scholarly journals Laboratory In-Situ Production of Autochthonous and Allochthonous Fluorescent Organic Matter by Freshwater Bacteria

2021 ◽  
Vol 9 (8) ◽  
pp. 1623
Author(s):  
Bethany G. Fox ◽  
Robin M. S. Thorn ◽  
Darren M. Reynolds
Keyword(s):  
Organic Matter ◽  
Binary Classification ◽  
Model Systems ◽  
Laboratory Model ◽  
Bacterial Cells ◽  
Extracellular Material ◽  
Bacterial Colony ◽  
Freshwater Bacteria ◽  
The Impact

This work investigates the origin and range of fluorescent organic matter (FOM) produced in-situ by environmentally sourced freshwater bacteria. Aquatic FOM is an essential component in global carbon cycling and is generally classified as either autochthonous, produced in-situ via microbial processes, or allochthonous, transported into aquatic systems from external sources. We have demonstrated that, within laboratory model systems, environmentally sourced mixed microbial communities and bacterial isolates can produce and/or export FOM associated with both autochthonous and allochthonous material. This study focuses on fluorescence peak B, T, M, C and C+, exploring (1) the cellular nature of FOM produced, (2) FOM exported as extracellular material into the water column and (3) the impact of physical cell lysis on FOM signature. For the laboratory model systems studied, Peak T fluorescence is retained within bacterial cells (>68%), while Peak C fluorescence is mainly observed as extracellular material (>80%). Peak M is identified as both cellular and extracellular FOM, produced by all isolated freshwater microorganisms investigated. The origin of Peak C+ is postulated to originate from functional metabolites associated with specific microorganisms, seen specifically within the Pseudomonas sp. monoculture here. This work challenges the binary classification of FOM as either allochthonous or autochthonous, suggesting that FOM processing and production occurs along a dynamic continuum. Within this study, fluorescence intensity data for the environmental bacteria isolate monocultures are presented as enumeration corrected data, for the first time providing quantitative fluorescence data per bacterial colony forming unit (cfu). From this, we are able to assess the relative contribution of different bacteria to the autochthonous FOM pool and if this material is cellular or extracellular.

scholarly journals Phages associated with horses provide new insights into the dominance of lateral gene transfer in virulent bacteriophages evolution in natural systems

2019 ◽  
Author(s):  
V.V. Babenko ◽  
A.K. Golomidova ◽  
P.A. Ivanov ◽  
M.A. Letarova ◽  
E.E. Kulikov ◽  
...  
Keyword(s):  
Time Scale ◽  
Natural Habitat ◽  
Local Population ◽  
Point Mutations ◽  
Major Effect ◽  
Model Systems ◽  
Laboratory Model ◽  
Short Time Scale ◽  
Short Time ◽  
The Impact

AbstractTailed bacteriophages (Caudovirales order) are omnipresent on our planet. Their impressive ecological and evolutionary success largely relies on the bacteriophage potential to adapt to great variety of the environmental conditions found in the Biosphere. It is believed that the adaptation of bacteriophages, including short time scale adaptation, is achieved almost exclusively via the (micro)evolution processes. In order to analyze the major mechanisms driving adaptation of phage genomes in a natural habitat we used comparative genomics of G7C-like coliphage isolates obtained during 7 years period from the feces of the horses belonging to a local population. The data suggest that even at this relatively short time scale the impact of various recombination events overwhelms the impact of the accumulation of point mutations. The access to the large pool of the genes of a complex microbial and viral community of the animal gut had major effect on the evolutionary trajectories of these phages. Thus the “real world” bacteriophage evolution mechanisms may differ significantly from those observed in the simplified laboratory model systems.

scholarly journals Soil mesofauna amount and diversity by returning fresh and compost of crops biomass waste in ultisols in-situ

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Junita Barus ◽  
DIAN MEITHASARI ◽  
JAMALAM LUMBANRAJA ◽  
HAMIM SUDARSONO ◽  
KUSWANTA FUTAS HIDAYAT ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chemical Properties ◽  
Soil Mesofauna ◽  
Biomass Waste ◽  
Rice Plants ◽  
Abundance And Diversity ◽  
Living Organisms ◽  
The Impact ◽  
Crop Biomass

