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Showing total 7,053 results
Start Over Publication Year Range Last 10 years Journal applied microbiology and biotechnology Publisher springer berlin heidelberg
7,053 results

10. Wood-water relationships and their role for wood susceptibility to fungal decay

Author

Gry Alfredsen and Christian Brischke

Subjects
Wood-water interactions, Brown rot, Vapour pressure of water, chemistry.chemical_element, Fungal degradation, Applied Microbiology and Biotechnology, complex mixtures, Soft rot, Durability, 03 medical and health sciences, chemistry.chemical_compound, Pile test, Mycology, Physiological limit, Wood decomposition, 030304 developmental biology, 0303 health sciences, Moisture, 030306 microbiology, technology, industry, and agriculture, Fungi, General Medicine, Mini-Review, Pulp and paper industry, chemistry, Carbon dioxide, White rot, Minimum moisture threshold, Environmental science, Sorption, Wood-decay fungi, Carbon, Biotechnology
Abstract

Abstract Wood in service is sequestering carbon, but it is principally prone to deterioration where different fungi metabolize wood, and carbon dioxide is released back to the atmosphere. A key prerequisite for fungal degradation of wood is the presence of moisture. Conversely, keeping wood dry is the most effective way to protect wood from wood degradation and for long-term binding of carbon. Wood is porous and hygroscopic; it can take up water in liquid and gaseous form, and water is released from wood through evaporation following a given water vapour pressure gradient. During the last decades, the perception of wood-water relationships changed significantly and so did the view on moisture-affected properties of wood. Among the latter is its susceptibility to fungal decay. This paper reviews findings related to wood-water relationships and their role for fungal wood decomposition. These are complex interrelationships not yet fully understood, and current knowledge gaps are therefore identified. Studies with chemically and thermally modified wood are included as examples of fungal wood substrates with altered moisture properties. Quantification and localization of capillary and cell wall water – especially in the over-hygroscopic range – is considered crucial for determining minimum moisture thresholds (MMThr) of wood-decay fungi. The limitations of the various methods and experimental set-ups to investigate wood-water relationships and their role for fungal decay are manifold. Hence, combining techniques from wood science, mycology, biotechnology and advanced analytics is expected to provide new insights and eventually a breakthrough in understanding the intricate balance between fungal decay and wood-water relations. Key points • Susceptibility to wood-decay fungi is closely linked to their physiological needs. • Content, state and distribution of moisture in wood are keys for fungal activity. • Quantification and localization of capillary and cell wall water in wood is needed. • New methodological approaches are expected to provide new insights

Published
2020

18. The mechanisms of granulation of activated sludge in wastewater treatment, its optimization, and impact on effluent quality

Author

Oskar Modin, Britt-Marie Wilén, Raquel Liébana, Frank Persson, and Malte Hermansson

Subjects
Wash-out dynamics, Settling time, Microorganism, 0208 environmental biotechnology, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, Applied Microbiology and Biotechnology, Waste Disposal, Fluid, Water Purification, Microbial community composition, Granulation, Bioreactors, Effluent, Process performance, 0105 earth and related environmental sciences, Sewage, Granule (cell biology), Temperature, General Medicine, Mini-Review, Pulp and paper industry, Granulation mechanisms, Aerobiosis, 020801 environmental engineering, Activated sludge, Granule stability, Wastewater, Aerobic granular sludge, Environmental science, Sewage treatment, Water Microbiology, Biotechnology
Abstract

Granular activated sludge has gained increasing interest due to its potential in treating wastewater in a compact and efficient way. It is well-established that activated sludge can form granules under certain environmental conditions such as batch-wise operation with feast-famine feeding, high hydrodynamic shear forces, and short settling time which select for dense microbial aggregates. Aerobic granules with stable structure and functionality have been obtained with a range of different wastewaters seeded with different sources of sludge at different operational conditions, but the microbial communities developed differed substantially. In spite of this, granule instability occurs. In this review, the available literature on the mechanisms involved in granulation and how it affects the effluent quality is assessed with special attention given to the microbial interactions involved. To be able to optimize the process further, more knowledge is needed regarding the influence of microbial communities and their metabolism on granule stability and functionality. Studies performed at conditions similar to full-scale such as fluctuation in organic loading rate, hydrodynamic conditions, temperature, incoming particles, and feed water microorganisms need further investigations.

Published
2018

27. Bioreactors for lignocellulose conversion into fermentable sugars for production of high added value products

Author

Vincenza Faraco, Valeria Ventorino, Olimpia Pepe, Rossana Liguori, Liguori, Rossana, Ventorino, Valeria, Pepe, Olimpia, and Faraco, Vincenza

Subjects
0106 biological sciences, Crops, Agricultural, 020209 energy, Paddle blade magnetic impeller, Biomass, 02 engineering and technology, Single and double helical ribbon impeller, 01 natural sciences, Applied Microbiology and Biotechnology, Lignin, Zea mays, Rushton impeller, Peg-mixer, Bioreactors, Single and double helical ribbon impeller, Rushton impeller, S-shaped impeller, Anchor impeller, Pitched-blade impeller, Peg-mixer, Paddle blade magnetic impeller, 010608 biotechnology, Bioproducts, 0202 electrical engineering, electronic engineering, information engineering, Cellulose, Ethanol, business.industry, Hydrolysis, General Medicine, S-shaped impeller, Mini-Review, Pulp and paper industry, Pitched-blade impeller, Biotechnology, Saccharum, Energy crop, Anchor impeller, Corn stover, Biofuel, Fermentation, Environmental science, Carbohydrate Metabolism, Sunflower seed, business, Bagasse, Renewable resource
Abstract

Lignocellulosic biomasses derived from dedicated crops and agro-industrial residual materials are promising renewable resources for the production of fuels and other added value bioproducts. Due to the tolerance to a wide range of environments, the dedicated crops can be cultivated on marginal lands, avoiding conflict with food production and having beneficial effects on the environment. Besides, the agro-industrial residual materials represent an abundant, available, and cheap source of bioproducts that completely cut out the economical and environmental issues related to the cultivation of energy crops. Different processing steps like pretreatment, hydrolysis, and microbial fermentation are needed to convert biomass into added value bioproducts. The reactor configuration, the operative conditions, and the operation mode of the conversion processes are crucial parameters for a high yield and productivity of the biomass bioconversion process. This review summarizes the last progresses in the bioreactor field, with main attention on the new configurations and the agitation systems, for conversion of dedicated energy crops (Arundo donax) and residual materials (corn stover, wheat straw, mesquite wood, agave bagasse, fruit and citrus peel wastes, sunflower seed hull, switchgrass, poplar sawdust, cogon grass, sugarcane bagasse, sunflower seed hull, and poplar wood) into sugars and ethanol. The main novelty of this review is its focus on reactor components and properties.

Published
2015