A. Ortega Ballesteros

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RL5, a gene coding for a novel polyphenol oxidase, was identified through activity screening of a metagenome expression library from bovine rumen microflora. Characterization of the recombinant protein produced in Escherichia coli revealed a multipotent capacity to oxidize a wide range of substrates (syringaldazine > 2,6-dimethoxyphenol > veratryl alcohol >(More)
Laccases are multi-copper containing oxidases (EC 1.10.3.2), widely distributed in fungi, higher plants and bacteria. Laccase catalyses the oxidation of phenols, polyphenols and anilines by one-electron abstraction, with the concomitant reduction of oxygen to water in a four-electron transfer process. In the presence of small redox mediators, laccase offers(More)
Thermostable laccases with a high-redox potential have been engineered through a strategy that combines directed evolution with rational approaches. The original laccase signal sequence was replaced by the α-factor prepro-leader, and the corresponding fusion gene was targeted for joint laboratory evolution with the aim of improving kinetics and secretion by(More)
We have purified and characterized two isoenzymes from a commercial lipase preparation of Candida cylindracea. The purification procedure includes ethanol precipitation and DEAE-Sephacel and Sephacryl HR 100 chromatographies. Lipase A and lipase B were purified 11-fold with a 5% and 21% recovery in activity, respectively. The enzymes have similar amino acid(More)
BACKGROUND In the picture of a laboratory evolution experiment, to improve the thermostability whilst maintaining the activity requires of suitable procedures to generate diversity in combination with robust high-throughput protocols. The current work describes how to achieve this goal by engineering ligninolytic oxidoreductases (a high-redox potential(More)
We studied extracellular sterol esterase production by the ascomycete Ophiostoma piceae in liquid culture. Esterase activity was found in low levels in glucose medium but it was strongly induced by olive oil. An esterase was purified from the 0.5% olive oil-supplemented cultures using ultrafiltration followed by a single chromatographic step on a(More)
Modern biocatalysis is developing new and precise tools to improve a wide range of production processes, which reduce energy and raw material consumption and generate less waste and toxic side-products. Biocatalysis is also achieving new advances in environmental fields, from enzymatic bioremediation to the synthesis of renewable and clean energies and(More)
2 Abstract The use of olive oil mill wastewaters (OMW) as organic fertilizer is limited by its phytotoxic effect, due to the high concentration of phenolic compounds. As an alternative to physico-chemical methods for OMW detoxification, the laccase from Pycnoporus coccineus, a white-rot fungus that is able to decrease the chemical oxygen demand (COD) and(More)
Laccases are an interesting group of multi copper enzymes, which have received much attention of researchers in last decades due to their ability to oxidize both phenolic and non-phenolic lignin related compounds as well as highly recalcitrant environmental pollutants. This makes these biocatalysts very useful for their application in several(More)