Abstract. Barus J, Meithasari D, Lumbanraja J, Sudarsono H, Hidayat KF, Dermiyati. 2021. Soil mesofauna amount and diversity by returning fresh and compost of crops biomass waste in ultisols in-situ. Biodiversitas 21: 92-98. Newly added organic matter to the soil often has no significant effect on the physical and chemical properties of the soil. However, the addition of organic matter greatly affects the abundance and diversity of living organisms in the soil, because the addition of organic matter is one of the sources of food. The aim of this research was to study the impact of returning crop biomass waste in fresh or compost forms on the abundance and diversity of soil mesofauna. Three types of crop biomass residues (i.e. maize stover, rice straw, and soybean stover) were used at doses of 0, 2.5, 5.0, 7.5, and 10 t ha-1. Mesofauna observations were carried out three times, namely at two weeks after biomass waste application (before planting rice), at eight weeks (there were rice plants in the soil), and at fourteen weeks (after rice harvest). The soil sample for mesofauna observation was dry extracted using a Berlese funnel set up, and to calculate and identified using a binocular microscope. The result showed that the number and diversity of mesofauna in the addition of compost was higher than that of fresh biomass waste. Increasing the dose of biomass waste has an effect on increasing the number and diversity of soil mesofauna. The presence of rice plants in the soil at the time of observation also affected the abundance of soil mesofauna.

Investigating the in-situ bacterial production of aquatic fluorescent organic matter using a freshwater laboratory model

2020 ◽  
Author(s):  
Eva Perrin ◽  
John Attridge ◽  
Robin Thorn ◽  
Stephanie Sargeant ◽  
Darren Reynolds
Keyword(s):  
Organic Matter ◽  
Nutrient Availability ◽  
Bacterial Production ◽  
Nutrient Loading ◽  
Laboratory Model ◽  
Freshwater Systems ◽  
Laboratory Conditions ◽  
Fluorescence Characteristics ◽  
High Nutrient

<p>This research explores the <em>in-situ</em> bacterial production of aquatic fluorescent organic matter (AFOM) under controlled laboratory conditions. Whilst fluorescence techniques have long been used to monitor AFOM distribution, origin and dynamics within aquatic systems, the extent to which AFOM characteristics are defined by microbial processing in surface freshwaters has largely been overlooked. Current convention champions the assumption that humic-like (Peak C) and protein-like (Peak T) fluorescence signatures are exclusively derived from terrestrial (allochthonous) or microbial (autochthonous) origins respectively, with Peak T having been directly correlated with microbial enumeration. Under intensifying anthropogenic perturbations and changing catchment characteristics, the complexities associated with bacterial-organic matter (OM) interactions in freshwater systems are increasing, challenging our understanding as to the origin and fate of aquatic OM. To what extent the observed AFOM in freshwater systems is defined by bacterial processing and how such processing may be influenced by nutrient availability are key knowledge gaps that need to be addressed. Previous research has observed the <em>in-situ</em> bacterial production of humic-like compounds in a laboratory model system with a high-nutrient and high-carbon content synthetic growth medium. This work describes a non-fluorescing, simulated freshwater matrix which is low in both nutrient and organic carbon concentrations. Using this model, growth curve incubation experiments have been undertaken over a 48-hour period with a monoculture laboratory strain of <em>Pseudomonas aeruginosa</em>. Microbiological and fluorescence analyses undertaken at regular time intervals demonstrate the bacterial production of humic-like OM (Peak C) under oligotrophic (after 8hrs) and simulated high-nutrient conditions (after 6hrs). These findings, albeit under laboratory conditions, are important as they show that this fluorescence region, currently viewed as allochthonous in origin, can also represent labile OM generated <em>in-situ</em> by bacteria and, furthermore, that this bacterial production increases as a function of nutrient loading. In addition, the data quantitatively demonstrates that fluorescence intensities increase independently of cell density. These results challenge the assumption that humic-like AFOM is exclusively terrestrial in origin and suggest that bacteria may “engineer” OM<em> in-situ</em> that gives rise to these fluorescence characteristics as a function of metabolism. Importantly, nutrient availability is a key driver of metabolic activity, outlining the potential for the use of fluorescence as a marker for stream metabolism as opposed to a measure of bacterial numbers. Further development of the laboratory model via the utilisation of environmentally-sourced bacterial communities is required. Ultimately, this laboratory model will inform field studies that look to improve our understanding of how microbial communities respond to catchment stressors, and how these responses influence AFOM fluorescence signatures and ultimately the origin and fate of OM in freshwater systems.</p>

scholarly journals Influence of Cold Atmospheric Plasma on Acinetobacter baumannii

