scholarly journals Variation of salinity and nitrogen concentration affects the pentacyclic triterpenoid inventory of the haloalkaliphilic aerobic methanotrophic bacterium Methylotuvimicrobium alcaliphilum

Extremophiles ◽  
2021 ◽  
Author(s):  
Alexmar Cordova-Gonzalez ◽  
Daniel Birgel ◽  
Andreas Kappler ◽  
Jörn Peckmann
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Environmental Parameters ◽  
Full Potential ◽  
Pentacyclic Triterpenoids ◽  
Cell Functions ◽  
Pentacyclic Triterpenoid ◽  
Nitrate Concentrations ◽  
Aerobic Methanotrophs ◽  
Bacterial Lipid

AbstractThe occurrence and activity of aerobic methanotrophs are influenced by environmental conditions, including pH, temperature, salinity, methane and oxygen concentrations, and nutrient availability. Aerobic methanotrophs synthesize a variety of lipids important for cell functions. However, culture-based experiments studying the influence of environmental parameters on lipid production by aerobic methanotrophs are scarce. Such information is crucial to interpret lipid patterns of methanotrophic bacteria in the environment. In this study, the alkaliphilic strain Methylotuvimicrobium alcaliphilum was cultivated under different salinities and different nitrate concentrations to assess the effect of changing conditions on the inventory of pentacyclic triterpenoids. The results indicate that hopanoid abundance is enhanced at lower salinity and higher nitrate concentration. The production of most pentacyclic triterpenoids was favored at low salinity, especially for aminotriol. Interestingly, 3-methyl-aminotetrol and tetrahymanol were favored at higher salinity. Bacteriohopanepolyols (BHPs), particularly aminotriol and 3-methyl-aminotriol, increased considerably at higher nitrate concentrations. Four novel N-containing BHPs—aminodiol, 3-methyl-aminodiol, and isomers of aminotriol and 3-methyl-aminotriol—were identified. This study highlights the significance of environmental factors for bacterial lipid production and documents the need for cultivation studies under variable conditions to utilize the full potential of the biomarker concept.

Development of an autonomous robotic system for beard shaving assistance of disabled people based on an adaptive force tracking impedance control

2021 ◽  
pp. 095440622098482
Author(s):  
Oladayo S Ajani ◽  
Samy FM Assal
Keyword(s):  
Impedance Control ◽  
Environmental Parameters ◽  
Robotic System ◽  
Robotic Systems ◽  
Full Potential ◽  
Robotic Assistance ◽  
Head Pose ◽  
Detection And Tracking ◽  
Control Scheme ◽  
Force Tracking

Recently, people with upper arm disabilities due to neurological disorders, stroke or old age are receiving robotic assistance to perform several activities such as shaving, eating, brushing and drinking. Although the full potential of robotic assistance lies in the use of fully autonomous robotic systems, these systems are limited in design due to the complexities and the associated risks. Hence, rather than the shared controlled or active robotic systems used for such tasks around the head, an adaptive compliance control scheme-based autonomous robotic system for beard shaving assistance is proposed. The system includes an autonomous online face detection and tracking as well as selected geometrical features-based beard region estimation using the Kinect RGB-D camera. Online trajectory planning for achieving the shaving task is enabled; with the capability of online re-planning trajectories in case of unintended head pose movement and occlusion. Based on the dynamics of the UR-10 6-DOF manipulator using ADAMS and MATLAB, an adaptive force tracking impedance controller whose parameters are tuned using Genetic Algorithm (GA) with force/torque constraints is developed. This controller can regulate the contact force under head pose changing and varying shaving region stiffness by adjusting the target stiffness of the controller. Simulation results demonstrate the system capability to achieve beard shaving autonomously with varying environmental parameters that can be extended for achieving other tasks around the head such as feeding, drinking and brushing.

scholarly journals Taming the Wild West of Molecular Tools Application in Aquatic Research and Biomonitoring

