The aim of this study was to increase the antibacterial spectrum of modified hen egg white lysozyme (HEWL) with thermal and chemical treatments against Gram-negative bacteria. The antibacterial activity of heat-denatured HEWL and chemical denatured HEWL against Gram-negative and Gram-positive bacteria was evaluated in 15 h of incubation tests. HEWL was denatured by heating at pH 6.0 and pH 7.0 and chemical denaturing was carried out for 1.0, 1.5, 2.0, and 4.0 h with DL-Dithiothreitol (DTT). HEWL modified by thermal and chemical treatments was characterized using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method. Heat-denatured HEWL lytic activity against Micrococcus lysodeikticus lessened with increasing temperature and time of incubation with the chemical agent (DTT). The loss of lytic activity in modified HEWL suggests that the mechanism of action of the antibacterial activity is not dependent on the lytic activity. Thermal and chemical treatments of HEWL enabled the production of oligoforms and increased antibacterial activity over a wider spectrum. Heat-denatured HEWL at pH 6.0 and chemically-denatured HEWL increased the HEWL antibacterial spectrum against Gram-negative bacteria (Escherichia coli ATCC 25922). HEWL at 120 °C and pH 6.0 (1.0 mg/mL) inhibited 78.20% of the growth of E. coli. HEWL/DTT treatment for 4.0 h (1.0 mg/mL) inhibited 68.75% of the growth E. coli. Heat-denatured HEWL at pH 6.0 and pH 7.0 and chemically-denatured HEWL (1.0, 1.5, 2.0, and 4.0 h with DTT) were active against Gram-positive bacteria (Staphylococcus carnosus CECT 4491T). Heat-denatured and chemical-denatured HEWL caused the death of the bacteria with the destruction of the cell wall. LIVE/DEAD assays of fluorescent dye stain of the membrane cell showed membrane perturbation of bacteria after incubation with modified HEWL. The cell wall destruction was viewed using electron microscopy. The results obtained in this study suggest that heat-denatured HEWL at pH 6.0 and chemical-denatured HEWL treatments increase the HEWL antibacterial activity against Gram-negative bacteria.

This paper problematizes the meaning of subjectivity constructed by Colombian English Teachers in response to a National Bilingual Program and its system of reason to produce English teachers' identity and promote bilingual education. The double-side character of subjection/subjectification (Foucault, 1982) is used to analyze English teachers' work of the self and contestarian/resistance practices to affirm themselves as researchers and critical thinkers but also to claim recognition as educators who produce relevant and situated knowledge. Historical Discourse Analysis, through archeological procedures (Foucault, 1972) to trace back English teachers' discursive and non-discursive practices, were key to unveiling how teachers think of themselves as English teachers, oppose policies and respond to dominant discourses in relation to English teaching. More than 100 English teachers' academic publications were revised and confronted with normalized discourses circulating in political programs, print media and experts' documents. Findings contribute to EFL teachers' understanding of their own struggles and the role of their resistance practices to affirm their subjectivities.

The role of an inquiry-based practicum in the education of future teachers has been identified as a key component to foster student-teachers' abilities to face problems, try to solve them, work on doubts and produce situated and valuable learning from their own practices (Cochran-Smith & Little, 2001;Beck, 2001). The interaction between mentors and student-teachers involved in this process requires feeding the mutual understanding to collaboratelly make decisions to work on difficulties. In this reflective study, the practicum was the perfect scenario to evaluate how student-teachers and mentors engaged in inquiry-based work to face problems on a daily basis in schools in the context of teachers education. This article shows how a group of 12 student-teachers and their mentors experienced difficulties within an inquiry-based practicum in an undergraduate programme while conducting an instructional intervention, designing, implementing and applying a project relevant to their teaching context. Given the qualitative nature of this study, some stages of the process were analysed over a period of a year, bringing as a result relevant insights to enhance their teaching practicum-process in Colombian public schools.

The purpose of this paper is to examine and compare the concepts of linguistic colonialism and cultural alienation in University textbooks for teaching English as opposed to the theories about culture in the decolonial turn. Dichotomous categories were established based on the analysis of the cultural component of the textbooks for the teaching of English. The corpus consisted of six textbooks produced by multinational publishers and used in Colombia during the years 2006-2018. Documentary analysis procedures were used to discuss emergent themed contents in relation to cultural components from a critical perspective that unveiled imperialism practices. Results showed that the textbook contents dealt with high levels of alienation burden, superficial cultural components and instrumentation to the submissive person who favors the dominant culture of English and does not offer possibilities to embrace interculturality in ELF teaching contexts.

As a coeditor of CALJ, I would like to draw your attention to the rising importance of identity studies in the EFL setting and their contribution to the field. The Socratic imperative “know thyself” has inspired teacher researchers around the world (Benwell & Stokoe, 2006; Cheung, 2015; Johnson & Golombek, 2016; Norton, 2013) to raise awareness towards knowledge-power relations affecting our own constitution as subjects (Foucault, 1980). From a post-structuralist view, the comprehension of identity as something not given but constituted has illuminated a type of research more interested in revealing how interior and exterior forces—in Deleuze’s (1993) words—influence our constitution as subjects of a practice. In the field of EFL, research examining identity contributes to the understanding of who English teachers and learners are and how these identities are related to the teaching and learning process.