2019 ◽  
Vol 16 (1) ◽  
pp. 0151 ◽  
Author(s):  
Atta Et al.
Keyword(s):  
Atmospheric Plasma ◽  
Bacterial Cells ◽  
Standard Strain ◽  
Important Conclusion ◽  
Bacterial Colony ◽  
Cold Atmospheric Plasma ◽  
Sds Page ◽  
Bacterial Morphology ◽  
The Impact ◽  
Sequencing Result

baumannii is an aerobic gram negative coccobacilli, it is considered multidrug resistance pathogen (MDR) and causes several infections that are difficult to treat. This study is aims to employ physical methods in sterilization and inactivation of A. baumannii, as an alternative way to reduce the using of drugs and antibiotics.             Cold Atmospheric Plasma was generated by one electrode at 20KV, 4 power supply and distance between electrode and sample was fixed on 1mm. A. baumannii (ATCC 19704 and HHR1) were exposed to  Dielectric Barrier Discharge type of Cold Atmospheric Plasma (DBD-CAP) for several periods of time (15, 30, 45, and 60 sec.) . After sterilization test, several methods were done to analyze the effect of DBD-CAP on bacterial morphology, proteins and DNA. Change in morphology was assessed by cover slid method. Damaged DNA was investigated by PCR technique, and DNA sequencing. The impact of DBD-CAP on the entity of proteins was detected by SDS-PAGE. The observed inactivation of bacterial colony on agar plates has been quantified by measuring the inactivation diameter. The important conclusion that HHR1 more resistance to DBD-CAP than ATCC 17904 because it is more virulence than standard strain; thus, the growth of both strains is largely affected by plasma and this influence is increased by increasing the time of exposure, also the plasma affects the DNA especially on standard strain as it is explained in sequencing result, so it causes more deletion in DNA sequence. In addition, plasma also has been showed to damage proteins and morphology thus, the bacterial cells transform from cocco-bacillus to bacillus.

scholarly journals Variations of Colored Dissolved Organic Matter in the Mandovi Estuary, Goa, During Spring Inter-Monsoon: A Comparison With COVID-19 Outbreak Imposed Lockdown Period

2021 ◽  
Vol 8 ◽  
Author(s):  
Albertina Dias ◽  
Siby Kurian ◽  
Suresh Thayapurath ◽  
Anil K. Pratihary
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Anthropogenic Activities ◽  
Upstream Region ◽  
Colored Dissolved Organic Matter ◽  
Study Region ◽  
Autochthonous Production ◽  
Mandovi Estuary ◽  
The Impact

Colored dissolved organic matter (CDOM) is one of the important fractions of dissolved organic matter (DOM) that controls the availability of light in water and plays a crucial role in the cycling of carbon. High CDOM absorption in the Mandovi Estuary (Goa) during spring inter-monsoon (SIM) is largely driven by both in-situ production and anthropogenic activities. Here we have presented the CDOM variation in the estuary during SIM of 2014–2018 and compared it with that of 2020 when the COVID-19 outbreak imposed lockdown was implemented. During 2020, low CDOM absorption was observed at the mid-stream of the estuary as compared to the previous years, which could be attributed to low autochthonous production and less input from anthropogenic activities. On the other hand, high CDOM observed at the mouth during 2020 is linked to autochthonous production, as seen from the high concentrations of chlorophyll a. High CDOM in the upstream region could be due to both autochthonous production and terrestrially derived organic matter. Sentinel-2 satellite data was also used to look at the variations of CDOM in the study region which is consistent with in-situ observations. Apart from this, the concentration of nutrients (NO3–, NH4+, and SiO44–) in 2020 was also low compared to the previous reports. Hence, our study clearly showed the impact of anthropogenic activities on CDOM build-up and nutrients, as the COVID-19 imposed lockdown drastically controlled such activities in the estuary.

