Flux balancing of light and nutrients in a biofilm photobioreactor for maximizing photosynthetic productivity

2014 ◽  
Vol 30 (2) ◽  
pp. 348-359 ◽  
Author(s):  
Thomas E. Murphy ◽  
Halil Berberoglu
Keyword(s):  
Photosynthetic Productivity

Effect of Ordered Transplanting and Optimized Broadcasting on Super High Yield and Photosynthetic Productivity and Exploration of Rice Super High Yield Model

2013 ◽  
Vol 39 (9) ◽  
pp. 1652 ◽  
Author(s):  
Ke XU ◽  
Bao-Wei GUO ◽  
Hong-Cheng ZHANG ◽  
Xing-Tao ZHOU ◽  
Hou-Cun CHEN ◽  
...  
Keyword(s):  
High Yield ◽  
Yield Model ◽  
Photosynthetic Productivity

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

scholarly journals Primary Productivity of Phytoplankton in Loch Leven, Kinross

1974 ◽  
Vol 74 ◽  
pp. 157-181 ◽  
Author(s):  
Margaret E. Bindloss
Keyword(s):  
Photosynthetic Capacity ◽  
Photochemical Oxidation ◽  
Light Extinction ◽  
Poor Correlation ◽  
Dark Bottle ◽  
Gross Photosynthesis ◽  
Ph Values ◽  
Photosynthetic Productivity ◽  
Loch Leven ◽  
Crop Density

SynopsisPhotosynthetic productivity of phytoplankton in Loch Leven was studied over a 4-year period (1968–71), using the oxygen light and dark bottle technique. Marked seasonal changes in hourly and daily rates of gross photosynthetic productivity are described within the range 0·02 to 1·59 g O2/m2.h and 0·4 to 21·0 g O2/m2.day respectively. Hourly rates are shown to be relatively insensitive to variations in surface light intensity, whereas daily rates are influenced to a considerable extent by the duration of incident radiation (daylength).The phytoplankton itself exerts a dominant influence on underwater light penetration, accounting for ca 75 per cent of light extinction at highest crop densities. This self-shading effect contributes to the poor correlation observed between crop density and areal gross productivity. The chlorophyll a content per unit area in the euphotic zone often approached its estimated theoretical limit of 430 mg/m2.In general, increase in photosynthetic capacity (per unit content of chlorophyll a) accompanied increase in water temperature. During certain periods an inverse relationship between photosynthetic capacity and population density was evident. Reduction in photosynthetic capacity is attributed, in part, to the high pH values (> 9·5) with concomitant CO2-depIetion associated with dense phytoplankton crops.Estimates of net photosynthetic productivity were frequently zero or negative, even over periods when algal populations were increasing and dissolved oxygen and pH values were above their respective air-equilibrium values. Underestimation of gross photosynthesis due to photochemical oxidation, photorespiration or the use of stationary bottles could not account for this apparent anomaly. The most probable sources of error in the estimates of net photosynthetic productivity are discussed.

The roles of photochemical and non-photochemical quenching in regulating photosynthesis depend on the phases of fluctuating light conditions

2021 ◽  
Author(s):  
Jimei Han ◽  
Lianhong Gu ◽  
Jeffrey M Warren ◽  
Anirban Guha ◽  
David A Mclennan ◽  
...  
Keyword(s):  
Interactive Effects ◽  
Photochemical Quenching ◽  
Limiting Factor ◽  
Require Time ◽  
Photosynthetic Productivity ◽  
Fluctuating Environments ◽  
Precise Relationship ◽  
New Perspective ◽  
High Level ◽  
Non Photochemical Quenching

Abstract The induction and relaxation of photochemistry and non-photochemical quenching (NPQ) are not instantaneous and require time to respond to fluctuating environments. There is a lack of integrated understanding on how photochemistry and NPQ influence photosynthesis in fluctuating environments. We measured the induction and relaxation of chlorophyll a fluorescence and gas exchange in poplar and cotton at varying temperatures under saturating and fluctuating lights. When the light shifted from dark to high, the fraction of open reaction centers in photosystem II (qL) gradually increased while NPQ increased suddenly and then remained stable. Temperature significantly changed the response of qL but not that of NPQ during the dark to high light transition. Increased qL led to higher photosynthesis but their precise relationship was affected by NPQ and temperature. qL was significantly related to biochemical capacity. Thus, qL appears to be a strong indicator of the activation of carboxylase, leading to the similar dynamics between qL and photosynthesis. When the light shifted from high to low intensity, NPQ is still engaged at a high level, causing a stronger decline in photosynthesis. Our finding suggests that the dynamic effects of photochemistry and NPQ on photosynthesis depend on the phases of environmental fluctuations and interactive effects of light and temperature. Across the full spectra of light fluctuation, the slow induction of qL is a more important limiting factor than the slow relaxation of NPQ for photosynthesis in typical ranges of temperature for photosynthesis. The findings provided a new perspective to improve photosynthetic productivity with molecular biology under natural fluctuating environments.

