Table II.A.1 Growth characteristics of various microalgal strains collected in 1985

Re-Distributed by http://www.tpub.com

National Renewable Energy Laboratory

Temperature-salinity growth contours are provided for these strains in the 1986 ASP Annual

Report (Barclay et al. 1986).

Table II.A.1 Growth characteristics of various microalgal strains collected in 1985

Strain

Maximum

Optimal

Optimal Medium Type

Growth Rate

Temperature

Conductivity

(dependent on temperature

(°C)

(doubling.day-1)

(mmhos.cm-1)

and conductivity used)

AMPHO1

1.7

10-25

Type I, ASW

AMPHO2

2.48

30-35

40-70

Type I, Type II

CHAET14

2.87

25-70

Type II, ASW

CYCLO2

1.63

30-35

10-70

Type I, ASW

MONOR2

2.84

25-30

Type I, II, ASW

NAVIC1

2.77

10-40

Type I, Type II

Experiments were also conducted in an attempt to identify the chemical components of SERI Type

I and Type II media most important for controlling the growth of the various algal strains.

Bicarbonate and divalent cation concentrations were found to be important determinants in

controlling the growth of Boekelovia sp. (BOEKE1) and Monoraphidium (MONOR2). The

growth rate of MONOR2 increased by more than fivefold as the bicarbonate concentration of

Type II/25 medium was increased from 2 to 30 mM, and the growth of BOEKE1 by

approximately 60% over this range. These results make sense, since media enriched in

bicarbonate would have more dissolved carbon available for photosynthesis. An unexpected

finding was that there was a decrease of nearly 50% in the growth rate of BOEKE1 as the divalent

cation concentration increased from 5 mM to 95 mM (in Type I/10 medium containing altered

amounts of calcium and magnesium). The effects of magnesium and calcium concentration on

the growth of MONOR2 were less pronounced. These results indicate that matching the chosen

strain for a particular production site to the type of water available for mass cultivation will be

important.

Lipid content.

The lipid contents of several strains were determined for cultures in exponential growth phase and

for cultures that were N-limited for 7 days or Si-limited for 2 days. In general, nutrient deficiency

led to an increase in the lipid content of the cells, but this was not always the case. The highest

lipid content occurred with NAVIC1, which increased from 22% in exponential phase cells to

49% in Si-deficient cells and to 58% in N-deficient cells. For the green alga MONOR2, the lipid

content increased from 22% in exponentially growing cells to 52% for cells that had been N-

starved for 7 days. CHAET14 also exhibited a large increase in lipid content in response to Si and

N deficiency, increasing from 19% to 39% and 38%, respectively. A more modest increase

A Look Back at the Aquatic Species Program--Technical Review