scholarly journals Structure of the phytoplankton community in the Cachoeira Dourada reservoir (GO/MG), Brazil

2011 ◽  
Vol 71 (3) ◽  
pp. 587-600 ◽  
Author(s):  
M. Teixeira de Oliveira ◽  
O. Rocha ◽  
AC. Peret
Keyword(s):  
Phytoplankton Community ◽  
Driving Forces ◽  
Climatic Factors ◽  
Euphotic Zone ◽  
Taxonomic Composition ◽  
Nitrogen And Phosphorus ◽  
Physical And Chemical Variables ◽  
Algal Assemblages ◽  
Physical And Chemical

The limnological features and the phytoplankton community of the Cachoeira Dourada reservoir were analyzed in December 2006, May 2007 and November 2007. Temporal changes in the taxonomic composition, density, diversity and dominance of species were analyzed in relation to climatic factors and the physical and chemical characteristics of the water. A positive correlation was found between some of the physical and chemical variables and the phytoplankton community. According to the CCA, variables such as the extent of the euphotic zone, temperature, pH, nitrogen and phosphorus concentrations directly affected the phytoplankton dynamics. Organisms belonging to the class Cyanophyceae were the most representative in all the sampling periods, comprising the functional groups K, S1, M and H. Hydrodynamics and seasonal fluctuations of environmental factors were the driving forces determining the composition and abundance of the algal assemblages. Despite the prevalence of Cyanobacteria, the reservoir is still oligotrophic. The absence of blooms and the relatively low population abundances indicated that the quality of the reservoir's water still lies within the limits required for its multiples uses.

scholarly journals Seasonal dynamics of cyanobacteria in a eutrophic reservoir (Arcoverde) in a semi-arid region of Brazil

2012 ◽  
Vol 72 (3) ◽  
pp. 533-544 ◽  
Author(s):  
MC. Bittencourt-Oliveira ◽  
SN. Dias ◽  
AN. Moura ◽  
MK. Cordeiro-Araújo ◽  
EW. Dantas
Keyword(s):  
Phytoplankton Community ◽  
Climatic Factors ◽  
Principal Component ◽  
Taxonomic Composition ◽  
Dry Season ◽  
Northeastern Brazil ◽  
Cylindrospermopsis Raciborskii ◽  
Physical And Chemical Variables ◽  
Semi Arid Region ◽  
Cyanobacterial Biomass

Environmental conditions favor the predominance of dense populations of cyanobacteria in reservoirs in northeastern Brazil. The aim of this study was to understand cyanobacterial population dynamics in the rainy and dry seasons at two depths in the Arcoverde reservoir. Microalgae and cyanobacteria samples were collected during 24 hours with intervals of 4 hours (nycthemeral) at sub-surface and 10 m using a van Dorn bottle and a determined biomass. Physical and chemical variables were obtained and the data were analyzed using the principal component analysis (PCA). No nycthemeral variations in the taxonomic composition or distribution of the populations of cyanobacteria were found between the different times of day in either the rainy or dry season. In both seasons, the greatest biomass of the phytoplankton community was made up of cyanobacteria at two depths and all times of the day. Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju was dominant at all times of the day on both the surface and at the bottom. In the rainy season, the differences in cyanobacterial biomass between the surface and bottom were less significant than in the dry season. The differences in cyanobacterial biomass between surface and bottom were less pronounced than those found in the dry season. We concluded that a) physical variables better explain the alterations of species in the phytoplankton community in an environment dominated by cyanobacteria throughout the year; b) seasonal climatic factors associated to periods of stratification and de-stratification are important for alterations in the community and variations in biomass and, c) the turbidity caused by rainfall favored the emergence and establishment of other cyanobacteria, especially Planktothrix agardhii (Gomont) Anagnostidis & Komárek.