2019 ◽  
Vol 3 ◽  
Author(s):  
Alexander Weigand ◽  
Agnès Bouchez ◽  
Pieter Boets ◽  
Kat Bruce ◽  
Fedor Ciampor ◽  
...  
Keyword(s):  
Working Group ◽  
High Throughput Sequencing ◽  
Group Structure ◽  
Time Budget ◽  
Good Practice ◽  
Dna Barcode ◽  
Environmental Parameters ◽  
Full Potential ◽  
Molecular Tools ◽  
Wild West

Modern high-throughput sequencing technologies are becoming a game changer in many fields of aquatic research and biomonitoring. To unfold their full potential, however, the independent development of approaches has to be streamlined. This discussion must be fuelled by stakeholders and practitioners and, scientific results collaboratively filtered to identify the most promising avenues. Furthermore, aspects such as time, budget, skills and the application context have to be considered, finally communicating good practice strategies to target audiences. Since 2016, the EU COST Action DNAqua-Net is taming the wild west of molecular tools application in aquatic research and biomonitoring. After nucleating available knowledge by the formation of a highly international and transdisciplinary network of scientists, stakeholders, practitioners and enterprises, fields of high methodological diversity were identified. Relevant aspects are currently ground truthed, thereby reducing the plethora of pipelines, parameters and protocols to a subset of good practices or standardisations. To effectively bridge the science-application interface, the very same network is exploited for the dissemination of results (Leese et al. 2018). The internal working group structure of DNAqua-Net is used to provide an overview of existing methodological fields of diversity in DNA-based aquatic biomonitoring: WG1 -DNA Barcode References: Different marker systems are targeted for the same organism group. Even in case the same molecular marker is investigated, different primer pairs are frequently applied for DNA metabarcoding. Both aspects challenge the further development of high-quality and complete DNA barcode reference libraries (Weigand et al. 2019). WG2 -Biotic Indices & Metrics: Index systems are developed from molecular data in various ways: from the estimation of species' biomass (as a proxy for abundance) from sequence reads, to the correlation of presence/absence data of molecular operational taxonomic units (MOTUs) with environmental parameters (Pawlowski et al. 2018). WG3 -Field & Lab Protocols: Using environmental DNA (eDNA) metabarcoding as an example, diverse sampling techniques based on varying water volumes, different filter systems and collection devices as well as a multitude of laboratory protocols for PCR, replication and sequencing are considered. WG4 -Data Analysis & Storage: During the process of MOTU identification, varying threshold values and conceptually different pipelines are used, potentially impacting the final list of MOTUs or species retrieved. Furthermore, routine storage concepts for big biodiversity data are only in development and some sample types (e.g. eDNA) have no sophisticated metadata descriptions. WG5 -Implementation Strategy & Legal Issues: The working group picks up collaboratively filtered good practice strategies and generates room for discussions at the science-policy interface (Hering et al. 2018). The CEN working group WG28 "DNA methods" has been initiated and the development of standardisations is fostered.

Confocal Microscopy in Ecophysiological Studies of Algae: A Door to Understanding Autofluorescence in Red Algae

2021 ◽  
pp. 1-9
Author(s):  
Teresa Coronado-Parra ◽  
Mónica Roldán ◽  
Marina Aboal
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Nitrogen Concentration ◽  
Monochromatic Light ◽  
Environmental Parameters ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Scale Production ◽  
Light Intensities

Alga in the genus Chroothece have been reported mostly from aquatic or subaerial continental environments, where they grow in extreme conditions. The strain Chroothece mobilis MAESE 20.29 was exposed to different light intensities, red and green monochromatic light, ultraviolet (UV) radiation, high nitrogen concentrations, and high salinity to assess the effect of those environmental parameters on its growth. Confocal laser scanning microscopy (CLSM) was used as an “in vivo” noninvasive single-cell method for the study. The strain seemed to prefer fairly high light intensities and showed a significant increase in allophycocyanin (APC) and chlorophyll a [photosystem I (PSI) and photosystem II (PSII)] fluorescence with 330 and 789 μM/cm2/s intensities. Green monochromatic light promoted a significant increase in the fluorescence of APC and chlorophyll a (PSI and PSII). UV-A significantly decreased phycocyanin and increased APC, while UV-A + B showed a greater decreasing effect on c-Phycocyanin but did not significantly change concentrations of APC. The increase in nitrogen concentration in the culture medium significantly and negatively affected all pigments, and no effect was observed with an increase in salinity. Our data show that CLSM represents a very powerful tool for ecological research of microalgae in small volumes and may contribute to the knowledge of phycobiliproteins in vivo behavior and the parameters for the large-scale production of these pigments.

