Phycobiliprotein recovery coupled to the tertiary treatment of wastewater in semi-continuous photobioreactors. Tracking contaminants of emerging concern.

This study evaluated a tertiary wastewater treatment technology using cyanobacteria to recover value-added phycobiliproteins. The presence of contaminants of emerging concern (CECs) in wastewater, cyanobacterial biomass and pigments recovered were also analyzed. For this, a wastewater-borne cyanobacterium (Synechocystis sp. R2020) was used to treat secondary effluent from a municipal wastewater treatment plant, with and without nutrients supplementation. Then, the stability of phycobiliprotein production was assessed by operating the photobioreactor in semi-continuous mode. Results showed similar biomass productivity with and without nutrients supplementation (153.5 and 146.7 mg L-1 d-1, respectively). Upon semi-continuous operation, the phycobiliprotein content was stable and reached up to 74.7 mg gDW-1. The phycocyanin purity ratio ranged from 0.5 to 0.8, corresponding to food grade (>0.7). Out of 22 CECs detected in secondary effluent, only 3 were present in the phycobiliprotein extracts. In order to identify applications, prospective research should focus on CECs removal during pigment purification.

Production of phycobiliproteins, bioplastics and lipids by the cyanobacteria Synechocystis sp. treating secondary effluent in a biorefinery approach.

Cyanobacteria have been identified as promising organisms to reuse nutrients from waste effluents and produce valuable compounds such as lipids, polyhydroxyalkanoates (PHAs), and pigments. However, almost all studies on cyanobacterial biorefineries have been performed under lab scale and short cultivation periods. The present study evaluates the cultivation of the cyanobacterium Synechocystis sp. in a pilot scale 30 L semi-continuous photobioreactor fed with secondary effluent for a period of 120 days to produce phycobiliproteins, polyhydroxybutyrate (PHB) and lipids. To this end, the harvested biomass from the semi-continuous photobioreactor was transferred into 5 L vertical column batch photobioreactors to perform PHB and lipid accumulation under nutrient starvation. Three hydraulic retention times (HRT) (6, 8 and 10 days) were tested in the semi-continuous photobioreactor to evaluate its influence on biomass growth and microbial community. A maximum biomass concentration of 1.413 g L-1 and maximum productivity of 173 mg L-1 d-1 was reached under HRT of 8 days. Microscopy analysis revealed a shift from Synechocystis sp. to Leptolyngbya sp. and green algae when HRT of 6 days was used. Continuous, stable production of phycobiliproteins in the semi-continuous photobioreactor was obtained, reaching a maximum content of 7.4%dcw in the biomass. In the batch photobioreactors a PHB content of 4.8%dcw was reached under 7 days of nitrogen and phosphorus starvation, while a lipids content of 44.7%dcw was achieved under 30 days of nitrogen starvation. PHB and lipids production was strongly dependent on the amount of nutrients withdrawn from the grow phase. In the case of lipids, their production was stimulated when there was only phosphorus depletion. While Nitrogen and phosphorus limitation was needed to enhance the PHB production. In conclusion, this study demonstrates the feasibility of cultivating cyanobacteria in treated wastewater to produce bio-based valuable compounds within a circular bioeconomy approach.

Venting percutaneous radiologic gastrostomy in malignant bowel obstruction: safety and effectiveness in a comprehensive cancer centre.

OBJECTIVE: Approximately 20% of established malignant bowel obstruction (MBO) patients do not respond to pharmacological treatment. In these cases, venting percutaneous radiologic gastrostomy (VPRG) may be useful. Existing evidence is based on retrospective studies with methodological limitations. The purpose of this study is to describe safety and effectiveness for symptom control after VPRG placement in a prospective cohort of MBO patients. METHODS: Complications of VPRG placement, symptom control, destination on discharge and survival were analysed. RESULTS: Twenty-one patients were included, 13 (61.9%) of whom were women. Mean age was 62.7 years (36-85). Local pain (n=8, 38.1%) and peristomal leakage (n=4, 19%) were the most frequent minor complications. No major complications occurred. Nausea and vomiting were relieved in most patients (n=20, 95.2%) after VPRG, and small quantities of liquid diet were introduced to these patients. Median time to death after VPRG was 13 days (IQR 8.6-17.4). Thirteen patients (61.9%) were discharged, with seven of them (33.3%) returning home. CONCLUSIONS: When pharmacological treatment fails, the use of VPRG in MBO patients may be feasible, safe and effective.

A Review of Web-Based Nutrition Information in Spanish for Cancer Patients and Survivors.

Nutrition education resources are of interest for cancer patients and survivors throughout the cancer continuum. We examined the web-based nutrition information in Spanish for cancer patients and survivors provided by national cancer organizations (NCOs). The Guide to Internet Resources for Cancer and the membership list of the Union for International Cancer Control were searched to identify the NCOs. The International Patients Decisions Aid Standards (IPDAS) was used to describe the quality of the available information. We identified 20 NCOs that provided nutrition information aimed at a general audience on their websites. Web-based resources of nine NCOs were selected for presentation in this review. Website scores ranged between 20 and 24 in the IPDAS scale (maximum score = 31). The selected NCOs offered reliable and safe information. Healthy eating information for cancer patients and management of side-effects was provided by all websites. Information was more limited for cancer survivors. We recommend that NCOs increase the possibilities for personalized recommendations and interaction with the content by including instrumental tools on their websites.

Inhibition of Intestinal Lipid Absorption by Cyanobacterial Strains in Zebrafish Larvae.

Obesity is a complex metabolic disease, which is increasing worldwide. The reduction of dietary lipid intake is considered an interesting pathway to reduce fat absorption and to affect the chronic energy imbalance. In this study, zebrafish larvae were used to analyze effects of cyanobacteria on intestinal lipid absorption in vivo. In total, 263 fractions of a cyanobacterial library were screened for PED6 activity, a fluorescent reporter of intestinal lipases, and 11 fractions reduced PED6 activity > 30%. Toxicity was not observed for those fractions, considering mortality, malformations or digestive physiology (protease inhibition). Intestinal long-chain fatty acid uptake (C16) was reduced, but not short-chain fatty acid uptake (C5). Alteration of lipid classes by high-performance thin-layer chromatography (HPTLC) or lipid processing by fluorescent HPTLC was analyzed, and 2 fractions significantly reduced the whole-body triglyceride level. Bioactivity-guided feature-based molecular networking of LC-MS/MS data identified 14 significant bioactive mass peaks (p < 0.01, correlation > 0.95), which consisted of 3 known putative and 11 unknown compounds. All putatively identified compounds were known to be involved in lipid metabolism and obesity. Summarizing, some cyanobacterial strains repressed intestinal lipid absorption without any signs of toxicity and could be developed in the future as nutraceuticals to combat obesity.