scholarly journals Phytoplankton abundance, dominance and coexistence in an eutrophic reservoir in the state of Pernambuco, Northeast Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1313-1326 ◽  
Author(s):  
Giulliari A. S. T. Lira ◽  
Elcida L. Araújo ◽  
Maria Do Carmo Bittencourt-Oliveira ◽  
Ariadne N. Moura
Keyword(s):  
Rainy Season ◽  
Phytoplankton Community ◽  
Dry Season ◽  
Cylindrospermopsis Raciborskii ◽  
Phytoplankton Abundance ◽  
Vertical Variation ◽  
Total Phytoplankton ◽  
Physical And Chemical Variables ◽  
Different Depths ◽  
Physical And Chemical

The present study reports the phytoplankton abundance, dominance and co-existence relationships in the eutrophic Carpina reservoir, Pernambuco, Brazil. Sampling was carried out at six different depths bimonthly at a single reservoir spanning two climatic periods: dry season (January, September, and November 2006) and rainy season (March, May, and July 2006). Density, abundance, dominance, specific diversity and equitability of the community were determined, along with chlorophyll a, and physical and chemical variables of the environment. Eight species were considered abundant, and their densities corresponded to more than 90% of the total phytoplankton community quantified. Cyanobacteria represented more than 80% of this density. Cylindrospermopsis raciborskii was the only dominant taxon in the dry season, and was co-dominant in the rainy season. C. raciborskii, Planktothrix agardhii and Geitlerinema amphibium had the greatest densities and lowest vertical variation coefficients. The statistical analysis indicated relationships with vertical and seasonal variations in the phytoplankton community and the following variables: total dissolved solids, water temperature, electrical conductivity and pH. The changes in the environmental variables were discrete and regulated by the establishment of precipitation however, they were able to promote vertical and seasonal instability in the structure of the phytoplankton community.

scholarly journals Environmental quality evaluation of lakes in the Rio Grande do Sul coastal plain

2007 ◽  
Vol 50 (4) ◽  
pp. 673-685 ◽  
Author(s):  
Catarina da Silva Pedrozo ◽  
Odete Rocha
Keyword(s):  
Environmental Quality ◽  
Sewage Treatment ◽  
Principal Component ◽  
Organic Pollution ◽  
Physical And Chemical Variables ◽  
Environmental Element ◽  
Different Characteristics ◽  
Physical And Chemical ◽  
The Town

The purpose of the present work was to evaluate the environmental quality of Marcelino, Pinguela, Peixoto, Palmital, Malvas and Do Passo lakes, interconnected by canals and located in the district of Osório, RS. In this context, 29 physical and chemical variables were analyzed with sampling carried out in January, May, July and October 1997 to verify the environmental quality of the system and the existence of a gradient of quality. Canonical Analysis was applied to the data of all environmental variables measured, and showed that the lakes had different characteristics as a consequence of the organic pollution received. Marcelino lake received continuous input of organic matter from the sewage treatment works in the town of Osório, whereas Peixoto, Pinguela, Palmital, Malvas and Do Passo lakes resembled other water bodies described in the region, not showing, so far, signs of degradation caused by the input of effluents. Principal Component Analysis selected environmental element were directly linked to organic pollution, that reflected sequential non-recent effects of contamination.

scholarly journals Heterogeneity and Anthropogenic Impacts on a Small Lowland Stream

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2002
Author(s):  
Somlyai ◽  
Berta ◽  
Nagy ◽  
Dévai ◽  
Ács ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Human Impacts ◽  
Anthropogenic Impacts ◽  
Anthropogenic Effects ◽  
Nitrogen And Phosphorus ◽  
Buffer Zones ◽  
Small Surface ◽  
Great Heterogeneity ◽  
Physical And Chemical Variables ◽  
Physical And Chemical

