BUSCADOR RECOLECTA

39 p.-7 fig.-1 tab., Interkingdom communication is of particular relevance in polymicrobial biofilms. In this work, the ability of the fungus Ophiostoma piceae to form biofilms individually and in consortium with the bacterium Pseudomonas putida, as well as the effect of fungal and bacterial signal molecules on the architecture of the biofilms was evaluated. P. putida KT2440 is able to form biofilms through the secretion of exopolysaccharides and two large extracellular adhesion proteins, LapA and LapF. It has two intercellular signalling systems, one mediated by dodecanoic acid and an orphan LuxR receptor that could participate in the response to AHL‐type quorum sensing molecules (QSMs). Furthermore, the dimorphic fungus O. piceae uses farnesol as QSM to control its yeast to hyphae morphological transition., Results show for the first time the ability of this fungus to form biofilms alone and in mixed cultures with the bacterium. Biofilms were induced by bacterial and fungal QSMs. The essential role of LapA‐LapF proteins in the architecture of biofilms was corroborated, LapA was induced by farnesol and dodecanol, while LapF by 3‐oxo‐C6‐HSL and 3‐oxo‐C12‐HSL. Our results indicate that fungal signals can induce a transient rise in the levels of the secondary messenger c‐di‐GMP, which control biofilm formation and architecture., This work was supported by the Spanish project BIO2015-73697-JIN-AEI/FEDER/UE.
M.J. Martínez and J. Barriuso would also like to thank IBISBA1.0 H2020 project 730976
(https://www.ibisba.eu/) and the SusPlast Interdisciplinary platform (http://www.susplastcsic.org/) from the Spanish National Research Council (CSIC), Peer reviewed

26 p.-5 fig., Lipases are enzymes able to catalyze the hydrolysis or synthesis of triglycerides, depending on the reaction conditions, whereas sterol esterases show the same ability on sterol esters. Structurally, both kinds of enzymes display an α/β-hydrolase fold, with a substrate-binding pocket formed by a hydrophobic cavity covered by a mobile lid. However, it has been reported that some lipases from the Candida rugosa-like family display wide substrate specificity on both triglycerides and sterol esters. Among them, enzymes with different biotechnological applications, such as the lipase isoenzymes produced by C. rugosa and the sterol esterase from Ophiostoma piceae, have been exhaustively characterized and their crystal structures are available. Differences in substrate affinity among these proteins have been attributed to changes in their hydrophobicity. In this work, we analyzed the full catalytic mechanisms of these proteins using molecular dynamics tools, gaining insight into their mechanistic properties. In addition, we developed an in silico protocol to predict the substrate specificity using C. rugosa and O. piceae lipases as model enzymes and triglycerides and cholesterol esters with different fatty acid chain lengths as model substrates. The protocol was validated by comparing the in silico results with those described in the literature. These results would be useful to perform virtual screening of substrates for enzymes of the C. rugosa-like family with unknown catalytic properties., This work was supported by the Spanish projects BIO2015-73697-JIN from MEICOMP co-financed with FEDER funds and RETOPROSOST2 S/2018/EMT-4459 from Comunidad de Madrid. The authors would also like to thank IBISBA1.0 project
(H2020 730976) and the SusPlast-CSIC Interdisciplinary Platform for their support., Peer reviewed

1 p., La actividad humana en el planeta genera un gran volumen de residuos que en muchas ocasiones son contaminantes y difíciles de gestionar, entre los más abundantes se encuentran los derivados de la agricultura (e.g. biomasa lignocelulósica) y los derivados de la industria (e.g. CO2 y plásticos). Por otra parte, nuestra actividad productiva necesita disminuir su dependencia del petróleo para obtener productos químicos, materiales y combustibles. En el marco de la economía circular los residuos agro-industriales pueden ser utilizados como sustratos renovables y transformados en productos de valor añadido, como biopolímeros y biocombustibles, utilizando herramientas biotecnológicas.El uso de microorganismos en aplicaciones industriales normalmente se restringe a monocultivos o al uso de sus enzimas de forma aislada. En nuestro laboratorio, utilizando herramientas de la biología sintética y de sistemas, explotamos el potencial de consorcios microbianos compuestos por organismos con distintas capacidades metabólicas. Aprovechamos y fomentamos las capacidades naturales de estos microorganismos para cooperar, estudiamos el comportamiento del microbioma, y diseñamos consorcios “sintéticos” con distintas aplicaciones biotecnológicas.En este trabajo se presentará como hongos saprófitos, con un amplio arsenal de enzimas degradativas,y bacterias ambientales, con un metabolismo versátil, pueden asociarse y coordinar sus actividades metabólicas utilizando mecanismos de comunicación célula a célula conocidos como mecanismos
de quorum sensing. Estos consorcios pueden formar biofilms catalíticos, lo que mejora los procesos de biocatálisis degradando residuos agro-industriales y produciendo compuestos de valor añadido.
Actualmente trabajamos en la modificación genética y modelado, tanto metabólico como ecológico,de estos consorcios para mejorar su eficacia., Proyectos BIO2015-73697-JIN (MINECO/FEDER), MINECO/FEDER BIO2015-68387-R, CM
S2013/MAE-2907, S2018/EMT-4459, IBISBA1.0 (H2020 730976), BioSFerA (H2020 884208) and
CO2SMOS (H2020 101000790)., Peer reviewed

1 p., Peer reviewed

Polylactic acid (PLA) is the main biobased plastic manufactured on an industrial scale. This polymer is synthetized by chemical methods, and there is a strong demand for the implementation of clean technologies. This work focuses on the microbial fermentation of agro-industrial waste rich in starch for the production of lactic acid (LA) in a consolidated bioprocess, followed by the enzymatic synthesis of PLA. Lactic acid bacteria (LAB) and the fungus Rhizopus oryzae were evaluated as natural LA producers in pure cultures or in fungal–lactobacteria co-cultures formed by an LAB and a fungus selected for its metabolic capacity to degrade starch and to form consortia with LAB. Microbial interaction was analyzed by scanning electron microscopy and biofilm production was quantified. The results show that the fungus Talaromyces amestolkiae and Lactiplantibacillus plantarum M9MG6-B2 establish a cooperative relationship to exploit the sugars from polysaccharides provided as carbon sources. Addition of the quorum sensing molecule dodecanol induced LA metabolism of the consortium and resulted in improved cooperation, producing 99% of the maximum theoretical yield of LA production from glucose and 65% from starch. Finally, l-PLA oligomers (up to 19-LA units) and polymers (greater than 5 kDa) were synthetized by LA polycondensation and enzymatic ring-opening polymerization catalyzed by the non-commercial lipase OPEr, naturally produced by the fungus Ophiostoma piceae., This research was funded by the Comunidad de Madrid (S2018/EMT-4459, RETOPROSOST-2-CM Program), the AEI/FEDER/UE (BIO2015-73697-JIN, FungiQuorum), the MCIN/AEI (PID2020-114210RB-I00, MICODE) and the MCIN/AEI/“NextGenerationEU”/PRTR (TED2021-130096B-I00, DEMO)., Peer reviewed