Role of Pentacyclic Triterpenoid Acids in the Treatment of Bladder Cancer

2021 ◽  
Vol 21 ◽  
Author(s):  
Anindita Ghosh ◽  
Chinmay Kumar Panda
Keyword(s):  
Bladder Cancer ◽  
In Vivo Studies ◽  
Pentacyclic Triterpenoids ◽  
Pentacyclic Triterpenoid ◽  
Anticancer Effects ◽  
Antitumor Compounds ◽  
Resistance To Chemotherapy

: Bladder cancer carries a poor prognosis and has proven resistance to chemotherapy. Pentacyclic Triterpenoid Acids (PTAs) are natural bioactive compounds that have a well-known impact on cancer research because of their cytotoxic and chemopreventive activities. This review focuses on bladder cancer which can no longer be successfully treated by DNA damaging drugs. Unlike most of the existing drugs against bladder cancer, PTAs are non-toxic to normal cells. Collecting findings from both in vitro and in vivo studies, it has been concluded that PTAs may serve as promising agents in future bladder cancer therapy. In this review, the roles of various PTAs in bladder cancer have been explored, and their mechanisms of action in the treatment of bladder cancer have been described. Specific PTAs have been shortlisted from each of the chief skeletons of pentacyclic triterpenoids, which could be effective against bladder cancer because of their mode of action. This review thereby throws light on the multi targets and mechanisms of PTAs, which are responsible for their selective anticancer effects and provides guidelines for further research and development of new natural antitumor compounds.

Enhanced growth and lipid production in psychrotolerant Acutodesmus by controlling temperature-dependent nitrogen concentration

2019 ◽  
Vol 127 ◽  
pp. 105267 ◽  
Author(s):  
Nakyeong Lee ◽  
Hyung-Seok Oh ◽  
Hee-Mock Oh ◽  
Hee-Sik Kim ◽  
Chi-Yong Ahn
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Temperature Dependent

scholarly journals Spatial variability of ammonium, nitrite and nitrate concentrations in water of Batang Arau River, West Sumatera, Indonesia

2020 ◽  
Vol 20 (4) ◽  
pp. 1484-1492
Author(s):  
Denny Helard ◽  
Shinta Indah ◽  
Michella Oktavia
Keyword(s):  
Spatial Variability ◽  
Anthropogenic Activities ◽  
Nitrogen Concentration ◽  
Monitoring Program ◽  
Quality Standard ◽  
Nitrite Concentration ◽  
Sampling Locations ◽  
Maximum Permissible Concentrations ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations

Abstract The objective of this study is to analyze the spatial variability of ammonia, nitrite, and nitrate concentrations along the Batang Arau River, one of the most important rivers in West Sumatera, Indonesia. The results showed that the ammonium, nitrite, and nitrate concentrations were in the range of 0.180–0.510 mg/L, 0.0–0.178 mg/L, and 0.675–1.165 mg/L, respectively. The ammonium and nitrate concentrations were still below the maximum permissible concentrations for the river water quality standard of class II established by the Regulation Governor of West Sumatera at all of the sampling locations, except at midstream for ammonium, while the nitrite concentration had exceeded the quality standard from midstream to downstream of the river. The increase of the nitrogen concentration was observed from upstream to downstream of the river. Spatial analysis shows significant differences in nitrogen concentrations were obtained between the upstream and the midstream of the Batang Arau River (p < 0.05) but were not observed between the midstream and the downstream. This indicates the effect of different anthropogenic activities along the river. Based on the obtained results, for an effective monitoring program of the nitrogen concentration along the Batang Arau River, reducing the sampling locations from eight to five could be implemented.

