Found this link from a suggestion at the popular Oil from Algae Yahoo group. This was suggested by a group member David Miller, thanks David!
"
The Effects of Light Intensity on the Growth Rates of Green Algae.
1,2,3, Constantine Sorokin4 and Robert W. Krauss
DEPARTMENT OF BOTANY, UNIVERSITY OF MARYLAND, COLLEGE PARK, MARYLAND
see the full paper @ http://tinyurl.com/g9td4, PDF version: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=541035&blobtype=pdf
David's comments:
"It graphs out the relationship between growth rate of various species with light intensity. One species in particular was very dependent on temperature, and could tolerate and use much more light at 39 degrees C vs 25...
In a nutshell then, each species had some minimum light level required
to keep them alive but not growing at all, and growth seemed
proportional to light intensity from there for "a ways' before it
leveled off and began to decline. They found species with optimal
light intensities ranging from 2.5% (chlorella vulgaris) to 14% of
full sunlight. They expressed it as 250 to 1400 ftcandles and
wikipedia lists full sun as 10000 fc."
This is quite a useful paper, folks
See also in the same forum, a related comment by Abhishek Narain (thanks Narain), to a different question though:
"
The growth profile of algae shows a proportional increase with increase in light intensity. However after a certain light intensity, the growth profile shows declination with further increase in light intensity. This value of light intensity from where the declination starts is termed to cause the phenomena of LIGHT INHIBITION, such that the growth of algae decreases due to damage in light pigments at high intensity.
What this value of light intensity shoul be, is a function of the photobioreactor design, and in particular the arrangement and kind of light source. Ideally, one should aim to avoid a light source which has large amount of that wavelength of light spectra, which are not unsed in photosynthesis, typically the Violet region and the Red region. These wavelength merely are a waste of energy. However, if source of light is the light from sun, then you save money by not wasting aftificial sources of energy.
There are a lot of photobioreactor design available in literature, but none that is good for large scale production with efficient distribution of light and carbon-dioxide and with a compact geometry.
Hope that helps.
Regards
Narain
"
Another research paper citation on "Effects of Light Intensity", this time posted by Tom Catino, thanks Tom!
"Effects of light intensity, CO2 and nitrogen supply on lipid class
composition of Dunaliella viridis
Journal Journal of Applied Phycology
Publisher Springer Netherlands
ISSN 0921-8971 (Print) 1573-5176 (Online)
Subject Biomedical and Life Sciences
Issue Volume 10, Number 2 / April, 1998
DOI 10.1023/A:100806702 2973
Pages 135-144
Online Date Monday, November 29, 2004
Add to marked items
Add to saved items
Recommend this article
Effects of light intensity, CO2 and nitrogen supply on lipid class
composition of Dunaliella viridis
Francisco J. L. Gordillo1, Madeleine Goutx2, Felix L. Figueroa1 and
F. Xavier Niell1
(1) Departamento de Ecologia. Facultad de Ciencias, Universidad de
Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain
(2) Microbiologie Marine (CNRS, U.P.R. 223), Campus de Luminy, CASE
907, 13288 Marseille cedex 9, France
Abstract Lipid class composition of Dunaliella viridis Teodoresco
was analysed using thin layer chromatography coupled with flame
ionisation detection (TLC/FID technique). D. viridis was cultured
under four different photon fluence rates and in darkness, and under
two different conditions of CO2 supply (atmospheric and 1%) with and
without nitrogen sufficiency. Nine lipid classes were identified and
quantified. Total lipids per cell and acetone-mobile polar lipids
decreased with light, while the percentage of sterols and
triglycerides increased with increasing irradiance. Total
phospholipids increase was related with growth rate while
hydrocarbons, wax esters and sterol esters accumulated in darkness.
There were almost no changes in total lipids per cell because of
nitrogen limitation; however, nitrogen limitation led to higher
changes in lipid class composition under 1% CO2 than under
atmospheric CO2 levels. The main reserve lipid, triglycerides,
accumulated in high amounts under 1% CO2 and nitrogen limitation,
increasing from 1% to 22% of total lipids. The ratio sterols/acetone-
mobile polar lipids could be an index of the 'light status'
independently of nitrogen limitation, while the ratio
triglycerides/ total phospholipids could indicate any physiological
stress uncoupling C and N metabolism and affecting the growth rate.
Light - CO2 - nitrogen - lipids - thin layer chromatography - flame
ionisation - microalga - batch culture - Dunaliella viridis
This revised version was published online in June 2006 with
corrections to the Cover Date.
http://www.springerlink.com/content/t271hk066q243u54/
"
Some more links were quoted by Tom Catino & Bobby Yates Emory (Thanks Bobby)
"
That seemed like a lot of reading so I restricted it to lipids:
http://159.189.176.5/portal/server.pt?
in_hi_space=NBIISearchAS&in_hi_control=NBIISearchControl&in_hi_result
s=true&in_cb_source=-2&in_cb_source=201&in_tx_ query=algae+ LIPID&in_ su_b1=Search#
or:
http://tinyurl.com/qjqb9
and quickly found a twenty year old article that said they were
encountering naturally growing algae in a temperate climate that
were 1/3 oil:
http://159.189.176.141/xml/CSA/231/8903215.html
Maybe someone needs to take a vacation trip to Normandy Lake and
start a cultivation program like Patrick.
(I only looked at the first 15 - there are 53 total.)
database search turned up 7000+ hits for "algae" search...
http://tinyurl. com/g388o
"
Cheers
Ec
Oilgae - Oil & Biodiesel from Algae
Oilgae Blog
algOS - Biodiesel from Algae Open Source
Oilgae - Oil & Biodiesel from Algae provides links, provides directory and web links resources for the algae-based biofuels & biodiesel. It is intended to be useful for research, information, inputs, news for buyers, sellers, manufacturers, traders, suppliers, producers, exporters and importers of algal oil and algal fuels. It will make an effort to provide info on biofuel feedstock, algal feedstocks, algae oil info and link, details on fuel from algae, bio-fuel, bio-diesel, bio-fuels, algal oils production and uses, and biofuels trade & market resources, data, statistics such as price, prices, demand-supply for buyer, seller, manufacturer, trader, supplier, exporter and producer
No comments:
Post a Comment