Uzgoj bakterije Methylobacterium organophilum u metanolu za istodobnu proizvodnju proteina i korisnih metabolita

Research background. This study aims to monitor the growth of the methylotrophic bacteria Methylobacterium organophilum in a culture medium with methanol as a carbon source and to verify the production of unicellular proteins and other biomolecules, such as carotenoids, exopolysaccharides and polyhydroxyalkanoates, making them more attractive as animal feed. Experimental approach. Bacterial growth was studied in shake flasks using different carbon/nitrogen (C:N) ratios to determine their best ratio for achieving the highest volumetric productivity of cells and substrate consumption rate. This optimal parameter was further used in a fed-batch operating bioreactor system to define the kinetic profile of cell growth. Methanol consumption was measured by HPLC analysis and the extracted pigments were analyzed by liquid chromatography/mass spectrometry. Chemical composition and rheological properties of the produced exopolysaccharides were also determined. Results and conclusions. The best experimental parameters were verified using an initial methanol concentration of 7 g/L in the culture medium. The same initial substrate concentration was used in the fed-batch operation and after 60 h of cultivation 5 g/L of biomass were obtained. The accumulation of carotenoids associated with cell growth was monitored, reaching a concentration of 1.6 mg/L at the end of the process. These pigments were then analyzed and characterized as a set of xanthophylls (oxidized carotenoids). In addition, two other product types were identified during the fed-batch operation: exopolysaccharides, which reached a concentration of 8.9 g/L at the end of the cultivation, and an intracellular granular structure that was detected by transmission electron microscopy (TEM), suggesting the accumulation of polyhydroxyalkanoate (PHA), most likely polyhydroxybutyrate. Novelty and scientific contribution. Methylobacterium organophilum demonstrated a unique ability to produce compounds of commercial interest. The distinct metabolic diversity of this bacterium makes room for its use in biorefineries.Pozadina istraživanja. Svrha je ovoga istraživanja bila pratiti rast metilotrofne bakterije Methylobacterium organophilum u podlozi s metanolom kao izvorom ugljika, te potvrditi sposobnost tog jednostaničnog organizma da proizvodi proteine i druge biomolekule, kao što su karotenoidi, egzopolisaharidi i polihidroksialkanoati, a koji se mogu upotrijebiti u proizvodnji stočne hrane. Eksperimentalni pristup. Rast bakterije ispitan je na tresilici pri različitim omjerima ugljika i dušika (C:N), radi utvrđivanja njihovog optimalnog omjera za postizanje najveće volumetrijske produktivnosti stanica i najboljeg iskorištenja supstrata. Zatim je pomoću tog optimalnog omjera hranjiva određen kinetički profil rasta stanica u šaržnom bioreaktoru. Potrošnja metanola mjerena je metodom HPLC, a izolirani su pigmenti ispitani tekućinskom kromatografijom spregnutom s masenom spektrometrijom. Također su određeni kemijski sastav i reološka svojstva dobivenih egzopolisaharida. Rezultati i zaključci. Najbolji eksperimentalni parametri potvrđeni su pri početnoj koncentraciji metanola u podlozi od 7 g/L. Ista je početna koncentracija korištena u šaržnom bioreaktoru, gdje je nakon 60 h uzgoja dobiveno 5 g/L biomase. Tijekom uzgoja je praćena akumulacija karotenoida, čija je koncentracija pri završetku procesa bila 1,6 mg/L. Pigmenti su zatim ispitani i okarakterizirani kao ksantofili (podvrsta karotenoida). Osim toga, tijekom šaržne fermentacije identificirana su još dva proizvoda: egzopolisaharidi, čija je koncentracija na kraju uzgoja bila 8,9 g/L; te granularna struktura otkrivena pomoću transmisijskog elektronskog mikroskopa, koja upućuje na to da je u stanici došlo do nakupljanja polihidroksialkanoata (PHA), i to najvjerojatnije polihidroksibutirata. Novina i znanstveni doprinos. Bakterija Methylobacterium organophilum ima jedinstveno svojstvo proizvodnje spojeva od komercijalnog interesa. Iznimna metabolička raznolikost ove bakterije omogućuje njezinu primjenu u biorafinerijama

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries