Tortajada M.,Biopolis SL |
da Silva L.F.,University of Sao Paulo |
Prieto M.A.,CSIC - Biological Research Center
International Microbiology | Year: 2013
Polyhydroxyalkanoates (PHAs) are biodegradable biocompatible polyesters, which accumulate as granules in the cytoplasm of many bacteria under unbalanced growth conditions. Medium-chain-length PHAs (mcl-PHAs), characterized by C6-C14 branched monomer chains and typically produced by Pseudomonas species, are promising thermoelastomers, as they can be further modified by introducing functional groups in the side chains. Functionalized PHAs are obtained either by feeding structurally related substrates processed through the β-oxidation pathway, or using specific strains able to transform sugars or glycerol into unsaturated PHA by de novo fatty-acid biosynthesis. Functionalized mcl- PHAs provide modified mechanical and thermal properties, and consequently have new processing requirements and highly diverse potential applications in emergent fields such as biomedicine. However, process development and sample availability are limited due to the toxicity of some precursors and still low productivity, which hinder investigation. Conversely, improved mutant strains designed through systems biology approaches and cofeeding with low-cost substrates may contribute to the widespread application of these biopolymers. This review focuses on recent developments in the production of functionalized mcl-PHAs, placing particular emphasis on strain and bioprocess design for cost-effective production.
Silva-Angulo A.B.,Biopolis SL |
Zanini S.F.,Federal University of Espirito Santo |
Rodrigo D.,CSIC - Institute of Agricultural Chemistry and Food Technology |
Rosenthal A.,Embrapa Food Technology |
Martinez A.,CSIC - Institute of Agricultural Chemistry and Food Technology
Food Control | Year: 2014
The aim of this work was to compare the growth kinetics of Listeria innocua and Listeria monocytogenes serovar 4b exposed to carvacrol, considering two initial inoculum sizes, and the occurrence of sublethal damage in these cell populations, by plating them in selective and non-selective medium. Bacteria were grown in TSB supplemented with carvacrol: 0.0μL/mL (control), 0.100μL/mL and 0.175μL/mL. The increase in carvacrol concentration resulted in an extended lag phase and lower maximum growth rate in comparison with the untreated cells (p≤0.05). In the presence of carvacrol, the lower inoculum size showed an increased growth rate and relatively longer lag phase compared to the higher inoculum size (p≤0.05). The cells of L.innocua and L.monocytogenes had a greater extension of lag time, slower growth rate and higher percentage of injured cells when treated with carvacrol (p≤0.05). Results also indicated that L.monocytogenes grows faster than L.innocua when treated with carvacrol, this scenery could compromise the use of L.innocua as a surrogate for L.monocytogenes serovar 4b for this antimicrobial substance. Finally, it was shown that good growth control of Listeria was achieved with 0.175μL/mL of carvacrol. © 2013 Elsevier Ltd.
Tortajada M.,Biopolis SL |
Llaneras F.,Polytechnic University of Valencia |
Pico J.,Polytechnic University of Valencia
BMC Systems Biology | Year: 2010
Background: Constraint-based models enable structured cellular representations in which intracellular kinetics are circumvented. These models, combined with experimental data, are useful analytical tools to estimate the state exhibited (the phenotype) by the cells at given pseudo-steady conditions.Results: In this contribution, a simplified constraint-based stoichiometric model of the metabolism of the yeast Pichia pastoris, a workhorse for heterologous protein expression, is validated against several experimental available datasets. Firstly, maximum theoretical growth yields are calculated and compared to the experimental ones. Secondly, possibility theory is applied to quantify the consistency between model and measurements. Finally, the biomass growth rate is excluded from the datasets and its prediction used to exemplify the capability of the model to calculate non-measured fluxes.Conclusions: This contribution shows how a small-sized network can be assessed following a rational, quantitative procedure even when measurements are scarce and imprecise. This approach is particularly useful in lacking data scenarios. © 2010 Tortajada et al; licensee BioMed Central Ltd.
Ramon D.,Biopolis SL
Arbor | Year: 2014
For thousands of years man has been applying genetics to improve both foodstuffs and food products. Using selective breeding and/or spontaneous mutations, a large number of plant varieties, animal breeds and microbial strains have been produced. In fact, food biotechnology is the oldest form of biotechnology. Recently, recombinant DNA techniques have been applied in food technology, creating so-called ‘genetically modified foods’ (GM foods). Examples include transgenic potatoes able to act as an oral vaccine against cholera, recombinant wine yeasts that produce wine with a fruitier bouquet, and transgenic cows or ewes producing milk with high levels of pharmaceutical proteins. However, the starting date for the future of food biotechnology was the publication in 2001 of the first draft of the human genome. This paved the way for the search for the genes that are activated or deactivated in response to specifics nutrients. It is now also possible to determine the genetic differences underlying individuals’ different nutritional responses. Furthermore, every day more genomes of animals, plants or microorganisms that are common components of our diet like rice, bread yeast, the probiotic bacterium Bifidobacterium bifidum or pathogens responsible for food poisoning, like Escherichia coli, are published. This provides information about key genes, making it possible to devise strategies for improvement using classical and genetic engineering techniques, demarcate defence mechanisms to combat pathogenicity, and define new physiological functions. Biotechnology’s applications in food and nutrition are more advanced than many people imagine. © 2014 CSIC.
Complutense University of Madrid and Biopolis S.L. | Date: 2013-07-22
The invention relates to a method for producing 2,3-butanediol using improved strains of