[ad#PhycoBiosciences AIM Interview]

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
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...
U.S. farmers and biofuels makers are watching for the Environmental Protection Agency’s (EPA’s) final decision on the 2014 Renewable Fuel Standard rules, which will set t...
Iran-based Qeshm Microalgae Biorefinery Co. (QMAB) has launched a biofuel being marketed as BAYA®, produced from a species of Nannochloropsis (strain 6016) isolated from ...
Developing renewable fuel from wet algae is one of the latest innovations Richland, Washington-based Pacific Northwest National Laboratory (PNNL) has successfully driven ...
James Goodman writes in the democratandchronicle.com about Jeffrey Lodge, an associate professor of biological sciences at Rochester Institute of Technology, who knows wh...
The European (FP7) algae project Sustainable PoLymers from Algae Sugars and Hydrocarbons (SPLASH) has been developing a platform technology for the conversion of third ge...
Simris Alg, a pioneering agribusiness producing omega-3 from farmed algae, has been declared one of Sweden’s 33 hottest companies in new technology. The renowned list is ...
Murdoch University researchers are investigating whether the effluent from piggeries can be effectively treated with micro- and macroalgae so that species of the organism...
Natacha Tatu writes in Worldcrunch about a 72-year old French chef who has taken on the challenge of bringing spirulina to the malnourished youth of the Central Africa. F...
S V Krishna Chaitanya writes for the New Indian Express that a scientist from Chennai, the capital city of the Indian state of Tamil Nadu, in South India, is playing a ke...
Algae may hold the key to feeding the world’s burgeoning population. If algae’s efficiency at taking in carbon dioxide from the air could be transferred to crops, we coul...
Kuo Chia-erh reports for Taipei Times that Taiwan Cement Corp, the nation’s leading cement supplier, has announced plans to expand its microalgae farm, which produces ast...