Providencia sp. strain X1 showing the highest xylanase activity among six bacterial isolates was isolated from saw-dust decomposing site. Strain X1 produced cellulase-free extracellular xylanase, which was higher in wheat bran medium than in xylan medium, when cultivated at pH 8.0 and 35°C. Zymogram analysis of crude preparation of enzymes obtained while growing on wheat bran and birchwood xylan revealed the presence of seven and two distinct xylanases with estimated molecular weight of 33; 35; 40; 48; 60; 75; and 95 kDa and 33 and 44 kDa, respectively. The crude xylanases were produced on wheat bran medium and showed optimum activity at pH 9.0 and 60°C. The thermotolerance studies showed activity retention of 100% and 85% at 40°C and 60°C after 30 min preincubation at pH 9.0. It was tolerant to lignin, ferulic acid, syringic acid, and guaiacol and retained 90% activity after ethanol treatment. The enzyme preparation was also tolerant to methanol and acetone and showed good activity retention in the presence of metal ions such as Fe2+, Mg2+, Zn2+, and Ca2+. The crude enzyme preparation was classified as endoxylanase based on the product pattern of xylan hydrolysis. Pretreatment of kraft pulp with crude xylanases for 3 h at 60°C led to a decrease in kappa number by 28.5%. The properties of present xylanases make them potentially useful for industrial applications.
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http://dx.doi.org/10.1155/2013/386769 | DOI Listing |
Int J Biol Macromol
December 2024
Beijing Institute of Radiation Medicine, Beijing 100850, China. Electronic address:
Ionizing radiation-induced injury often occurs in nuclear accidents or large-dose radiotherapy, leading to acute radiation syndromes characterized by hematopoietic and gastrointestinal injuries even to death. However, current radioprotective drugs are only used in hospitals with unavoidable side effects. Here, we heated the aqueous solution of inulin, a polysaccharide dietary fiber, forming colon-retentive gel as a radiation protector in radiotherapy.
View Article and Find Full Text PDFMetabolites
December 2024
Cryptobiotix SA, 9052 Ghent, Belgium.
Background: Using dietary interventions to steer the metabolic output of the gut microbiota towards specific health-promoting metabolites is often challenging due to interpersonal variation in treatment responses.
Methods: In this study, we combined the ex vivo SIFR (Systemic Intestinal Fermentation Research) technology with untargeted metabolite profiling to investigate the impact of carrot-derived rhamnogalacturonan-I (cRG-I) on ex vivo metabolite production by the gut microbiota of 24 human adults.
Results: The findings reveal that at a dose equivalent to 1.
Ageing Res Rev
December 2024
Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Youyidong Road, Xi'an, Shaanxi, 710000, China; Shaanxi Key Laboratory of Spine Bionic Treatment, Xi'an, Shaanxi, 710000, China. Electronic address:
Current research primarily focuses on the pathological mechanisms of spinal cord injury (SCI), seeking to promote spinal cord repair and restore motorial and sensory functions by elucidating mechanisms of cell death or axonal regeneration. However, SCI is almost irreversible, and patients often struggle to regain mobility or self-care abilities after injuries. Consequently, there has been significant interest in modulating systemic symptoms following SCI to improve patients' quality of life.
View Article and Find Full Text PDFAllergy
December 2024
Department of Paediatrics, Faculty of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
Food allergies are increasing globally, particularly in Asia; however, the etiologies of allergic diseases remain poorly understood despite comprehensive studies conducted across a variety of populations. Epidemiological research demonstrates that food allergy is more prevalent in Westernized or urbanized societies than in rural or developing ones. As such, comparing the distribution and patterns of food allergies as well as the environmental exposures between regions may provide insight into potential causal and protective factors of food allergy.
View Article and Find Full Text PDFFood Sci Nutr
December 2024
Department of Food Science and Technology, Science and Research Branch Islamic Azad University Tehran Iran.
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