Algal Mass Culture Research Articles

On the mass culture of microalgae: Areal density as an important factor for achieving maximal productivity

Scenedesmus obliquus was grown in a bioreactor under constant light and at a temperature of 24°C. From measurements of biomass production, it was possible to determine the influence of areal density on productivity in open as well as closed cultures. Maximal productivity occurred at an areal density of 40 to 45 g(dw) M −2, which was in good agreement with predicted values from a model. The optimal areal density for maximal productivity was influenced by factors such as culture depth, algal species, turbulence, available light, etc., and hence the establishment and maintenance of an optimal areal density is seen as one of the most important operational procedures for the mass culture of algae. Supersaturated concentrations of oxygen resulted in lower productivities due to photorespiration and/or oxidation.

Potential enhancement of photosynthetic energy conversion in algal mass culture

Actual laboratory data obtained from steady-state Dunaliella tertiolecta cultures grown under a wide range of photon flux densities were used in a simple model to calculate daily production in a conventional algal mass culture system. In spite of large physiological and biochemical variations between low-light- (LL) and high light- (HL) adapted cultures, the overall calculated daily productivity is almost identical for both strains grown at optimal conditions. When production of fine biochemicals is considered, however, a hypothetical HL strain, which cannot shade adapt, is advantageous. Based on biochemical and biophysical analysis of D. tertiolecta responses to growth irradiance levels, specific targets are defined for genetic manipulation to enhance productivity in algal mass culture systems. The targets identified are (1) amplification of the carboxylation enzyme ribulose-1,5-bisphosphate carboxylase-oxygenase relative to the electron transport complexes, which should increase photosynthetic capacity at light saturation, and (2) enlargement of the light-harvesting complexes by varying their pigment composition in order to increase light harvesting at low photon flux densities.

An inexpensive inorganic medium for the mass cultivation of freshwater microalgae

A new and inexpensive inorganic medium (‘DS medium’) for the mass cultivation of freshwater blue-green algae (Cyanobacteria) and green algae has been developed. It consists basically of distilled or demineralized water (90%) and seawater (10%) and requires only little addition of pure purchasable chemicals (phosphate, trace elements, if necessary nitrate). No addition of macronutrients (NaCl, MgCl 2 or MgSO 4, KCl or K 2SO 4, CaCl 2) and of boron is required because they are sufficiently provided by the seawater. Decalcified water may also be suitable instead of demineralized water. For the cultivation of green algae, a higher trace element concentration is recommended than for blue-green algae. Because of its low total salt concentration the DS medium is freshwater-like. It is easy to prepare and effects rapid algal growth. It may be of special value for algal mass culture in regions which are close to the sea.

The influence of nitrogen and phosphorus on algal growth and quality in outdoor mass algal cultures

An adequate supply of nitrogen and phosphorus is imperative to ensure high production rates in mass microalgal cultures. High yield coefficients, low crude protein contents and low productivities were measured at low supplies of these nutrients. The highest production rates were measured at N and P concentrations exceeding 25 and 2 mg litre −1 respectively, at which supply the highest crude protein contents were measured. Although the carbohydrate content followed, under certain N supply conditions, an inverse relationship with the crude protein content, it was generally not affected by changes in N and P concentrations. Scenedesmus-Chlorella types had higher crude protein contents than Monoraphidium, but the latter displayed the highest productivity. A nitrogen supply ratio of NO 3N:NH 3N = 3:1, gave the highest production rates. Nitrogen losses of up to 69% of the supply concentrations were measured under certain conditions.

Laboratory studies on the suitability of a fertilizer–tap water medium for mass culture of algae

Biotechnology and BioengineeringVolume 27, Issue 11 p. 1572-1576 Communications to the EditorFree Access Laboratory studies on the suitability of a fertilizer–tap water medium for mass culture of algae D. J. Geldenhuys, D. J. Geldenhuys Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this authorR. D. Walmsley, R. D. Walmsley Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this authorD. F. Toerien, D. F. Toerien Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this author D. J. Geldenhuys, D. J. Geldenhuys Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this authorR. D. Walmsley, R. D. Walmsley Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this authorD. F. Toerien, D. F. Toerien Institute for Environmental Sciences, University of the Orange Free State, P.O. Box 339, Bloemfontein 9300, South AfricaSearch for more papers by this author First published: November 1985 https://doi.org/10.1002/bit.260271108Citations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume27, Issue11November 1985Pages 1572-1576 ReferencesRelatedInformation

