scholarly journals Effects of the Light Irradiance on the Growth and Lipids Content of Amphidinium Carterae (Dinophyceae) for Biofuels Production

Author(s):  
Armando Mendoza-Flores ◽  
Clara Elizabeth Galindo-Sánchez ◽  
M. del Pilar Sánchez-Saavedra

Abstract The irradiance level used to the microalgae cultures can modify the growth and proximate composition, however, this response is specie specific. The dinoflagellate group had the potential to be used as a source to biofuel production. In this study was evaluated the effect of five irradiance levels (50, 100, 150, 200, and 250 µmol photon m-2 s­-1) on the growth rate, proximal composition, pigment content, and photosynthesis of Amphidinium carterae. The highest cell concentration was for the cultures at 150 µmol photon m-2 s-1 (130 × 103 cells mL-1), and the lowest values for 50 µmol photon m-2 s-1 (49 × 103 cells mL-1). The cultures maintained under the low irradiance (50 µmol photon m-2 s-1) had the highest values of total dry weight (TDW) (13418 pg cell-1), organic dry weight (ODW) (3836 pg cell-1), and inorganic dry weight (IDW) (9582 pg cell-1). The protein content as the general trend increases significantly concerning the irradiance level, with the higher values (87.47 pg cell-1) at high irradiance (250 µmol photon m-2 s-1). Carbohydrate content was different by the effect of irradiance, with the higher values (32.85 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). Lipid content was modified by the effect of irradiance, with the highest values (534.74 pg cell-1) at the low irradiance used (50 µmol photon m-2 s-1). As a general trend, the high irradiances increased the photosynthesis curves. These findings demonstrate that the strain of A. carterae used in this work can grow in high irradiances (100 to 250 µmol photon m-2 s-1) and increase significantly the lipid content on low irradiance used (50 µmol photon m-2 s-1).

1969 ◽  
Vol 60 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Charles S. Nicoll

ABSTRACT The response of the pigeon crop-sac to systemically acting prolactin (injected subcutaneously) was evaluated by measuring the wet weight of the responsive lateral lobes of the organ and by determining the dry weight of a 4 cm diameter disc of mucosal epithelium taken from one hemicrop. Of several different injection schedules tested, administration of prolactin in four daily injections was found to yield optimal responses. When compared with a graded series of prolactin doses, measurement of the mucosal dry weight proved to be a better method of response quantification than determination of the crop-sac wet weight with respect to both assay sensitivity and precision. The submucosal tissue of the crop-sac was estimated to constitute about 64 % of the total dry weight of the unstimulated organ and it was found to be relatively unresponsive to prolactin stimulation in comparison with the mucosa. The lipid content of the mucosal epithelium was determined using unstimulated crop-sacs or tissues which showed varying degrees of prolactin-induced proliferation. The fat content of the mucosal epithelial cells increased only slightly more rapidly than the dry weight or the defatted dry weight of the mucosa. Suggestions are made for the further improvement of the systemic crop-sac assay for prolactin.


1938 ◽  
Vol 125 (838) ◽  
pp. 115-123 ◽  

Garner and Allard (1931) showed that plants grown in alternating light and dark periods of equal duration respond differently according to the length of the period. They found that the growth of Cosmos sulphureus, for example, was progressively poorer as the alternating periods decreased from 12 hr. to 1 min., after which it improved rapidly so that at 5 sec. intermittency the plants were of fairly normal appearance, i.e. like those in 12 hr. alternations. No measurements of these effects however were made. Portsmouth (1937) carried out similar experiments with cucumber plants, and has shown that the increase in total dry weight is greatest in continuous light, only slightly less in 12 hr. alternations and considerably less in 1 min. alternations. He suggests that the effects observed were related to carbohydrate deficiency occasioned by a falling net assimilation rate and partial closure of the stomata at 1 min. alternations. Gregory and Pearse (1937) have shown that short alternating light and dark periods are accompanied by a closing of the stomata in Pelargonium , and here again the effect was at a maximum with intermittencies of about 1 min. duration. In view of the above results it was decided to repeat and extend the growth-rate determinations with Lemna minor , which is simple in structure and is eminently suitable for experimental work under laboratory conditions. It had also the advantage, as its stomatal opening does not change, that should results similar to those of Garner and Allard, and Portsmouth, be obtained it would be possible to assess the value of stomatal closure at rapid intermittencies on growth rate. 2. Experimental procedure Two different stocks of Lemna were employed, one, coming originally from the Chelsea Physic Garden, had been used previously in this de-partment, while the other was a fresh stock obtained from Sutton. Each stock was established in the first instance from a single individual. In all cases colonies were grown under 12 hr. alternating light and darkness for 14 days before being placed under the lighting conditions in which their growth rate was to be measured. Apart from the light factor all environmental conditions were the same during the preliminary 14 days as when measurements were being made. The plants were grown in a culture solution made up as follows: CaH 4 (PO 4 ) 2 . H 2 O 0·100 g., KNO 3 0·800 g., MgSO 4 . 7H 2 O 0·25 g., FeCl 3 0·002g., distilled water 1000 ml. In some cases the water used was condensed on glass, in others on copper. The culture solution was changed only when the plants were being measured; it was not aerated but always shaken up with air immediately before being used. The solution was made up in amounts of 2 litres, but as the number of colonies to be supplied varied from time to time the several lots lasted for different periods.


