scholarly journals A Quantitative Analysis on the Effect of Varying Nitrate Concentrations on pH levels on the Growth of Algae

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Nathaniel Tak ◽  
Pranshu Wagh ◽  
Sumer Sandhu ◽  
Akshay Reddy ◽  
Himanshu Wagh
Keyword(s):  
Growth Rate ◽  
Acetic Acid ◽  
Algal Blooms ◽  
Nitrate Concentration ◽  
Algal Growth ◽  
Optimal Growth ◽  
American River ◽  
Rivers And Lakes ◽  
Nitrate Concentrations ◽  
Optimal Ph

The objective of this experiment was to determine what nitrate concentration and pH would provide the most optimal growth for algae. In order to determine this, algae from the American River was taken and grown in solutions with different concentrations of nitrate, and H+ ions. It was hypothesized that the algae would grow best in solutions with neutral pH levels or solutions with high nitrate concentrations. Different amounts of sodium nitrate were added to beakers with similar amounts of water and algae in order to create environments with varying concentrations of nitrate. Different amounts of NaOH and acetic acid were added to beakers with similar amounts of water and algae in order to simulate environments with varying pH levels. This experiment was conducted in order to determine how fertilizer runoffs affect algal growth. Fertilizer run offs carry nitrate ions into rivers and lakes, which cause algal blooms to form. It was hypothesized that as the concentration of nitrate increases, the growth rate of the algae would also increase. This is due to the fact that the literature supports the idea that as nitrate is added to rivers and lakes the number of algae present increases. The results from the experiment demonstrated that the most optimal concentration of nitrate in the water for algal growth was in between 1-2 Molar and that the most optimal pH for algal growth was in between 7-8.

scholarly journals TEMPERATURE AND NITRATE CONCENTRATION EFFECT ON THE ABUNDANCE AND GROWTH RATE OF MELOSIRA SP.

2021 ◽  
Vol 7 (2) ◽  
pp. 185-194
Author(s):  
Nita Rukminasari ◽  
Sharifuddin Andy Omar ◽  
Muhammad Lukman
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Free Fatty Acids ◽  
Culture Media ◽  
Nitrate Concentration ◽  
Dry Weight ◽  
Organic C ◽  
Randomized Design ◽  
Significant Difference ◽  
Nitrate Concentrations

Microalgae are one of the natural resources that have high potential as a source of biofuels, one of them is the marine microalgae Melosira sp.. The objective of this study was to determine the effect of increasing temperature and nitrate concentration on the abundance, growth rate, biomass, organic C-content and free fatty acids of Melosira sp.. A Completely Randomized Design was used for this experiment with four temperature treatments and three nitrate concentrations treatments  in microalgae test planting media. The test microalgae were cultured for 21 days, while the abundance of Melosira sp..was carried out every 3rd day, while for other parameters measurements were made at the end of the experiment. The results showed that the increasing in temperature and nitrate concentration in culture media significantly affected the abundance of Melosira sp.. Meanwhile, the results of statistical analysis showed that the increase in temperature and concentration of culture media did not have a significant effect on biomass except at 30°C treatment, the dry weight of Melosira sp. was only significantly different between the nitrate concentrations of 0.0 g/L and 0.4 g/L. For the content of C-organic and free fatty acids generally showed a significant difference between treating temperature and nitrate concentration in the culture media.

scholarly journals Bioavailability of Mineral-Bound Iron to a Snow Algal-Bacterial Coculture and Implications for Albedo-Altering Snow Algal Blooms

2018 ◽  
Vol 84 (7) ◽  
Author(s):  
Z. R. Harrold ◽  
E. M. Hausrath ◽  
A. H. Garcia ◽  
A. E. Murray ◽  
O. Tschauner ◽  
...  
Keyword(s):  
Growth Rate ◽  
Algal Blooms ◽  
Mineral Dust ◽  
Algal Growth ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Control Analysis ◽  
Content Type ◽  
Snow Albedo ◽  
Snow Algae