DIMENSIONING OF A MASS ALGAL CULTURE FACILITY FOR THE TEMPERATE ZONE NURSERY CULTURE OF BIVALVE MOLLUSCS

ABSTRACTAquacultural Research Corporation (ARC) has operated a continuous mass algal culture facility for the nursery culture of the hard clam (Mercenaria mercenaria) for twenty years. Procedures have been developed for the mass culture of selected species of microalgae that are of proven nutritional value for rearing bivalve spat. Within the past three years a 60% increase in algal yield has been achieved by selection of small centric diatoms for mass culture and by empirical determination of optimum depths and seasonal dilution rates for the light limited 40 m3 continuous cultures. Cell densities of the diatoms Thalassiosira pseudonana (3H) and Skeletonema sp. have averaged over 109 cells/liter from March through November. The algal pond surface area necessary to support a hypothetical nursery with a monthly average clam biomass of 8 kg dry meat weight (ca 13 × lo6 clam seed) was calculated for latitude 41°N during the four seasons of the year. These calculations were based on 1982–1983 algal yields and an assumed food chain efficiency of 10%. The required minimum algal pond surface area ranged from 192 m2 in summer to 750 m2 in winter. The current ARC nursery operation is compared with this hypothetical model. Costs of nursery seed production and a proposed strategy for minimizing the seasonal algal areal requirements of a temperate zone bivalve nursery are discussed.

Control of a unicellular blue-green alga, Synechocystis sp., in mass algal culture

Algal species succession in high-rate pond cultures receiving swine waste was studied for a period of 6 years. Seasonal patterns of succession were consistent on a yearly basis and were not strongly affected by waste loading or pre-treatment. The unicellular, blue-green alga, Synechocystis sp., was found to have a competitive advantage over other algal species during summer and fall seasons under unmixed or intermittently mixed conditions. Continuous flow-mixing at 20–30 cm/s was effective in suppressing this alga. The removal mechanism was bioflocculation and eventual sedimentation.

Mass algal culture in outdoor plastic‐covered minipond systems

SUMMARYA comparative study was undertaken to evaluate the performance of algal cultures grown in plastic‐covered outdoor minipond systems. It was demonstrated that production in enclosed miniponds was higher than in open ones on account of the stimulatory effects of elevated temperatures which developed in the enclosed systems. Although the plastic covering reduced the amount of light which was available for photosynthesis, this had minimal effects on production due to the light saturation characteristics of the algal cells. The practice of enclosing mass algal cultures with transparent plastic appears to show promise in semi‐arid regions not only as a procedure to reduce evaporation, but also as one for increasing algal yields.

A model to predict water temperature in plastic-covered outdoor mass algal culture systems

The design, construction and operation of a 100 m 2 rectangular plastic-covered culture system for green algae ( chlorella, scenedesmus) is described. A simple simulation model which predicts water temperature with an accuracy acceptable for estimating algal growth rate has been developed. Although simulated and measured observations showed significant statistical agreement, the model tends to underestimate daily maximum temperature and overestimate daily minimum temperature. The model can be readily adapated for usage in other parts of the world.

Zooplankton control in mass algal cultures

Infestations of rotifers ( Brachionus rubens) and cladocerans ( Diaphanosoma brachyurum) in a 0.1-ha high-rate algal pond were eliminated by temporarily raising the un-ionized (free) ammonia concentration to approximately 20 mg/l (as N) by addition of ammonium hydroxide solution. The 24-h LD 100 for Brachionus was found to be 17 mg/l free ammonia-N and that for Diaphanosoma just under 20 mg/l. Ammonium hydroxide treatments did not inhibit microalgal populations but rather promoted rapid recovery of algal densities to pre-infestation levels. Manipulation of free ammonia concentrations provides an economical and effective means of zooplankton control in mass algal cultures.

