scholarly journals Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Indrayani Indrayani ◽  
Haslianti Haslianti ◽  
Asmariani Asmariani ◽  
Wellem Muskita ◽  
Abdul Muis Balubi
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
High Growth ◽  
Biomass Productivity ◽  
Dry Weight ◽  
High Light Intensity ◽  
High Growth Rate ◽  
Lipid Productivity ◽  
Marine Diatom ◽  
Light Intensities

Abstract. Indrayani I, Haslianti H, Asmariani A, Muskita WH, Balubi M. 2020. Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities. Biodiversitas 21: 1498-1503. Light is one of the important factors affecting growth and biochemical composition of microalgae. The aim of this study was to determine growth, biomass and lipid productivity of a newly isolated marine diatom, Skeletonema sp.UHO29 under different light intensities. The Skeletonema sp. was cultured in 300 mL conical flasks containing 150 mL of f/2 medium under three different light intensities (28, 60 and 110 μmol photons m-2 s-1 ) with three replications. The cultures were incubated under ambient room temperatures, and a cycle of 12 hours light and 12 hours dark, in batch modes for two weeks. The results showed that the highest specific growth rate (0.56 d-1) was achieved at the highest light intensity (110 μmol photons m-2 s-1) and the lowest (0.11 d-1) was obtained at the lowest light intensity (28 μmol photons m-2 s-1). The highest biomass yield (0.62 g L-1) and biomass productivity (0.34 g L-1 d-1) was achieved at the highest light intensity. However, the highest lipid yield (0.175 g L-1), lipid content (28.78% ash-free dry weight) and lipid productivity (0.067 g L-1 d-1) were achieved at medium light intensity. The alga prefers high light intensity for higher growth rate and biomass productivity but it produces more lipids at medium light intensity. This study indicated that the Skeletonema sp.UHO29 is a potential species for outdoor mass cultivation and is a promising microalgal strain for use as a biodiesel feedstock due to its high growth rate, high biomass and lipid productivity.

scholarly journals Light Intensity and Nitrogen Concentration Impact on the Biomass and Phycoerythrin Production by Porphyridium purpureum

Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 460 ◽  
Author(s):  
Juan Eduardo Sosa-Hernández ◽  
Laura Isabel Rodas-Zuluaga ◽  
Carlos Castillo-Zacarías ◽  
Magdalena Rostro-Alanís ◽  
Reynaldo de la Cruz ◽  
...  
Keyword(s):  
Light Intensity ◽  
Biomass Yield ◽  
Nitrogen Concentration ◽  
Biomass Productivity ◽  
Dry Weight ◽  
High Light Intensity ◽  
High Biomass ◽  
Porphyridium Purpureum ◽  
Nitrogen Concentrations ◽  
Low Nitrogen

Several factors have the potential to influence microalgae growth. In the present study, nitrogen concentration and light intensity were evaluated in order to obtain high biomass production and high phycoerythrin accumulation from Porphyridium purpureum. The range of nitrogen concentrations evaluated in the culture medium was 0.075–0.450 g L−1 and light intensities ranged between 30 and 100 μmol m−2 s−1. Surprisingly, low nitrogen concentration and high light intensity resulted in high biomass yield and phycoerythrin accumulation. Thus, the best biomass productivity (0.386 g L−1 d−1) and biomass yield (5.403 g L−1) were achieved with NaNO3 at 0.075 g L−1 and 100 μmol m−2 s−1. In addition, phycoerythrin production was improved to obtain a concentration of 14.66 mg L−1 (2.71 mg g−1 of phycoerythrin over dry weight). The results of the present study indicate that it is possible to significantly improve biomass and pigment production in Porphyridium purpureum by limiting nitrogen concentration and light intensity.

Relationship between growth rate and the development of hollow stem in broccoli

2009 ◽  
Vol 60 (10) ◽  
pp. 995 ◽  
Author(s):  
M. Boersma ◽  
A. J. Gracie ◽  
P. H. Brown
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Dry Weight ◽  
High Growth Rate ◽  
Planting Density ◽  
Boron Deficiency ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Possible Cause

Boron deficiency is widely accepted as the dominant cause of hollow stem in broccoli (Brassica oleracea L. var. italica Plenck), although high growth rate has also been mentioned in the literature as a possible cause of the disorder. In this study, we investigated the role of growth rate and boron in the development of hollow stem. Two experiments were conducted with broccoli cv. Marathon, using planting density to manipulate growth rate. In the first experiment, plants were grown at 3 planting densities (19 512, 32 520, and 69 686 plants/ha) and either supplemented or not supplemented with foliar boron applications (0.35 kg B/ha) on two occasions. In the second experiment, broccoli plants at 2 planting densities (32 520 and 100 000 plants/ha) were treated in factorial combination from inflorescence initiation onwards with complete trace element fertiliser (1.5% B), 57% light interception, and paclobutrazol (480 g a.i./ha). The incidence and severity of hollow stem were assessed using digital image analysis and were found to increase with plant spacing but were not affected by boron application. The probability of hollow stem occurring increased with absolute growth rate in the first trial, but not the second. Absolute growth rate, measured as dry weight accumulation, was suppressed independently of planting density by the shading treatment, but did not influence the incidence or severity of hollow stem. The application of paclobutrazol did not influence absolute growth rate but reduced the severity of hollow stem at the lowest planting density. Our data support the hypothesis that the rate and pattern of growth are involved in the development of hollow stem, and that a boron deficiency is not the major causal factor.

