Brown pigmentation in Serratia marcescens cultures associated with tyrosine metabolism

1989 ◽  
Vol 35 (11) ◽  
pp. 1037-1042 ◽  
Author(s):  
Joaquim Trias ◽  
Miquel Viñas ◽  
Jesus Guinea ◽  
José G. Lorèn
Keyword(s):  
Serratia Marcescens ◽  
Minimal Medium ◽  
Brown Pigment ◽  
Activity Levels ◽  
Amino Acid Catabolism ◽  
Catabolic Pathway ◽  
Tyrosine Metabolism ◽  
High Concentrations ◽  
Low Activity ◽  
Production Conditions

Serratia marcescens produced a brown pigment when grown in minimal medium in the presence of tyrosine and high concentrations of copper(II) ion. The pigment was not related to the melanin pigments, but was similar to the pigment produced by autooxidation and polymerization of 3,4-dihydroxyphenylacetate, which is synthesized in S. marcescens from tyrosine through the 3,4-dihydroxyphenylacetate catabolic pathway. The enzymes of this pathway were induced under pigment production conditions; however, 3,4-dihydroxyphenylacetate 2,3-dioxygenase remained at low activity levels, permitting the accumulation and excretion of the substrate. Mutants unable to use tyrosine as a sole carbon and energy source were able to produce brown pigments only if the step blocked by the mutation was after the synthesis of 3,4-dihydroxyphenylacetate. The ability to produce brown pigments was common to all the S. marcescens strains tested.Key words: brown pigment, 3,4-dihydroxyphenylacetate 2,3-dioxygenase, Serratia marcescens, tyrosine, aromatic amino acid catabolism.

scholarly journals Drosophila have distinct activity-gated pathways that mediate attraction and aversion to CO2

2017 ◽  
Author(s):  
Floris van Breugel ◽  
Ainul Huda ◽  
Michael H. Dickinson
Keyword(s):  
Laboratory Experiments ◽  
Respiratory Acidosis ◽  
Future Research ◽  
Yeast Fermentation ◽  
Activity Levels ◽  
Behavioral Differences ◽  
Natural Processes ◽  
Broad Signal ◽  
High Concentrations ◽  
Low Activity

Carbon dioxide is a volatile and broad signal of many organic processes, and serves as a convenient cue for insects in search of blood hosts1–6, flowers7, decaying matter8–11, communal nests12, fruit13, and wildfires14. Curiously, although Drosophila melanogaster feed on yeast that produce CO2 and ethanol during fermentation, laboratory experiments suggest that flies actively avoid CO215–25. Here, we resolve this paradox by showing that both flying and walking fruit flies do actually find CO2 attractive, but only when they are in an active state associated with foraging. Aversion at low activity levels may be an adaptation to avoid CO2-seeking-parasites, or succumbing to respiratory acidosis in the presence of high concentrations of CO2 that are occasionally found in nature26,27. In contrast to CO2, flies are attracted to ethanol in all behavioral states, and invest twice as much time searching near ethanol compared to CO2. These behavioral differences reflect the fact that whereas CO2 is a generated by many natural processes, ethanol is a unique signature of yeast fermentation. Using genetic tools, we determined that the evolutionarily ancient ionotropic co-receptor IR25a is required for both CO2 and ethanol attraction, and that the receptors previously identified for CO2 avoidance are not involved. Our study lays the foundation for future research to determine the neural circuits underlying both state- and odorant-dependent decision making in Drosophila.

scholarly journals High-Efficiency Production of Radiopharmaceuticals via Droplet Radiochemistry: A Review of Recent Progress

2020 ◽  
Vol 19 ◽  
pp. 153601212097309
Author(s):  
Jia Wang ◽  
R. Michael van Dam
Keyword(s):  
High Efficiency ◽  
State Of The Art ◽  
System Size ◽  
Scaling Up ◽  
Activity Levels ◽  
Synthesis Time ◽  
Molar Activity ◽  
Reagent Consumption ◽  
Prosthetic Groups ◽  
Low Activity

