scholarly journals Synthetic algal-bacteria consortia for space-efficient microalgal growth in a simple hydrogel system

2021 ◽  
Author(s):  
Noah Martin ◽  
Tatum Bernat ◽  
Julie Dinasquet ◽  
Andrea Stofko ◽  
April Damon ◽  
...  
Keyword(s):  
Electron Transport ◽  
Growth Rates ◽  
Commercial Production ◽  
Light Curves ◽  
Optical Measurements ◽  
Natural Seawater ◽  
Biotechnological Applications ◽  
Spatial Efficiency ◽  
Green Microalga ◽  
Hydrogel System

AbstractPhotosynthetic microalgae are an attractive source of food, fuel, or nutraceuticals, but commercial production of microalgae is limited by low spatial efficiency. In the present study we developed a simple photosynthetic hydrogel system that cultivates the green microalga, Marinichlorella kaistiae KAS603, together with a novel strain of the bacteria, Erythrobacter sp. We tested the performance of the co-culture in the hydrogel using a combination of chlorophyll-a fluorimetry, microsensing, and bio-optical measurements. Our results showed that growth rates in algal–bacterial hydrogels were about threefold enhanced compared to hydrogels with algae alone. Chlorophyll-a fluorimetry–based light curves found that electron transport rates were enhanced about 20% for algal–bacterial hydrogels compared to algal hydrogels for intermediate irradiance levels. We also show that the living hydrogel is stable under different environmental conditions and when exposed to natural seawater. Our study provides a potential bio-inspired solution for problems that limit the space-efficient cultivation of microalgae for biotechnological applications.

scholarly journals Synthetic algal-bacteria consortia for space-efficient microalgal growth in a simple hydrogel system

2021 ◽  
Author(s):  
Noah Martin ◽  
Tatum Bernat ◽  
Julie Dinasquet ◽  
Andrea Stoftko ◽  
April Damon ◽  
...  
Keyword(s):  
Electron Transport ◽  
Growth Rates ◽  
Commercial Production ◽  
Light Curves ◽  
Optical Measurements ◽  
Natural Seawater ◽  
Biotechnological Applications ◽  
Spatial Efficiency ◽  
Green Microalga ◽  
Hydrogel System

AbstractPhotosynthetic microalgae are an attractive source of food, fuel or nutraceuticals, but commercial production of microalgae is limited by low spatial efficiency. In the present study, we developed a simple photosynthetic hydrogel system that cultivates the green microalga, Marinichlorella kaistiae KAS603, together with a novel strain of the bacteria Erythrobacter sp.. We tested the performance of the co-culture in the hydrogel using a combination of chlorophyll-a fluorimetry, microsensing and bio-optical measurements. Our results showed that growth rates in algal-bacterial hydrogels were about 3-fold enhanced compared to hydrogels with algae alone. Chlorophyll-a fluorimetry based light curves found that electron transport rates were enhanced about 20% for algal-bacterial hydrogels compared to algal hydrogels for intermediate irradiance levels. We also show that the living hydrogel is stable under different environmental conditions and when exposed to natural seawater. Our study provides a potential bio-inspired solution for problems that limit the space-efficient cultivation of microalgae for biotechnological applications.

scholarly journals Photomorphogenesis in the Picocyanobacterium Cyanobium gracile Includes Increased Phycobilisome Abundance Under Blue Light, Phycobilisome Decoupling Under Near Far-Red Light, and Wavelength-Specific Photoprotective Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Gábor Bernát ◽  
Tomáš Zavřel ◽  
Eva Kotabová ◽  
László Kovács ◽  
Gábor Steinbach ◽  
...  
Keyword(s):  
Electron Transport ◽  
Growth Rates ◽  
Incident Light ◽  
Red Light ◽  
Photosynthetic Performance ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Strong Light ◽  
Antenna Size ◽  
Moderate Growth

