Nutrient removal and biogas upgrade using co-cultivation of Chlorella vulgaris and three different bacteria under various GR24 concentrations by induction with 5-deoxystrigol.

Algae symbiosis technology shows great potential in the synchronous treatment of biogas slurry and biogas, which has promising applications. For improving nutrients and CO2 removal rates, the present work constructed four microalgal systems: Chlorella vulgaris (C. vulgaris) monoculture, C. vulgaris-Bacillus licheniformis (B. licheniformis), C. vulgaris-activated sludge, and C. vulgaris-endophytic bacteria (S395-2) to simultaneously treat biogas as well as biogas slurry under GR24 and 5DS induction. Our results showed that the C. vulgaris-endophytic bacteria (S395-2) showed optimal growth performance along with photosynthetic activity under the introduction of GR24 (10-9 M). Under optimal conditions, CO2 removal efficiency form biogas, together with chemical oxygen demand, total phosphorus and total nitrogen removal efficiencies from biogas slurry reached 67.25 ± 6.71%, 81.75 ± 7.93%, 83.19 ± 8.32%, and 85.17 ± 8.26%, respectively. The addition of symbiotic bacteria isolated from microalgae can promote the growth of C. vulgaris, and the exogenous addition of GR24 and 5DS can strengthen the purification performance of the algae symbiosis to achieve the maximum removal of conventional pollutants and CO2.

Performance of co-culture strategy on nutrient removal and biogas upgrading by strigolactone induction.

In this study, we investigated the performance and elucidated the synergistic effects of microalgae-fungi symbionts co-cultured with 10-7 and 10-9  mol L-1 of GR24 and supplemented with endophytic bacteria, multi-walled carbon nanotubes (MWCNTs) or vitamin B12 (VB12), on nutrient removal and biogas upgrading. The results showed that the microalgae-fungi-bacteria symbiotic system co-cultured with 10-9  mol L-1 GR24 presented the optimal growth performance of 0.368 ± 0.04 d-1 , chlorophyll a of 249.36 ± 22.31 µg L-1 , and extracellular carbonic anhydrase activity of 42.55 ± 3.755 enzyme units. In this co-culture system, the organic matter, nutrients, and CO2 purification obtained the highest removal efficiency, with 81.35 ± 7.96% for chemical oxygen demand, 83.56 ± 7.91% total nitrogen, 84.17 ± 7.95% total phosphorus, and 63.72 ± 6.06% CO2 . The symbiont system also greatly increased the methane content in the biogas by 30.67%. The remarkable performance of the microalgae-fungi-bacteria symbiotic system shows its ability to be broadly applied in simultaneous biogas upgrading and wastewater treatment. PRACTITIONER POINTS: The optimal GR24 concentration for microalgae-fungi consortia was 10-9  M. Endophytic bacteria were superior to MWCNTs and VB12. Fungi-algae-bacteria consortia presented excellent growth and removal performance. Removal efficiencies of COD, TN, and TP were about 81% under optimum treatment.

Supplementation of 5-deoxystrigol for higher pollutant removal and biogas quality improvement by different microalgae-based technologies.

The treatment of biogas slurry by microalgae technology has the characteristics of low cost, environmental protection, and high efficiency. In this paper, the effects of four microalgae technologies, namely, monoculture of Scenedesmus obliquus (S. obliquus), co-culture of S. obliquus-activated sludge, co-culture of S. obliquus-Ganoderma lucidum (G. lucidum), and co-culture of S. obliquus-G. lucidum-activated sludge, on the treatment of biogas slurry were investigated. In addition, the effects of 5-deoxystrigol (5-DS) concentration and mixed light wavelengths (red-blue light intensity ratio) on nutrient removal and biogas upgrading were also investigated. The results showed that 5-DS significantly promoted the growth and photosynthetic performance of the microalgal system. The best purification performance could be achieved by co-cultivation of S. obliquus-G. lucidum-activated sludge when the 5-DS concentration was 10-11  M, and the red-blue light intensity ratio was 5:5 (225:225 µmol m-2  s-1 ). The maximum average removal efficiencies for chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and carbon dioxide (CO2 ) were 83.25 ± 7.87%, 83.62 ± 7.78%, 84.19 ± 8.25%, and 71.68 ± 6.73%, respectively. The co-culture technology of S. obliquus-G. lucidum-activated sludge had great potential and superiority in removing nutrients from biogas slurry and upgrading biogas at the same time. The results of this study will provide a reference for the simultaneous purification of wastewater and upgrading of biogas using microalgae technology. PRACTITIONER POINTS: S. obliquus-G. lucidum-activated sludge consortium showed the best removal performance. 10-11 M 5-DS greatly promoted the purification performance. Removal efficiencies of COD, TN, and TP were more than 83%.

Safety of bevacizumab in treating metastatic colorectal cancer: a systematic review and meta-analysis of all randomized clinical trials.

BACKGROUND AND OBJECTIVE: The incidence rates of colorectal cancer (CRC) are increasing in a number of different regions, and recent studies have indicated that addition of bevacizumab to CRC therapy is beneficial. To better understand the relative risk (RR) of adverse events associated with use of bevacizumab, we systematically reviewed published clinical trials that studied use of bevacizumab in treatment of patients affected by metastatic CRC (mCRC). METHODS: The National Library of Medicine PubMed, MEDLINE, Ovid, Cochrane Library and Chinese Biomedicine databases were searched. The RR and number needed to harm (NNH) values for major side effects with 95% confidence intervals (CIs) were calculated in a fixed-effects model and a random-effects model, where appropriate. RESULTS: Fifteen controlled trials totalling 6,937 patients were eligible for this analysis. Compared with the control group, the bevacizumab treatment group had a slightly higher risk of any severe adverse event (pooled RR 1.07 [95% CI 1.02-1.12]). The pooled risk difference was 5% [95% CI 2-9%], with an NNH of 20 treated patients. Analyses showed a statistically significantly higher risk of secondary endpoints, including the discovery that bevacizumab was associated with a threefold higher risk of hypertension (pooled RR 3.06 [95% CI 2.45-3.83]), a twofold higher risk of gastrointestinal haemorrhage/perforation and a lower risk of neutropenia (pooled RR 0.75 [95% CI 0.26-2.19]). CONCLUSION: Bevacizumab has efficacy in all treatment regimens for advanced CRC. However, our meta-analysis raises safety concerns regarding an increased risk of serious adverse events associated with use of bevacizumab among patients with mCRC. Our findings warrant cautious use of bevacizumab in clinical oncology.