scholarly journals Effect of Nutrient, Light Intensity and Temperature on the Growth Rates and Metabolism of a Stress-Resistant Bacillariophyta – Entomoneis sp. - in Izmir Bay (Aegean Sea)

2020 ◽  
Vol 21 (1) ◽  
pp. 1
Author(s):  
SEZGI ADALIOĞLU ◽  
GÜLIZAR ÇALIŞKAN
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
High Growth ◽  
Aegean Sea ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Process Time ◽  
Izmir Bay ◽  
Annual Range ◽  
Nutrient Conditions

A unicellular marine microalga, Entomoneis sp. was isolated and studied as had become the dominant species according to other bacillariophyta species in different environmental fluctuations in Izmir Bay. Because of our effort to better understand the dynamics of this microalga that facilitates unprecedented domination, we conducted on a monoculture isolation study.In this study, experiments were planned with the annual range of the Izmir Bay temperature, and the demonstrated behavior of the species in light and nutrient conditions. The stock culture medium was illuminated by approximately 50μmol photons m-2s-1 of illumination with 14/24 daylight. The temperature of the climate chamber was set on the summer (T1 (21±1oC)), spring (T2 (17±1oC)) and winter (T3 (13±1oC)) of Izmir Bay. Experiments were also applied with four different light intensities (L1 (50 μmol photons m-2s-1), L2 (25 μmol photons m-2s-1), L3 (5 μmol photons m-2s-1) and L4 (dark)). In this context, nutrient measurements were made on samples of the exponential, stationary and death phase of the culture and nutrient analyses were carried out. The results, which were designed according to ceteris paribus assumptions, were adapted to Michaelis-Menten kinetics. Consequently, considering the lifetime of the diatom at different temperature conditions, T3 was determined as an optimum temperature. Maximum growth rate and process time were observed at this temperature. This is the evidence why these diatoms are available in the winter. Once the light intensity was increased, the growth rate was increased at the T1 and T2 temperatures. However, T3 had a high growth rate in the nearly L1 light intensity. Considering the consumption and transformation of different nutrient conditions, different results for both types of microalgae were obtained. 

scholarly journals Study of Algal Species Isolated From River Ginzo in Katsina State, as a Potential Source for Biodiesel Production

2021 ◽  
Vol 25 (5) ◽  
pp. 793-798
Author(s):  
L. Umar ◽  
A. Bashir ◽  
I. Haruna ◽  
G.A. Hadiza ◽  
A.J. Shamsudeen
Keyword(s):  
Growth Rate ◽  
Algal Species ◽  
High Growth ◽  
Biomass Productivity ◽  
High Growth Rate ◽  
Biodiesel Production ◽  
Cell Counts ◽  
Candidate Species ◽  
Chlorella Species ◽  
Ph Range

An ecological study of algae at River Ginzo in Katsina town was carried out for six weeks at three different sites. In this study, various strains of native microalgae were identified and isolated. The water's physicochemical properties were analyzed at Kofar Marusa, Kofar Sauri, and Kofar Durbi of River Ginzo in Katsina State. The physicochemical parameters studied showed temperature and pH range of 28oC to 31oC and 6.42 to 7.36. A total of eighteen (18) algal species were identified, out of which Ten (10) species belong to the Class Chlorophyceae with Spirogyra species having the highest cell counts, five (5) species belong to the Class Cyanophyceae with Oscillatoria species having the highest cell count and three (3) species belong to the Class Bacillariophyceae with Nitzchia spp having the highest cell counts. Among the isolates, Chlorella species showed an increased growth rate with higher biomass productivity of (88.67±2.57) X 104 (cell/ml) after six days of incubation. The results showed that Chlorella, Spirogyra, and Oocystis species could be a possible candidate species for producing oils for sustainable biodiesel production, based on their high growth rate and presence in all the locations.

Exploring SiC Growth Limitation of Vapor-Liquid-Solid Mechanism when Using Two Different Carbon Precursors

2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
High Growth Rate ◽  
Carbon Precursor ◽  
Growth Limitation ◽  
Vapor Liquid Solid ◽  
Partial Pressures ◽  
Vapor Liquid Solid Mechanism ◽  
Vls Growth ◽  
Vapor Liquid

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.

Very High Growth Rate of 4H-SiC Using MTS as Chloride-Based Precursor

2008 ◽  
Vol 600-603 ◽  
pp. 115-118 ◽  
Author(s):  
Henrik Pedersen ◽  
Stefano Leone ◽  
Anne Henry ◽  
Franziska Christine Beyer ◽  
Vanya Darakchieva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Linear Dependence ◽  
Growth Rates ◽  
Molar Fraction ◽  
High Growth ◽  
High Growth Rate ◽  
Epitaxial Layers ◽  
Single Precursor ◽  
Very High

The chlorinated precursor methyltrichlorosilane (MTS), CH3SiCl3, has been used to grow epitaxial layers of 4H-SiC in a hot wall CVD reactor, with growth rates as high as 170 µm/h at 1600°C. Since MTS contains both silicon and carbon, with the C/Si ratio 1, MTS was used both as single precursor and mixed with silane or ethylene to study the effect of the C/Si and Cl/Si ratios on growth rate and doping of the epitaxial layers. When using only MTS as precursor, the growth rate showed a linear dependence on the MTS molar fraction in the reactor up to about 100 µm/h. The growth rate dropped for C/Si < 1 but was constant for C/Si > 1. Further, the growth rate decreased with lower Cl/Si ratio.

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