While screening for polyhydroxyalkanoate (PHA) producing strains, using glycerol rich by-product as carbon source, it was observed that extracellular polymers were also secreted into the culture broth. The scope of this study was to characterize both intracellular and extracellular polymers, produced by Pseudomonas putida NRRL B-14875 and Pseudomonas chlororaphis DSM 50083, mostly focusing on those novel extracellular polymers. It was found that they fall into the class of bioemulsifiers (BE), as they showed excellent emulsion stability against different hydrocarbons/oils at various pH conditions, temperature and salinity concentrations. Cytotoxicity tests revealed that BE produced by P. chlororaphis inhibited the growth of highly pigmented human melanoma cells (MNT-1) by 50% at concentrations between 150 and 200 μg/mL, while no effect was observed on normal skin primary keratinocytes and melanocytes. This is the first study reporting mcl-PHA production by P. putida NRRL B-14785 and bioemulsifier production from both P. putida and P. chlororaphis strains.
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http://dx.doi.org/10.1016/j.biortech.2019.02.066 | DOI Listing |
Environ Pollut
January 2025
Universidad de Alcalá, Departamento de Química Analítica, Química Física e Ingeniería Química, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares, Madrid, Spain.
Plastics, as synthetic polymers, are emerging contaminants that can harm organisms and ecosystems. This study investigates the presence of microplastics in sediments of two rivers in western Cuba, assessing their temporal variability, diversity, and characterizing the types of microplastics in these ecosystems. Additionally, the study examines the relationship between microplastic concentrations, the extracellular enzymatic activity of benthic microbial communities, and nutrient levels in sediments.
View Article and Find Full Text PDFJ Transl Med
January 2025
School of Nursing, Nanjing Medical University, Nanjing, 211166, China.
Background: Tumor-associated fibrosis modifies the tumor microenvironment (TME), hinders the infiltration and activity of cytotoxic immune cells, and is a critical pathological process leading to the ineffectiveness of tumor immunotherapy in gastric cancer (GC). However, the specific mechanisms and interventions are yet to be fully explored.
Methods: Our study included 375 gastric cancer samples from TCGA, 1 single-cell RNA sequencing (scRNA-seq) dataset comprising of 15 gastric cancer samples from GEO, 19 cohorts of immunotherapy and 2 GWAS datasets.
ACS Macro Lett
January 2025
Materials Science and Engineering Department, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
In complex networks and fluids such as the extracellular matrix, the mechanical properties are substantially affected by the movement of polymers both part of and entrapped in the network. As many cells are sensitive to the mechanical remodeling of their surroundings, it is important to appreciate how entrapped polymers may inhibit or facilitate remodeling in the network. Here, we explore a molecular-level understanding of network remodeling in a complex hydrogel environment through successive compressive loading and the role that noninteracting polymers may play in a dynamic network.
View Article and Find Full Text PDFCNS Neurosci Ther
January 2025
Children's Medical Center, Department of Pediatric Neurology, Peking University First Hospital, Beijing, China.
Aims: Alexander disease (AxD) is a leukodystrophy caused by mutations in the astrocytic filament gene GFAP. There are currently no effective treatments for AxD. Previous studies have rarely established AxD models with the patient's original GFAP mutations.
View Article and Find Full Text PDFPlant J
January 2025
Systems Biotechnology Group, Department Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, 04318, Germany.
Biophotovoltaics offers a promising low-carbon footprint approach to utilize solar energy. It aims to couple natural oxygenic photosynthetic electrons to an external electron sink. This lays the foundation for a potentially high light-to-energy efficiency of the Biophotovoltaic process.
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