the Trichoderma inoculum type. The use of non-viable Rhizoctonia solani mycelium in mycelium-inoculated Trichoderma harzianum culture, yielded(More)
AIMS To evaluate the production and stability of laccases by Pleurotus ostreatus in liquid co-cultures with Trichoderma viride as a function of infection time and agitation rate. METHODS AND RESULTS Pleurotus ostreatus cultures were infected with T. viride spores at 30 and 48 h. Maximal laccase volumetric activity was seen after 48 h (control cultures) or(More)
The influence of the agitation conditions on biomass growth, morphology, carbon metabolism, viability, and 6-pentyl-alpha-pyrone (6PP) production by Trichoderma harzianum were studied in an extractive fermentation system. Batch spore-inoculated cultures developed at dissolved oxygen concentrations above 35% of air saturation were carried out in a 14 L(More)