Search results for " microbiology."
showing 10 items of 4051 documents
Novel biocatalysts for glycerol conversion into 2,3-butanediol
2016
Abstract Bioconversion of biodiesel-derived waste glycerol into high-value products is proposed as a solution to improve economic viability of biorefineries. Several microorganisms are able to metabolize glycerol into 2,3-butanediol (2,3-BD), a promising bulk chemical with wide applications: solvent, fuel additive, and feedstock for synthetic rubber production, among them. In the present work, a wide screening of microorganisms present both into the waste water treatment system in a biodiesel industry and in culture collections was carried out in order to evaluate their potential as new 2,3-BD producer biocatalysts. Two microorganisms for 2,3-BD production from glycerol as sole carbon sourc…
Anhydrobiosis in yeasts: Glutathione synthesis by yeast Ogataea (Hansenula) polymorpha cells after their dehydration-rehydration.
2019
The possibility of using active dry microbial preparations in biotechnological processes is essential for the development of new modern industrial technologies. In this study, we show the possibility of obtaining such preparations of the genetically engineered yeast strain Ogataea (Hansenula) polymorpha with glutathione overproduction. Special pre-treatment involving the gradual rehydration of dry cells in water vapour led to the restoration/reactivation of almost 100% of dehydrated cells. Furthermore, dry cells do not lose their viability during storage at room temperatures. Application of dry cells as the inoculum provides the same levels of glutathione synthesis as that of a native yeast…
Specific binding of Bacillus thuringiensis Cry1Ea toxin, and Cry1Ac and Cry1Fa competition analyses in Anticarsia gemmatalis and Chrysodeixis include…
2019
AbstractAnticarsia gemmatalis (velvetbean caterpillar) and Chrysodeixis includens (soybean looper) are two important defoliation pests of soybeans. In the present study, we have investigated the susceptibility and brush border membrane-binding properties of both species to Bacillus thuringiensis Cry1Ea toxin. Bioassays performed in first-instar larvae demonstrated potent activity against both soybean pests in terms of mortality or practical mortality. Competition-binding studies carried out with 125Iodine-labelled Cry1Ea, demonstrated the presence of specific binding sites on the midgut brush border membrane vesicles (BBMV) of both insect species. Heterologous competition-binding experiment…
Ultraviolet radiation accelerates photodegradation under controlled conditions but slows the decomposition of senescent leaves from forest stands in …
2019
Depending on the environment, sunlight can positively or negatively affect litter decomposition, through the ensemble of direct and indirect processes constituting photodegradation. Which of these processes predominate depends on the ecosystem studied and on the spectral composition of sunlight received. To examine the relevance of photodegradation for litter decomposition in forest understoreys, we filtered ultraviolet radiation (UV) and blue light from leaves of Fagus sylvatica and Bettda pendula at two different stages of senescence in both a controlled-environment experiment and outdoors in four different forest stands (Picea abies, Pagus sylvatica, Acer platanoides, Betula pendula). Co…
How to fight multiple enemies : target-specific chemical defences in an aposematic moth
2017
Animals have evolved different defensive strategies to survive predation, among which chemical defences are particularly widespread and diverse. Here we investigate the function of chemical defence diversity, hypothesizing that such diversity has evolved as a response to multiple enemies. The aposematic wood tiger moth (Arctia plantaginis) displays conspicuous hindwing coloration and secretes distinct defensive fluids from its thoracic glands and abdomen. We presented the two defensive fluids from laboratory-reared moths to two biologically relevant predators, birds and ants, and measured their reaction in controlled bioassays (no information on colour was provided). We found that defensive…
¿Qué formación didáctica recibe el futuro profesorado de clarinete en el grado superior? Reflexiones y propuesta curricular
2017
Successive education reforms of advanced-level music teaching have greatly increased the workload of future professionals. However, these reforms have not brought about curricular changes in the work situation, clearly related to teaching at different levels. This article offers a comparative analysis of the curricula of the different autonomous communities, and concludes with a number of suggestions on how to improve educational training for clarinet graduates.
’Structural constraints in cyanobacteria-mediated whole-cell biotransformation of methoxylated and methylated derivatives of 2′-hydroxychalcone
2019
Halophilic and freshwater strains of cyanobacteria representing the Oscillatoriales, Nostocales, Chroococcales, and Synechococcales orders of Cyanophyta were examined to determine (i) the resistance of their cultures when suppressed by the presence of exogenous methoxylated and methylated derivatives of 2'-hydroxychalcone, (ii) morphological changes in cells treated with the tested chalcones and, most importantly, (iii) whether these photoautotrophic microorganisms transform chalcone derivatives in a structure- or strain-dependent manner. The growth of cyanobacterial cultures depended on chalcone derivatives and the strain; nevertheless, trends for correlations between these parameters are …
From the roots to the stem: unveiling pear root colonization and infection pathways by Erwinia amylovora
2020
ABSTRACT Fire blight caused by Erwinia amylovora affects pome fruit worldwide, generating serious economic losses. Despite the abundant literature on E. amylovora infection mechanisms of aerial plant organs, root infection routes remain virtually unexplored. Assessing these infection pathways is necessary for a full understanding of the pathogen's ecology. Using the pathosystem Pyrus communis–E. amylovora and different experimental approaches including a green fluorescent protein transformant (GFP1) and epifluorescence microscopy (EFM) and laser confocal scanning microscopy (LCSM), we demonstrated the pathogen's ability to infect, colonize and invade pear roots and cause characteristic fire…
A self-inducible heterologous protein expression system in Escherichia coli
2016
AbstractEscherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for heterologous protein expression in E. coli. Isopropyl-β-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter’s transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG inducti…
Chaenothecopsis schefflerae (Ascomycota: Mycocaliciales): a widespread fungus on semi-hardened exudates of endemic New Zealand Araliaceae
2017
Ascomycetes specialised to live on hardened plant exudates occur worldwide, but the number of species so far described is relatively small (c.30). Particularly within the genus Chaenothecopsis (Ascomycota:Mycocaliciales), many species produce their ascomata on hardened but still relatively fresh outpourings of conifer resin or angiosperm exudate. Temperate rainforests of New Zealand provide habitat for several endemic Chaenothecopsis species, including Chaenothecopsis schefflerae, which was previously known from a single sample collected from the exudate of Schefflera digitata (Araliaceae) in the early 1980s. Here we show that C.schefflerae is neither lost nor very rare, but occurs sporadic…