New platforms are enabling radiochemistry to be carried out in tiny, microliter-scale volumes, and this capability has enormous benefits for the production of radiopharmaceuticals. These droplet-based technologies can achieve comparable or better yields compared to conventional methods, but with vastly reduced reagent consumption, shorter synthesis time, higher molar activity (even for low activity batches), faster purification, and ultra-compact system size. We review here the state of the art of this emerging direction, summarize the radiotracers and prosthetic groups that have been synthesized in droplet format, describe recent achievements in scaling up activity levels, and discuss advantages and limitations and the future outlook of these innovative devices.

scholarly journals Ambulatory Physical Activity Performance in Youth With Cerebral Palsy and Youth Who Are Developing Typically

2007 ◽  
Vol 87 (3) ◽  
pp. 248-257 ◽  
Author(s):  
Kristie F Bjornson ◽  
Basia Belza ◽  
Deborah Kartin ◽  
Rebecca Logsdon ◽  
John F McLaughlin
Keyword(s):  
Cerebral Palsy ◽  
Activity Levels ◽  
Ambulatory Activity ◽  
Cross Sectional ◽  
Walking Activity ◽  
Activity Performance ◽  
Cross Sectional Design ◽  
Low Activity ◽  
Gmfcs Level ◽  
Daily Total

Background and Purpose Assessment of walking activity in youth with cerebral palsy (CP) has traditionally been “capacity-based.” The purpose of this study was to describe the day-to-day ambulatory activity “performance” of youth with CP compared with youth who were developing typically. Subjects Eighty-one youth with CP, aged 10 to 13 years, who were categorized as being in Gross Motor Function Classification System (GMFCS) levels I to III and 30 age-matched youth who were developing typically were recruited. Methods Using a cross-sectional design, participants wore the StepWatch monitor for 7 days while documenting average daily total step counts, percentage of time they were active, ratio of medium to low activity levels, and percentage of time at high activity levels. Results The youth with CP demonstrated significantly lower levels of all outcomes than the comparison group. Discussion and Conclusion Daily walking activity and variability decreased as functional walking level (GMFCS level) decreased. Ambulatory activity performance within the context of the daily life for youth with CP appears valid and feasible as an outcome for mobility interventions in CP.

scholarly journals Disruption of hmgA by DNA Duplication is Responsible for Hyperpigmentation in a Vibrio anguillarum Strain

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Veronica Batallones ◽  
Jennifer Fernandez ◽  
Brett Farthing ◽  
Jordan Shoemaker ◽  
Keizen Li Qian ◽  
...  
Keyword(s):  
Vibrio Anguillarum ◽  
Early Termination ◽  
Whole Genome Sequence ◽  
Brown Pigment ◽  
Insertion Sequences ◽  
Genome Sequence Analysis ◽  
Recombinant Clone ◽  
Tyrosine Metabolism ◽  
Intergenic Regions ◽  
Diseased Fish

Abstract Vibrio anguillarum 531A, isolated from a diseased fish in the Atlantic Ocean, is a mixture composed of about 95 and 5% of highly pigmented cells (strain 531Ad) and cells with normal levels of pigmentation (strain 531Ac), respectively. Analysis of the V. anguillarum 531Ad DNA region encompassing genes involved in the tyrosine metabolism showed a 410-bp duplication within the hmgA gene that results in a frameshift and early termination of translation of the homogentisate 1,2-dioxygenase. We hypothesized that this mutation results in accumulation of homogentisate that is oxidized and polymerized to produce pyomelanin. Introduction in E. coli of recombinant clones carrying the V. anguillarum hppD (4-hydroxyphenylpyruvate-dioxygenase), and a mutated hmgA produced brown colored colonies. Complementation with a recombinant clone harboring hmgA restored the original color to the colonies confirming that in the absence of homogentisate 1,2-dioxygenase the intermediary in tyrosine catabolism homogentisate accumulates and undergoes nonenzymatic oxidation and polymerization resulting in high amounts of the brown pigment. Whole-genome sequence analysis showed that V. anguillarum 531 Ac and 531Ad differ in the hmgA gene mutation and 23 mutations, most of which locate to intergenic regions and insertion sequences.

