Susana Bernardino

A new biocatalyst: Penicillin G acylase immobilized in sol-gel micro-particles with magnetic properties

The present work focuses on the development and basic characterization of a new magnetic biocatalyst, namely penicillin G acylase (PGA), immobilized in sol-gel matrices with magnetic properties, ultimately aimed for application in cephalexin (CEX) synthesis. A mechanically stable carrier, based on porous xerogels silica matrixes starting from tetramethoxysilane (TMOS), was prepared leading to micro-carriers with medium sized particles of 30 microm, as determined by scanning electron microscopy. An immobilization yield of 95-100% and a recovered activity of 50-65% at 37 degrees C, as determined by penicillin G (PG) hydrolysis (pH STAT method), were observed. These results clearly exceed those reported in a previous work on PGA immobilization in sol-gel, where only 10% of activity was recovered. The values of activity were kept constant for 6 months. Immobilized PGA (682 U/g(dry weight)) retained high specific activity throughout ten consecutive runs for PG hydrolysis, suggesting adequate biocatalyst stability. The CEX synthesis was performed at 14 degrees C, using the free and immobilized PGA in aqueous medium. Phenylglycine methyl ester was used as acyl donor at 90 mM and 7-aminodeacetoxycephalosporanic acid was the limiting substrate at 30 mM. The CEX stoichiometric yield after 1-h reaction was close to 68% (23 mM CEX/h) and 65% (19 mM CEX/h), respectively.

Financing social ventures by crowdfunding: the influence of entrepreneurs’ personality traits

Studies on the profile of the social entrepreneurs that use crowdfunding (CF) for financing social projects are relatively rare, specifically in the context of Social Stock Exchange platforms. This research aims to understand the role played by social entrepreneurs’ personality traits on the choice between the traditional donation model and social CF to finance social projects. The particular case of the Portuguese Social Stock Exchange (PSSE) is presented and a quantitative and exploratory approach is used. The data were collected through a questionnaire that was emailed to non-governmental organizations in Portugal and founders of the projects listed on PSSE. Logistic regression is employed to predict the probability that a social entrepreneur would use PSSE rather than traditional financing. The predictor variables are based on the Big Five personality traits. Our investigation reveals that the conscientiousness personality trait is the only factor that might explain the use of the PSSE platform.

Improved specific productivity in cephalexin synthesis by immobilized PGA in silica magnetic micro-particles.

There is a marked trend in pharmaceutical industry towards the replacement of classical organic methods by “green” alternatives that minimize or eliminate the generation of waste and avoid, where possible, the use of toxic and/or hazardous reagents and solvents. In this work the kinetically controlled synthesis of cephalexin by soluble and penicillin G acylase immobilized in sol–gel micro‐particles with magnetic properties was performed in aqueous media with PGME and 7‐ADCA as substrates, at different concentrations of substrate, temperature, pH, enzyme to substrate ratio and acyl donor to nucleophile ratio. Excess acyl donor had a strong effect on cephalexin productivity. A PGME/7‐ADCA ratio of 3 was considered optimum. A maximum specific productivity of

Microcredit: Role of Entrepreneurial Ventures in Development of Cabo Verde

5.9\,{\rm mmol}\,{\rm h}^{ - 1} \,{\rm g}_{{\rm biocatalyst}}^{ - 1}

The legacy of European Capitals of Culture to the “smartness” of cities: The case of Guimarães 2012

at 160 mM 7‐ADCA, 480 mM PGME and low enzyme to substrate ratio at 32.5 U mmol−1 7‐ADCA was obtained with immobilized PGA in full aqueous medium, suggesting that diffusional limitations were minimized when compared with other commercial biocatalysts. A half‐life of 133 h for the immobilized biocatalyst was estimated during cephalexin synthesis in the presence of 100 mM 7‐ADCA and 300 mM PGME, in 50 mM Tris/HCl at pH 7.2 and 14°C. These results compare quite favorably with those previously reported for the kinetically controlled synthesis of cephalexin. Biotechnol. Bioeng. 2010;107: 753–762.

Social entrepreneur and gender: what’s personality got to do with it?

Microcredit provides small loans to the most deprived populations for whom credit is difficult to obtain from the traditional banking system. These microcredits have no collateral backing and work on the basis of a small group-based borrowing mechanism. The funds are often used for financing productive and educational purposes related to entrepreneurial activities and self-employment. For this reason, microcredit is pointed out as a valuable tool in the economic, social and cultural development of poor countries.

Implicações do contexto político-legal para o lançamento de novas iniciativas sociais em Portugal

ABSTRACT The objective of the paper is to examine the extent to which the legacy of European Capitals of Culture (ECOC) increases the “smartness” of cities. A qualitative approach based on semi-structured interviews and desk research was used to assess the impact on the smart citys dimensions hypothesized by Giffinger et al. (2007). The research revealed that this kind of mega-event reinforces the smartness of the city in which it is hosted in terms of attributes such as living, economy, people and environment. No significant legacy is observed with respect to the mobility dimension.

Optimization in the immobilization of penicillin G acylase by entrapment in xerogel particles with magnetic properties

Purpose Research on economic entrepreneurship identifies a gender gap that is favorable to men. In the social entrepreneurship arena, the existing evidence is slightly fuzzy, as this gender gap is less preeminent. This paper aims to identify how gender differences in social entrepreneurial ventures creation are explained by different personality traits, by analyzing the extent to which female and male social entrepreneurs exhibit the same personality traits and whether potential differences are able to explain the differences in predisposition for the creation of new social entrepreneurial ventures. Design/methodology/approach A review of the literature on gender differences and personality traits in social entrepreneurship details the main theoretical developments and builds the hypotheses. Based on the Big Five model, the investigation uses a hypothesis testing quantitative approach. Primary data were collected through a questionnaire that was e-mailed and applied to the social entrepreneurs engaged in the creation of social ventures in Portugal. Findings The data gathered suggest that both female and male social entrepreneurs have personalities characterized by high levels of openness to experience, agreeableness, conscientiousness, extraversion and emotional stability. Based on the analysis of variance (ANOVA) between the two groups and logistic regression, the investigation reveals that women and men who launch a new social venture only differ in one personality dimension – agreeableness – wherein women scored more highly. No significant differences are found in the other personality traits. Research limitations/implications The research assumes that most aspects of human personality structure are represented in the Big Five model. Practical implications The knowledge about whether gender differences are explained by different personality traits is critical to public entities that might design appropriate public policies to stimulate social entrepreneurship. Also, social entrepreneurs’ capacity building programs should be delineated in accordance with a deeper understanding about gender and personality traits differences. Social implications The knowledge of the factors that affects the creation of new social ventures has an important potential contribution on social value creation and the promotion of gender equality. Originality/value This paper links two important topics – gender and entrepreneurs’ personality traits – scarcely explored in the social entrepreneurship literature. Thus, the paper adds new empirical evidence to support (or not) the belief that personality and gender matter in the decision to launch a new social venture.