ABSTRACTSnow algae can form large-scale blooms across the snowpack surface and near-surface environments. These pigmented blooms can decrease snow albedo and increase local melt rates, and they may impact the global heat budget and water cycle. Yet, the underlying causes for the geospatial occurrence of these blooms remain unconstrained. One possible factor contributing to snow algal blooms is the presence of mineral dust as a micronutrient source. We investigated the bioavailability of iron (Fe)-bearing minerals, including forsterite (Fo90, Mg1.8Fe0.2SiO4), goethite, smectite, and pyrite as Fe sources for aChloromonas brevispina-bacterial coculture through laboratory-based experimentation. Fo90was capable of stimulating snow algal growth and increased the algal growth rate in otherwise Fe-depleted cocultures. Fo90-bearing systems also exhibited a decrease in the ratio of bacteria to algae compared to those of Fe-depleted conditions, suggesting a shift in microbial community structure. TheC. brevispinacoculture also increased the rate of Fo90dissolution relative to that of an abiotic control. Analysis of 16S rRNA genes in the coculture identifiedGammaproteobacteria,Betaproteobacteria, andSphingobacteria, all of which are commonly found in snow and ice environments. Archaea were not detected.CollimonasandPseudomonas, which are known to enhance mineral weathering rates, comprised two of the top eight (>1%) operational taxonomic units (OTUs). These data provide unequivocal evidence that mineral dust can support elevated snow algal growth under otherwise Fe-depleted growth conditions and that snow algal microbial communities can enhance mineral dissolution under these conditions.IMPORTANCEFe, a key micronutrient for photosynthetic growth, is necessary to support the formation of high-density snow algal blooms. The laboratory experiments described herein allow for a systematic investigation of the interactions of snow algae, bacteria, and minerals and their ability to mobilize and uptake mineral-bound Fe. Results provide unequivocal and comprehensive evidence that mineral-bound Fe in Fe-bearing Fo90was bioavailable toChloromonas brevispinasnow algae within an algal-bacterial coculture. This evidence includes (i) an observed increase in snow algal density and growth rate, (ii) decreased ratios of bacteria to algae in Fo90-containing cultures relative to those of cultures grown under similarly Fe-depleted conditions with no mineral-bound Fe present, and (iii) increased Fo90dissolution rates in the presence of algal-bacterial cocultures relative to those of abiotic mineral controls. These results have important implications for the role of mineral dust in supplying micronutrients to the snow microbiome, which may help support dense snow algal blooms capable of lowering snow albedo and increasing snow melt rates on regional, and possibly global, scales.

scholarly journals Characteristics of Phomopsis juglandina (Sacc.) Hohn. Associated with Dieback of Walnut in the Climatic Conditions of Southern Romania

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Cristina Mihaescu ◽  
Daniel Dunea ◽  
Adrian Gheorghe Bășa ◽  
Loredana Neagu Frasin
Keyword(s):  
Growth Temperature ◽  
Potential Evapotranspiration ◽  
Optimal Growth ◽  
Climatic Conditions ◽  
Cultural Characteristics ◽  
Optimal Growth Temperature ◽  
Conidial State ◽  
Optimal Ph

Phomopsis juglandina (Sacc.) Höhn., which is the conidial state of Diaporthe juglandina (Fuckel) Nitschke, and the main pathogen causing the dieback of branches and twigs of walnut was recently detected in many orchards from Romania. The symptomatological, morphological, ultrastructural, and cultural characteristics, as well as the pathogenicity of an isolate of this lignicolous fungus, were described and illustrated. The optimum periods for infection, under the conditions prevailing in Southern Romania, mainly occur in the spring (April) and autumn months (late September-beginning of October). Strong inverse correlations (p < 0.001) were found between potential evapotranspiration and lesion lengths on walnut branches in 2019. The pathogen forms two types of phialospores: alpha and beta; the role of beta phialospores is not well known in pathogenesis. In Vitro, the optimal growth temperature of mycelial hyphae was in the range of 22–26 °C, and the optimal pH is 4.4–7. This pathogen should be monitored continuously due to its potential for damaging infestations of intensive plantations.

