scholarly journals The global impact of bacterial processes on carbon mass

2020 ◽  
Vol 20 (3) ◽  
pp. 1777-1794
Author(s):  
Barbara Ervens ◽  
Pierre Amato
Keyword(s):  
Cell Growth ◽  
Growth Conditions ◽  
Water Soluble ◽  
Cloud Formation ◽  
Cloud Droplets ◽  
Spatial And Temporal Scales ◽  
Adverse Health Effects ◽  
Oh Reactions ◽  
Carbon Mass ◽  
High Concentrations

Abstract. Many recent studies have identified biological material as a major fraction of ambient aerosol loading. A small fraction of these bioaerosols consist of bacteria that have attracted a lot of attention due to their role in cloud formation and adverse health effects. Current atmospheric models consider bacteria as inert quantities and neglect cell growth and multiplication. We provide here a framework to estimate the production of secondary biological aerosol (SBA) mass in clouds by microbial cell growth and multiplication. The best estimate of SBA formation rates of 3.7 Tg yr−1 is comparable to previous model estimates of the primary emission of bacteria into the atmosphere, and thus this might represent a previously unrecognized source of biological aerosol material. We discuss in detail the large uncertainties associated with our estimates based on the rather sparse available data on bacteria abundance, growth conditions, and properties. Additionally, the loss of water-soluble organic carbon (WSOC) due to microbial processes in cloud droplets has been suggested to compete under some conditions with WSOC loss by chemical (OH) reactions. Our estimates suggest that microbial and chemical processes might lead to a global loss of WSOC of 8–11 and 8–20 Tg yr−1, respectively. While this estimate is very approximate, the analysis of the uncertainties and ranges of all parameters suggests that high concentrations of metabolically active bacteria in clouds might represent an efficient sink for organics. Our estimates also highlight the urgent need for more data concerning microbial concentrations, fluxes, and activity in the atmosphere to evaluate the role of bacterial processes as net aerosol sinks or sources on various spatial and temporal scales.

scholarly journals The global impact of bacterial processes on carbon mass

2019 ◽  
Author(s):  
Barbara Ervens ◽  
Pierre Amato
Keyword(s):  
Cell Growth ◽  
Organic Carbon ◽  
Growth Conditions ◽  
Water Soluble ◽  
Microbial Processes ◽  
Cloud Formation ◽  
Cloud Droplets ◽  
Spatial And Temporal Scales ◽  
Adverse Health Effects ◽  
Oh Reactions

Abstract. Many recent studies have identified biological material as a major fraction of ambient aerosol loading. A small fraction of these bioaerosols consist of bacteria that have attracted a lot of attention due to their role in cloud formation and adverse health effects. Current atmospheric models consider bacteria as inert quantities and neglect cell growth and multiplication. We provide here a framework to estimate the production of secondary biological aerosol (SBA) mass in clouds by microbial cell growth and multiplication. The best estimate of SBA formation rates of 3.7 Tg yr-1 are comparable to previous model estimates of the primary emission of bacteria into the atmosphere, and thus might represent a previously unrecognized source of biological aerosol material. We discuss in detail the large uncertainties associated with our estimates based on the rather sparse available data on bacteria abundance, growth conditions and properties. Additionally, the loss of water-soluble organic carbon (WSOC) due to microbial processes in cloud droplets has been suggested to compete under some conditions with WSOC loss by chemical (OH) reactions. Our estimates suggest that microbial and chemical processes might lead to a global loss of WSOC of 8–11 Tg yr-1 and 8–20 Tg yr-1, respectively. While also this estimate is very approximate, the analysis of the uncertainties and ranges of all parameters gives hints about the conditions under which microbial processes cannot be neglected as organic carbon sinks in clouds. Our estimates also highlight the urgent needs for more data concerning microbial concentrations, fluxes and activity in the atmosphere to evaluate the role of bacterial processes as net aerosol sink or source on various spatial and temporal scales.

scholarly journals Incorporation of alternative amino acids into cyanophycin by different cyanophycin synthetases heterologously expressed in Corynebacterium glutamicum

