Process

Increasing algae’s productivity via light regulation

November 7, 2013
AlgaeIndustryMagazine.com

Photomicrograph of cyanobacterial mat from a California salt marsh. (Wayne Lanier/UC Berkeley)

Photomicrograph of cyanobacterial mat from a California salt marsh. (Wayne Lanier/UC Berkeley)

A“proof of concept” experiment described in the upcoming Dec. 2 issue of the journal Current Biology has shown that growing algae in constant light can dramatically boost the amount of valuable compounds that they can produce. The study found that when the biological clocks of cyanobacteria (blue-green algae) were stopped in their daylight setting, the amount of several biomolecules that they were genetically altered to produce increased by as much as 700 percent.

“We have shown that manipulating cyanobacteria’s clock genes can increase its production of commercially valuable biomolecules,” said Carl Johnson, Stevenson Professor of Biological Sciences at Vanderbilt University, who performed the study with collaborators at the J. Craig Venter Institute in Rockville, MD and Waseda University in Tokyo. “In the last 10 years, we have figured out how to stop the circadian clocks in most species of algae and in many higher plants as well, so the technique should have widespread applicability.”

Professor Carl Johnson, of Vanderbilt University

Professor Carl Johnson, of Vanderbilt University

In 2004, Johnson was a member of the team that determined the molecular structure of a circadian clock protein for the first time. Subsequent work mapped the entire clock mechanism in cyanobacteria, which is the simplest bioclock found in nature. The researchers discovered that the clock consisted of three proteins: KaiA, KaiB and KaiC. Detailed knowledge of the clock’s structure allowed them to determine how to switch the clock on and off.

In the current study, the researchers discovered that two components of the clock, KaiA and KaiC, act as switches that turn the cell’s daytime and nighttime genes on and off. They have dubbed this “yin-yang” regulation. When KaiA is up-regulated (produced in larger amounts) and KaiC is down-regulated (produced in smaller amounts), the 95 percent of the cell’s genes that are active during daylight are turned on, and the 5 percent of the cell’s genes that operate during the night are turned off. However, when KaiC is up-regulated and KaiA is down-regulated, then the day genes are turned off and the night genes are turned on.

“As a result, all we have to do to lock the biological clock into its daylight configuration is to genetically up-regulate the expression of KaiA, which is a simple manipulation in the genetically malleable cyanobacteria,” Johnson said.

To see what effects this capability has on the bacteria’s ability to produce commercially important compounds, the researchers inserted a gene for human insulin in some of the cyanobacteria cells, a gene for a fluorescent protein (luciferase) in other cells and a gene for hydrogenase, an enzyme that produces hydrogen gas, in yet others. They found that the cells with the locked clocks produced 200 percent more hydrogenase, 500 percent more insulin and 700 percent more luciferase when grown in constant light than they did when the genes were inserted in cells with normally functioning clocks.

Coauthors of the study include Research Associate Professor Yao Xu, Postdoctoral Fellow Ximing Qin and Graduate Student Jing Xiong from Vanderbilt; Assistant Professor Philip Weyman and Group Leader Qing Xu from the J. Craig Venter Institute in Rockville, Md., and Graduate Student Miki Umetani and Professor Hideo Iwasaki at Waseda University in Tokyo.

The research was funded by National Institute of General Medical Sciences grants GM067152 and GM088595, Department of Energy grant DE-FG36-05GO15027, Japanese Society for the Promotion of Science grants 23657138 and 23687002, the Asahi Glass Foundation and the Yoshida Scholarship Foundation.

Read More

More Like This…

HOME Algae Industry Jobs

Copyright ©2010-2013 AlgaeIndustryMagazine.com. All rights reserved. Permission granted to reprint this article in its entirety. Must include copyright statement and live hyperlinks. Contact editorial@algaeindustrymagazine.com. A.I.M. accepts unsolicited manuscripts for consideration, and takes no responsibility for the validity of claims made in submitted editorial.

From The A.I.M. Archives

— Refresh Page for More Choices
By sending algae into space, a U.S. Department of Agriculture (USDA) scientist and his team will be able to study some of the key mechanisms that control plant growth and...
A new, outdoor system at the University of Dayton Research Institute has been producing a high volume of algae since its installation in the summer of 2013, even through ...
Kazuaki Nagata reports from Japan that while the Fukushima nuclear disaster has prompted vigorous discussion about alternative energy in Japan, there is a lack of a paral...
A University of New South Wales (UNSW)-led team of researchers has discovered how algae that survive in very low levels of light are able to switch on and off a weird qua...
The Guardian reports that Prince Edward Island (P.E.I.), Canada-based Solarvest has created an inventive system utilizing a specific algal strain to grow and produce EPA ...
Kyae Mone Win reports in the Myanmar Times that spirulina has been harvested from Twin Daung lake in Sagaing’s Bu Ta Lin township for over a decade, but climate change an...
A recent discovery in the multicellular green alga, Volvox carteri,has revealed the origin of male and female sexes, showing how they evolved from a more primitive mating...
Following a request from the European Commission, the European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies (NDA) was recently asked t...
Matthew Carr was recently named executive director of the Algae Biomass Organization (ABO), the leading trade association for the algae industry. His presence will soon b...
Chase Ezell writes in Earth911.com about the irony of Algenol’s biggest friction source on the way to marketing their carbon reducing algal-based ethanol being — the EPA ...
Portuguese cement facility, Secil, and microalgae biotechnology company, A4F, also based in Portugal, have formed AlgaFarm, a joint venture to develop the use of cement f...
SCHOTT AG, of Mitterteich, Germany, and Algatechnologies Ltd. (Algatech), based at Israel’s Kibbutz Ketura, have signed an R&D agreement to strengthen their partnersh...
Analia Murias 
reports for fis.com that Chilean exports of products made from macroalgae generated a total of $195 million US in the first seven months of 2014, according...
Arizona is taking advantage of its open land and ample sunshine to assume a leadership position in the algae biofuel field. The state is home to two national algae testbe...
With their new CO₂ processing-platform called AstaCos, AlgaeBiotech can produce waxy particles of only 50-100 µm in size with a loading of 25% astaxanthin oleoresin. The ...
MicroBio Engineering, Inc., of San Luis Obispo, California, has introduced a full suite of open pond microalgae growth systems designed for quick deployment of research- ...
Phys.org reports that, in collaboration with the Berlin, Germany LED manufacturer FutureLED, scientists at the Technische Universität München have developed a unique comb...
Cyanobacteria, also known as blue-green algae because of their color, have endured for more than 2.5 billion years, providing ample time to adapt to changes in the Earth'...