Comparative Studies on the Biosurfactant Production Capacity of Bacillus Subtilis and Pseudomonas Aeruginosa Using Engine Oil and Diesel Respectively as Substrate

The study was carried out to compare the the production capabilities and the biosurfactant activity of the bacteria, Bacillus subtilis and Pseudomonas aeruginosa using engine oil and diesel as the substrates respectively. The test organisms were isolated from engine oil contaminated soil as in the case of the Bacillus subtilis, which was collected from an automobile workshop in Samaru, Zaria and hydrocarboncontaminated water in the case of the Pseudomonas aeruginosa. The medium used for the experiment was a mineral medium supplemented with 2% engine oil and 2% diesel as the sole source of carbon and energy for Bacillus subtilis and Pseudomonas aeruginosa respectively. Production of biosurfactant was assayed by monitoring the increase in cell concentration, biosurfactant concentration, emulsification index and decrease in surface tension. Highest level of cell concentration and biosurfactant concentration (3.3 x 108 CFU/ml and 0.0106mg/ml respectively) were obtained at 144 h for the Pseudomonas aeruginosa using diesel as source of carbon and energy while the highest level of cell concentration and biosurfactant concentration (3.2 x 108 CFU/ml and 0.0096mg/ml respectively) were obtained at 120hrs for the Bacillus subtilis using engine oil as source of carbon and energy. The research show that Pseudomonas aeruginosa using diesel as the sole source of carbon and energy is better for the production of biosurfactant than Bacillus subtilis using engine oil as the sole source of carbon and energy.Key words: Biosurfactant, engine oil, diesel, Pseudomonas aeruginosa, Bacillus subtilis

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