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramona Wördemann ◽  
Lars Wiefel ◽  
Volker F. Wendisch ◽  
Alexander Steinbüchel
Keyword(s):  
Amino Acids ◽  
Dry Weight ◽  
Growth Conditions ◽  
Amino Acid Biosynthesis ◽  
Water Soluble ◽  
Lysine Content ◽  
Polyaspartic Acid ◽  
Acid Biosynthesis ◽  
Cyanophycin Synthetase ◽  
Potential Precursor

AbstractCyanophycin (multi-l-arginyl-poly-l-aspartic acid; also known as cyanophycin grana peptide [CGP]) is a biopolymer that could be used in various fields, for example, as a potential precursor for the synthesis of polyaspartic acid or for the production of CGP-derived dipeptides. To extend the applications of this polymer, it is therefore of interest to synthesize CGP with different compositions. A recent re-evaluation of the CGP synthesis in C. glutamicum has shown that C. glutamicum is a potentially interesting microorganism for CGP synthesis with a high content of alternative amino acids. This study shows that the amount of alternative amino acids can be increased by using mutants of C. glutamicum with altered amino acid biosynthesis. With the DM1729 mutant, the lysine content in the polymer could be increased up to 33.5 mol%. Furthermore, an ornithine content of up to 12.6 mol% was achieved with ORN2(Pgdh4). How much water-soluble or insoluble CGP is synthesized is strongly related to the used cyanophycin synthetase. CphADh synthesizes soluble CGP exclusively. However, soluble CGP could also be isolated from cells expressing CphA6308Δ1 or CphA6308Δ1_C595S in addition to insoluble CGP in all examined strains. The point mutation in CphA6308Δ1_C595S partially resulted in a higher lysine content. In addition, the CGP content could be increased to 36% of the cell dry weight under optimizing growth conditions in C. glutamicum ATCC13032. All known alternative major amino acids for CGP synthesis (lysine, ornithine, citrulline, and glutamic acid) could be incorporated into CGP in C. glutamicum.

scholarly journals NMR Structure and Action on Nicotinic Acetylcholine Receptors of Water-soluble Domain of Human LYNX1

2011 ◽  
Vol 286 (12) ◽  
pp. 10618-10627 ◽  
Author(s):  
Ekaterina N. Lyukmanova ◽  
Zakhar O. Shenkarev ◽  
Mikhail A. Shulepko ◽  
Konstantin S. Mineev ◽  
Dieter D'Hoedt ◽  
...  
Keyword(s):  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Nmr Structure ◽  
Water Soluble ◽  
Gpi Anchor ◽  
Nicotinic Acetylcholine ◽  
Brain Functions ◽  
The Central Nervous System ◽  
High Concentrations

Discovery of proteins expressed in the central nervous system sharing the three-finger structure with snake α-neurotoxins provoked much interest to their role in brain functions. Prototoxin LYNX1, having homology both to Ly6 proteins and three-finger neurotoxins, is the first identified member of this family membrane-tethered by a GPI anchor, which considerably complicates in vitro studies. We report for the first time the NMR spatial structure for the water-soluble domain of human LYNX1 lacking a GPI anchor (ws-LYNX1) and its concentration-dependent activity on nicotinic acetylcholine receptors (nAChRs). At 5–30 μm, ws-LYNX1 competed with 125I-α-bungarotoxin for binding to the acetylcholine-binding proteins (AChBPs) and to Torpedo nAChR. Exposure of Xenopus oocytes expressing α7 nAChRs to 1 μm ws-LYNX1 enhanced the response to acetylcholine, but no effect was detected on α4β2 and α3β2 nAChRs. Increasing ws-LYNX1 concentration to 10 μm caused a modest inhibition of these three nAChR subtypes. A common feature for ws-LYNX1 and LYNX1 is a decrease of nAChR sensitivity to high concentrations of acetylcholine. NMR and functional analysis both demonstrate that ws-LYNX1 is an appropriate model to shed light on the mechanism of LYNX1 action. Computer modeling, based on ws-LYNX1 NMR structure and AChBP x-ray structure, revealed a possible mode of ws-LYNX1 binding.

scholarly journals Control by fibroblast growth factor of differentiation in the BC3H1 muscle cell line.