Monthly deposition of cadmium in rural and industrial areas of Germany (Bayern, Pfalz, Ruhr district) and its influences upon an agricultural model system

Monthly depositions of cadmium were collected by a modified Bergerhoff method and measured by AAS during a 3-year period in rural areas of the Pfalz and in an industrial area of the Ruhr district. Another one year period included measurements in rural areas of southern Bavaria and on a Dutch island. The log-normally distributed deposition rates of cadmium at the rural areas in southern Germany amounted to only 20% of those of the industrial district. The depositions on the Dutch island were twice as high as the depositions on the rural areas of southern Germany. The monthly cadmium deposition rates show only little periodical fluctuation during the year and scatter around more or less constant median values of 25 and 120 μg · m −2 · month −1 at the rural and industrial areas, respectively. When open air mass cultures of algae were taken as an agricultural model, the organisms, depending on their growth rate, accumulated 0.4–4.0 ppm of cadmium (dry matter based). The course of the cadmium accumulation reflects the deposition rate of the area where the algae were grown. No growth depression of the algae due to cadmium can be observed under the given deposition rates.

Water Pollution – Phycological Perspectives

AbstractWater pollution exerts a pressure of selection on algal populations. In spite of a possible adaptation, often a changed diversity and sociological structure result, from which other effects on higher levels of the nutrient chain may emanate. There are represented some biological indices for characterizing algal communities which may serve as a biological measure of pollution and selfpurification, the problem of diversity being especially taken into account. Moreover, algal tests are used for representing the trophic situation and for determining the limiting nutrient, but also for determining the toxic influencing of biocenosis by hydrocarbons, too. Special attention is paid to heavy metals with regard to their synergistic action and bioaccumulation. On the other hand, the mass culture of algae is a valuable method of wastewater treatment and the recovery of valuable materials, and algae ponds provide an important technique for advanced wastewater purification.

Theory of the Upper Limit to Phytoplankton Production per Unit Area in Natural Waters

AbstractUsing the maximum quantum yield of photosynthesis, the maximum daily integral of photosynthetically active radiation (PAR) and the euphotic zone depth as a basis, general formulae for the upper limits to gross and net carbon fixation in natural waters are derived by theoretical considerations. The results are compared with a set of extremely high production data published by independently working authors, including data from algal mass cultures, oxidation ponds, freshwater and salt lakes, reservoirs, rivers and canals, coastal and other marine waters, including upwelling areas. The comparison reveals a quite surprising degree of agreement and suggests that the derived formulae represent a new, theoretically sound general approach to phytoplankton production. In particular, it can be shown that the upper limit to phytoplankton production in natural waters is about three times higher than earlier estimates in the literature. The maximum energy efficiency is of the same order of magnitude as in terrestrial plant communities.

Research into the Mass Culture of Algae in Closed Systems

Research into the Mass Culture of Algae in Closed Systems

Application of a nutrient-saturated growth model to phytoplankton management in freshwater prawn ( Macrobrachium rosenbergii) ponds in Hawaii

With significant modification in only two of nine parameter values, a model of nutrient-saturated growth of Chlorella was found to give an excellent description of experimental data collected from six large experimental tanks and one earthern production pond. The results indicate that in order to maintain system stability with respect to oxygen fluctuations, primary production rates in other commercial ponds are usually kept well below levels that could be attained under optimal conditions. Application of the model to field data shows that phytoplankton populations in prawn ponds should be kept between 150 and 400 mg·m −3 Chl a in order to prevent anoxia in worst case situations such as calm nights. Due to a negative correlation between light-limited growth rates and Chl a concentrations, there is little increase in photosynthesis if Chl a concentrations are raised above 2 g·m −3, and there is a negative correlation between photosynthesis and Chl a concentrations for Chl a > 5 g·m −3. Therefore even under ideal conditions 1-m deep ponds should probably be operated with Chl a concentrations < 2 g·m −3. The success of the light-limited model in describing data from both monospecific continuous culture systems and from diverse populations in prawn ponds suggests that the model may have wide applicability in algal mass culture systems.

Outdoor algal mass cultures—I. Applications

Algal mass culturing research has been carried out in many parts of the world for past 30 yr. Whereas early efforts were directed towards single-celled protein production for human consumption, many new applications have evolved including wastewater treatment, water renovation, nutrient recycling, production of chemicals, aquaculture and bioconversion of solar energy. Photosynthetic yields over 30g dry wt m −2day −1 have been attained on occasion in many locations for short periods and yields between 15 and 25 g dry wt m −2 day −1 for longer periods are now common. It appears that bioconversion of solar energy with algal cultures is not attractive because of the tremendous quantities of land, water and nutrients required. Similarly, single-celled protein from microalgae is beset with numerous problems associated with nutritional quality, toxicology and economics. The main attractiveness of algal mass cultures is that they have great versatility to be integrated into multi-use systems for simultaneously solving several environmental problems. Their use probably will be limited to small specific applications and not on the massive scale projected in the past.

