Sunday, June 9, 2019 admin Comments(0)

Algal Culturing Techniques presents a comprehensive reference and guidebook covering all aspects of the isolation and cultivation of marine and freshwater. Algal Culturing Techniques is a comprehensive reference on all aspects of the isolation and cultivation of marine and freshwater algae, including seaweeds. The development of efficient culture systems is necessary for algal mass . techniques borrowed from microbiology are available for obtaining unialgal isolates.

Language:English, Spanish, Portuguese
Published (Last):20.09.2015
ePub File Size:17.36 MB
PDF File Size:8.33 MB
Distribution:Free* [*Sign up for free]
Uploaded by: CHUN

CONTRIBUTORS. VII. PREFACE. IX. 1. Historical Review of Algal. Culturing Techniques. 1. Hans R. Preisig. Robert A. Andersen. 2. Freshwater Culture Media. download Algal Culturing Techniques - 1st Edition. Print Book & E-Book. Unavailable. Price includes VAT/GST. DRM-free (EPub, PDF, Mobi). × DRM-Free. Traditional Microalgae PREFACE IX Isolation Techniques 83 Robert A. Andersen 1. Historical Review of Algal Masanobu Kawachi Culturing Techniques 1 7.

John Berges J. At least some of the Andersen, Robert A. ISBN: The book begins with a review of algal culturing history Chapter 1. The review dates the pioneer work of algal culturing back to

Copper may indeed be toxic, particularly to more primitive algae, and hence copper, if added to culture media at all, should be kept at low concentrations. The provision of manganese, zinc and cobalt in culture medium should not be problematical since even fairly high concentrations are not thought to be toxic to algae. It is recommended that these vitamins are routinely added to seawater media.

No other vitamins have ever been demonstrated to be required by any photosynthetic microalgae. Soil extract has historically been an important component of culture media. The solution provides macronutrients, micronutrients, vitamins, and trace metal chelators in undefined quantities, each batch being different, and hence having unpredictable effects on microalgae.

With increasing understanding of the importance of various constituents of culture media, soil extract is less frequently used. Soil extract should only be used on a non-experimental basis.

Buffers The control of pH in culture media is important since certain algae grow only within narrowly defined pH ranges, and in order to prevent the formation of precipitates.

Except under unusual conditions, the pH of natural seawater is around 8. Because of the large buffering capacity of natural seawater due to a bicarbonate buffering system, HCO3 being present at c. The buffer system is overwhelmed only during autoclaving, when high temperatures drive CO2 out of solution and hence cause a shift in the bicarbonate buffer system and an increase in pH, or in very dense cultures of microalgae, when enough CO2 is taken up to produce a similar effect.

As culture medium cools after autoclaving, CO2 reenters solution from the atmosphere, but certain measures must be taken if normal pH is not fully restored: The pH of seawater may be lowered prior to autoclaving adjustment to pH Certain media recipes include additions of extra buffer, either as bicarbonate, Tris Tris-hydroxymethyl-aminomethane , or glycylglycine to supplement the natural buffering system.

Tris may also act as a Cu buffer, but has occasionally been cited for its toxic properties to microalgae. Glycylglycine is rapidly metabolized by bacteria and hence can only be used with axenic cultures.

Algal Culturing Techniques

These additions are generally not necessary if media are filter sterilized, unless very high cell densities are expected. The problem of CO2 depletion in dense cultures may be reduced by having a large surface area of media exposed to the atmosphere relative to the volume of the culture, or by bubbling with either air CO2 concentration c.

Unless there is a large amount of biomass taking up the CO2, the higher concentrations could actually cause a significant decline in pH. When bubbling is employed, the gas must first pass through an in line 0. Millipore Millex GS to maintain sterile conditions. For many microalgal species, aeration is not an option since the physical disturbance may inhibit growth or kill cells.

Always use reagant grade chemicals and bidistilled or purer water to make stock solutions of enrichments. When preparing a stock solution containing a mixture of compounds, dissolve each individually in a minimal volume of water before mixing, then combine and dilute to volume.

Algal Culturing Techniques

Seawater, stock solutions of enrichments and the final media must be sterile in order to prevent or more realistically minimize biological contamination of unialgal cultures. Several methods are available for sterilization: autoclaving is the most widely used technique for sterilizing culture media, and is the ultimate guarantee of sterility including the destruction of viruses.