1985 ◽  
Vol 100 (5) ◽  
pp. 1540-1547 ◽  
Author(s):  
B Lathrop ◽  
E Olson ◽  
L Glaser
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
Fibroblast Growth Factor ◽  
Cell Line ◽  
Calf Serum ◽  
Specific Protein ◽  
Fibroblast Growth ◽  
Mouse Muscle ◽  
Differentiated Cells ◽  
High Concentrations

The regulation of creatine phosphokinase (CPK) expression by polypeptide growth factors has been examined in the clonal mouse muscle BC3H1 cell line. After arrest of cell growth by exposure to low concentrations of serum, BC3H1 cells accumulate high levels of muscle-specific proteins including CPK. The induction of this enzyme is reversible in the presence of high concentrations of fetal calf serum, which cause quiescent, differentiated cells to reenter the cell cycle. Under these conditions, the rate of CPK synthesis is drastically reduced. We show in the present communication that either pituitary-derived fibroblast growth factor (FGF) or brain-derived FGF are as effective as serum in repressing the synthesis of CPK when added to quiescent, differentiated cells. The decrease in the rate of synthesis of CPK occurs within 22 h after the addition of pituitary FGF to the cells. Pituitary FGF had very little effect, if any, on the rate CPK degradation. The overall rate of protein synthesis and the pattern of synthesis of the major polypeptides made by these cells was not altered by the addition of FGF. Although pituitary FGF was mitogenic for BC3H1 cells, the rate of cell growth was not absolutely correlated with the extent of repression of CPK. Brain-derived FGF fully repressed CPK induction under conditions where it showed no significant mitogenic activity. These results show that the expression of a muscle-specific protein, CPK, can be controlled by a single defined polypeptide growth factor in fully differentiated cultures, and that initiation of cell division is not required for their regulation to take place.

Intracellular distribution of lead in Tetrahymena during continuous exposure to the metal

1979 ◽  
Vol 39 (1) ◽  
pp. 383-396
Author(s):  
J.R. Nilsson
Keyword(s):  
Cell Growth ◽  
Growth Medium ◽  
Food Vacuole ◽  
Continuous Exposure ◽  
Organic Growth ◽  
Food Vacuoles ◽  
Entire Cell ◽  
Membrane Bound ◽  
Lag Period ◽  
High Concentrations

Lead acetate (0.1–0.2%) forms a precipitate with the organic growth medium. The Tetrahymena cells ingest this lead-containing precipitate and cell growth is resumed after a variable lag period. Ingested lead is observed as electron-dense material in food vacuoles. Soon after exposure, cytoplasmic lead (preserved with certain fixation only) is revealed as electron-dense particles in cilia and in a halo around digestive vacuoles. Later the lead particles pervade the entire cell but after the lag period they are confined to membrane-bound spaces. In dilute growth medium, high concentrations of lead inhibit food-vacuole formation and cell growth. Under these conditions lead is deposited in alveoli of the pellicle and is also found in autophagic vacuoles and other membrane-limited structures. The study has revealed that lead enters Tetrahymena through the membrane of digestive vacuoles and through the cell surface. The change in distribution of lead during the lag period indicates that a mechanism is activated for removal of lead into membrane-bound spaces. The final storage of lead seems to be in lysosomes.

scholarly journals Characteristics of aerosol pollution during heavy haze events in Suzhou, China

2016 ◽  
Vol 16 (11) ◽  
pp. 7357-7371 ◽  
Author(s):  
Mi Tian ◽  
Huanbo Wang ◽  
Yang Chen ◽  
Fumo Yang ◽  
Xiaohua Zhang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Inorganic Ions ◽  
Weather Conditions ◽  
Water Soluble ◽  
Chemical Components ◽  
Formation Mechanisms ◽  
Visibility Impairment ◽  
Aerosol Pollution ◽  
Haze Formation ◽  
High Concentrations

Abstract. Extremely severe haze weather events occurred in many cities in China, especially in the east part of the country, in January 2013. Comprehensive measurements including hourly concentrations of PM2.5 and its major chemical components (water-soluble inorganic ions, organic carbon (OC), and elemental carbon (EC)) and related gas-phase precursors were conducted via an online monitoring system in Suzhou, a medium-sized city in Jiangsu province, just east of Shanghai. PM2.5 (particulate matter with an aerodynamic diameter of 2.5 µm or less) frequently exceeded 150 µg m−3 on hazy days, with the maximum reaching 324 µg m−3 on 14 January 2013. Unfavorable weather conditions (high relative humidity (RH), and low rainfall, wind speed, and atmospheric pressure) were conducive to haze formation. High concentrations of secondary aerosol species (including SO42−, NO3−, NH4+, and SOC) and gaseous precursors were observed during the first two haze events, while elevated primary carbonaceous species emissions were found during the third haze period, pointing to different haze formation mechanisms. Organic matter (OM), (NH4)2SO4, and NH4NO3 were found to be the major contributors to visibility impairment. High concentrations of sulfate and nitrate might be explained by homogeneous gas-phase reactions under low RH conditions and by heterogeneous processes under relatively high RH conditions. Analysis of air mass trajectory clustering and potential source contribution function showed that aerosol pollution in the studied areas was mainly caused by local activities and surrounding sources transported from nearby cities.

