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Journal ArticleDOI

Interference by pigment in the estimation of microalgal biomass concentration by optical density.

TL;DR: Optical density is used as a convenient indirect measurement of biomass concentration in microbial cell suspensions using a suitable standard curve to estimate biomass under normal pigment conditions, but inaccuracies can be introduced when the pigment content of the cells changes.
About: This article is published in Journal of Microbiological Methods.The article was published on 2011-05-01. It has received 323 citations till now. The article focuses on the topics: Absorbance.
Citations
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Journal ArticleDOI
TL;DR: The most promising species overall were the freshwater algae Scenedesmus and C. vulgaris and the marine algae C. fusiformis and Nannochloropsis, and the Chlorophyta had the highest growth rates and showed the greatest increase in lipid content in response to nitrogen limitation.
Abstract: Microalgae are a promising alternative source of oil for biodiesel production. Identification of a species with desirable characteristics is a key component towards achieving economic feasibility for the process. This has been compromised by a lack of data allowing effective interspecies comparison. Eleven species of microalgae, selected on the basis of available literature data, were tested for lipid productivity, gravity sedimentation and the suitability of their fatty acid profiles for biodiesel production. The response to nitrogen limitation was species-specific. Lipid yields and productivity were higher at 150 mg L−1 nitrate than at 1,500 mg L−1 for all species tested except Spirulina platensis. The Chlorophyta, particularly Chlorella vulgaris and Scenedesmus, had the highest growth rates and showed the greatest increase in lipid content in response to nitrogen limitation. Cylindrotheca fusiformis, S. platensis, Scenedesmus and Tetraselmis suecica had the fastest settling rates and highest biomass recoveries after 24 h of gravity sedimentation. For most species, the fuel would need to be blended or culture conditions to be optimised to achieve the correct lipid profile in order for microalgal fuel to meet the European standards for biodiesel production (EN 14214). The most promising species overall were the freshwater algae Scenedesmus and C. vulgaris and the marine algae C. fusiformis and Nannochloropsis.

307 citations


Cites background or methods from "Interference by pigment in the esti..."

  • ...Biomass and lipid quantification Biomass was measured by optical density at 750 nm, according to Griffiths et al. (2011)....

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  • ...Culture conditions Microalgae were grown in batch culture in airlift photobioreactors....

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Journal ArticleDOI
TL;DR: The results show that sufficiently high N concentrations are needed to ensure effective P removal from wastewater due to the positive effect of N on the accumulation of P.

265 citations


Cites background from "Interference by pigment in the esti..."

  • ...7H2O, 12.6 mg L 1 NaHCO3, trace metals and vitamins (Guillard and Lorenzen, 1972)....

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Book ChapterDOI
01 Jan 2013
TL;DR: Among the major methods discussed here are: cell counting, measuring growth techniques and biochemical compositions (lipid, carbohydrates and protein), which have general applicability to different laboratories.
Abstract: The purpose of this chapter is to present a summary of techniques for measuring growth and analysing chemical composition of microalgae. There are perhaps as many methods and modifications to these methods as there are active phycologists today. Investigators generally employ their own particular adapted methodology. Here, we have attempted to include in this chapter those methods generally employed by several investigators, as well as having general applicability to different laboratories. Among the major methods discussed here are: cell counting, measuring growth techniques and biochemical compositions (lipid, carbohydrates and protein). The audience for whom this chapter is intended is diverse and includes junior to experienced phycologist and/or non-phycologists.

198 citations

Journal ArticleDOI
TL;DR: The use of cheese whey permeate in mixotrophic microalgae cultures is proposed, showing that pure lactose, the main constituent of WP, can support Scenedesmus growth under heterotrophic culture conditions (absence of light).
Abstract: Microalgae mass cultivation for biodiesel production might very well become the next marketable biofuel The main challenge to overcome however is the development of high efficiency strategies for the large-scale production of oleaginous microalgae at low costs In the present work, the use of cheese whey permeate (WP) in mixotrophic microalgae cultures is proposed Pure lactose, the main constituent of WP (> 80% w/w of the total dissolved solids), can support Scenedesmus growth under heterotrophic culture conditions (absence of light) Substituting 40% (v/v) of the culture medium with WP significantly stimulates Scenedesmus obliquus growth under mixotrophic (μ max = 1083 ± 0030 day − 1 ) and heterotrophic (μ max = 0702 ± 0025 day − 1 ) conditions, compared to photoautotrophic control cultures (μ max = 0267 ± 0083 day − 1 ) As growth occurs in the presence of lactose, a significant reduction of its concentration is observed, while the galactose and glucose concentrations actually increase in the culture medium Culture medium analyses showed complete exhaustion of extracellular nitrogen (nitrate and ammonium), while intracellular lipid analyses showed neutral lipid (NL) accumulation, particularly under conditions of high pH (> 95) Photoautotrophic control cultures accumulated more lipids (per dry weight) than WP-supplemented cultures, an aspect which is discussed in the context of lipid enrichment strategies A fast and simple method for NL cellular content estimation is also described

