Field Determination of the Critical Nutrient Concentrations for Cladophora in Streams

1976 ◽  
Vol 33 (1) ◽  
pp. 85-92 ◽  
Author(s):  
S. L. Wong ◽  
B. Clark

Many streams in southern Ontario experience excessive seasonal growth of aquatic plants such as Cladophora and Potamogeton. A direct relation, with a regression coefficient of 0.87, was observed between ambient P concentration in the water and P content of plant tissue in six rivers. Critical or growth controlling total P concentration of 60 μg/liter in stream water and 1.6 mg/gram dry weight in plant tissue were determined. Unlike P, no significant correlation was observed between N content of plant tissue and N concentration in water. The correlation of total P with plant growth can be used to estimate the waste load which would result in maximum growth rate of Cladophora.


1980 ◽  
Vol 58 (14) ◽  
pp. 1601-1606 ◽  
Author(s):  
P. E. Pope

Inoculation of Platanus occidentalis seedlings with Glomus fasciculatus significantly increased plant dry weight and foliar phosphorus (P) concentration when compared with the uninoculated control. After 12 weeks inoculated seedlings were 73% taller and 200% greater in total dry weight. The largest dry weight increase was recorded for foliage (212%) followed in order by stem (202%) and root (171%). Averaged overall nutrient treatments, foliar P concentration was 22% greater for the inoculated seedlings. Nutrient regimes representing 1×, 2×, and 4× Hoagland's No. 2 solution and a control significantly influenced seedling height, dry weight, percentage of foliar N, P, and K, and the degree of root colonization. Maximum growth and foliar nutrient concentrations were associated with the 2× Hoagland's nutrient regime followed in order by the 4× and 1× nutrient treatments and the control. Degree of root colonization by G. fasciculatus increased from 42% of the root length in the unfertilized control to 48% at the 1× Hoagland's regime and sharply declined at the 2× and 4× levels. Total dry weight of inoculated seedlings was significantly greater than the noninoculated control at each nutrient level. Incremental differences were 2.71, 4.03, 4.37, and 3.08 g for the control, 1×, 2×, and 4× Hoagland's nutrient regimes, respectively. Seedling growth attributed to G. fasciculatus is directly related to degree of mycorrhizal colonization and inversely related to the amount of extractable soil P.



1973 ◽  
Vol 30 (12) ◽  
pp. 1825-1830 ◽  
Author(s):  
P. R. Walne

Estimates were made of the increase in live and dry weights and in the content of ash, organic matter, carbohydrate (as glucose), and nitrogen when juveniles of the clam Saxidomus giganteus were fed for 21 days at various concentrations of Tetraselmis chui, Isochrysis galbana, and Phaeodactylum tricornutum. The condition index (organic weight as a percent of total dry weight) increased in all the experimental conditions with a mixture of I. galbana and T. chui, yielding a significantly higher index than either species on its own. The relative gain in glucose was greater than the increase in live weight or in nitrogen. The increase in live weight was such that the nigrogen content was approximately constant at 6–7 μgN/mg live weight irrespective of the feeding conditions. The N:glucose ratio decreased with increasing concentrations of I. galbana and P. tricornutum, and at the higher concentrations, where the maximum growth rate of clams occurred, the ratios were lower than in any of the clams fed on T. chui.



2009 ◽  
Vol 75 (9) ◽  
pp. 2784-2791 ◽  
Author(s):  
Jean-Paul Meijnen ◽  
Johannes H. de Winde ◽  
Harald J. Ruijssenaars

ABSTRACT The oxidative d-xylose catabolic pathway of Caulobacter crescentus, encoded by the xylXABCD operon, was expressed in the gram-negative bacterium Pseudomonas putida S12. This engineered transformant strain was able to grow on d-xylose as a sole carbon source with a biomass yield of 53% (based on g [dry weight] g d-xylose−1) and a maximum growth rate of 0.21 h−1. Remarkably, most of the genes of the xylXABCD operon appeared to be dispensable for growth on d-xylose. Only the xylD gene, encoding d-xylonate dehydratase, proved to be essential for establishing an oxidative d-xylose catabolic pathway in P. putida S12. The growth performance on d-xylose was, however, greatly improved by coexpression of xylXA, encoding 2-keto-3-deoxy-d-xylonate dehydratase and α-ketoglutaric semialdehyde dehydrogenase, respectively. The endogenous periplasmic glucose dehydrogenase (Gcd) of P. putida S12 was found to play a key role in efficient oxidative d-xylose utilization. Gcd activity not only contributes to d-xylose oxidation but also prevents the intracellular accumulation of toxic catabolic intermediates which delays or even eliminates growth on d-xylose.



Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2233 ◽  
Author(s):  
Tomasz Bochenski ◽  
Tanmay Chaturvedi ◽  
Mette Hedegaard Thomsen ◽  
Jens Ejbye Schmidt

Implementing microalgae biorefinery in arid environments requires utilization of strains that can grow at high temperatures (above 28 °C) and salinity levels (above 30 ppt). In this study, we investigate the newly isolated seawater strain, Synechococcus, native to the United Arab Emirates, and evaluate its value as a perspective organism for cultivation (for fuel and bio-products) in regions with freshwater scarcity. The strain displayed tolerance to a wide range of temperature (22–37 °C) and salinity (20–41 ppt), with maximum biomass concentration of 0.72 g L−1 and a maximum growth rate of 82 mg L−1 d−1 at 25 °C and 33 ppt salinity. Lipids accumulation reached up to 26% of dry weight in nitrogen-depleted conditions (with 1.8 mM of nitrates addition to the media), whereas protein content exceeded 50% dry weight. In this study, harvesting is investigated using three chemical agents: Ferric chloride, sodium hydroxide, and chitosan. Cell disruption is analyzed for four distinct treatments: Enzymatic, alkaline, ultrasonic, and hydrothermal. Among tested methods, flocculation with sodium hydroxide and ultrasonication were found to be the most efficient techniques for harvesting and cell disruption, respectively. The growth characteristics of the local strain and the potential to derive protein and lipids from it makes it a promising biomass in a biorefinery context.



2010 ◽  
Vol 160-162 ◽  
pp. 171-175 ◽  
Author(s):  
Jing Dong ◽  
Jia Ying Xin ◽  
Ying Xin Zhang ◽  
Lin Lin Chen ◽  
Hong Ye Liang ◽  
...  

Methane-utilizing mixed culture HD6T was successfully cultivated in a brief non-sterile process using methanol as a sole carbon and energy source for the production of poly-β-hydroxybutyrate(PHB). Shake-flask experiments showed HD6T could grow well in the mineral salt medium with the addition of methanol exposed to the air directly. This non-sterile process and the use of cheap substrates (methanol) can reduce the production costs of PHB. It was found that HD6T grew better and PHB production in a more effective way with an initial liquid methanol concentration of 0.15%(v/v).The lag phase duration, the maximum growth rate, the biomass concentration and the PHB yield, for the optimal conditions were, respectively, 12.03h, 0.04h-1(OD600), 1.54g/l(dry weight), 0.424g/l(dry weight). Methane-utilizing mixed culture HD6T appears to be a promising organism for PHB production.



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



Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1003
Author(s):  
Chonthicha Pakwan ◽  
Arunothai Jampeetong ◽  
Hans Brix

This study aimed to assess effect of nitrogen (N) form and phosphorus (P) level on the growth and mineral composition of hybrid Napier grass. Experimental plants were grown with different N forms (NO3−, NH4NO3, and NH4+; 500 µM) and P concentrations (100 and 500 µM) under greenhouse conditions for 42 days. Growth rate, morphology, pigments, and mineral nutrients in the plant tissue were analysed. At the low P concentration, the better growth was found in the plants supplied with NH4+ (relative growth rate (RGR) = 0.05 g·g−1·d−1), but at the high P concentration, the NH4+-fed plants had 37% lower growth rates and shorter roots and stems. At the high P level, the NH4NO3−-fed plants had the highest RGR (0.04 g·g−1·d−1). The mineral nutrient concentrations in the plant tissues were only slightly affected by N form and P concentration, although the P concentrations in the plant tissue of the NO3−-fed plants supplied with the high P concentration was 26% higher compared to the low P concentration plants. The N concentrations in the plant tissues did not vary between treatments. The results showed that the optimum N form for the plant growth and biomass productivity of hybrid Napier grass depends on P level. Hybrid Napier grass may be irrigated by treated wastewater containing high concentrations of N and P, but future studies are needed to evaluate biomass production and composition when irrigating with real wastewater from animal farms.