scholarly journals High concentrations of coarse particles emitted from a cattle feeding operation

2011 ◽  
Vol 11 (16) ◽  
pp. 8809-8823 ◽  
Author(s):  
N. Hiranuma ◽  
S. D. Brooks ◽  
J. Gramann ◽  
B. W. Auvermann
Keyword(s):  
United States ◽  
Particulate Matter ◽  
Chemical Properties ◽  
Field Measurements ◽  
The United States ◽  
Water Soluble ◽  
Size Distributions ◽  
Cattle Feeding ◽  
High Concentrations ◽  
Organic Particles

Abstract. Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m−3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was present in internal mixtures with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences may lead to errors in estimates of aerosol effects on local air quality, visibility, and public health.

scholarly journals Characteristics, seasonality and sources of carbonaceous and ionic components in the tropical Indian aerosols

2011 ◽  
Vol 11 (2) ◽  
pp. 3937-3976 ◽  
Author(s):  
C. M. Pavuluri ◽  
K. Kawamura ◽  
S. G. Aggarwal ◽  
T. Swaminathan
Keyword(s):  
Organic Carbon ◽  
Atmospheric Aerosols ◽  
Atmospheric Transport ◽  
Indian Subcontinent ◽  
Ionic Species ◽  
Water Soluble ◽  
Carbonaceous Aerosols ◽  
Mass Fractions ◽  
High Concentrations ◽  
Ionic Components

Abstract. To better characterize South and Southeast Asian aerosols, PM10 samples collected from tropical Chennai, India (13.04° N; 80.17° E) were analyzed for carbonaceous and water-soluble ionic components. Concentration ranges of elemental carbon (EC) and organic carbon (OC) were 2.4–14 μg m−3 and 3.2–15.6 μg m−3 in winter samples whereas they were 1.1–2.5 μg m−3 and 4.1–17.6 μg m−3 in summer samples, respectively. Concentration of secondary organic carbon (SOC) retrieved from EC-tracer method was 4.6 ± 2.8 μg m−3 in winter and 4.3 ± 2.8 μg m−3 in summer. SO42- (8.8 ± 2.5 μg m−3 and 4.1 ± 2.7 μg m−3 in winter and summer, respectively) was found as the most abundant ionic species (57% on average, n = 49), followed by NH4+ (15%) > NO3− > Cl− > K+> Na+ > Ca2+ > MSA− > Mg2+. The mass fractions of EC, organic matter (OM) and ionic species varied seasonally, following the air mass trajectories and corresponding source strength. Based on mass concentration ratios of selected components and relations of EC and OC to marker species, we found that biofuel/biomass burning is the major source of atmospheric aerosols in South and Southeast Asia. The high concentrations of SOC and WSOC/OC ratios (ave. 0.45; n = 49) as well as good correlations between SOC and WSOC suggest that the secondary production of organic aerosols during long-range atmospheric transport is also significant in this region. This study provides the baseline data of carbonaceous aerosols for southern part of the Indian subcontinent.

scholarly journals Influence of soluble content losses on the ability of aerobic fungi to improve the nutritional content of pre-treated forages

2020 ◽  
Vol 47 (3) ◽  
pp. 298-308
Author(s):  
K. R. Idowu ◽  
A. S. Chaudhry ◽  
J. Dolfing ◽  
V. O. A. Ojo
Keyword(s):  
Secondary Metabolites ◽  
Growth Conditions ◽  
Water Soluble ◽  
Optimal Conditions ◽  
Similar Reduction ◽  
Filtering Method ◽  
Nutritive Quality ◽  
Andropogon Gayanus ◽  
The Impact