Extracellular endodextranase from the yeast Lipomyces starkeyi

1983 ◽  
Vol 29 (9) ◽  
pp. 1092-1095 ◽  
Author(s):  
E. Webb ◽  
I. Spencer-Martins
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Minimal Medium ◽  
Enzyme Preparation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Extracellular Fluid ◽  
Sole Source ◽  
Optimum Temperature ◽  
Lipomyces Starkeyi ◽  
High Concentrations

Strain IGC 4047 of the yeast Lipomyces starkeyi grew well with dextran as sole source of carbon and energy, and was able to hydrolyse blue dextran and Sephadex G-100. The enzyme was partially purified by fractionated isopropanol precipitation from the extracellular fluid of cultures grown in a minimal medium with dextran. The enzyme preparation showed only one band by polyacrylamide gel electrophoresis. The enzyme had the following properties: molecular weight, 23 000; optimum temperature and pH for activity, around 50 °C and pH 5.0, respectively; pH stability, pH 3.5–7.5; after 2 h at 50 °C and pH 5.0, 30% reduction in activity; isoelectric point, pI = 5.4; final products of dextran hydrolysis, isomaltooligosaccharides from glucose up to isomaltohexaose, with high concentrations of isomaltose and isomaltotriose. These results suggest that the enzyme is an endodextranase.

Neural networks with low activity levels

1992 ◽  
Vol 86 (2) ◽  
pp. 309-315 ◽  
Author(s):  
Bruce M. Forrest ◽  
Andrea Loettgers
Keyword(s):  
Neural Networks ◽  
Activity Levels ◽  
Low Activity

The fate of plutonium, 241Am, 90Sr and 137Cs in the Antarctic ecosystem

2000 ◽  
Vol 12 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Guogang Jia ◽  
C. Triulzi ◽  
F. Nonnis Marzano ◽  
M. Belli ◽  
M. Vaghi
Keyword(s):  
Major Part ◽  
Ross Sea ◽  
Central Italy ◽  
Activity Level ◽  
Activity Levels ◽  
Northern Adriatic ◽  
Terra Nova Bay ◽  
High Concentrations ◽  
Nuclear Weapon Tests ◽  
The Antarctic

A radioecological survey around Terra Nova Bay showed that 239 + 240Pu, 238Pu, 241Am, 90Sr and 137Cs activities were detectable in nearly all the samples. The 239 + 240Pu and 241Am concentrations in seawater were slightly lower than those in the northern Pacific Ocean. The activity level of 239 + 240Pu, 241Am and 137Cs in Antarctic sediments (Ross Sea) was c. 5–20 times lower than in northern Adriatic sediments (Mediterranean Sea), but the 238Pu activities were relatively high. The 90Sr concentrations in all the sediment samples from both the Ross and Adriatic seas tended to be low which might be due to an easier exchange of 90Sr in seawater. On the other hand, high concentrations were detected in Antarctic mosses, lichens and algae and their activity levels are comparable to those in central Italy. The radionuclide ratio analyses show that the major part of 239 + 240Pu, 241Am, 90Sr and 137Cs is the result of nuclear weapon tests. A higher 241Am/239 + 240Pu ratio might be due to the fallout of earlier atmospheric nuclear tests. The 238Pu239 + 240Pu ratio in the Antarctic matrices is about seven times higher than in the Northern Hemisphere and this could suggest that the major part of 238Pu originated from the SNAP-9A satellite accident.

scholarly journals Efficacy of an Online Physical Activity Intervention Coordinated With Routine Clinical Care: Protocol for a Pilot Randomized Controlled Trial

