scholarly journals Marine proteorhodopsins rival photosynthesis in solar energy capture

2017 ◽  
Author(s):  
Laura Gómez-Consarnau ◽  
Naomi M. Levine ◽  
Lynda S. Cutter ◽  
Deli Wang ◽  
Brian Seegers ◽  
...  
Keyword(s):  
Solar Energy ◽  
Mediterranean Sea ◽  
Carbon Cycling ◽  
Light Energy ◽  
Energy Capture ◽  
Energy Flows ◽  
Eastern Atlantic Ocean ◽  
Vertical Distributions ◽  
Energy Converting

All known phototrophic metabolisms on Earth are based on one of three energy-converting pigments: chlorophyll-a, bacteriochlorophyll-a, and retinal, which is the chromophore in rhodopsins [1]. While the contribution of chlorophylls to global energy flows and marine carbon cycling has been studied for decades, the role of retinal-based phototrophy remains largely unexplored [1,2]. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Eastern Atlantic Ocean. The highest proteorhodopsin concentrations were observed above the deep chlorophyll-amaxima, and their geographical distribution tended to be inversely related to that of chlorophyll-a. We further show that proteorhodopsins potentially absorb as much or more light energy than chlorophyll-a–based phototrophy and this energy is sufficient to sustain bacterial basal metabolism. Our results suggest that ubiquitous proteorhodopsin-containing heterotrophs are important contributors to the light energy captured in the sea.

scholarly journals Microbial rhodopsins are major contributors to the solar energy captured in the sea

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw8855 ◽  
Author(s):  
Laura Gómez-Consarnau ◽  
John A. Raven ◽  
Naomi M. Levine ◽  
Lynda S. Cutter ◽  
Deli Wang ◽  
...  
Keyword(s):  
Solar Energy ◽  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Geographical Distribution ◽  
Proton Pumping ◽  
Basal Metabolism ◽  
Energy Capture ◽  
Surface Ocean ◽  
Vertical Distributions ◽  
Energy Converting

All known phototrophic metabolisms on Earth rely on one of three categories of energy-converting pigments: chlorophyll-a (rarely -d), bacteriochlorophyll-a (rarely -b), and retinal, which is the chromophore in rhodopsins. While the significance of chlorophylls in solar energy capture has been studied for decades, the contribution of retinal-based phototrophy to this process remains largely unexplored. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Atlantic Ocean. The highest rhodopsin concentrations were observed above the deep chlorophyll-a maxima, and their geographical distribution tended to be inversely related to that of chlorophyll-a. We further show that proton-pumping proteorhodopsins potentially absorb as much light energy as chlorophyll-a–based phototrophy and that this energy is sufficient to sustain bacterial basal metabolism. This suggests that proteorhodopsins are a major energy-transducing mechanism to harvest solar energy in the surface ocean.

Energy Management of Electromechanical Systems on the Board of a Ship

2020 ◽  
Vol 26 (3) ◽  
pp. 14-19
Author(s):  
Laurențiu Bogdan Asalomia ◽  
Gheorghe Samoilescu
Keyword(s):  
Energy Management ◽  
Management System ◽  
Integrated Management ◽  
Integrated Management System ◽  
Management Actions ◽  
Energy Flows ◽  
Reduce Emissions ◽  
Technical Solutions ◽  
Productive Time

AbstractThe paper analyzes, starting from the Integrated Management System, the role of automation, the role of the officer and the role of the Energy Management System on board the ship. The implementation of an EnMS establishes the structure and discipline of identifying energy flows, implementing management actions and, finally, applying technical solutions, which significantly reduce energy costs, reduce non-productive time in production, and reduce emissions. of Greenhouse Gases in the environment. The steps to be highlighted in the realization of energy management are analyzed.

Microbiological Detoxification of Hazardous Organic Contaminants: The Crucial Role of Substrate Interactions

1992 ◽  
Vol 25 (11) ◽  
pp. 403-410 ◽  
Author(s):  
B. E. Rittmann
Keyword(s):  
Organic Pollutants ◽  
Information Flow ◽  
Organic Contaminants ◽  
Crucial Role ◽  
Substrate Utilization ◽  
Energy Flows ◽  
Hazardous Pollutants ◽  
Primary Substrate ◽  
Substrate Types

Microbiological detoxification of hazardous organic pollutants is highly promising, but its reliable implementation requires a sophisticated understanding of several different substrate types and how they interact. This paper carefully defines the substrate types and explains how their interactions affect the bacteria's electron and energy flows, information flow, and degradative activity. For example, primary substrates, which are essential for growth and maintenance of the bacteria, also interact with degradation of specific hazardous pollutants by being inducers, inhibitors, and direct or indirect cosubstrates. The target contaminants, which often are secondary substrates, also have the interactive roles of self-inhibitor, inhibitor of primary-substrate utilization, inducer, and a part of an aggregate primary substrate.

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

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