scholarly journals 261 Increasing dietary amylose reduces rate of starch digestion and increases microbial fermentation in weaned pigs

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 86-86
Author(s):  
F P Y Tan ◽  
L F Wang ◽  
E Beltranena ◽  
R T Zijlstra
Keyword(s):  
Growth Rate ◽  
Block Design ◽  
Optimal Growth ◽  
Metabolite Profile ◽  
Proximal Colon ◽  
Starch Digestion ◽  
Gut Health ◽  
Weaned Pigs ◽  
Ileal Digestibility ◽  
Beneficial Effects

Abstract Beneficial effects of SCFA in modulating gut health stimulated interest on dietary strategies to increase intestinal microbial activity and digesta SCFA. Amylose has lower apparent ileal digestibility (AID) than amylopectin. In the large intestine, undigested starch is fermented by microbes producing SCFA. The objective was to determine effects of increasing dietary amylose on starch flow and metabolite profile along the intestinal tract in weaned pigs. Weaned pigs (n=32; initial BW, 8.4 kg) were randomly allocated to 4 diets containing 67% starch with 0, 20, 35, or 70% amylose in a randomized complete block design. On day 21, pigs were euthanized to collect digesta and feces for evaluating starch digestion and metabolite profiles. Apparent hindgut fermentation (AHF) was calculated as apparent total tract digestibility minus AID. Feed intake was 12% lower (P &lt; 0.05) and growth rate was 18% lower (P &lt; 0.05) for pigs fed 70% amylose than pigs fed 0, 20, or 35% amylose. Feed efficiency was greatest (P &lt; 0.05) for pigs fed with 35% amylose. The AID of starch was 44% lower (P &lt; 0.05) in pigs fed 70% amylose. Starch was completely digested by the proximal colon in pigs fed 0, 20, or 35% amylose, but AHF of starch was 14% greater (P &lt; 0.05) in pigs fed 70% amylose. Increasing dietary amylose did not alter digesta SCFA in the small intestine, but increased (P &lt; 0.05) digesta SCFA in the cecum, specifically acetate and total SCFA, and increased (P &lt; 0.05) propionate and valerate in all sections of the colon. In conclusion, increasing dietary amylose in weaned pigs stimulated hindgut fermentation of starch with a corresponding increase in digesta total SCFA in the cecum and colon. Optimizing dietary amylose may exert its effect as dietary prebiotic while promoting an optimal growth rate in young pigs.

Selection of water source for water transfer based on algal growth potential to prevent algal blooms

2021 ◽  
Vol 103 ◽  
pp. 246-254
Author(s):  
Yongjun Song ◽  
Jing Qi ◽  
Le Deng ◽  
Yaohui Bai ◽  
Huijuan Liu ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Algal Growth ◽  
Water Source ◽  
Water Transfer ◽  
Growth Potential ◽  
Algal Growth Potential ◽  
Selection Of

Enhancement of Hydrocarbon Productivity of Botryococcus braunii by an Adenine Type Phytohormone

2012 ◽  
Vol 512-515 ◽  
pp. 397-400
Author(s):  
Jun Zhi Liu ◽  
Ya Ming Ge ◽  
Guang Ming Tian
Keyword(s):  
Growth Rate ◽  
Low Dose ◽  
Algal Growth ◽  
Botryococcus Braunii ◽  
Biofuel Production ◽  
Carotenoid Content ◽  
Algae Biofuels ◽  
Hydrocarbon Content ◽  
Algal Growth Rate ◽  
Hydrocarbon Productivity