During our work, we investigated the physical and chemical variables of a small surface watercourse to investigate how different anthropogenic effects affect its water quality. Along this small watercourse, there are well-separated areas that are affected by various anthropogenic effects. In addition to its origin and branches, in many places it is surrounded by agricultural land with insufficient buffer zones, which burdens the small watercourse with nitrogen and phosphorus forms. In the lower stages, artificial damming inhibits the natural flow of the Tócó Canal, thereby creating eutrophicated stagnant water areas. This is further strengthened by, in many cases, illegal communal and used water intake that further burdens the small watercourse. Considering the experience of our investigation, it can be stated that the examined small watercourse could barely suffer human impacts, and it could be described with great heterogeneity using physical and chemical variables. We experienced that this heterogeneity caused by anthropogenic effects appeared in all hydrologic states and seasons. Furthermore, our research showed that these small watercourses had such high heterogeneity that their monitoring and examination should be taken just as seriously as when it comes to larger watercourses.

Six Sigma Methodology in Increasing Spirulina Production

Minerva ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 23-28
Author(s):  
Daniel Freire ◽  
Omar Flor ◽  
Gabriela Alvarez
Keyword(s):  
Six Sigma ◽  
Culture Media ◽  
Arthrospira Platensis ◽  
Lean Six Sigma ◽  
Growth Monitoring ◽  
Current State ◽  
Physical And Chemical Variables ◽  
Six Sigma Methodology ◽  
Physical And Chemical

This work presents results of improvement in the productivity of Arthrospira platensis (spirulina) in a company dedicated to its production. The six sigma methodology was applied in production processes that require the use of bioreactors. Starting from the analysis of the current state, aspects, physical and chemical variables that directly influence the productivity achieved were identified. Various culture media were tested and subsequently scaled for industrial production. In addition, the incorporation of carbon into the culture medium was controlled, optimizing the range of potential hydrogen pH. The identified parameters were measured and six sigma methodology strategies were assigned. An improvement in productivity corresponding to 66% was verified with the same quality of final product. Keywords: Six sigma, Bioreactors, Productivity, Arthrospira platensis. References [1]E. Ariawan and A. Makalew, “Smart Micro Farm: Sustainable Algae Spirulina Growth Monitoring System” in 10th International Conference on Information Technology and Electrical Engineering (ICITEE), Bali, 2018, pp.1-4. [2]L. Socconini and C. Reato, Lean six sigma: sistema de gestión para liderar empresas. Primera edición. Barcelona: Marge Books, 2019. [3]H. Gutiérrez, Calidad and productividad. Cuarta edición. México D.F.: McGraw-Hill Interamericana, 2014. [4]G. Usharani, P. Saranraj and D. Kanchana, “Spirulina Cultivation: A Review” in International Journal of Pharmaceutical & Biological Archives, vol. 3, no. 6, pp. 1327-1336, December 2012. [5]J. Udin, O. Gani, A. Mahato, I. Sakib and M. Rakiuzzaman, SPIRULINA (Spirulina platensis) PRODUCTION IN DIFFERENT PHOTOBIOREACTORS ON ROOFTOP, International Journal of Business, Social and Scientific Research, vol. 8, no. 1, pp. 15-19, January 2020. [6]M. Arredondo, Contabilidad y análisis de costos. Primera edición. México D.F.: Grupo Editorial Patria, 2015. [7]J. García, Contabilidad de costos. Cuarta edición. México D.F.: McGraw-Hill Interamericana, 2014. [8]L. Socconini, Certificación Lean Six Sigma Green Belt para la excelencia en los negocios. Primera edición. Barcelona: Marge Books, 2015. [9]A. Vian, Introducción a la Química Industrial. Segunda edición. Buenos Aires: Reverté, 2012. [10]S. Milton, Estadística para Biología y Ciencias de la Salud. Tercera edición. Madrid: McGraw-Hill Interamericana, 2014.