Photomorphogenesis is a process by which photosynthetic organisms perceive external light parameters, including light quality (color), and adjust cellular metabolism, growth rates and other parameters, in order to survive in a changing light environment. In this study we comprehensively explored the light color acclimation of Cyanobium gracile, a common cyanobacterium in turbid freshwater shallow lakes, using nine different monochromatic growth lights covering the whole visible spectrum from 435 to 687 nm. According to incident light wavelength, C. gracile cells performed great plasticity in terms of pigment composition, antenna size, and photosystem stoichiometry, to optimize their photosynthetic performance and to redox poise their intersystem electron transport chain. In spite of such compensatory strategies, C. gracile, like other cyanobacteria, uses blue and near far-red light less efficiently than orange or red light, which involves moderate growth rates, reduced cell volumes and lower electron transport rates. Unfavorable light conditions, where neither chlorophyll nor phycobilisomes absorb light sufficiently, are compensated by an enhanced antenna size. Increasing the wavelength of the growth light is accompanied by increasing photosystem II to photosystem I ratios, which involve better light utilization in the red spectral region. This is surprisingly accompanied by a partial excitonic antenna decoupling, which was the highest in the cells grown under 687 nm light. So far, a similar phenomenon is known to be induced only by strong light; here we demonstrate that under certain physiological conditions such decoupling is also possible to be induced by weak light. This suggests that suboptimal photosynthetic performance of the near far-red light grown C. gracile cells is due to a solid redox- and/or signal-imbalance, which leads to the activation of this short-term light acclimation process. Using a variety of photo-biophysical methods, we also demonstrate that under blue wavelengths, excessive light is quenched through orange carotenoid protein mediated non-photochemical quenching, whereas under orange/red wavelengths state transitions are involved in photoprotection.

scholarly journals Comparative Study of Pleurotus ostreatus Mushroom Grown on Modified PAN Nanofiber Mats

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 475 ◽  
Author(s):  
Lilia Sabantina ◽  
Franziska Kinzel ◽  
Thomas Hauser ◽  
Astrid Többer ◽  
Michaela Klöcker ◽  
...  
Keyword(s):  
Comparative Study ◽  
Growth Rates ◽  
Pleurotus Ostreatus ◽  
Edible Mushroom ◽  
Fungal Mycelium ◽  
Specific Substrate ◽  
Biotechnological Applications ◽  
Mushroom Species ◽  
Nanofiber Mats ◽  
Pan Nanofiber

Pleurotus ostreatus is a well-known edible mushroom species which shows fast growth. The fungus can be used for medical, nutritional, filter, or packaging purposes. In this study, cultivation experiments were carried out with Pleurotus ostreatus growing on polyacrylonitrile (PAN) nanofiber mats in the presence of saccharose and Lutrol F68. The aim of this study was to find out whether modified PAN nanofiber mats are well suited for the growth of fungal mycelium, to increase growth rates and to affect mycelium fiber morphologies. Our results show that Pleurotus ostreatus mycelium grows on nanofiber mats in different morphologies, depending on the specific substrate, and can be used to produce a composite from fungal mycelium and nanofiber mats for biomedical and biotechnological applications.

scholarly journals The Spin-Up Rate of the White Dwarf in GK Per

2004 ◽  
Vol 190 ◽  
pp. 120-123
Author(s):  
Christopher W. Mauche
Keyword(s):  
White Dwarf ◽  
Light Curves ◽  
Optical Measurements ◽  
Pulse Period ◽  
X Ray ◽  
Spin Period

AbstractWe use hard X-ray light curves measured by the Chandra HETG and RXTE PCA during the late rise and plateau phases of the 2002 March–April outburst of the intermediate polar GK Per to determine that its X-ray pulse period P = 351.332 ± 0.002 s. Combined with previous X-ray and optical measurements of the spin period of the white dwarf, we find that its spin-up rate Ṗ = 0.00027 ± 0.00005 s yr−1.

scholarly journals Growth rates of large and small Southern Ocean diatoms in relation to availability o iron in natural seawater

2001 ◽  
Vol 46 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Klaas R. Timmermans ◽  
Loes J. A. Gerringa ◽  
Hein J. W. de Baar ◽  
Bas van der Wagt ◽  
Marcel J. W. Veldhuis ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Growth Rates ◽  
Natural Seawater

The Role of the Substrate Surface Morphology and Water in Growth of Vertically Aligned Single-Walled Carbon Nanotubes

2008 ◽  
Vol 8 (11) ◽  
pp. 6158-6164 ◽  
Author(s):  
Cary Pint ◽  
Sean Pheasant ◽  
Nolan Nicholas ◽  
Charles Horton ◽  
Robert Hauge
Keyword(s):  
Carbon Nanotubes ◽  
Growth Rates ◽  
Substrate Surface ◽  
Single Walled Carbon Nanotubes ◽  
Optical Measurements ◽  
Diameter Distribution ◽  
Single Walled Carbon ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

Growth of high quality, vertically aligned single-walled carbon nanotubes (carpets) is achieved using a rapid insertion hot filament chemical vapor deposition (HF-CVD) technique. The effect of the substrate morphology on growth is explored by comparing carpets grown on epitaxially polished MgO substrates to those grown on "as-cut," macroscopically rough MgO substrates. Depending on the substrate morphology, we observe differences in both the overall carpet morphology as well as the diameter distribution of nanotubes grown in the carpet based on optical measurements. In addition, we explore the role of water in the growth of carpets on MgO and the conventional Al2O3 coated Si substrates. We find that the addition of a small amount of water is beneficial to the growth rates of the SWNT carpets, enhancing the growth rates by up to eight times.