This study examined the effects of an adenine-type cytokinin 6-benzylaminopurine (6-BA) on the growth and metabolism characteristics of Botryococcus braunii, one of the most promising oil-rich algae for biofuel production. The results showed that 6-BA of low dose (0.1-1.0 mg L-1) would enhance the algal growth rate and biochemical synthesis, whereas too much (5.0 mg L-1) would be lethally toxic for B. braunii. Noticingly, though the maximum algal growth rate, chlorophyll and β-carotenoid content were observed in the treatment with 0.5 and/or 1.0 mg L-1 6-BA, both the maximum algal hydrocarbon content and the highest hydrocarbon productivity were observed in the treatment with 0.1 mg L-1 6-BA, which were respectively 2.45 and 3.48 times of the control (39.1% vs. 16.0%, 546 mg L-1 vs. 157 mg L-1). This finding has great implications for improving algae biofuels production by phytohormone.

scholarly journals UTILITY MAXIMIZATION IN A BINOMIAL MODEL WITH TRANSACTION COSTS: A DUALITY APPROACH BASED ON THE SHADOW PRICE PROCESS

2014 ◽  
Vol 17 (04) ◽  
pp. 1450022 ◽  
Author(s):  
CHRISTIAN BAYER ◽  
BEZIRGEN VELIYEV
Keyword(s):  
Growth Rate ◽  
Asymptotic Expansion ◽  
Transaction Costs ◽  
Continuous Time ◽  
Shadow Price ◽  
Optimal Growth ◽  
Order Effect ◽  
Explicit Construction ◽  
Binomial Model ◽  
Price Process

We consider the problem of optimizing the expected logarithmic utility of the value of a portfolio in a binomial model with proportional transaction costs with a long time horizon. By duality methods, we can find expressions for the boundaries of the no-trade-region and the asymptotic optimal growth rate, which can be made explicit for small transaction costs (in the sense of an asymptotic expansion). Here we find that, contrary to the classical results in continuous time, see Janeček and Shreve (2004), Finance and Stochastics8, 181–206, the size of the no-trade-region as well as the asymptotic growth rate depend analytically on the level λ of transaction costs, implying a linear first-order effect of perturbations of (small) transaction costs, in contrast to effects of orders λ1/3 and λ2/3, respectively, as in continuous time models. Following the recent study by Gerhold et al. (2013), Finance and Stochastics17, 325–354, we obtain the asymptotic expansion by an almost explicit construction of the shadow price process.

scholarly journals Endogenous hormonal content during grain development in hexaploid and tetraploid wheat

1970 ◽  
Vol 33 (3) ◽  
pp. 493-502 ◽  
Author(s):  
Sridhar Gutam ◽  
Virendra Nath ◽  
GC Srivastava
Keyword(s):  
Growth Rate ◽  
Acetic Acid ◽  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Grain Growth ◽  
Indole Acetic Acid ◽  
Tetraploid Wheat ◽  
Weight Basis ◽  
Ploidy Levels ◽  
Hormonal Content

A pot experiment was conducted in the rabi (post rainy) seasons of 2001 and 2002 to study the genotypic differences in grain growth rate and endogenous hormonal content in the developing grains of hexaploid and tetraploid wheat. The endogenous hormonal contents of grains in both the ploidy levels had changed in sequence. At 5 days after anthesis (DAA), gibberellic acid (GA3); at 15 DAA (rapid growth phase), indole-acetic acid (IAA); at 25 DAA (dough stage), abscisic acid (ABA) were maximum. At 35 DAA, all the endogenous hormonal level decreased and among the hormones, ABA was highest followed by IAA and GA3. Hexaploids recorded higher concentrations of endogenous hormones (13.38% IAA, 17.89% GA3, and 14.7% ABA) on fresh weight basis and resulted in higher seed weight (56.99 mg/grain) and grain growth rate (0.009 g/g/day) compared to tetraploids (49.08 mg/grain; 0.008 g/g/day) on dry weight basis by better mobilization of photosynthates during grain filling. Key Words: Grain growth rate, hormones, indole-acetic acid, gibberellic acid, abscisic acid. doi:10.3329/bjar.v33i3.1608 Bangladesh J. Agril. Res. 33(3) : 493-502, September 2008

scholarly journals Effect on nitrate concentration in stream water of agricultural practices in small catchments in Brittany: I. Annual nitrogen budgets

