Obtaining Bioproducts from the Studies of Signals and Interactions between Microalgae and Bacteria

The applications of microalgae biomass have been widely studied worldwide. The classical processes used in outdoor cultivations of microalgae, in closed or open photobioreactors, occur in the presence of bacteria. Understanding how communication between cells occurs through quorum sensing and evaluating co-cultures allows the production of microalgae and cyanobacteria to be positively impacted by bacteria, in order to guarantee safety and profitability in the production process. In addition, the definition of the effects that occur during an interaction, promotes insights to improve the production of biomolecules, and to develop innovative products. This review presents the interactions between microalgae and bacteria, including compounds exchanges and communication, and addresses the development of new pharmaceutical, cosmetic and food bioproducts from microalgae based on these evaluations, such as prebiotics, vegan skincare products, antimicrobial compounds, and culture media with animal free protein for producing vaccines and other biopharmaceutical products. The use of microalgae as raw biomass or in biotechnological platforms is in line with the fulfillment of the 2030 Agenda related to the Sustainable Development Goals (SDGs)

Cultivation of the red seaweed Kappaphycus alvarezii using biofloc effluent

The aim of this work was to evaluate the use of effluent from a Biofloc System (BFT) as a fertilizer for the red seaweed Kappaphycus alvarezii cultivated in tanks and analyze its influence on carrageenan yield and quality. Firstly, the optimum effluent concentration and period for enrichment were determined by an in vitro study. The seedlings were then cultivated for 7 days in two different culture media: 50% von Stosch solution (V) and 25% BFT (B), both diluted in sterilized seawater. Seaweeds cultivated only in sterilized seawater were used as a control (C). After this period, all plants were grown in only sterilized seawater for a further 28 days. Seedlings from V (1.05 +/- 0.02% day(-1)) and B (1.13 +/- 0.01% day(-1)) showed no significant differences in growth rates, being both higher than the control (0.91 +/- 0.06% day(-1)). Seedlings from V and B also removed a greater quantity of nitrate (58.39% and 22.97%, respectively). Seedlings from V removed 100% phosphate, while those from B removed 83.58%. The tissue nitrogen content was higher only in the V. Although no significant differences were observed among treatments in the carrageenan yield, significantly higher gel strength and viscosity were observed in B (248.85 g cm(-2) and 19.89 mPa s, respectively). According to the results, BFT effluent can be used to replace von Stosch solution to grow K. alvarezii in tanks. At the same time, the seaweed, together with bacteria and microalgae from the effluent, can be an effective biofilter in IMTA systems using bioflocs.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [308631/2017-0

Resistant Hypertension On Treatment (ResHypOT): sequential nephron blockade compared to dual blockade of the renin-angiotensin-aldosterone system plus bisoprolol in the treatment of resistant arterial hypertension – study protocol for a randomized controlled trial

Abstract Background Resistant hypertension is characterized when the blood pressure (BP) remains above the recommended goal after taking three antihypertensive drugs with synergistic actions at their maximum recommended tolerated doses, preferably including a diuretic. Identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether acting on the control of intravascular volume or sodium balance, or acting on the effects of the renin-angiotensin-aldosterone system (RAAS) on the kidney. Methods/design This is a randomized, open-label, clinical trial is designed to compare sequential nephron blockade and its contribution to the intravascular volume component with dual blockade of the RAAS plus bisoprolol and the importance of serum renin in maintaining BP levels. The trial has two arms: sequential nephron blockade versus dual blockade of the RAAS (with an angiotensin converting enzyme (ACE) inhibitor plus a beta-blocker) both added-on to a thiazide diuretic, a calcium-channel blocker and an angiotensin receptor-1 blocker (ARB). Sequential nephron blockade consists in a progressive increase in sodium depletion using a thiazide diuretic, an aldosterone-receptor blocker, furosemide and, finally, amiloride. On the other hand, the dual blockade of the RAAS consists of the progressive addition of an ACE inhibitor until the maximum dose and then the administration of a beta-blocker until the maximum dose. The primary outcomes will be reductions in the systolic BP, diastolic BP, mean BP and pulse pressure (PP) after 20 weeks of treatment. The secondary outcomes will evaluate treatment safety and tolerability, biochemical changes, evaluation of renal function and recognition of hypotension (ambulatory BP monitoring (ABPM)). The sample size was calculated assuming an alpha error of 5% to reject the null hypothesis with a statistical power of 80% giving a total of 40 individuals per group. Discussion In recent years, the cost of resistant hypertension (RH) treatment has increased. Thus, identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether by acting on the control of intravascular volume or sodium balance, or by acting on the effects of the RAAS on the kidney. Trial registration Sequential Nephron Blockade vs. Dual Blockade Renin-angiotensin System + Bisoprolol in Resistant Arterial Hypertension (ResHypOT). ClinicalTrials.gov, ID: NCT02832973. Registered on 14 July 2016. First received: 12 June 2016. Last updated: 18 July 2016