Optimization of pectinase production by Aspergillus niger using central composite design

Pectinases are a group of enzymes that catalyze the breakdown of pectin. Pectinase producing Aspergillus niger was obtained from a five-day old Eba (Cassava flakes). Response surface methodology was used for optimizing the process of the pectinase produced. Four independent variables which are, temperature, pH, substrate concentration and time of Heating at  70oC were used to optimize the significant correlation between the effects of the variables on pectinase production. A second-order polynomial was fitted to data and validated by ANOVA. The results revealed maximum pectinase production at pH 6.0, 50oC Temperature, 0.02% substrate concentration and the enzyme lost all its activity within 7 min of heating at 70oC. The study revealed that optimization of pectinase through RSM could improve the enzymatic characteristics and yield of the enzyme. The models used were highly significant with a correlation coefficient (R2) of 0.901Keywords: Pectinase; Aspergillus niger; Response Surface Methodology; Central Composite Desig

Butanol extract of Manihot esculenta leaf modulated cigarette butt leachate-mediated liver mitochondrial membrane permeabilization and its functional capacity

Objective: The experiment was designed to investigate the modulatory effects of the butanol extract of Manihot esculenta leaf, in vivo, and against the effects of cigarette butt leachate, in vitro on liver mitochondrial membrane permeability transition (MMPT), and its possible hepatoprotection in female Wistar rats.Methods: The powdery form of fresh, air-dried and pulverized M. esculenta leaves were extracted in 95% butanol using Soxhlet apparatus and concentrated to a sticky mass using rotary evaporator. Ethical approval for animal use was obtained from Ladoke Akintola University of Technology, Osogbo, Nigeria (LTH/EC/2014/10/237). Twelve Wistar rats were randomly assigned into 2 groups of 6 rats each, and a separate group of 4 rats were used for the in vitro study. The first set of rats was orally treated daily with the extract for 21 days. Following an overnight fast, the rats were sacrificed by cervical dislocation and the liver mitochondria isolated by standard methods. Mitochondrial swelling and liver function assays were done spectrophotometrically.Results: In vivo, the extract significantly induced low amplitude pore opening in the absence of exogenous Ca2+; whereas when it was present, the extract slightly inhibited same. Two concentrations of cigarette butt leachate caused appreciable low amplitude swelling in control and treated animals in the presence of Ca2+; in the absence of which highly significant inhibitory effects were observed at the same concentrations, in vitro. Significant increases were also recorded for AST, ALT, bilirubin, total protein and ALP, in vivo.Conclusion: The extract showed promise for hepato-protection against cigarette butt leachate toxicity in the liver of normal rats in the presence of exogenous Ca2+, in vitro.Keywords: Manihot esculenta leaf extract, cigarette butt leachate, mitochondrial membrane permeability transition pore, liver functio

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

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