Biodegradation of plastics by white-rot fungi: A review.

Plastic pollution is one of the most environmental problems in the last two centuries, because of their excessive usage and their rapidly increasing production, which overcome the ability of natural degradation. Moreover, this problem become an escalating environmental issue caused by inadequate disposal, ineffective or nonexistent waste collection methods, and a lack of appropriate measures to deal with the problem, such as incineration and landfilling. Consequently, plastic wastes have become so ubiquitous and have accumulated in the environment impacting ecosystems and wildlife. The above, enhances the urgent need to explore alternative approaches that can effectively reduce waste without causing harsh environmental consequences. For example, white-rot fungi are a promising alternative to deal with the problem. These fungi produce ligninolytic enzymes able to break down the molecular structures of plastics, making them more bioavailable and allowing their degradation process, thereby mitigating waste accumulation. Over the years, several research studies have focused on the utilization of white-rot fungi to degrade plastics. This review presents a summary of plastic degradation biochemistry by white-rot fungi and the function of their ligninolytic enzymes. It also includes a collection of different research studies involving white-rot fungi to degrade plastic, their enzymes, the techniques used and the obtained results. Also, this highlights the significance of pre-treatments and the study of plastic blends with natural fibers or metallic ions, which have shown higher levels of degradation. Finally, it raises the limitations of the biotechnological processes and the prospects for future studies.

Assessing the impact of the COVID-19 pandemic among Venezuelan refugees and migrants in Colombia using respondent-driven sampling (RDS).

OBJECTIVES: To determine factors associated with adherence to COVID-19 mitigation measures, related symptoms and testing, as well as pandemic-related income loss among Venezuelan refugee and migrant adults in urban and border areas of Colombia. DESIGN: Phone-based respondent-driven sampling SETTING: Bogotá and Norte de Santander, Colombia. PARTICIPANTS: 605 adult Venezuelan refugees and migrants residing in Bogotá (n=305) and Norte de Santander (n=300), who arrived in Colombia after 2014 and completed the survey in August and September 2020. PRIMARY AND SECONDARY OUTCOME MEASURES: Full COVID-19 compliance (vs incomplete or no compliance), any COVID-19-related symptoms (vs none) and income loss due to isolation measures in Colombia (vs no income change or increase in income). RESULTS: Older age was associated with lower odds of compliance with physical distancing measures (0.94, 0.90-0.99; p=0.01) for those in Bogotá. Nearly 15% of refugees and migrants in both locations (81 of 605) experienced at least one symptom consistent with COVID-19. Having a health condition was associated with higher odds of experiencing COVID-19-related symptoms in Bogotá (4.00, 1.22-13.06; p=0.02) and Norte de Santander (6.99, 1.95-24.99; p=0.003). Around 8% in both locations (48 of 605) were tested for COVID-19. Around 90% in both locations (537 of 605) had trouble earning an income after the introduction of isolation measures, and the median reported monthly income decreased by half in Bogotá and by 30% in Norte de Santander. A higher level of education (3.46, 1.02-11.75; p=0.05) was associated with higher odds of income loss among participants in Norte de Santander. CONCLUSIONS: Results indicate high compliance with COVID-19 mitigation measures, low testing rates and high pandemic-related income loss among Venezuelan refugees and migrants in Colombia. This study provides insights into a hard-to-reach refugee and migrant population in Colombia; additional study on the effects of the pandemic on hidden populations is warranted.

Production, characterization and kinetic model of biosurfactant produced by lactic acid bacteria

BACKGROUND Biosurfactants are surface active molecules produced by microorganisms which have the ability to disrupt the plasma membrane. Biosurfactant properties are important in the food, pharmaceu tical and oil industries. Lactic acid bacteria can produce cell-bound and excreted biosurfactants. RESULTS The biosurfactant-producing ability of three Lactobacillus strains was analyzed, and the effects of carbon and nitrogen sources and aeration conditions were studied. The three species of lactobacillus eval uated were able to produce biosurfactants in anaerobic conditions, which was measured as the capacity of one extract to reduce the surface tension compared to a control. The decreasing order of biosurfactant production was L. plantarum>Lactobacillus sp.>L. acidophilus. Lactose was a better carbon source than glu cose, achieving a 23.8% reduction in surface tension versus 12.9% for glucose. Two complex nitrogen sources are required for growth and biosurfactant production. The maximum production was reached at 48 h under stationary conditions. However, the highest level of production occurred in the exponential phase. Biosurfactant exhibits a critical micelle concentration of 0.359 ± 0.001 g/L and a low toxicity against E. coli. Fourier transform infrared spectroscopy indicated a glycoprotein structure. Additionally, the kinetics of fermentation were modeled using a logistic model for the biomass and the product, achieving a good fit (R2 > 0.9). CONCLUSIONS L. plantarum derived biosurfactant production was enhanced using adequate carbon and nitrogen sources, the biosurfactant is complex in structure and because of its low toxicity could be applied to enhance cell permeability in E. coli

Seasonal and Pandemic A (H1N1) 2009 influenza vaccination coverage and attitudes among health-care workers in a Spanish University Hospital.

Influenza vaccination coverage among health-care workers (HCWs) remains the lowest compared with other priority groups for immunization. Little is known about the acceptability and compliance with the pandemic (H1N1) 2009 influenza vaccine among HCWs during the current campaign. Between 23 December 2009 and 13 January 2010, once the workplace vaccination program was over, we conducted a cross-sectional, questionnaire-based survey at the University Hospital 12 de Octubre (Madrid, Spain). Five hundred twenty-seven HCWs were asked about their influenza immunization history during the 2009-2010 season, as well as the reasons for accepting or declining either the seasonal or pandemic vaccines. Multiple logistic-regression analysis was preformed to identify variables associated with immunization acceptance. A total of 262 HCWs (49.7%) reported having received the seasonal vaccine, while only 87 (16.5%) affirmed having received the pandemic influenza (H1N1) 2009 vaccine. "Self-protection" and "protection of the patient" were the most frequently adduced reasons for acceptance of the pandemic vaccination, whereas the existence of "doubts about vaccine efficacy" and "fear of adverse reactions" were the main arguments for refusal. Simultaneous receipt of the seasonal vaccine (odds ratio [OR]: 0.27; 95% confidence interval [95% CI]: 0.14-0.52) and being a staff (OR: 0.08; 95% CI: 0.04-0.19) or a resident physician (OR: 0.16; 95% CI: 0.05-0.50) emerged as independent predictors for pandemic vaccine acceptance, whereas self-reported membership of a priority group was associated with refusal (OR: 5.98; 95% CI: 1.35-26.5). The pandemic (H1N1) 2009 influenza vaccination coverage among the HCWs in our institution was very low (16.5%), suggesting the role of specific attitudinal barriers and misconceptions about immunization in a global pandemic scenario.