Impact of the leaf miner Cameraria ohridella on whole-plant photosynthetic productivity of Aesculus hippocastanum: insights from a model

Trees ◽  
2004 ◽  
Vol 18 (6) ◽  
pp. 714-721 ◽  
Author(s):  
Andrea Nardini ◽  
Fabio Raimondo ◽  
Mauro Scimone ◽  
Sebastiano Salleo
Keyword(s):  
Leaf Miner ◽  
Aesculus Hippocastanum ◽  
Photosynthetic Productivity ◽  
Whole Plant

scholarly journals Comparative genomics reveals the molecular determinants of rapid growth of the cyanobacteriumSynechococcus elongatusUTEX 2973

2018 ◽  
Vol 115 (50) ◽  
pp. E11761-E11770 ◽  
Author(s):  
Justin Ungerer ◽  
Kristen E. Wendt ◽  
John I. Hendry ◽  
Costas D. Maranas ◽  
Himadri B. Pakrasi
Keyword(s):  
Growth Rate ◽  
Photosynthetic Rate ◽  
Rapid Growth ◽  
Mutational Analysis ◽  
Specific Activity ◽  
Synechococcus Elongatus ◽  
Fast Growth ◽  
Close Relative ◽  
Genetic Changes ◽  
Photosynthetic Productivity

Cyanobacteria are emerging as attractive organisms for sustainable bioproduction. We previously describedSynechococcus elongatusUTEX 2973 as the fastest growing cyanobacterium known.Synechococcus2973 exhibits high light tolerance and an increased photosynthetic rate and produces biomass at three times the rate of its close relative, the model strainSynechococcus elongatus7942. The two strains differ at 55 genetic loci, andsome of these loci must contain the genetic determinants of rapid photoautotrophic growth and improved photosynthetic rate. Using CRISPR/Cpf1, we performed a comprehensive mutational analysis ofSynechococcus2973 and identified three specific genes,atpA,ppnK, andrpaA, with SNPs that confer rapid growth. The fast-growth–associated allele of each gene was then used to replace the wild-type alleles inSynechococcus7942. Upon incorporation, each allele successively increased the growth rate ofSynechococcus7942; remarkably, inclusion of all three alleles drastically reduced the doubling time from 6.8 to 2.3 hours. Further analysis revealed that our engineering effort doubled the photosynthetic productivity ofSynechococcus7942. We also determined that the fast-growth–associated allele ofatpAyielded an ATP synthase with higher specific activity, while that ofppnKencoded a NAD+kinase with significantly improved kinetics. TherpaASNPs cause broad changes in the transcriptional profile, as this gene is the master output regulator of the circadian clock. This pioneering study has revealed the molecular basis for rapid growth, demonstrating that limited genetic changes can dramatically improve the growth rate of a microbe by as much as threefold.

scholarly journals Influence of the growth regulator “Regoplant” and microfertilizer “Ultramag Kombi” on photosynthetic activity of potatoes in the forest-steppe zone Republic of North Ossetia-Alania

2021 ◽  
Vol 210 (07) ◽  
pp. 55-65
Author(s):  
Larisa Ikoeva ◽  
Oksana Haeva
Keyword(s):  
Growth Regulator ◽  
Field Experiments ◽  
Photosynthetic Activity ◽  
Low Cost ◽  
Weather Conditions ◽  
Steppe Zone ◽  
Practical Significance ◽  
Forest Steppe ◽  
Photosynthetic Productivity ◽  
North Ossetia

Abstract. The purpose of the work is to study the influence of the growth regulator “Regoplant” and microfertilizer “Ultramag Kombi” on the photosynthetic productivity of the potatoes of the Barna variety based on the results of field experiments in the forest-steppe zone Republic of North Ossetia-Alania. Methods. Studies on the tasks were carried out in 2018–2020. at the experimental site of the NCRIMFA branch of the VSC of RAS in the conditions of the forest-steppe zone Republic of North Ossetia-Alania according to generally accepted methods. The soil of the experimental plot is medium-power heavy loamy leached chernozem, lined with pebbles. Results. It is established, that biological products under identical soil and weather conditions assisted different progress of plants and approach of phases of vegetation. For all variants of the experiment, the number of stems increased by 0,3–0,7 pcs., the height of the stems of potato plants – by 3,8–4,9 cm in comparison with the control. An intense increase in the mass of tops occurred when using a tank mixture (growth regulator “Regoplant” (25 ml/ha) + microfertilizer “Ultramag Combi” (0,75 l/ha)) – by 74 g/bush, or 15.5 % compared with the control variant. During the growing season, the sum of the photosynthetic potential (FP) was 1,070 thousand m2 •days/ha in the control, and on average 1198–1406 thousand m2•days/ha in the experimental variants. The greatest accumulation of dry matter was noted when using a tank mixture – 917 g/m2. The maximum pure photosynthetic productivity was observed in experimental variant IV – 6,52 g/m2•day compared to the control option. Scientific novelty. For the first time in the forest-steppe zone Republic of North Ossetia-Alania the effect of the growth regulator “Regoplant” and microfertilizer “Ultramag Kombi” on photosynthetic activity of potatoes was studied. Practical significance. The studies carried out make it possible to recommend in potato production the use of a tank mixture of an effective growth regulator “Regoplant” at a dose of 25 ml/ha and microfertilizer “Ultramag Combi” at a dose of 0,75 l/ha, as an ecologically safe and low-cost agricultural method when processing vegetative plants, providing an increase in yield and quality of tubers.

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