scholarly journals A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenhua Yang ◽  
Yue Zhao ◽  
Zhiyong Liu ◽  
Chenfeng Liu ◽  
Zhipeng Hu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Lipid Synthesis ◽  
Quantitative Relationship ◽  
Chlorella Sorokiniana ◽  
High Lipid ◽  
Nitrogen Concentrations

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.

scholarly journals Repeated Batch Fermentation Biotechnology for the Biosynthesis of Lipid and Gamma-Linolenic Acid byCunninghamella bainieri2A1

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Marjan Ganjali Dashti ◽  
Peyman Abdeshahian ◽  
Wan Mohtar Wan Yusoff ◽  
Mohd Sahaid Kalil ◽  
Aidil Abdul Hamid
Keyword(s):  
Linolenic Acid ◽  
Glucose Concentration ◽  
Batch Fermentation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Ammonium Tartrate ◽  
Gamma Linolenic Acid ◽  
Harvesting Time ◽  
Repeated Batch Fermentation ◽  
Repeated Batch

The biosynthesis of biomedical products including lipid and gamma-linolenic acid (GLA) byCunninghamella bainieri2A1 was studied in repeated batch fermentation. Three key process variables, namely, glucose concentration, ammonium tartrate concentration, and harvesting time, were optimized using response surface methodology. Repeated batch fermentation was carried out by the cultivation ofCunninghamella bainieri2A1 in nitrogen-limited medium with various nitrogen concentration (1–4 g/L) and glucose concentration (20–40 g/L) at three time intervals (12 h, 24 h, and 48 h). Experimental results showed that the highest lipid concentration of 6.2 g/L and the highest GLA concentration of 0.4 g/L were obtained in optimum conditions, where 20.2 g/L glucose, 2.12 g/L ammonium tartrate, and 48 h harvesting time were utilized. Statistical results showed that the interaction between glucose and ammonium tartrate concentration had highly significant effects on lipid and GLA biosynthesis (P<0.01). Moreover, harvesting time had a significant interaction effect with glucose and ammonium tartrate concentration on lipid production (P<0.05).

The Effect of Composition on the Properties of Semiconducting Transition Metal Nitrides

2007 ◽  
Vol 1040 ◽  
Author(s):  
Maria G. Moreno-Armenta ◽  
Reyes-Serrato Armando ◽  
Soto H. Gerardo
Keyword(s):  
Nitrogen Concentration ◽  
Stoichiometric Composition ◽  
Full Potential ◽  
Transition Metal Nitrides ◽  
Conducting Phase ◽  
Wide Range ◽  
Structural And Electronic Properties ◽  
Ideal Stoichiometry ◽  
Nitrogen Concentrations ◽  
The Stability

AbstractUsing the full potential linearized augmented plane wave (FP-LAPW) method, we investigate the bulk structural and electronic properties in the scandium-, yttrium-, and copper-nitrides over a wide range of nitrogen concentrations. The N atom was gradually incorporated into metal matrix with and without metal vacancies. The ground state properties like densities of states (DOS) and formation energies are determined for each calculated alloy. We have found that the semi-conducting state in copper nitride have a tinny compositional margin. Any deviation of the ideal stoichiometry will produce a metallic character. What is more, the stabilities of the conductive phases are very close to the stability of the semi conducting phase, with a little margin favorable to the conducting phases. The calculations of scandium- and yttrium nitrides show, that for very low nitrogen incorporations, the hexagonal and fcc phases may coexist. However, for high nitrogen concentration the cubic phases are favored. For non-stoichiometric nitrogen content, the materials behave as metal, whereas at stoichiometric composition the DOS becomes zero at Fermi level (EF), confirming in this way the semiconductor character of these nitrides.

Sign in / Sign up

Export Citation Format

Share Document