The two-dimensional distribution of flow patterns and their dynamic change due to microbial activity were investigated in naturally fractured chalk cores. Long-term biodegradation experiments were conducted in two cores ( approximately 20 cm diameter, 31 and 44 cm long), intersected by a natural fracture. 2,4,6-tribromophenol (TBP) was used as a model contaminant and as the sole carbon source for aerobic microbial activity. The transmissivity of the fractures was continuously reduced due to biomass accumulation in the fracture concurrent with TBP biodegradation. From multi-tracer experiments conducted prior to and following the microbial activity, it was found that biomass accumulation causes redistribution of the preferential flow channels. Zones of slow flow near the fracture inlet were clogged, thus further diverting the flow through zones of fast flow, which were also partially clogged. Quantitative evaluation of biodegradation and bacterial counts supported the results of the multi-tracer tests, indicating that most of the bacterial activity occurs close to the inlet. The changing flow patterns, which control the nutrient supply, resulted in variations in the concentrations of the chemical constituents (TBP, bromide and oxygen), used as indicators of biodegradation.
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http://dx.doi.org/10.1016/j.jconhyd.2005.06.007 | DOI Listing |
Biotechnol Biofuels Bioprod
January 2025
Section II: Electrobiotechnology, Institute of Process Engineering in Life Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.
Background: Parageobacillus thermoglucosidasius is a facultatively anaerobic thermophile that is able to produce hydrogen (H) gas from the oxidation of carbon monoxide through the water-gas shift reaction when grown under anaerobic conditions. The water-gas shift (WGS) reaction is driven by a carbon monoxide dehydrogenase-hydrogenase enzyme complex. Previous experiments exploring hydrogenogenesis with P.
View Article and Find Full Text PDFBioprocess Biosyst Eng
January 2025
Department of Chemical Engineering, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
Cellobiose lipids (CBLs) are a class of glycolipid biosurfactants produced by various fungal strains. These compounds have gained significant interest due to their surface-active and antifungal properties, which are comparable to traditional synthetic surfactants and antimicrobials. Despite their potential applicability in various cosmetic, pharmaceutical, and agricultural formulations, significantly less research has been focused on their production and purification in comparison to other glycolipid biosurfactants, such as mannosylerythritol lipids (MELs) and sophorolipids.
View Article and Find Full Text PDFCurr Microbiol
January 2025
Department of Microbiology and Immunology, School of Medicine, Soonchunhyang University, Cheonan-si, Chungnam, 31151, Republic of Korea.
Lactic acid bacteria (LAB), traditionally consumed as fermented foods, are now being applied to the medical field beyond health-functional food as probiotics. Therefore, it is necessary to continuously discover and evaluate new strains with suitable probiotic characteristics, mainly focusing on safety. In this study, we isolated eight new strains from postmenopausal vaginal fluid using culturomics approaches, an emerging area of interest.
View Article and Find Full Text PDFSci Rep
January 2025
Faculty of Pharmacy, Universidad San Pablo-CEU Universities, 28668-Boadilla del Monte, Madrid, Spain.
The synthesis of nanomaterials from PGPB is an exciting approach and it's often used in agriculture as nano-fertilizers and nano-pesticides. The present study reports a new approach to biosynthesis of silver nanoparticles (AgNP), using bacterial metabolites as agents to reduce Ag, which will remain as coating agents able to prevent microbial growth. Silver NP were biosynthesized using the bacterial metabolites produced by the beneficial strain Pseudomonas sp.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Science and Technology for Sustainable Development and One Health, Unit of Food Science and Nutrition, Università Campus Bio-Medico di Roma, Rome, 00128, Italy.
Defined by the World Health Organization (WHO) as indigenous knowledge and practices used for maintaining health and treating illnesses, traditional medicine (TM) represents a rich reservoir of ancient healing practices rooted in cultural traditions and accumulated wisdom over centuries. Five indigenous Kenyan plant species traditionally used in African TM, named Afzelia quanzensis, Azadirachta indica, Gigasiphon macrosiphon, Grewia bicolor, and Lannea schweinfurthii, represent a valuable resource in healing practices, yet their chemical composition and bioactivity remain understudied. To depict a primary bio-chemical characterization of these plants, their antioxidant and antimicrobial features have been evaluated by the use of methods validated in this context.
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