Table II.A.4. Strains in the Arizona State University collection with the highest apparent lipid productivity during exponential growth, based on Nile Red staining

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

National Renewable Energy Laboratory

Table II.A.4. Strains in the Arizona State University collection with the highest

apparent lipid productivity during exponential growth, based on Nile Red staining.

Strain

Genus

Class

Triolein

equivalents

(mg.L-1.day--1)

AMPHO27

Amphora

Bacillariophyceae

345

CHLOC4

Eremosphaera/Chlorococcum

Chlorophyceae

117

SYNEC5

Synechococcus

Cyanophyceae

AMPHO46

Amphora

Bacillariophyceae

SYNEC4

Synechococcus

Cyanophyceae

AMPHO45

Amphora

Bacillariophyceae

NITZS55

Nitzschia

Bacillariophyceae

OOCYS9

Oocystis

Chlorophyceae

NITZS52

Nitzschia

Bacillariophyceae

SERI researchers also started to evaluate various strains by the rapid screening procedure. Initial

work focused on 25 partially characterized strains. These strains were analyzed for growth and

Nile Red fluorescence in exponentially growing cultures and in cultures grown under N-deficient

conditions for 4 days. The results of the SERI and Sommerfeld laboratories cannot be compared

directly, because Nile Red units are expressed differently and the time duration of N deficiency

was not the same. The best strains of the 25 tested (based on the highest Nile Red fluorescence

normalized to ash-free dry weight (AFDW) and rapid exponential growth) were determined to be

CHAET9 (muelleri), NAVIC2 (Navicula saprophila), and NITZS12 (Nitzschia pusilla).

Twenty-eight strains of Chaetoceros were also examined using this screening protocol. The best

strains indentified were CHAET21, CHAET22, CHAET23, and CHAET25 (all muelleri). All

but the latter strain were isolated from various regions of the Great Salt Lake in Utah.

The departure of Dr. Bill Barclay and Dr. Jeff Johansen from the ASP, along with a greater

emphasis on genetic improvement of strains, marked the end of the in-house collection and

screening work. As a consequence, many of the 3,000 strains collected by ASP researchers during

the course of this research effort were never analyzed via this rapid screening protocol.

Nonetheless, enough strains had been analyzed at SERI and at the laboratories of various

subcontractors to obtain a substantial number of promising strains. The next step was to

determine their ability to grow in actual outdoor mass culture ponds. This work is described in

Section III.

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