Effect of Biaxial Stress on Solid Phase Epitaxy of Silicon

1992 ◽  
Vol 263 ◽  
Author(s):  
Guo-Quan Lu ◽  
Tapan K. Gupta
Keyword(s):  
Growth Kinetics ◽  
Growth Rates ◽  
Solid Phase ◽  
Biaxial Stress ◽  
Optical Measurements ◽  
Back Side ◽  
Time Resolved ◽  
Tensile Stresses ◽  
Rate Retardation ◽  
Amorphous Surface

ABSTRACTThe effect of biaxial stress on solid phase epitaxial growth (SPEG) rate of crystalline Si(100) into self-implanted amorphous surface layer has been measured. Biaxial stresses in the crystalline and amorphous phases were generated by bending the silicon wafer using the residual stresses in Ge films deposited on the back side of the wafer. Stresses were determined at SPEG temperatures by optical measurements of wafer bending curvatures. Tensile stresses up to 13 MPa in the crystalline phase and 34 MPa in the amorphous phasewere achieved during SPEG at 530ºC. An optical system based on the time-resolved reflectivity (TRR) technique was devised to measure the growth rates of two adjacent samples during a single SPEG run. This enables a direct comparison of the growth rates under different stress conditions without concern for run-to-run temperature variations. We found that the growth kinetics in all the samples were retarded as the c/a interface approached the free surface. However, the extent of this rateretardation was reducedin the stressed samples, leading to stress-enhanced growth kinetics. We speculate that the application of the biaxial tensile stresses might slow down the incorporation of hydrogen into the amorphous phase, a mechanism for the rate-retardation.

Changes in Yellow Perch (Perca flavescens) Populations of Lake Michigan, 1954–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1821-1829 ◽  
Author(s):  
LaRue Wells
Keyword(s):  
Population Dynamics ◽  
Growth Rates ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Perca Flavescens ◽  
Commercial Production ◽  
Alosa Pseudoharengus ◽  
Exploitation Competition ◽  
Sport Fishery ◽  
High Production

In the early and mid-1960s the abundance of yellow perch (Perca flavescens) in Lake Michigan declined abruptly. The decline began in the northern part of the lake and spread progressively southward. Circumstantial evidence suggests that the nonnative alewife (Alosa pseudoharengus), by interfering with perch reproduction, was the primary cause of the decline. The alewife was first reported in northeastern Lake Michigan in 1949, and had become extremely abundant throughout the lake before an enormous die-off in 1967 reduced its numbers by an estimated 70%. An intensive fishery hastened the decline of perch. In most areas the decline was immediately preceded by a period of conspicuously high commercial production. This high production appears to have been related in part to increased growth rates of perch resulting from much lower density of younger fish. A sport fishery for perch in shallow water collapsed a few years before the species declined in abundance. The most logical explanation is that heavy concentrations of alewives physically displaced the perch from nearshore areas. Although perch populations increased in some areas in the 1970s, a full recovery is unlikely unless alewife numbers are further reduced. Key words: Percidae, Lake Michigan, Perca, population dynamics, exploitation, competition

scholarly journals EUVE Photometry of SS Cygni: Dwarf Nova Outbursts and Oscillations

1996 ◽  
Vol 152 ◽  
pp. 317-324
Author(s):  
Christopher W. Mauche
Keyword(s):  
Accretion Disk ◽  
Outer Edge ◽  
Light Curves ◽  
Optical Measurements ◽  
Dwarf Nova ◽  
Sinusoidal Oscillations ◽  
Deep Survey ◽  
Different Response ◽  
June July ◽  
Nova Outbursts

I present EUVE Deep Survey photometry and AAVSO optical measurements of the 1993 August and 1994 June/July outbursts of the dwarf nova SS Cygni. The EUV and optical light curves are used to illustrate the different response of the accretion disk to outbursts which begin at the inner edge and propagate outward, and those which begin at the outer edge and propagate inward. Furthermore, we describe the properties of the quasi-coherent 7-9 s sinusoidal oscillations in the EUV flux detected during the rise and plateau stages of these outbursts.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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