Microalgae being photosynthetic and having quick growth cycles can prove to be excellent candidates as biofactories for the production of aromatic compounds like para-hydroxybenzoic acid (pHBA) that act as a monomer in liquid crystal polymers. We developed transgenic lines of the model alga Chlamydomonas reinhardtii by performing nuclear transformation using electroporation. The transgenic cell lines expressed the ubiC gene that utilized chorismate from the shikimate pathway as a substrate to produce pHBA. The maximum yield of pHBA measured in these lines was 80 mg/L. Accruing pHBA can be toxic to the cells and the mechanism by which C. reinhardtii could detoxify pHBA is not known. C. reinhardtii genome was thus scanned for sequences similar to UDP-glucosyltransferase (UGT) that can transfer the glucose moiety to pHBA, rendering it non-toxic to the cell lines. Our analysis suggested the absence of any potential UGTs that could glycosylate pHBA and detoxify it. We further performed feeding experiments to test the ability of wt-type C. reinhardtii cells to detoxify pHBA and understand its fate. C. reinhardtii cells were fed with varying concentrations of pHBA and harvested at different time intervals. The HPLC chromatograms indicated a majority of the pHBA was catabolized. Based on these results, …

Prolonged exposure to microgravity is known to invoke physiological changes which predispose individuals to orthostatic intolerance upon readaptation to the earth's gravitational field. Attenuated baroreflex responsiveness has been implicated in contributing to this inability to withstand orthostatic stress. To test this hypothesis, eight individuals were exposed to 15 days of simulated microgravity exposure using the 6° head-down bed rest model. Prior to, and after the simulated microgravity exposure, the following were assessed: a) aortic baroreflex function; b) carotid baroreflex function; c) cardiopulmonary baroreflex function; and d) the degree of interaction between the cardiopulmonary and carotid baroreflexes.