10.2196/18891 ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. e18891
Author(s):  
Bonny Rockette-Wagner ◽  
Gary S Fischer ◽  
Andrea M Kriska ◽  
Molly B Conroy ◽  
David Dunstan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Physical Activity Intervention ◽  
Controlled Trial ◽  
Clinical Care ◽  
Online Intervention ◽  
Activity Levels ◽  
Randomized Controlled ◽  
Low Activity ◽  
Pilot Randomized Controlled Trial ◽  
Clinical Referral

Background Most adults are not achieving recommended levels of physical activity (150 minutes/week, moderate-to-vigorous intensity). Inadequate activity levels are associated with numerous poor health outcomes, and clinical recommendations endorse physical activity in the front-line treatment of obesity, diabetes, dyslipidemia, and hypertension. A framework for physical activity prescription and referral has been developed, but has not been widely implemented. This may be due, in part, to the lack of feasible and effective physical activity intervention programs designed to coordinate with clinical care delivery. Objective This manuscript describes the protocol for a pilot randomized controlled trial (RCT) that tests the efficacy of a 13-week online intervention for increasing physical activity in adult primary care patients (aged 21-70 years) reporting inadequate activity levels. The feasibility of implementing specific components of a physical activity clinical referral program, including screening for low activity levels and reporting patient program success to referring physicians, will also be examined. Analyses will include participant perspectives on maintaining physical activity. Methods This pilot study includes a 3-month wait-listed control RCT (1:1 ratio within age strata 21-54 and 55-70 years). After the RCT primary end point at 3 months, wait-listed participants are offered the full intervention and all participants are followed to 6 months after starting the intervention program. Primary RCT outcomes include differences across randomized groups in average step count, moderate-to-vigorous physical activity, and sedentary behavior (minutes/day) derived from accelerometers. Maintenance of physical activity changes will be examined for all participants at 6 months after the intervention start. Results Recruitment took place between October 2018 and May 2019 (79 participants were randomized). Data collection was completed in February 2020. Primary data analyses are ongoing. Conclusions The results of this study will inform the development of a clinical referral program for physical activity improvement that combines an online intervention with clinical screening for low activity levels, support for postintervention behavior maintenance, and feedback to the referring physician. Trial Registration ClinicalTrials.gov NCT03695016; https://clinicaltrials.gov/ct2/show/NCT03695016. International Registered Report Identifier (IRRID) DERR1-10.2196/18891

scholarly journals Bioassay and alpha spectrometry in indirect monitoring of Spanish workers exposed to enriched uranium

2019 ◽  
Vol 70 (3) ◽  
pp. 201-206
Author(s):  
Inmaculada Sierra ◽  
Carolina Hernández ◽  
Paula Albendea ◽  
Maria Antonia López
Keyword(s):  
Alpha Spectrometry ◽  
Internal Exposure ◽  
Internal Dosimetry ◽  
Activity Levels ◽  
Risk Of Exposure ◽  
Enriched Uranium ◽  
The Individual ◽  
Fuel Elements ◽  
Low Activity

AbstractWorkers at risk of exposure to uranium compounds should be monitored and their internal exposure quantified in terms of committed effective dose E(50) in mSv. In vitro bioassay methods can quantify uranium in urine and faeces at low activity levels. Alpha spectrometry (AS) is the most common method used for monitoring alpha-emitting radionuclides in internal dosimetry services. It provides isotopic information and low minimum detectable activity (MDA) values (≤0.50 mBq per sample). This study reports the results of a five-year monitoring of workers exposed to uranium at a Spanish Juzbado facility, which produces nuclear fuel elements enriched with up to 5 % of 235U. Monitoring included about 100 workers per year, most of whom had worked at the facility for more than 10 years before the individual monitoring programme was established. We analysed nearly 550 samples of more than 200 workers over five years. The obtained results indicate that workers were adequately protected from uranium exposure through inhalation and had an acceptably low chronic intake at the facility.

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