Aims: This study aimed to isolate and identify hydrocarbon-utilising bacteria from oil- polluted sites and to develop a microbial consortium for use in pilot trial and commercial scale bioremediation treatment systems in the future. Methodology and results: Ten hydrocarbon-utilising bacterial strains were isolated using enrichment culture technique from oil-polluted sites using crude oil as sole carbon source. The strains were tentatively identified on the basis of colony morphology, microscopic examination and biochemical characteristics. The growth of each strain was assessed by growing the bacteria in mineral salt medium amended with diesel oil as sole carbon source. The isolates exhibited differences in growth with the order of biomass production being Enterobacter sp. (OD620=1.283)> Bacillus subtilis subsp. subtilis (OD620=1.245) > Aerococcus sp. (OD620=1.100) > Bacillus firmus (OD620=0.970) > Corynebacterium sp. (OD620=0.886) > Bacillus lentus (OD620=0.743) > Micrococcus luteus (OD620=0.656) > Bacillus subtilis (OD620=0.367) > Bacillus cereus (OD620=0.110) > Kocuria flavus (OD620=0.065). Conclusion, significance and impact of study This study is a prerequisite for the design of future full-scale bioremediation treatment of oil-polluted sites using hydrocarbon-utilising bacteria. An efficient consortium was developed comprising the best three hydrocarbon-utilising strains, which include Enterobacter sp., Bacillus subtilis subsp. subtilis and Aerococcus sp. This efficient microbial consortium is suggested to be used in future to rehabilitate oil-polluted sites in Sudan.
Oil and Gas Fields--microbiology

Arthroscopy ; Humans ; Miners ; Oil and Gas Fields ; Osteoarthritis, Knee ; surgery

An endotracheal tube (ETT) may be thought of as a mechanical burden to a spontaneously breathing patient because increases in airway resistance might result in increases in the work of breathing,when diameter of airway is decreased in the intubated patient compared with his own tracheal diameter. We hypothesized that air removal from ETT cuff would permit the airflow between ETT and tracheal wall and could make the airway resistance decrease. Postanesthetic patients after abdominal surgery were divided into two groups. ETT cuff was inflated in group 1 (n=25) and deflated in group 2 (n=25), while 5 l/min of oxygen was delivered through the ETT via a simple oxygen supplement device without a gas reservoir. The effects of balloon on gas exchange and respiratory pattern were evaluated at 5 and 30 minutes after admission to the recovery room. Postanesthetic PaO2 was increased compared to preanesthetic value with oxygen supply. PaCO2 values revealed no significant changes in preanesthetic and postanesthetic periods. Postanesthetic respiratory rate was increased significantly but there was no difference between two groups. However, there were three hypoxemic patients whose PaO2 were below 70mmHg in group 1. It was concluded that the use of balloon of ETT in postanesthetic recovery period might contribute to airway resistance and the work of breathing. Although almost of patients could make compensations to overcome the effects of balloon, there is a risk of postoperative hypoxemia if compensated inadequately.
Airway Resistance ; Anoxia ; Humans ; Oil and Gas Fields ; Oxygen ; Recovery Room ; Respiration ; Respiratory Rate ; Work of Breathing

Objective: To investigate the level of psychosocial factors in workplace and their health effects among workers in a natural gas field. Methods: A prospective and open cohort of natural gas field workers was established to study the level of workplace psychosocial factors and their health effects, with a follow-up every 5 years. In October 2018, a cluster sampling method was used to conduct a baseline survey of 1737 workers in a natural gas field, including a questionnaire survey on demographic characteristics, workplace psychosocial factors and mental health outcomes, physiological indicators such as height and weight, and biochemical indicators such as blood routine, urine routine, liver function and kidney function. The baseline data of the workers were statistically described and analyzed. The psychosocial factors and mental health outcomes were divided into high and low groups according to the mean score, and the physiological and biochemical indicators were divided into normal and abnormal groups according to the reference range of normal values. Results: The age of 1737 natural gas field workers was (41.8±8.0) years old, and the length of service was (21.0±9.7) years. There were 1470 male workers (84.6%). There were 773 (44.5%) high school (technical secondary school) and 827 (47.6%) college (junior college) graduates, 1490 (85.8%) married (including remarriage after divorce), 641 (36.9%) smokers and 835 (48.1%) drinkers. Among the psychosocial factors, the detection rates of high levels of resilience, self-efficacy, colleague support and positive emotion were all higher than 50%. Among the mental health outcomes evaluation indexes, the detection rates of high levels of sleep disorder, job satisfaction and daily stress were 41.82% (716/1712), 57.25% (960/1677) and 45.87% (794/1731), respectively. The detection rate of depressive symptoms was 22.77% (383/1682). The abnormal rates of body mass index (BMI), triglyceride and low density lipoprotein were 46.74% (810/1733), 36.50% (634/1737) and 27.98% (486/1737), respectively. The abnormal rates of systolic blood pressure, diastolic blood pressure, uric acid, total cholesterol and blood glucose were 21.64% (375/1733), 21.41% (371/1733), 20.67% (359/1737), 20.55% (357/1737) and 19.17% (333/1737), respectively. The prevalence rates of hypertension and diabetes were 11.23% (195/1737) and 3.45% (60/1737), respectively. Conclusion: The detection rates of high level psychosocial factors in natural gas field workers are high, and their effects on physical and mental health remain to be verified. The establishment of a cohort study of the levels and health effects of psychosocial factors provides an important resource for confirming the causal relationship between workplace psychosocial factors and health.
Humans ; Male ; Adult ; Middle Aged ; Natural Gas ; Cohort Studies ; Prospective Studies ; Oil and Gas Fields ; Workplace/psychology* ; Surveys and Questionnaires

Most main oilfields in China have already entered a "double high" development stage (high water cut, high recovery degree). To further enhance oil recovery in reservoirs after polymer flooding (RAPFs), an efficient activator formulation for promoting metabolism of endogenous microorganism was studied by aerogenic experiments, physical simulation experiments, electron microscopy scanning and pyrophosphate sequencing. Results show that the activator could activate the endogenous microorganisms in the injected water and make the pressurized gas reach 2 MPa after 60 d static culture of the activator in a high pressure vessel. The oil recovery efficiency of natural core physical simulation flooding can be improved by more than 3.0% (OOIP) in RAPFs when injected 0.35 PV activator with 1.8% mass concentration, and a lot of growth and reproduction of activated endogenous microorganism in the core was observed by electron microscopy scanning. Field trial with 1 injector and 4 producers was carried out in the east of south II block of Sa Nan in December 2011. By monitoring four effective production wells, changes of carbon isotope δ13C (PDB) content of methane and carbon dioxide were -45 per thousand to -54 per thousand and 7 per thousand to 12 per thousand. Compared with east II of Sa Nan block, the oil amount increased by 35.9%, water cut stabled at 94%. The incremental oil was 5 957 t during the three and a half years, which provides an alternative approach for further improving oil recovery in similar reservoirs.
Carbon Dioxide ; chemistry ; Carbon Isotopes ; analysis ; China ; Diphosphates ; chemistry ; Methane ; chemistry ; Oil and Gas Fields ; microbiology ; Polymers ; Water ; Water Microbiology

Cross-Sectional Studies ; Depression/epidemiology* ; Humans ; Job Satisfaction ; Occupational Stress/epidemiology* ; Oil and Gas Fields ; Stress, Psychological ; Surveys and Questionnaires