Transcription of the Hydrogenase Gene during H2 Production in Scenedesmus Obliquus and Chlorella Vulgaris

Abstract

There is ongoing research related to the production of molecular hydrogen today and algae have proven to be good biological models for producing several compounds of interest. We analyzed how genetic variations in hydrogenase genes (hyd) can affect the production of molecular hydrogen in the algae Chlorella vulgaris and Scenedesmus obliquus. Through isolation and genetic characterization of hyd genes in S. obliquus and C. vulgaris, we made in-silico 3D modeling of the hydrogenase proteins and compared these in 11 algal genera. The 3D structure of hydrogenases indicated its structural conservation in 10 genera of algae, and the results of our grouping according to the aa characteristics of the proteins showed the formation of two groups, which were unrelated to the algae’s phylogenetic classification. By growing C. vulgaris and S. obliquus in anaerobic conditions (in darkness) during 24 h and after exposing the cultures to light, we observed H2 production values of 9.0 ± 0.40 mL H2/L and 16 ± 0.50 mL H2/L, respectively. The highest global relative expression of hyd genes was reached during the first 30 min of exposure to light. The behavior of the expression of the hyd genes in these species of algae proved to be species specific and involved in the production of H2. Future identification of isoforms of hyd genes in algae would allow a better understanding of the regulation of the hydrogenase enzyme.

Port Topography in Atlantic and Mediterranean Hispania

“…Urbanism has been widely studied by historiography 86 describing an environment in constant evolution and conditioned by its riverbed that, despite the lack of some data, the existing information highlights the leading role it played as annona port. 87 In this port settlement, two functionally differentiated areas can be distinguished; on the one hand, the entire western limit of the city, which was systematically exploited by the fishing/canning industry, with numerous port infrastructures oriented to this activity -wharves, warehouses, hydraulic infrastructures, etc.and which occupied the territory between the Roman 86 COLLANTES 1977;BLANCO 1979;CAMPOS 1986;CAMPOS 1990;BLANCO 1992;CAMPOS 1993;GONZÁLEZ 1993;GONZÁLEZ 2010;GONZÁLEZ 2011;GONZÁLEZ 2012;CABRERA 2014 population centre and the Guadalquivir banks, needing to expand the walled perimeter. 88 On the other hand, with the economic progress of the city and its positioning as an output port for the hinterland of Hispania Baetica, its southern side where the Guadalquivir and Tagarete converged was selected the main port area of the city.…”