142 citations

Journal ArticleDOI
TL;DR: The presence of AOM was found to inhibit flocculation for allFlocculation methods resulting in an increase of dosage demand and the dosage required to achieve 85% flocculations increased only 2-fold when Aom was present.

133 citations


Cites methods from "Interference by pigment in the esti..."

  • ...Growth of the microalgae was monitored by measuring the absorbance at 550 nm (Griffiths et al., 2011)....

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References
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Book
01 Jan 1992
TL;DR: The most widely read reference in the water industry, Water Industry Reference as discussed by the authors, is a comprehensive reference tool for water analysis methods that covers all aspects of USEPA-approved water analysis.
Abstract: Set your standards with these standard methods. This is it: the most widely read publication in the water industry, your all-inclusive reference tool. This comprehensive reference covers all aspects of USEPA-approved water analysis methods. More than 400 methods - all detailed step-by-step; 8 vibrant, full-color pages of aquatic algae illustrations; Never-before-seen figures that will help users with toxicity testing and the identification of apparatus used in the methods; Over 300 superbly illustrated figures; A new analytical tool for a number of inorganic nonmetals; Improved coverage of data evaluation, sample preservation, and reagant water; And much more!

78,324 citations

Journal ArticleDOI
TL;DR: In this paper, specific absorption coefficients for individual carotenoids and chlorophylls a and b, as well as the E 1% 1cm values for combined carotensoids, have been (re)estimated using 6 solvents (80 % acetone, chloroform, diethyl ether, dimethyl formamide and methanol) using two different types of spectrophotometer (0.1-0.5 nm and 1-4 nm band pass resolution).

4,156 citations

Journal ArticleDOI
TL;DR: The biotechnology of microalgae has gained considerable importance in recent decades and this group of organisms represents one of the most promising sources for new products and applications.
Abstract: The biotechnology of microalgae has gained considerable importance in recent decades. Applications range from simple biomass production for food and feed to valuable products for ecological applications. For most of these applications, the market is still developing and the biotechnological use of microalgae will extend into new areas. Considering the enormous biodiversity of microalgae and recent developments in genetic engineering, this group of organisms represents one of the most promising sources for new products and applications. With the development of sophisticated culture and screening techniques, microalgal biotechnology can already meet the high demands of both the food and pharmaceutical industries.

