Characterization of the cellulase-secretome produced by the Antarctic bacterium Flavobacterium sp. AUG42

Flavobacterium sp. AUG42 is a cellulase-producing bacterium isolated from the Antarctic oligochaete Grania sp. (Annelida). In this work, we report that AUG42 produces a glycoside hydrolase cocktail with CMCase, PASCase and cellobiase activities (optimum pHs and temperatures ranging from 5.5 to 6.5 and 40 to 50 °C, respectively). The time-course analyses of the bacterial growth and cellulase production showed that the cocktail has maximal activity at the stationary phase when growing at 16 °C with filter paper as a cellulosic carbon source, among the tested substrates. The analyses of the CAZome and the identification of secreted proteins by shotgun Mass Spectrometry analysis showed that five glycoside hydrolyses are present in the bacterial secretome, which probably cooperate in the degradation of the cellulosic substrates. Two of these glycoside hydrolyses may harbor putative carbohydrate binding modules, both with a cleft-like active site. The cellulolytic cocktail was assayed in saccharification experiments using carboxymethylcellulose as a substrate and results showed the release of glucose (a fermentable sugar) and other reducing-sugars, after 24 h incubation. The ecological relevance of producing cellulases in the Antarctic environment, as well as their potential use in the bio-refinery industry, are discussed

A Tn antigen binding lectin from Myrsine coriacea displays toxicity in human cancer cell lines.

International audienceThe Tn antigen (GalNAc-O-Ser/Thr) is one of the most specific human cancer-associated structures. In the present study we characterize the biochemical and functional properties of the Myrsine coriacea lectin (McL). We show that McL is an unusual high molecular weight highly glycosylated protein, which displays a strong Tn binding activity. The lectin exhibits in vitro inhibition of proliferation in the six cancer cell lines evaluated, in a dose-dependent manner (the strongest activity being against HT-29 and HeLa cells), whereas it does not exhibit toxicity against normal lymphocytes. McL could be exploited in the design of potential new tools for the diagnosis or treatment of cancer

Cross-fertilization between genetically modified and non-genetically modified maize crops in Uruguay

The cultivation of genetically modified (GM) Bt maize (Zea mays L.) events MON810 and Bt11 is permitted in Uruguay. Local regulations specify that 10% of the crop should be a non-GM cultivar as refuge area for biodiversity, and the distance from other non-GM maize crops should be more than 250 m in order to avoid cross-pollination. However, the degree of cross-fertilization between maize crops in Uruguay is unknown. The level of adventitious presence of GM material in non-GM crops is a relevant issue for organic farming, in situ conservation of genetic resources and seed production. In the research reported here, the occurrence and frequency of cross-fertilization between commercial GM and non-GM maize crops in Uruguay was assessed. The methodology comprised field sampling and detection using DAS-ELISA and PCR. Five field-pair cases where GM maize crops were grown near non-GM maize crops were identified. These cases had the potential to cross-fertilize considering the distance between crops and the similarity of the sowing dates. Adventitious presence of GM material in the offspring of non-GM crops was found in three of the five cases. Adventitious presence of event MON810 or Bt11 in non-GM maize, which were distinguished using specific primers, matched the events in the putative sources of transgenic pollen. Percentages of transgenic seedlings in the offspring of the non-GM crops were estimated as 0.56%, 0.83% and 0.13% for three sampling sites with distances of respectively 40, 100 and 330 m from the GM crops. This is a first indication that adventitious presence of transgenes in non-GM maize crops will occur in Uruguay if isolation by distance and/or time is not provided. These findings contribute to the evaluation of the applicability of the “regulated coexistence policy” in Uruguay

Nanoparticle-mediated monitoring of carbohydrate-lectin interactions using transient magnetic birefringence

© 2014 American Chemical Society. The development of sensitive and easy-to-use biosensors that allow an adequate characterization of specific weak biological interactions like carbohydrate-lectin interactions still remains challenging today. Nanoparticles functionalized with carbohydrates are one of the most powerful systems for studying carbohydrate-lectin interactions, because they mimic the multivalent presentation of carbohydrates encountered in nature, for example when viruses and bacteria bind to cells. On the basis of the model system glucose-Concanavalin A (ConA), we explore the application of Transient Magnetic Birefringence (TMB) to study these weak interactions, using glucose-functionalized colloidal magnetite nanoparticles (NPs) as probes. We demonstrate that the binding dynamics can be monitored and derive a model to obtain the apparent cooperativity. For our studies, we use nanoparticles of 6 and 8 nm in diameter. The ConA-generated response shows apparent cooperativity, due to the cross-linking of nanoparticles by the ConA tetramer which has four binding sites. Cooperativity is higher for 6 nm NPs, possibly due to a better accessibility of all four ConA binding sites on smaller NPs, enhancing cross-linking. For this system, we find a detection limit of 3-23 nM. (Chemical Equation Presented).This work has been supported by the Spanish Ministry of Education and Science (NAN2004-09125-C07-02), the Spanish National Research Council (projects 200550F0172 and 2009UY0024), the Spanish Ministry of Industry (FIT-010000-2006-98), the Spanish Ministry of Science and Innovation (CTQ2008-03739/PPQ), and the European Research Council (Starting Grant NANOPUZZLE). M.K. gratefully acknowledges support through a PhD fellowship I3P financed by the Spanish National Research Council and the European Commission. M.M. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (CONSOLIDER-NANOBIOMED).Peer Reviewe

Production of Capsular Polysaccharide of Streptococcus pneumoniae Type 14 and Its Purification by Affinity Chromatography

We describe a rapid and efficient method for producing the capsular polysaccharide of Streptococcus pneumoniae by fermentation on tryptic soy broth and purification of this compound by using immobilized soybean lectin as an affinity adsorbent. In principle, the same strategy can be used to produce purified capsular polysaccharides from other streptococcal serotypes by selecting the appropriate lectin adsorbents

Switching long acting antipsychotic medications to aripiprazole long acting once-a-month: Expert consensus by a panel of Italian and Spanish psychiatrists

Introduction: Aripiprazole long acting once-monthly (AOM) is a long acting atypical antipsychotic with proven efficacy in schizophrenia and with a pharmacological and a side effect profile that is different from other antipsychotics. These and other characteristics make AOM a possible alternative in patients requiring a change in long acting antipsychotic treatment due to issues such as lack of efficacy or persistent side effects. Both clinical and pharmacological factors should be considered when switching antipsychotics, and specific guidelines for long acting antipsychotic switching that address all these factors are needed.Areas covered: A panel of Italian and Spanish experts in psychiatry met to discuss the strategies for the switch to AOM in patients with schizophrenia. Real life clinical experiences were shared and the clinical strategies to improve the likelihood of success were discussed.Expert Opinion: Due to its specific pharmacological and tolerability profile, AOM represents a suitable alternative for patients with schizophrenia requiring a switch to a new LAI treatment because of lack of efficacy or persistent side effects from another LAI. Possible strategies for the switch to AOM are presented in this expert consensus paper in an attempt to provide guidance throughout the entire switching proces