2002 ◽  
Vol 6 (3) ◽  
pp. 497-506 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
P. Durand ◽  
C. Martin ◽  
F. Vertès ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Stream Water ◽  
Agricultural Practices ◽  
Climatic Conditions ◽  
Nitrogen Budgets ◽  
Annual Variations ◽  
Nitrate Concentrations ◽  
The Mean ◽  
Small Catchments

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments

scholarly journals <sup>210</sup>Pb-<sup>226</sup>Ra chronology reveals rapid growth rate of <i>Madrepora oculata</I> and <i>Lophelia pertusa</i> on world's largest cold-water coral reef

2011 ◽  
Vol 8 (6) ◽  
pp. 12247-12283
Author(s):  
P. Sabatier ◽  
J.-L. Reyss ◽  
J. M. Hall-Spencer ◽  
C. Colin ◽  
N. Frank ◽  
...  
Keyword(s):  
Growth Rate ◽  
Coral Reef ◽  
Linear Growth ◽  
Cold Water ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Age And Growth ◽  
Linear Growth Rate ◽  
Lophelia Pertusa ◽  
Water Coral

Abstract. Here we show the use of the 210Pb-226Ra excess method to determine the growth rate of corals from one of the world's largest known cold-water coral reef, the Røst Reef off Norway. Two large branching framework-forming cold-water coral specimens, one Lophelia pertusa and one Madrepora oculata were collected alive at 350 m water depth from the Røst Reef at ~67° N and ~9° E. Pb and Ra isotopes were measured along the major growth axis of both specimens using low level alpha and gamma spectrometry and the corals trace element compositions were studied using ICP-QMS. Due to the different chemical behaviors of Pb and Ra in the marine environment, 210Pb and 226Ra were not incorporated the same way into the aragonite skeleton of those two cold-water corals. Thus to assess of the growth rates of both specimens we have here taken in consideration the exponential decrease of initially incorporated 210Pb as well as the ingrowth of 210Pb from the decay of 226Ra. Moreover a~post-depositional 210Pb incorporation is found in relation to the Mn-Fe coatings that could not be entirely removed from the oldest parts of the skeletons. The 226Ra activities in both corals were fairly constant, then assuming constant uptake of 210Pb through time the 210Pb-226Ra chronology can be applied to calculate linear growth rate. The 45.5 cm long branch of M. oculata reveals an age of 31 yr and a~linear growth rate of 14.4 ± 1.1 mm yr−1, i.e. 2.6 polyps per year. However, a correction regarding a remaining post-depositional Mn-Fe oxide coating is needed for the base of the specimen. The corrected age tend to confirm the radiocarbon derived basal age of 40 yr (using 14C bomb peak) with a mean growth rate of 2 polyps yr−1. This rate is similar to the one obtained in Aquaria experiments under optimal growth conditions. For the 80 cm-long specimen of L. pertusa a remaining contamination of metal-oxides is observed for the middle and basal part of the coral skeleton, inhibiting similar accurate age and growth rate estimates. However, the youngest branch was free of Mn enrichment and this 15 cm section reveals a growth rate of 8 mm yr−1 (~1 polyp every two to three years). However, the 210Pb growth rate estimate is within the lowermost ranges of previous growth rate estimates and may thus reflect that the coral was not developing at optimal growth conditions. Overall, 210Pb-226Ra dating can be successfully applied to determine the age and growth rate of framework-forming cold-water corals, however, removal of post-depositional Mn-Fe oxide deposits is a prerequisite. If successful, large branching M. oculata and L. pertusa coral skeletons provide unique oceanographic archive for studies of intermediate water environmentals with an up to annual time resolution and spanning over many decades.

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