scholarly journals The impact of pressure on β-Cyclodextrin·acetaminophen inclusion complexes

2014 ◽  
Vol 70 (a1) ◽  
pp. C264-C264 ◽  
Author(s):  
Sofiane Saouane ◽  
Wolfgang Morgenroth ◽  
Hanns-Peter Liermann ◽  
Carsten Paulmann ◽  
Francesca Fabbiani
Keyword(s):  
High Pressure ◽  
Inclusion Complex ◽  
Aqueous Solubility ◽  
Crystal Form ◽  
Model Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
The Impact

Cyclodextrins (CDs) have attracted considerable interest as model systems in supramolecular host-guest chemistry. They are described as hollow truncated cones with a hydrophilic outer surface and a nonpolar inner cavity suitable for small molecules' encapsulation.[1] By virtue of their character, CDs are used as excipients to improve the aqueous solubility of active pharmaceutical ingredients (APIs). High-pressure crystallisation techniques have been established as a suitable tool for exploring the phenomenon of polymorphism and solvate formation of pharmaceutical compounds throughout numerous examples reported in the literature.[2] Thus, exploring the inclusion-complex formation and the polymorphic behaviour of CDs with APIs at high pressure would be an interesting extension of the technique. The present work describes the attempt of an in-situ crystallisation of β-CD·acetaminophen inclusion complex and compression studies of the known β-CD·acetaminophen complex[3] in different crystallisation media at pressures up to 1.0 GPa. A new high-pressure crystal form observed at 0.8 GPa as well as unexpected results are presented herein. The crystals have been characterised by means of polarised optical microscopy, Raman spectroscopy and single-crystal X-ray diffraction using both home and synchrotron sources.

scholarly journals Nutritional value of dual-purpose wheat genotypes pastures under grazing by dairy cows

2017 ◽  
Vol 39 (3) ◽  
pp. 303 ◽  
Author(s):  
Mauricio Pase Quatrin ◽  
Clair Jorge Olivo ◽  
Vinicius Felipe Bratz ◽  
Vinicius Alessio ◽  
Fabiene Tomazetti dos Santos ◽  
...  
Keyword(s):  
Organic Matter ◽  
Nitrogen Uptake ◽  
Nutritional Value ◽  
Neutral Detergent Fiber ◽  
Mineral Matter ◽  
Dual Purpose ◽  
Wheat Genotypes ◽  
Forage Availability ◽  
The Impact

In the south of Brazil, one of the major limitations to milk production is the low forage availability during autumn and early winter. The use of dual-purpose wheat genotypes is one alternative to minimize the impact of low forage availability in addition to produce grains. Therefore, this study aimed to evaluate the nutritional value of two dual-purpose wheat genotypes (BRS Tarumã and BRS Umbu). Structural composition and forage nitrogen uptake were evaluated. The nutritional value of the forage was analyzed for mineral matter (MM), organic matter (OM), neutral detergent fiber (NDF), crude protein (CP), total digestible nutrients (TDN), in situ organic matter digestibility (ISOMD) and in situ dry matter digestibility (ISDMD). Differences in NDF (49.03 vs. 46.44%), CP (24.4 vs. 27.4%), ISOMD (83.53 vs. 85.45%), ISDMD (83.59 vs. 86.65%) and TDN (75.37 vs. 78.39) for BRS Umbu and BRS Tarumã genotypes were detected, respectively. The BRS Umbu genotype had a lower leaf blade proportion and forage nitrogen uptake. The dual-purpose wheat genotype BRS Tarumã was superior in nutritive value.

scholarly journals Studying the Impact of the Temperature and Sorbed Water during Microwave-Induced In Situ Amorphization: A Case Study of Celecoxib and Polyvinylpyrrolidone

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 886
Author(s):  
Nele-Johanna Hempel ◽  
Matthias M. Knopp ◽  
Korbinian Löbmann ◽  
Ragna Berthelsen
Keyword(s):  
Microwave Radiation ◽  
Linear Correlation ◽  
Amorphous Solid ◽  
Magnesium Stearate ◽  
Model Systems ◽  
Drug Dissolution ◽  
Amorphous Solid Dispersion ◽  
Sorbed Water ◽  
The Impact