Fungal improvement of the nutritive content of low-quality forages can be affected by several factors among which loss of water-soluble content (WSC) plays a major role. To achieve this aim, two growth conditions i.e. forage-liquid ratios (1:3 and 1:5) and two inoculation times (14 and 28 days) were used to cultivate the selected fungi i.e. Pleurotus ostreatus (PO) at 30°C and Ceriporiopsis rivulosus (CR) at 20°C on Brachiaria decumbens (BD), Andropogon gayanus (AG), Triticum aestivum (TA) straw, Lolium perenne (LP), respectively with the view of selecting the optimal conditions that facilitate the release of WSC. The impact that losses of WSC have on the ability of fungi to improve the nutritive content (i.e. proximate, fibre, secondary metabolites and total antioxidant content) of the forages were then measured using 2 filtering methods i.e. light pump filtering method (LFM) and free flow filtering method (FFM). The optimal conditions that supported increased th soluble was identified as 28th day for both fungi; forage-liquid ratio of 1:5 for both fungi in most of the forages except BD (CR) and BD & AG (PO). The LFM led to lesser or no improvement in the nutritive quality of the upgraded forages while the opposite was recorded with the LFM. The LFM as against the FFM produced upgraded forages with lesser reduction in NDF; similar or higher ADF and lignin contents; and similar reduction in secondary metabolites and TAC when compared with un-improved forages. It can be concluded that the fungal improvement of the nutritive content of low-quality forages was negatively affected by the loss of WSC. It is therefore recommended that fungal improvement of the nutritive quality of low quality forages should be carried out with methods or techniques that facilitates little or no WSC loss in the upgraded forages.

scholarly journals Thermal stability analysis of particles incorporated in cirrus crystals and of non-activated particles in between the cirrus crystals: Comparing clean and polluted air masses

2003 ◽  
Vol 3 (4) ◽  
pp. 3659-3679 ◽  
Author(s):  
M. Seifert ◽  
J. Ström ◽  
R. Krejci ◽  
A. Minikin ◽  
A. Petzold ◽  
...  
Keyword(s):  
Temperature Regime ◽  
Water Soluble ◽  
Cloud Formation ◽  
Residual Fraction ◽  
Volatile Fraction ◽  
Air Masses ◽  
Temperature Regimes ◽  
Soluble Sulfate ◽  
Indirect Information ◽  
Cold Case

Abstract. A thermal volatility technique is used to provide indirect information about the chemical composition of the aerosol involved in cirrus cloud formation. The fraction of particles that disappears after being heated to 125°C is termed volatile and the fraction that disappears between 125 and 250°C is termed semi-volatile. Particles that still remain after being heated to 250°C make up the non-volatile fraction. The thermal composition of residual particles remaining from evaporated cirrus crystals is presented and compared to interstitial aerosol particles (non-activated particles in between the cirrus crystals) for two temperature regimes (cold: T<235 K, warm: 235<T<250 K), based on in-situ observations. The observations were conducted in cirrus clouds in the Southern Hemisphere (SH) and Northern Hemisphere (NH) midlatitudes during the INCA project. In the cold temperature regime, the non-volatile fraction of the residual particles was typically in the range 10 to 30% in the NH and 30 to 40% in the SH. In the warm temperature regime, the non-volatile residual fraction was typically 10 to 30% (NH) and 20 to 40% (SH). At high crystal number densities the non-volatile fraction in both temperature regimes was even higher: in the range of 30 to 40% (NH) and 40 to 50% (SH). The semi-volatile fraction was typically less than 10% in both hemispheres, causing the volatile fraction to essentially be a complement to the non-volatile fraction. In terms of the fractioning into the three types of particles, the SH cold case is clearly different compared to the other three cases (the two warm cases and the cold NH case), which share many features. In the NH data the distribution of different particle types does not seem to be temperature dependent. In all the cases, the non-volatile fraction is enriched in the residual particles compared to the fractions observed for the interstitial particles. This enrichment corresponds to about 15 (NH) and 30 (SH) percent units in the two cold cases and to 15–25 (NH) and 25–35 (SH) percent units in the two warm cases. In the NH cold case, there is a clear relation between the fractions observed in the interstitial particles and what is observed in the residual particles. The observed large fractions of non-volatile particles show that particles forming ice crystals are not entirely made up of water-soluble sulfate particles.

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