2007 ◽  
Vol 132 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Anke van der Ploeg ◽  
Ranathunga J.K.N. Kularathne ◽  
Susana M.P. Carvalho ◽  
Ep Heuvelink

To breed for more energy-efficient cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivars it is important to know the variation of the temperature response existing in modern cultivars. In a greenhouse experiment with 25 chrysanthemum cultivars, a significant variation was observed in temperature response (16 °C or 20 °C) for reaction time, total dry weight produced, stem length, and flower size and number. To study this genetic variation in temperature response over a larger range of temperatures (15 °C to 24 °C), four contrasting cultivars (Annecy, Delianne, Reagan, and Supernova) were selected in a second experiment. Furthermore, a third experiment was performed in which the cultivation period was split into three phases and the influence of temperature in each of these phases was studied for the four selected cultivars. Dry weight production in all cultivars was very sensitive to temperature during the long day period. Relative growth rate showed an optimum response to temperature, with the optimum around 24 °C. Net assimilation rate also showed an optimum response to temperature, whereas leaf area ratio increased linearly with temperature. Compared with these temperature effects during the long day, the effect of temperature on absolute growth rate during the short day was, depending on the cultivar, relatively small or even absent. The reaction time, on the other hand, was very temperature sensitive, showing an optimum that was cultivar dependent. The temperature response of the total dry weight production during the whole cultivation period was, therefore, very cultivar dependent. Furthermore, depending on the cultivar, stem length increased with temperature, especially during long day, as a result of both increasing internode number and average internode length. The response of both flower size and number to temperature was also highly cultivar specific. The possibilities of using this genetic variation for breeding are discussed.


1982 ◽  
Vol 33 (6) ◽  
pp. 1009 ◽  
Author(s):  
RJ Chamberlin ◽  
GL Wilson

Growth and development of two grain-sorghum hybrids (De Kalb E57 and Texas 610) were examined under glasshouse conditions by sequential harvesting and the use of I4C. The grain yield per plant of Texas 610 was higher than that of E57, with higher total biological yield and similar harvest indices. The contribution to grain weight at maturity, of carbon assimilated prior to anthesis, was about 10% for each hybrid. The leaves were the main source of this material. After anthesis, dry weight data indicated that temporary storage of assimilates before retranslocation to the grain was of greater importance in Texas 610 than E57. This storage was largely in the leaves (including sheaths), upper internodes, and roots. A high grain-growth rate was maintained for longer by Texas 610 than by E57. Total dry weight production after anthesis in both hybrids was, at all stages examined, more than sufficient to maintain grain growth.


1977 ◽  
Vol 57 (1) ◽  
pp. 193-197 ◽  
Author(s):  
D. J. MAJOR

Irrigated Polish rape (Brassica campestris L. cv. Span) and Argentine rape (B. napus L. cv. Zephyr) were harvested at 1-wk intervals at Lethbridge, Alberta and separated into leaves, stems, pods, and seed. Leaves reached maximum dry weight on 8 July for Span and 15 July for Zephyr and then senesced completely or to low levels. Maximum plant dry matter, which ranged from 312 to 1,174 g/m2, occurred in the last half of August. Although total dry weight increased substantially during the period that leaf dry weight was decreasing, crop growth rate also decreased, indicating that leaves were an important source of photosynthates for plant growth.


2014 ◽  
Vol 32 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fánor Casierra-Posada ◽  
Esteban Zapata-Casierra ◽  
Daniel A. Chaparro-Chaparro

To determine the effects of light quality on the growth indices of plants, Pencas Blancas cultivar chard plantlets were grown for 2 months under five different light treatments, obtained by filtering sunlight through colored polyethylene films. The treatments included: red, blue, green, yellow and transparent cover colors. A transparent cover (white light) was used as the control. The colored covers affected the plant growth. The plants grown under the yellow cover presented a better behavior with regards to growth, taken as: total dry weight per plant, leaf area, specific leaf area, absolute growth rate, relative growth rate, harvestable dry matter and root to shoot ratio. The dry matter partitioning in the leaves and roots was affected by the light quality, but not in the petioles, with a higher accumulation of dry mass in the leaves of plants grown under the yellow cover. As a consequence of the enhanced leaf area in the plants under the yellow cover, they also had the highest water uptake. On the other hand, the highest net assimilation rate value was found in plants grown under the transparent cover. These results open up the possibility of using yellow colored cover in leafy green vegetables, especially in chard plants grown under controlled conditions.