Effects of Environmental Variables on Growth Rates and Physiological Characteristics of Lake Superior Phytoplankton

1986 ◽  
Vol 43 (6) ◽  
pp. 1163-1170 ◽  
Author(s):  
C. Nalewajko ◽  
D. Voltolina
Keyword(s):  
Growth Rates ◽  
Lake Superior ◽  
Taxonomic Composition ◽  
Stepwise Multiple Regression ◽  
Regression Analyses ◽  
Lower Growth ◽  
Physical And Chemical Variables ◽  
Lower Light ◽  
Physical And Chemical ◽  
Isothermal Mixing

Phytoplankton taxonomic composition and biovolume, assimilation numbers [Formula: see text], phosphorus kinetics, as well as some physical and chemical variables were measured on 37 occasions during six cruises on Lake Superior during May 1980 – October 1981. A larger number of significant differences were detected between thermally stratified and isothermal stations than between inshore and offshore, or among seasons. Phytoplankton from isothermal waters was characterized by lower assimilation numbers and biovolume, showed symptoms of adaptation to a lower light regime and was less phosphorus deficient than populations from thermally stratified waters. The lower growth rates and the outcome of stepwise multiple regression analyses suggest that phytoplankton growth during isothermal mixing is limited primarily by light.

scholarly journals Production and quality of mini watermelon cv. Smile irrigated with saline water

2016 ◽  
Vol 20 (10) ◽  
pp. 897-902 ◽  
Author(s):  
Alan B. O. de Sousa ◽  
Sérgio N. Duarte ◽  
Osvaldo N. de Sousa Neto ◽  
Ana C. M. Souza ◽  
Pedro R. F. Sampaio ◽  
...  
Keyword(s):  
Experimental Design ◽  
Salt Tolerance ◽  
Dry Matter ◽  
Saline Water ◽  
Chemical Characteristics ◽  
Physical And Chemical Variables ◽  
Number Of Leaves ◽  
Physical And Chemical ◽  
Number Of Branches

ABSTRACT The purpose of this study was to evaluate the salt tolerance of mini watermelon (cv. Smile). The experiment was carried out in the greenhouse of the Department of Biosystems Engineering of ESALQ/USP. The experimental design was randomized blocks. The plants were irrigated with five levels of salinity (S1 = 1.0; S2 = 2.0; S3 = 3.0; S4 = 4.0 and S5 = 5.0 dS m-1). At 85 days after the beginning of the experiment, the plants and the physical and chemical variables of the fruit were evaluated. Salinity negatively affected the variables: length of the main stem, stem diameter, number of leaves, number of branches, leaf area, fresh and dry matter. Regarding the physical and chemical characteristics of fruits, salinity reduced the mass, diameter and the pH of the fruit, but increased its vitamin C content. In general, the results suggest that the mini watermelon (cv. Smile) is moderately sensitive to salinity.

scholarly journals Impact of agro-ecological conditions on protein synthesis in hexaploid wheat - spelt (Triticum spelta)

2016 ◽  
Vol 32 (1) ◽  
pp. 91-100
Author(s):  
Jela Ikanovic ◽  
Vera Popovic ◽  
Snezana Jankovic ◽  
Gordana Drazic ◽  
Slobodanka Pavlovic ◽  
...  
Keyword(s):  
Hexaploid Wheat ◽  
Nutritional Value ◽  
Climatic Factors ◽  
Wheat Bread ◽  
Bakery Products ◽  
Triticum Spelta ◽  
Chemical Indicators ◽  
Technological Quality ◽  
Physical And Chemical

Technological quality of wheat is defined by physical and chemical indicators of quality and its baking properties. To make wheat a commodity, there are certain requirements to be met, defined by minimum values of trade quality indicators. As hexaploid wheat, spelt (Triticum spelta L.) belongs to a group of alternative cereal grains high in gluten, and its flour is therefore used for making most pastries. Due to its high nutritional value, spelt flour is used to enhance the quality or flavour of wheat bread and other bakery products. Two-year research was conducted during 2011 and 2012 to investigate protein content in crops grown on the Eutric Cambisol soil type. The research was conducted on two spelt cultivars: Hungarian Ek? 10 and Serbian NS Nirvana. The results showed that NS Nirvana averaged a statistically significantly higher proteins content (16.76%) than Hungarian cultivar Ek? 10 (15.65%). Climatic factors, temperatures, the intensity of light and duration of seed filling had an impact on the investigated parameter.

