High cell-density production of poly(3-hydroxybutyrate) in a membrane bioreactor.

Agro-industrial residues with a low carbon content, such as whey, stillage or wastewater from plant oil mills are abundant and cheap. However, they cannot be used directly in highly productive industrial poly(3-hydroxybutyrate) (P3HB) production, as the classical fed-batch fermentation strategy requires highly concentrated feed streams. This problem has been circumvented in this report by retaining the cells during the fermentation in the bioreactor using an external microfiltration module. Synthetic medium containing a glucose concentration of 50g/L was continuously fed to Cupriavidus necator, which converted the sugar to P3HB. With this setup we were able to achieve high productivities (3.10g P3HB/(Lh)) and reach high cell densities (148g/L) containing 76% P3HB, and obtained good yields (0.33g P3HB/g added glucose). The added sugar from the feed was instantly consumed by the bacteria, resulting in a negligible loss of sugar to the permeate. This approach creates the possibility of polyhydroxyalkanoate production from a range of cheap and easily available substrates, for which only waste water treatment or biogas production has been cost-competitive until now.

Predicting long-term outcomes of acute aortic dissection: a focus on gender.

Acute aortic disease ranks as the 19th leading cause of death with steadily increasing incidence. The prevalence of aneurysms varies depending on the localization along the aorta with a mortality of aortic rupture of around 80%. Traditionally, aortic disease affects men more frequently than women, however, with a varying gender ratio. Nevertheless, in the setting of acute aortic dissection, the International Registry of Acute Aortic Dissections identified significant gender-related differences in the management of both sexes with acute aortic conditions. Current data suggest that women are at an increased risk of both dying from aortic dissection and having aorta-related complications than men. This review aims to report on current evidence of gender impact on natural history, treatment and outcomes in patients with acute aortic dissection.