RiL

V.A. SERI/NREL/DOE REPORTS AND PUBLICATIONS V.B. ADDITIONAL REFERENCES V.C. PATENTS

Laboratory Studies collection and screening. In addition to performing actual research in this area, SERI personnel were responsible for coordinating the efforts of the many subcontractors performing similar activities, and for standardizing certain procedures and analyses. These efforts ultimately resulted in the development of the SERI Microalgal Culture

Coilie(rtio}3,\W^fcaî^alIïaxoerMycdescSjbedri9 cftMteMës :

For the purposes of this report, microalgae are defined as microscopic organisms that can grow via photosynthesis. Many microalgae grow quite rapidly, and are considerably more productive than land plants and macroalgae (seaweed). Microalgae reproduction occurs primarily by vegetative (asexual) cell division, although sexual Tepreducewenao wi nn ^epsspfmicn^atp RroMîtriatSifpeowjpirigoîriiyicfflis.p igment composition, biochemical constituents, ultrastructure, and life cycle. Five groups were of primary importance to the ASP: diatoms (Class Bacillariophyceae), green algae (Class Chlorophyceae), golden-brown algae (Class Chrysophyceae), prymnesiophytes (Class Prymnesiophyceae), and the eustigmatophytes (Class Eustigmatophyceae). The blue-green algae, or cyanobacteria (Class Cyanophyceae), were also represented known. This group tends to dominate the phytoplankton of the oceans, but is commonly found in fresh-and brackish-water habitats as well. The cells are golden-brown because of the presence of high levels of fucoxanthin, a photosynthetic accessory pigment. Several other xanthophylls are present at lower levels, as well as p-carotene, chlorophyll a and chlorophyll c. The main storage compounds of diatoms are lipids (TAGs) and a p-1,3-linked carbohydrate known as chrysolaminarin. A distinguishing feature of diatoms is the presence of a cell wall that contains substantial quantities of polymerized Si. This has implications for media costs in a commercial production facility, because silicate is a relatively expensive chemical. On the other hand, Si deficiency is known to promote storage lipid accumulation in diatoms, and thus could provide a controllable means to induce lipid synthesis in a two-stage production process. Another characteristic of diatoms that distinguishes them from most other algal groups is that they are diploid (having two copies of each chromosome) during vegetative growth; most algae are haploid (with one copy of each chromosome) except for brief periods when the cells are reproducing sexually. The main ramification of this from a strain development perspective is that it

Was this article helpful?

0 0

Post a comment