Biodegradation of pretreated polyethylene film by Pseudomonas aeruginosa AMB-CD-1

A comparative study evaluated the acid, alkali, and heat-treated polyethylene biodegradation efficiency of Pseudomonas aeruginosa AMB-CD-1. The polyethylene (PE) pieces were separately treated with heat (50°C), acid (1N HCl), and alkali (1N NaOH) and then washed with water before use. All the treated samples were analyzed through thermogravimetric analysis. In addition, weight and temperature changes during the decomposition reactions were also measured and determined. In these treatments, the PE films of heat-treated and acid-treated low-density polyethylene (LDPE) indicated more significant weight loss at 120°C (48.99% and 40.75%, respectively) as compared to their control or untreated PE and alkali-treated LDPE (21.84% and 24.68%, respectively). A biodegradation assay was then conducted with treated and untreated LDPE films with P. aeruginosa AMB-CD-1 strain. Fourier transform infrared spectroscopy analysis revealed that the heat or acid-pretreated samples with isolate AMB-CD-1 displayed peaks at 2922.84, 2923.97, and 1450.31, 874.22 cm⁻¹ for C–H stretching deformation vibration, CH₂ scissoring vibration, –CHO stretching, and strong alkyl structure, respectively. Furthermore, the new peaks with a significant difference at 2500–2000 cm⁻¹ (O═C═O, O–H stretching vibration: carboxylic acid) and 1500–1000 cm⁻¹ (–CHO and C═O stretching) were noticed in the infrared spectral range of LDPE degradation. Modifications in the functional group provided evidence that biodegradation had impacted the chemical structure of the LDPE film. Additionally, it was demonstrated that pretreating LDPE films with heat or acid could speed up their biodegradation.     

Metalaxyl—its persistence and metabolism in soil

Different biotic and abiotic factors were found to play a vital role in attenuating metalaxyl residues in soil. In addition to metalaxyl many other products were found by HPLC and GC‐MS analysis while studying its soil metabolism in presence of natural sunlight. Three compounds were identified and characterized: 2,6‐dimethylaniline, 2,6‐dimethyl‐N‐ethylacetanilide and N‐(2,6‐dimethyl phenyl) alanine methyl ester.     

Unlocking ecosystem based adaptation opportunities in coastal Bangladesh

Coastal ecosystems generate diverse services, such as protection, production of food, climate regulation and recreation across the globe. These services are vital for extremely vulnerable coastal areas for enhancing present and future adaptation capacity under changing climate. Bangladesh has long coastline which provides opportunities to large population for multiple resource uses; and threats from extreme natural disasters. The CBACC-Coastal Afforestation is the priority initiative of Bangladesh NAPA that has come in actions under first LDCF adaptation project. The project has focused to reduce climatic vulnerability through enhancing resilience of coastal forests and adaptive capacity of communities. With a total of 6,100 ha of new mangrove plantation and introducing 10 important mangrove species in existing monoculture areas, the project increased protective and carbon rich forest coverage, and also functional capacity of coastal vegetation to adapt to current and future climatic shocks. Concurrently, the project developed co-benefit regime for community based adaptation through innovating integrated land uses for livelihoods of adjacent households. A new land use model (Forest, Fish and Fruit-Triple F) has been implemented to restore fallow coastal lands into community based livelihood adaptation practices. The Triple F practice has reduced inundation and salinity risks and freshwater scarcity in cultivation of agricultural crops and fish. The rational land uses improved household adaptation capacity of landless households through short-, mid- and long-term income generation. The project lesson has further focus to justify the land use innovation for harnessing potential opportunities of ecosystem based adaptation in coastal Bangladesh.