2019 ◽  
Vol 7 (1) ◽  
pp. 3-10
Author(s):  
Arif Rahmadi ◽  
Yeni Mulyani ◽  
Muhammad Wahyudin Lewaru

Chaetoceros muelleri is a microalgae class of Bacillariophyta (diatom) which is generally only used as feeds for fishes and shellfish larvae. Nevertheless, the biochemical content of this species is quite high and has the potential to be developed. This research aims to explain the effect of different salinity on the growth and lipid content of Chaetoceros muelleri cultured in a continuous photobioreactor. This research was carried out in August 2018 - February 2019. The research was conducted at the Laboratory of Marine Microbiology and the Laboratory of Bioprocess and Bioprospection of Natural Materials, Faculty of Fisheries and Marine Sciences, Padjadjaran University. The samples of Chaetoceros muelleri isolates were obtained from the Jepara Brackish Water Aquaculture Center. The methods used for the study was a ‘Completely Randomized Design’ (CRD) with four treatments. The salinity used is 15, 25, 35 and 45 ppt. The main parameters observed were growth and lipid content, while the supporting parameters were temperature, and pH. The results of this study showed that the highest lipid content was a salinity treatment of 35 ppt with a value of 25.37% of total dry weight obtained at the end of the culture. Based on growth, the highest density occurred in 25 ppt salinity with a maximum density of 3.80 ± 0.49 x 106 cells. ml-1 and maximum growth rate of 0.36 ± 0.008 div. day-1


2019 ◽  
Vol 80 (11) ◽  
pp. 2027-2036 ◽  
Author(s):  
Karthikeyan Sangapillai ◽  
Thirumarimurugan Marimuthu

Abstract The use of microalgae biomass as a suitable alternative feedstock for biofuel production has been promoted in the field of green biotechnology. In this present study, the microalgae were isolated from freshwater samples. The predominant strain was screened from the samples and grown in four different growth media, including modified Bold's Basal Medium (BBM), modified CFTRI medium, BG11 medium and CHU medium, to find the suitable growth medium to enrich biomass production. In total three microalgae colonies were identified based on their colony morphology microscopically by using a light microscope. The predominant strain was confirmed as Asterarcys quadricellulare using 18S rRNA sequencing. The growth of microalgae was investigated based on parameters like dry weight, pigment composition such as chlorophyll a, chlorophyll b, carotenoid and lipid content in the microalgae. Among the four different media, modified BBM medium showed maximum dry weight (1.44 ± 0.015 g/L), chlorophyll a (23.07 ± 0.049 mg/L), chlorophyll b (16.76 ± 0.010 mg/L), carotenoid (8.92 ± 0.031 mg/L) and lipid content (375 ± 0.020 mg/L) on the 25th day of culture. The gas chromatography mass spectrometry (GC/MS) analysis showed the presence of major fatty acids stearic acid, palmitic acid and oleyl alcohol in the microalgae. Therefore the high lipid content and fatty acid profiles of Asterarcys quadricellulare are becoming a promising suitable strain for biofuel production with modified BBM medium.


1973 ◽  
Vol 24 (4) ◽  
pp. 479 ◽  
Author(s):  
PS Cocks

The influence of temperature on the growth of high and low density communities of subterranean clover (Trifolium subterraneum L. cv. Mount Barker) was studied at four temperatures ranging from 12�C day/7�C night to 27�C day/22�C night. The response to temperature depended on leaf area index (LAI). When the LAI was low (0.2), growth rate increased with increasing temperature to a maximum at 22� day/ 17�C night. This agreed with the temperature response of single plants of the same species previously reported. However, when the LAI was 3 the growth rate was not influenced by temperature within the range tested. At a still higher value of LAI (5.5), the response in growth became negative with increasing temperature, communities at the highest temperature growing at only half the rate of those at the lowest. The frequency distribution of plant size in the dense communities was measured, at eight times during the experiment. The distribution was influenced by both temperature and the total dry weight of the community. At low temperature it was approximately symmetrical, but at high temperature it rapidly became asymmetric as total dry weight increased, the amount of skewness being greatest at the highest temperature and dry weight. Plant death was greatest at the high temperature. The communities were divided into five equally populated groups of ascending plant size. At high temperature the largest plants increased in size throughout the experiment, but each of the groups of smaller plants reached a maximum size, subsequently losing weight. At lower temperatures only the groups of smaller size lost weight, the number of groups losing weight depending on temperature. The distribution data were used to try to explain the interaction between temperature and LAI. It was proposed that community growth rate was best when canopy cover was complete and the distribution of plant weight was not strongly skewed.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 472c-472
Author(s):  
Douglas D. Archbold

Over 4 years, using estimates of fruit dry weight derived from diameter measurements in situ, cultivar variation in apple fruit relative growth rate (RGR) in the period following June drop was evident. These differences diminished as the season progressed however. Using estimates of dry weight per cell, fruit cell absolute growth rate increased over time and RGR showed no clear pattern in contrast to the RGR of whole fruit. There were no cultivar differences in carbohydrate allocation among the soluble, starch, and remaining ethanol-insoluble, non-hydrolyzable pools irrespective of cultivar RGR. The storage carbohydrate pool comprised an increasing fraction of the total dry weight over time with the starch pool comprising 10 to 25% of the storage carbohydrate, varying with season and cultivar. Neither fruit competition within a cluster nor post-June drop thinning altered fruit RGR or carbohydrate allocation patterns when compared to fruit thinned post-bloom.


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