[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
A team of Michigan State University algae researchers have discovered a cellular "snooze button" that has the potential to improve biofuel production and offer ...
On September 25, 2014, a photobioreactor for the cultivation of algae was officially unveiled during a seminar at Thomas More University College in Mechelen, Belgium. Und...
In an age where customer input is as easy as a click, OriginOil has tapped directly into its intended market to R&D their next generation algae harvester -- with a de...
Researchers Greg O’Neil of Western Washington University and Chris Reddy of Woods Hole Oceanographic Institution (WHOI), have exploited an unusual and untapped class of c...
As one of the most water-poor countries in the world, Jordan’s current water resources are significantly below the global water scarcity line. Annual rainfall falls under...
Sami Zaatari writes for the Middle East’s Gulf News that Abu Dhabi’s coastal sabkhas – the Arabic phonetic translation for salt flats – hold great potential for solar pow...
Biocrude oil obtained from hydrothermal liquefaction (HTL) of algae can be an energy-efficient replacement for the fossil crude oil normally used in the production of fue...
Jessie Rack reports for NPR that demand for plant protein of all types is growing in concert with the growing interest in the U.S. to reduce meat consumption. People, fro...
The Chesapeake Bay Seed Capital Fund, located in College Park, Maryland, has invested $150,000 into Manta Biofuel LLC, a company that produces crude oil from algae at a c...
Bloomberg reports that ANA Holdings Inc., Japan’s largest airline, plans to use a Euglena Co. biofuel made from algae. ANA will use a mix of about 10 percent of the algae...
Ewen Callaway writes in the jounal Nature that restrictions on harvests and exports of Gelidium seaweed in Morocco have affected the global supply of the lab reagent agar...
The new algae raceway testing facility, opening February 4 at Sandia National Laboratories in Livermore, California, paves a direct path between laboratory research and s...