Growth and competition of the marine diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. II. Light limitation

The marine diatoms Phaeodactylum tricornutum (Bohlin) and Thalassiosira pseudonana (Hasle and Heimdal) were grown under both continous illumination and a 14 h light: 10 h dark cycle at light intensities ranging from 1.53×10-4 to 2.95×10-1 ly min-1. Under both photoperiods, T. pseudonana exhibited higher division rates than P. tricornutum at high light intensities, but the reverse was true at all light intensities <3×10-3 ly min-1. Comparison of these results with available data on light-limited growth of other planktonic algae suggests that P. tricornutum may be unusually efficient at maintaining its cell division rate at low light intensity. This efficiency may contribute substantially to its success in turbid, nutrient-enriched mass algal culture systems, the only environments in which it is known to attain great numbers.

Solar energy applications in India

The third meeting of the Solar Energy Working Group (India) was held at Indian Institute of Technology (IIT), Kanpur, on 14 and 15 January 1971. Scientists from Indian Institute of Technology, New Delhi; Motilal Nehru Engineering College, Allahabad; and Space Science and Technology Center, Trivandrum, participated for the first time, in addition to others already active in the field. Dr. K. N. Mathur was the chief guest and gave a special address. From reports and papers presented, it seems that more interest is being shown in work on air-conditioning and refrigeration at I.I.T Delhi and Madras, and Motilal Nehru Engineering College, Allahabad. Scientists at IIT Kanpur are concentrating on mass culture of algae, heat transfer studies, and agricultural drying. Defence Research Laboratory, Kanpur, is working on silicon solar cells. Scientists from Space Science and Technology Centre, Trivandrum, presented an interesting paper on ‘Solar simulation—state of the art’ as a part of space research program. The Deputy Director General of Observatories, New Delhi, actively participated in this meeting and gave assurance of having an improved network of solar radiation measurement stations in the country by the new stations which are starting to supply data. It is noteworthy that solar radiation distribution maps of India have now been prepared. The representatives of the Planning Commission (Government of India) outlined the present energy consumption in the country and stressed that in the coming years attempts should be made to use solar energy to partly replace kerosene (an imported commodity), which is a common source of energy in the rural areas of the country. This meeting clearly revealed the growing interest of Indian workers in solar energy and also their attempts to work in more varied fields, such as space applications and the mass culture of algae.

27] Preparation of deuterated proteins and enzymes

This chapter describes the isolation of fully deuterated or isotope hybrid proteins, both from heterotrophic organisms and from algae. The preparation and purification of quantities of algal proteins of course require that large quantities of algae be continuously available. Many techniques have been used for the mass culture of algae. In the method described in the chapter, a 160-liter deep-tank apparatus was used for the production of kilogram quantities of ordinary, fully deuterated, and isotope hybrid algae. Because the heavy water is almost entirely recoverable, the cost of production of deuterated algae is little more than the cost of ordinary algae once the initial investment in apparatus is made. Organisms cultured in 2H2O can also be used as a source of biologically important compounds—such as proteins and enzymes—which are either fully deuterated or which contain both 1H and 2H. In these compounds, the isotopes are distributed in ways that make the compounds particularly suited for physical–chemical investigations.

NATURE AND ROLE OF BACTERIAL CONTAMINANTS IN MASS CULTURES OF THERMOPHILIC CHLORELLA PYRENOIDOSA.

A study was made of bacterial contaminants isolated from an algal mass-culture unit. The study was performed specifically to determine the dependence of the size of bacterial population on algal density and the nature of any association of the contaminants with the algal cell. Growth of the bacterial contaminants on standard medium was also investigated. An estimate was made of the O(2) uptake of the bacterial population under normal operating conditions of the algal massculture system. Viable numbers of bacteria tended to increase with increased algal density. Bacteria were found imbedded in the surface of algal cells when the cultures of algae were characterized by subnormal rates of growth and photosynthetic gas exchange. Bacterial isolates failed to grow in standard medium alone, thus implying a dependency of bacterial growth on material(s) produced by the algae. A slight inhibitory effect on algal growth was noted in the case of two of three of the bacterial isolates. Manometric studies demonstrated that the bacterial population normally found in the algal cultures did not appreciably effect total gas exchange.