36 research outputs found
Christianity, Sexuality and Citizenship in Africa: Critical Intersections
Citizenship in sub-Saharan Africa has undergone profound changes in recent decades as part of wider social and political dynamics. One notable development is the emergence of Christianity, especially in its Pentecostal-Charismatic forms, as a public religion. Christian actors, beliefs and practices have increasingly come to manifest themselves in the public sphere, actively engage with politics, define narratives of nationhood, and shape notions of citizenship. A second major development is the emergence of sexuality as a critical site of citizenship and nationhood in postcolonial Africa. On the one hand, many political and religious leaders are invested in a popular ideology of the heterosexual family as the basis of nation-building, while on the other hand, LGBT communities are becoming more visible and claim recognition from the state. The contributions to this special issue engage these two contrasting developments, examining the interconnections between Christianity, sexuality and citizenship empirically and theoretically through case studies in various African contexts and from several academic disciplines and critical perspectives
Isolation and Characterization of EstC, a New Cold-Active Esterase from Streptomyces coelicolor A3(2)
The genome sequence of Streptomyces coelicolor A3(2) contains more than 50 genes coding for putative lipolytic enzymes. Many studies have shown the capacity of this actinomycete to store important reserves of intracellular triacylglycerols in nutrient depletion situations. In the present study, we used genome mining of S. coelicolor to identify genes coding for putative, non-secreted esterases/lipases. Two genes were cloned and successfully overexpressed in E. coli as His-tagged fusion proteins. One of the recombinant enzymes, EstC, showed interesting cold-active esterase activity with a strong potential for the production of valuable esters. The purified enzyme displayed optimal activity at 35°C and was cold-active with retention of 25% relative activity at 10°C. Its optimal pH was 8.5–9 but the enzyme kept more than 75% of its maximal activity between pH 7.5 and 10. EstC also showed remarkable tolerance over a wide range of pH values, retaining almost full residual activity between pH 6–11. The enzyme was active toward short-chain p-nitrophenyl esters (C2–C12), displaying optimal activity with the valerate (C5) ester (kcat/Km = 737±77 s−1 mM−1). The enzyme was also very active toward short chain triglycerides such as triacetin (C2:0) and tributyrin (C4:0), in addition to showing good primary alcohol and organic solvent tolerance, suggesting it could function as an interesting candidate for organic synthesis of short-chain esters such as flavors