Don’t Run-Off – De-oiled, Solvent-free Algae as a Sustainable Biofertilizer
R. Connelly, R. Pearsall, M. Montoya, B. Morrison, K. Kaden, K. Murphy, L. Eisenberg, M. Werst, R. Hebner
University of Texas at Austin, Center for Electromechanics, Austin, TX
OpenAlgae LLC, Austin, TX
Significance of the Study Methods Results
Processed Algae Biomass Nutritional Analysis
Today, the Haber–Bosch synthetic fertilizer process
consumes more than one percent of the energy on Nutrient Content of Processed Algal Biomass
Earth and is responsible for feeding roughly one- The OpenAlgae Mobile Algae Processing (MAP) unit %
third of the world’s population. Over time, however, N (nitrogen) 8.8
aggressive fertilizer practices have become P (phosphorus) 5.1
K (potassium) 5.1
unsustainable and have led to a number of Oil Recovery Concentration Lysing
Ca (calcium) 0.2
environmental problems and ironically, diminished
Mg (magnesium) 0.2
Na (sodium) 0.1
N:P:K ratio (9:5:5)
The use of algae as a sustainable biofertilizer is
The nutritional content of processed algae is similar to chemical fertilizers.
particularly appealing for many reasons. Large The N:P:K ratio was determined to be (9:5:5), and also contained trace
scale growth of algae is accelerating and the elements necessary for plant growth.
University of Texas/OpenAlgae has developed cost-
effective technologies to recover algal oils for Comparison of AB and CF on Tomato Yield and Height
Source Harvesting Lysing Oil Separations Clean Biomass 50 50
independent sale, then use the de-oiled, solvent- open or closed pH floccualtion electric field membrane dried Algae
free biomass as a clean and sustainable biofertilizer. 40 40
UT conducted a pilot study to evaluate the effects
Number of Fruits
Height in Inches
The algae were concentrated via a pH-driven flocculation process, then lysed
of processed de-oiled algae on the promotion of via exposure to an electric field of ~9 kV/cm to liberate algal lipids. The lipids 30
were recovered with the OpenAlgae membrane technology without direct
plant growth and yield. The results showed that contact with solvents. The de-oiled processed biomass was then dried to a 20 20
the heights and yield of the biomass-conditioned powder consistency and analyzed for nitrogen (N), phosphorus (P), potassium
(K), and protein content.
plants were consistent with, or improved, over 10 10
plants conditioned with a commercial fertilizer 0 0
applied at the same concentration. These data Processed Algal Biofertilizer (AB) Greenhouse Study
There was no significant difference between algae- and commercial fertilizer-
indicate that de-oiled algal biomass processed treated plants.
using OpenAlgae technologies can be used as an
organic alternative to commercial fertilizers. Comparison of AB and CF on Basil Yield and Height
Weight in Grams
Height in Inches
Using OpenAlgae clean processing technologies, de 20 20
-oiled, solvent-free algal biomass can serve as a
sustainable biofertilizer. 10 10
Plants conditioned with algal biofertilizer (AB) will There was no significant difference between algae- and commercial fertilizer-
produce yields comparable to plants conditioned treated plants on plant height, but algae caused significantly more yield
(*p < 0.05).
with a commercially available chemical fertilizer.
Comparison of AB and CF on Lettuce Yield and Height
Tomatoes Basil Lettuce 350 350
Weight in Grams
Height in Inches
Freshwater algae , including Chlorella sp. and
Scenedesmus sp. were processed using the 30 30
OpenAlgae Mobile Algae Processing (MAP) unit 20 20
(Figure 1), then dried to a powder.
Commercial Processed Commercial Processed Commercial Processed 10 10
Fertilizer Algal Fertilizer Algal Fertilizer Algal
Biomass Biomass Biomass
The dried algae were analyzed for N:P:K and other 0
for nutrient content by Texas A & M AgriLife There was no significant difference between algae- and commercial fertilizer-
Services. treated plants
The soil used in this study was a commercial topsoil with no added nutrients.
The analyzed dried algae (9:5:5) was applied as a
In this triplicate greenhouse trial, the effect of AB on tomato, basil, and leaf
lettuce growth and yield compared to controls supplemented with the same
biofertilizer (12.5 kg/acre) to potted vegetables amount of commercial fertilizer. Plant height and yields (fruits or leaf
production) were recorded over the course of 8 weeks. At the conclusion of The heights and yields promoted by algae were
and herbs. The heights and yields of the algal the study, the bare root plants were weighed.
comparable to, or exceeded, those produced by the
biomass-conditioned plants were monitored and
commercial chemical fertilizer.
compared to plants conditioned with a
commercial fertilizer applied at the same
De-oiled, solvent-free algal biomass can be utilized
as a biofertilizer.
THE UNIVERSITY OFTEXAS AT AUSTIN