A commercial autoclave is best, but pressure cookers of various sizes are also suitable. Ensure the heating elements are covered with distilled water, and the escape valve should not be closed until a steady stream of steam is observed.

Autoclaving is a process which has many effects on seawater and its constituents, potentially altering or destroying inhibitory organic compounds, as well as beneficial organic molecules. Algal species for which viruses have been isolat- e. As an ed are listed and the types and life history of viruses important part of dinoflagellate life history, conditions are also described.

Yet it is often necessary Several other chapters are a nice addition to the to maintain one of a few to hundreds of cultures.

This theme of algal culturing. Chapter 19 deals with cul- book includes two chapters 10, 11 about methods to tures for studying physiological ecology of microalgae, maintain long-term cultures for microalgae and macro- and covers batch as well as continuous cultures for use alge. Matrices of the media as well as growth conditions in studying physiological effects of nutrients and light. Chapter 21 describes endogenous rhythms in macro- The chapters also demonstrate that a well-organized algae and daylength effects on algal development.

Although contamination is an large-scale algal cultures are introduced in Chapters 13 important issue for all cultures, it is especially critical for through The topics range from growing algae in the effort to maintain long-term cultures.

Another way indoor controlled culturing facility photobioreactor to minimize contamination is to cryopreserve the cul- and fermentor , to growing them in outdoor ponds, tures, which is also a way to preserve genetic identity of and to culturing seaweeds in aquaculture facilities. Bio- the culture. In Chapter 12, detailed account is given to logical principles, technical challenges and operational the facilities, cooling and thawing rates, storage temper- instructions are detailed.

All the informa- means of protecting threatened algal species. Although tion suggests that this may not be a technique accessible the list of recognized endangered species is still limited, for every laboratory, but the technical information pre- the analysis on potential growth of the red list and the sented in the chapter will be useful to those who would suggestion of culturing as a means to protect theses like to embark on this area when long term mainte- species is enlightening.

The 55 algal medium recipes and 7 test medium Phytoplankton cell counting is as essential as cultur- recipes in the Appendix are handy references. The ing the algae, and obtaining accurate cell counts can be number of recipes with form and concentration of nu- a challenge. Two chapters in this book 16, 17 are trients varying widely e. In Chapter 16, details are given for methods of ly for a beginner. However, as indicated in some of the sampling and preservation, statistical analysis on num- chapters e.

Chapter 6 , it is advisable to begin with ber of cells to count, choice of counting device, mani- low nutrient concentrations if the nutrient require- pulations and cleaning of the device, filling of the ment of the species to isolate is unknown. The test samples, settling cells and counting, and calculation medium recipe is helpful for detecting bacterium and of cell concentrations.

Algal culturing techniques / edited by Robert A. Andersen - Details - Trove

Chapter 17 illustrates how flow yeast contaminants. I highly recommend this book lineages.

In the case of high-density algal culture, the addition of carbon dioxide allows to correct for increased pH, which may reach limiting values of up to pH 9 during algal growth. The latter is of primary importance as the air contains the carbon source for photosynthesis in the form of carbon dioxide. For very dense cultures, the CO2 originating from the air containing 0. Depending on the scale of the culture system, mixing is achieved by stirring daily by hand test tubes, erlenmeyers , aerating bags, tanks , or using paddle wheels and jetpumps ponds.

However, it should be noted that not all algal species can tolerate vigorous mixing. If necessary, algal cultures can be cooled by a flow of cold water over the surface of the culture vessel or by controlling the air temperature with refrigerated air - conditioning units. Salinity Marine phytoplankton are extremely tolerant to changes in salinity.

Pdf techniques algal culturing

Most species grow best at a salinity that is slightly lower than that of their native habitat, which is obtained by diluting sea water with tap water. Salinities of g. Growth dynamics The growth of an axenic culture of micro-algae is characterized by five phases Fig.

Techniques pdf culturing algal

Cultures inoculated with exponentially growing algae have short lag phases, which can seriously reduce the time required for upscaling. The lag in growth is attributed to the physiological adaptation of the cell metabolism to growth, such as the increase of the levels of enzymes and metabolites involved in cell division and carbon fixation.

Figure 2. Five growth phases of micro-algae cultures. The specific growth rate is mainly dependent on algal species, light intensity and temperature.

Culturing pdf algal techniques

Cell density decreases rapidly and the culture eventually collapses. In practice, culture crashes can be caused by a variety of reasons, including the depletion of a nutrient, oxygen deficiency, overheating, pH disturbance, or contamination.