Studies on Scenedesmus acutus growth. I effect of autotrophic and mixotrophic conditions on the growth of Scenedesmus acutus.
Among sugars, glucose and mannose were found to be the most suitable substrates for mixotrophic growth, uptake of galactose and its influence on growth was negligible, and sucrose and fructose occupied intermediary positions. The optimum temperature for sugar uptake was 30 degrees C, both under light and in darkness. Enhancement in the photosynthetic oxygen-evolution rate, based on the utilization of substrates, was foremost in the presence of glucose, followed by mannose, sucrose, and fructose. Industrial by-products such as sugarcane molasses also were utilized to increase the algal growth under mixotrophic conditions. A maximum yield in biomass was obtained subsequent to the combined supply of sugarcane molasses with carbon dioxide to indoor as well as outdoor mixotrophic cultures. Doubling the carbon dioxide supply alone above a certain level, under autotrophic and mixotrophic outdoor conditions, did not produce a pronounced increase in the algal growth rate. The results on autotrophic and mixotrophic growth variations are discussed in the article.
Institut für Chemischtechnische Analyse and Chemische Lebensmitteltechnologie der Technischen Universität Müchen, 8050 Freising-Weihenstephan, West Germany.
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Shamala
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Drawert
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Leupold