Continuous cultivation of microorganisms in large open tanks in sunlight

Abstract

An open, continuous system for culturing Chaetoceros sp. microalgae includes a large outdoor container and full strength sunlight as a light source. The container is preferably a fiberglass tank having an open top, a diameter of approximately 18 inches, and a height of about 5 feet. The container holds a culture medium having the following characteristics: a carbon dioxide controlled pH of about 8.2, a starting nitrogen concentration of at least 3.0 mg N/liter, a starting phosphorous concentration of at least 2.75 mg P/liter, a starting vitamin B12 concentration of at least 5 micrograms/liter, a starting iron chloride concentration of at least 0.3 mg/liter, a starting copper sulfate concentration of at least 0.01 mg/liter, a starting silicate concentration of at least 10 mg SiO2/liter, and a Na2EDTA concentration of 5 mg/liter. The medium is inoculated with a seed stock of Chaetoceros sp. microalgae and exposed direct sunlight. A portion of the cultured microalgae, preferably in the 90% range, is harvested each day and replaced with new culture media. As sterile conditions are not required, seawater may be used as the replacing culture media.

Dependencies are inferred from the claim text.