Author(s):  
Kristian Spilling ◽  
Jukka Seppälä ◽  
Dagmar Schwenk ◽  
Heiko Rischer ◽  
Timo Tamminen

AbstractThere is a growing demand for marine omega-3 fatty acids (FAs) that is produced in high amounts by some microalgae. Here we determined the FA profiles of two cold water adapted diatoms, Chaetoceros wighamii and Thalassiosira baltica. The cultures were acclimated to different temperatures (3, 7, 11, 15, and 19 °C) and irradiance (20, 40, 130, and 450 μmol photons m−2 s−1) and the FA profiles were determined in exponential and stationary growth phases, the latter induced by different nutrient limitation (N, P, and Si). The maximum growth rate was obtained by both species at 11 °C, ≥ 130 μmol photons m−2 s−1 and was 0.8 day−1 and 0.6 day−1 for C. wighamii and T. baltica, respectively. Both species contained relatively high amounts of eicosapentaenoic acid (EPA). Thalassiosira baltica accumulated maximally ~ 30 mg EPA g−1 ash-free dry weight (AFDW) under Si-limitation. The content of docosahexaenoic acid (DHA) was lower, reaching up to 4 mg DHA g−1 AFDW in T. baltica. The concentration of EPA correlated positively with the chlorophyll a:carbon ratio, suggesting that it is bound to membranes in the photosynthetic apparatus and the EPA content in T. baltica was high enough to consider it as a potent candidate for cultivation under cold (< 15 °C) conditions. Covering a wide range of environmental conditions, the strongest differentiation in FA profiles was observed between the species with the growth phase/nutrient limitation pattern as the second most important driver of the FA composition.



2020 ◽  
Author(s):  
Shuang He ◽  
Fayong Li ◽  
XINQIANG LIANG ◽  
Hua Li ◽  
Sheng Wang ◽  
...  

Abstract Background: Rice paddy wetlands may serve as a nutrient source or sink in agricultural ecosystems. However, the pattern of nutrient loss on a watershed scale is not clear. A year-round on-site observation study based on 6-h intervals was conducted. Rainfall, temperature, runoff nutrient concentrations, and adjacent stream water samples were automatically monitored to uncover the temporal changes in the runoff losses of the predominant nutrient proxies (total N and total P) from a typical rice-planting area (120 ha) in the Yangtze delta region of China. Results: A high total N concentration in the rice-planting area was observed during the rice-planting season; however, significant fluctuation in the total P was evident throughout the year. The Δtotal N (drainage minus stream) parameter showed negative values with a mean of −0.25 mg L -1 , while Δtotal P showed positive values with a mean of 0.06 mg L −1 . The annual average N and P runoff from paddy field were 11.6 kg ha −1 and 1.5 kg ha −1 , respectively. The window phases for the total N loss were mainly concentrated in the rice-growing season. However, the window phase for the total P loss was more dispersive throughout the year. No apparent relationships were found between rainfall and N and P concentrations by self-organizing map analysis. Conclusions: The high-resolution monitoring, in this study, suggested that nutrient loss loading rather than nutrient concentration, was strongly related to surface runoff Therefore, fertilization before high-intensity rainfall should be avoided to mitigate the nutrient runoff losses and maintain the rice wetland eco-function.



Author(s):  
KS Nawrin ◽  
MJ Uddin ◽  
AHMZ Ali ◽  
MK Rahman

The effects of boron (B) and vermicompost (VC) on growth and yield of Chilli (Capsicum annum L.) and nutrient accumulation in its fruits was examined. The highest plant height (22 cm), leaf number per plant (73), leaf area (502.53 cm2/plant), dry weight (22.27g/plant), fruit length (8.97cm), fruit number per plant (6), fruit yield (11.76 g/plant) were recorded in B0.5 kg/ha + VC5 ton/ha at harvest. The results of growth and yield of Chilli varied significantly (p<0.05) and increased with time. The total nutrient concentrations in the fruits were measured and varied significantly (p<0.05). The highest concentration of total P (0.028 %), K (2.50%), S (0.20 %), Cu (8.0 mg/kg), Fe (410 mg/kg) and Mn (0.80 mg/kg) in the fruit were observed in B0.5 kg/ha +VC5 ton/ha treatment and total N (0.41 %) and Zn (3.50 mg/kg) were found in B1.5 kg/ha + VC5 ton/ha treatment. The overall best growth, yield and nutrient accumulation in the fruits of Chilli was achieved in B0.5 kg/ha + VC5 t/ha treatment. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(1): 31-36



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