1,876 citations

Book
20 Nov 1991
TL;DR: The author explains how the biotechnology and bioprocess engineering profession has changed in the modern era, and some examples of this change can be found in the chapters on Bioreactors for Suspension and Immobilized Cultures.
Abstract: Preface to the Second Edition. Preface to the First Edition. I. INTRODUCTION. 1. What is a Bioprocess Engineer? Introductory Remarks. Biotechnology and Bioprocess Engineering. Biologists and Engineers Differ in Their Approach to Research. The Story of Penicillin: How Biologists and Engineers Work Together. Bioprocesses: Regulatory Constraints. Suggestions for Further Reading. Problems. II. THE BASICS OF BIOLOGY: AN ENGINEER'S PERSPECTIVE. 2. An Overview of Biological Basics. Are All Cells the Same? Cell Construction. Cell Nutrients. Summary. Suggestions for Further Reading. Problems. 3. Enzymes. Introduction. How Enzymes Work. Enzyme Kinetics. Immobilized Enzyme Systems. Large-scale Production of Enzymes. Medical and Industrial Utilization of Enzymes. Summary. Suggestions for Further Reading. Problems. 4. How Cells Work. Introduction. The Central Dogma. DNA Replication: Preserving and Propagating the Cellular Message. Transcription: Sending the Message. Translation: Message to Product. Metabolic Regulation. How the Cell Senses Its Extracellular Environment. Summary. Appendix: Examples of Regulation of Complex Pathways. Suggestions for Further Reading. Problems. 5. Major Metabolic Pathways. Introduction. Bioenergetics. Glucose Metabolism: Glycolysis and the TCA Cycle. Respiration. Control Sites in Aerobic Glucose Metabolism. Metabolism of Nitrogenous Compounds. Nitrogen Fixation. Metabolism of Hydrocarbons. Overview of Biosynthesis. Overview of Anaerobic Metabolism. Overview of Autotrophic Metabolism. Summary. Suggestions for Further Reading. Problems. 6. How Cells Grow. Introduction. Batch Growth. Quantifying Growth Kinetics. How Cells Grow in Continuous Culture. Summary. Suggestions for Further Reading. Problems. 7. Stoichiometry of Microbial Growth and Product Formation. Introduction. Some Other Definitions. Stoichiometric Calculations. Theoretical Predictions of Yield Coefficients. Summary. Suggestions for Further Reading. Problems. 8. How Cellular Information is Altered. Introduction. Evolving Desirable Biochemical Activities through Mutation and Selection. Natural Mechanisms for Gene Transfer and Rearrangement. Genetically Engineering Cells. Genomics. Summary. Suggestions for Further Reading. Problems. III. ENGINEERING PRINCIPLES FOR BIOPROCESSES. 9. Operating Considerations for Bioreactors for Suspension and Immobilized Cultures. Introduction. Choosing the Cultivation Method. Modifying Batch and Continuous Reactors. Immobolized Cell Systems. Solid-state Fermentations. Summary. Suggestions for Further Reading. Problems. 10. Selection, Scale-Up, Operation, and Control of Bioreactors. Introduction. Scale-up and Its Difficulties. Bioreactor Instrumentation and Control. Sterilization of Process Fluids. Summary. Suggestions for Further Reading. Problems. 11. Recovery and Purification of Products. Strategies to Recover and Purify Products. Separation of Insoluble Products. Cell Disruption. Separation of Soluble Products. Finishing Steps for Purification. Integration of Reaction and Separation. Summary. Suggestions for Further Reading. Problems. IV. APPLICATIONS TO NONCONVENTIONAL BIOLOGICAL SYSTEMS. 12. Bioprocess Considerations in Using Animal Cell Cultures. Structure and Biochemistry of Animal Cells. Methods Used for the Cultivation of Animal Cells. Bioreactor Considerations for Animal Cell Culture. Products of Animal Cell Cultures. Summary. Suggestions for Further Reading. Problems. 13. Bioprocess Considerations in Using Plant Cell Cultures. Why Plant Cell Cultures? Plant Cells in Culture Compared to Microbes. Bioreactor Considerations. Economics of Plant Cell Tissue Cultures. Summary. Suggestions for Further Reading. Problems. 14. Utilizing Genetically Engineered Organisms. Introduction. How the Product Influences Process Decisions. Guidelines for Choosing Host-Vector Systems. Process Constraints: Genetic Instability. Considerations in Plasmid Design to Avoid Process Problems. Predicting HostDVector Interactions and Genetic Instability. Regulatory Constraints on Genetic Processes. Metabolic Engineering. Protein Engineering. Summary. Suggestions for Further Reading. Problems. 15. Medical Applications of Bioprocess Engineering. Introduction. Tissue Engineering. Gene Therapy Using Viral Vectors. Bioreactors. Summary. Suggestions for Further Reading. Problems. 16. Mixed Cultures. Introduction. Major Classes of Interactions in Mixed Cultures. Simple Models Describing Mixed-culture Interactions. Mixed Cultures in Nature. Industrial Utilization of Mixed Cultures. Biological Waste Treatment: An Example of the Industrial Utilization of Mixed Cultures. Summary. Suggestions for Further Reading. Problems. 17. Epilogue. Appendix: Traditional Industrial Bioprocesses. Anaerobic Bioprocesses. Aerobic Processes. Suggestions for Further Reading. Index.

1,399 citations

Book
28 Jan 1994
TL;DR: Algal production systems, culture media, and methods (indoors) and applications of algae culture collections are introduced.
Abstract: 1. Introduction 2. Algal production systems 3. Culture media 4. Cultivation methods (indoors) 5. Scaling up 6. Algal grouping 7. Strain selection 8. Growth kinetics 9. Measurement of algal growth 10. Large scale cultivation 11. Yield 12. Chemical composition 13. Nutrition 14. Applications of algae 15. Addresses of algae culture collections.

1,233 citations

Trending Questions (1)
What are the advantages and disadvantages of using a standard curve to determine the concentration of a microalgae sample?

The provided paper does not explicitly mention the advantages and disadvantages of using a standard curve to determine the concentration of a microalgae sample.