Microwave-induced in situ amorphization of a drug into a polymeric amorphous solid dispersion (ASD) has been suggested to follow a dissolution process of the drug into the polymeric network, at temperatures above the glass transition temperature (Tg) of the polymer. Thus, increasing the compact temperature, above the Tg of the polymer, is expected to increase the rate of drug dissolution in the mobile polymer, i.e., the rate of amorphization, in a direct proportional fashion. To test this hypothesis, the present study aimed at establishing a linear correlation between the compact temperature and the rate of drug amorphization using celecoxib (CCX) and the polymers polyvinylpyrrolidone (PVP) 12 and PVP17 as the model systems. Water sorbed into the drug–polymer compacts during 2 weeks of storage at 75% relative humidity was used as the dielectric heating source for the present drug amorphization process, and therefore directly affected the compact temperature during exposure to microwave radiation; the loss of water during heating was also studied. For this, compacts prepared with 30 wt% CCX, 69.5 wt% PVP12 or PVP17 and 0.5 wt% magnesium stearate (lubricant) were conditioned to have a final water content of approx. 20 wt%. The conditioned compacts were exposed to microwave radiation for 10 min at variable power outputs to achieve different compact temperatures. For compacts containing CCX in both PVP12 and PVP17, a linear correlation was established between the measured compact end temperature and the rate of drug amorphization during 10 min of exposure to microwave radiation. For compacts containing CCX in PVP12, a fully amorphous ASD was obtained after 10 min of exposure to microwave radiation with a measured compact end temperature of 71 °C. For compacts containing CCX in PVP17, it was not possible to obtain a fully amorphous ASD. The reason for this is most likely that a fast evaporation of the sorbed water increased the Tg of the conditioned drug–polymer compacts to temperatures above the highest reachable compact temperature during exposure to microwave radiation in the utilized experimental setup. Supporting this conclusion, evaporation of the sorbed water was observed to be faster for compacts containing PVP17 compared to compacts containing PVP12.

scholarly journals Influence of Cold Atmospheric Plasma on Acinetobacter baumannii

2019 ◽  
Vol 16 (1(Suppl.)) ◽  
pp. 0151 ◽  
Author(s):  
Atta Et al.
Keyword(s):  
Atmospheric Plasma ◽  
Bacterial Cells ◽  
Standard Strain ◽  
Important Conclusion ◽  
Bacterial Colony ◽  
Cold Atmospheric Plasma ◽  
Sds Page ◽  
Bacterial Morphology ◽  
The Impact ◽  
Sequencing Result

baumannii is an aerobic gram negative coccobacilli, it is considered multidrug resistance pathogen (MDR) and causes several infections that are difficult to treat. This study is aims to employ physical methods in sterilization and inactivation of A. baumannii, as an alternative way to reduce the using of drugs and antibiotics.             Cold Atmospheric Plasma was generated by one electrode at 20KV, 4 power supply and distance between electrode and sample was fixed on 1mm. A. baumannii (ATCC 19704 and HHR1) were exposed to  Dielectric Barrier Discharge type of Cold Atmospheric Plasma (DBD-CAP) for several periods of time (15, 30, 45, and 60 sec.) . After sterilization test, several methods were done to analyze the effect of DBD-CAP on bacterial morphology, proteins and DNA. Change in morphology was assessed by cover slid method. Damaged DNA was investigated by PCR technique, and DNA sequencing. The impact of DBD-CAP on the entity of proteins was detected by SDS-PAGE. The observed inactivation of bacterial colony on agar plates has been quantified by measuring the inactivation diameter. The important conclusion that HHR1 more resistance to DBD-CAP than ATCC 17904 because it is more virulence than standard strain; thus, the growth of both strains is largely affected by plasma and this influence is increased by increasing the time of exposure, also the plasma affects the DNA especially on standard strain as it is explained in sequencing result, so it causes more deletion in DNA sequence. In addition, plasma also has been showed to damage proteins and morphology thus, the bacterial cells transform from cocco-bacillus to bacillus.

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