When Vitreoscilla were grown in medium containing 60mM sodium nitrite under both normal and limited aeration conditions, the levels of Vitreoscilla hemoglobin (VHb) were decreased by greater than 90%, while the levels of the terminal respiratory oxidase, cytochrome bo, were increased 350% under normal aeration and 7-23% under limited aeration. Cytochrome function, as measured by both NADH and ubiquinol oxidases for cells grown under both conditions, increased in parallel (by 150-222% and 8-56%, respectively, for the two activities). Nitrite in the medium inhibited Vitreoscilla growth at both normal and limited aeration. The inhibition of VHb at 60mM nitrite decreased whole cell respiration to the greatest degree in stationary phase for growth in limited aeration conditions, which was the most oxygen poor condition tested. These results are consistent with the originally proposed role for VHb, as an aid to respiration under hypoxic conditions.
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http://dx.doi.org/10.1016/j.micres.2006.11.018 | DOI Listing |
Water Res
January 2025
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco- Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:
The flow through the grit chamber is non-biochemically treated wastewater, which contains microorganisms mainly from the source of wastewater generation. There are limited reports on aerosol particles generated by grit chambers compared with those produced by biochemical treatment tanks. This study analyzed the fugitive characteristics of aerosol particles produced in grit chambers at nine wastewater treatment plants in three regions of China.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Modulation of optical properties through smart protein matrices is exemplified by a few examples in nature such as rhodopsin (absorption wavelength tuning) and the green fluorescence protein (emission), but in general, the scope found in nature for the matrix-controlled photofunctions remains rather limited. In this review, we present cyclophane-based supramolecular host-guest complexes for which electronic interactions between the cyclophane host and mostly planar aromatic guest molecules can actively modulate excited-state properties in a more advanced way involving both singlet and triplet excited states. We begin by highlighting photofunctional host-guest systems for on-off fluorescence switching and chiroptical functions using bay-functionalized perylene bisimide cyclophanes.
View Article and Find Full Text PDFJ Environ Manage
January 2025
School of Environmental Science and Engineering, Changzhou University, Changzhou, Jiangsu, 213164, China. Electronic address:
Acoustic cavitation is a cutting-edge and eco-friendly advanced oxidation technology with significant efficacy in removing organic pollutants from water. Despite its potential, research on the degradation of o-cresol, a common and challenging phenolic pollutant, is limited. This study systematically investigates the optimal conditions for degrading o-cresol via acoustic cavitation and evaluates its application potential through extensive pilot tests.
View Article and Find Full Text PDFBioresour Technol
January 2025
School of Environment and Climate, Guangdong Engineering Research Center of Water Treatment Processes and Materials, and Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
Efficient nitrogen removal after organic capture is challenging through conventional nitrification-denitrification process. Two biofilm-based anoxic/oxic reactors, with a single intermittent zone (R1) or dual intermittent zones (R2), were compared in treating carbon-limited wastewater. Intermittent aeration integrated partial nitrification-anammox (PNA), partial denitrification-anammox (PDA), and denitrification, with anammox-related pathways contributing over 75% nitrogen removal in both reactors.
View Article and Find Full Text PDFJ Biol Eng
January 2025
Department of Bioprocess Engineering, Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstr. 12, 70599, Stuttgart, Germany.
Background: In biomanufacturing of surface-active agents, such as rhamnolipids, excessive foaming is a significant obstacle for the development of high-performing bioprocesses. The exploitation of the inherent tolerance of Pseudomonas putida KT2440, an obligate aerobic bacterium, to microaerobic conditions has received little attention so far. Here low-oxygen inducible promoters were characterized in biosensor strains and exploited for process control under reduction of foam formation by low aeration and stirring rates during biosynthesis of rhamnolipids.
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