scholarly journals Phytoplankton community in the last undammed stretch of the Paraná River: considerations on the distance from the dam

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Susicley Jati ◽  
Jascieli Carla Bortolini ◽  
Geovani Arnhold Moresco ◽  
Aline Caroline Magro de Paula ◽  
Luzia Cleide Rodrigues ◽  
...  
Keyword(s):  
Phytoplankton Community ◽  
Longitudinal Axis ◽  
Main Channel ◽  
Paraná River ◽  
Temporal And Spatial Distribution ◽  
Parana River ◽  
Physical And Chemical Variables ◽  
Temporal And Spatial ◽  
Species Richness And Abundance ◽  
Physical And Chemical

Abstract Aim: To evaluate the influence of upstream reservoirs on the temporal and spatial variation of the phytoplankton community in the Paraná River channel and the importance of its main tributaries in reducing the oligotrophication process along this stretch of the river. Materials and Methods Sampling of phytoplankton and physical and chemical variables was performed quarterly between August 2013 and May 2015, in the Paraná River main channel and in the mouth of the main tributaries, at the stretch located between downstream Porto Primavera reservoir and the backwaters of Itaipu reservoir. To summarize the variation of phytoplankton density in relation to the main physical and chemical variables, we performed a Redundancy Analysis (RDA). Results A total of 214 taxa were identified throughout the study. We registered low values of phytoplankton species richness and abundance, which showed no patterns of temporal and spatial distribution, both for the Paraná River and the tributaries. However, RDA results showed spatial segregation among samples from the Paraná River main channel, such that the stretch located closer to the dam was associated with higher values of water transparency and Cyanobacteria density, exported by upstream reservoirs, whereas the middle and lower stretches were associated with higher phytoplankton complexity and higher nutrient concentration and turbidity. Conclusion Through the analysis of the phytoplankton community we could verify a reduction in the effects of oligotrophication along the longitudinal axis of the Paraná River and the important role of the tributaries in diminishing this effect.

scholarly journals Acidity level control formulation of roselle tea functional drinks based on variations in the addition of flower petals and sugar type

Food Research ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 772-779 ◽  
Author(s):  
I.S.M. Purbowati ◽  
Karseno Karseno ◽  
A. Maksum
Keyword(s):  
Cane Sugar ◽  
Level Control ◽  
Two Factors ◽  
Physical And Chemical Variables ◽  
Ph Level ◽  
Functional Drink ◽  
Physical And Chemical ◽  
Acidity Level ◽  
Low Glycemic Index

Roselle (Hibiscus sabdariffa) tea was a phenolic acid and anthocyanin enriched-functional drink. The high antioxidant content of roselle tea benefits to prevent degenerative diseases, such as diabetes. The acidity flavor was due to the high content of phenolic compounds and anthocyanins. This led to the addition of low glycemic index sugar. Therefore, it is necessary to understand the formulation between the variation of flower petals and sugar type’s addition. The purpose of this study was to find out the best effect of petal flowers and sugar type addition towards physical, chemical and sensory quality of roselle tea. The research design used in this study was Complete Randomized trial with 2 (two) factors and 3 replications. The first factor comprises between flower petals addition (R) towards water (w/v) of 1:100 (R1), 4:100 (R2), 7:100 (R3), and 10:100 (R4). The second factor was sugar type (G): cane sugar (G1) which comprises coconut sugar (G2) and corn sugar (G3). Observed variables in this study were physical and chemical variables (color, total phenol, anthocyanin and pH level), and sensory variable (acidity and favorable level). The best combination was R4G1 with characteristics of anthocyanins of 5.25 mg/100 mL; phenol of 24.35 mg/100 mL; pH of 2.6; L amounted to 24.70

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