Today’s post continues a series of analyses of recent submissions to the U.S. Environmental Protection Agency for outdoor field tests of genetically modified microorganisms under the TERA (TSCA Environmental Release Application) provisions of the Agency’s biotechnology regulations under the Toxic Substances Control Act (TSCA). Today’s entry will describe two TERAs for research use of modified algae strains in open-ponds, as part of research programs ultimately aimed at developing commercial processes for production of fuels or high value chemicals.
As previously described, EPA’s TERA regulations were created to provide Agency overview over proposed outdoor experimentation using genetically modified microorganisms, within industrial sectors not regulated by other federal agencies. The requirement for prior EPA approval for such testing allows the Agency to review the potential environmental effects of the proposed activity, but on a shorter (60-day) timeframe compared to requirements for review of proposed commercial activities. The TERA process is well-suited to allow the assessment of the potential risks of proposed environmental uses of modified organisms, while also allowing outdoor uses of modified microorganisms to take place in a stepwise fashion under appropriate monitoring and agency oversight, to enable legitimate scientific issues of environmental risk assessment to be addressed with data from actual controlled small-scale environmental use, thus facilitating subsequent risk assessments for larger-scale uses.
Today’s post discusses two TERAs submitted by Arizona State University on behalf of the Producing Algae for Coproducts and Energy Consortium (PACE). Both applications proposed small-scale experiments entitled “Evaluation of Genetically‐Modified Chlorella sorokiniana in Open Ponds for Production of Biofuel Feedstock and High Value Co‐products”. Chlorella sorokiniana is a unicellular green alga that was described as a well-studied model organism that has long been used in research on photosynthesis and other R&D or industrial applications, including as a food additive. These applications were proposed to take place at the Arizona Center for Algae Technology and Innovation (AzCATI) test bed facility, a 4 acre site in Mesa, Arizona that features laboratories, greenhouses, a number of raceways and miniponds and a photobioreactor array for experimentation with algae technologies.
TERA R-17-0002 was submitted by ASU in May 2016. It proposed the testing of two modified strains of Chlorella sorokiniana. One strain was engineered to express pyrroline‐5‐carboxylate synthase from Vigna aconitifolia (mothbean), which is said to improve stress tolerance, and the other to express AHL‐lactonase from Bacillus sp. strain 240B1, which may play a role in disrupting quorum sensing in algae. Both genes were codon-optimized, and introduced into the recipient algae strain on a plasmid, for expression under the control of native Chlorella regulatory sequences. The goals of the study were to evaluate how well laboratory findings translated to performance in the open environment, and to compare the modified strains to wild type for resistance to environmental factors. The study also aimed to characterize the potential risks and environmental impacts of this open-environment use of modified algae, such as the possibility of dispersal beyond the test site.
TERA R-18-0001 was submitted by ASU in August 2017. It proposed the testing of one modified strain of Chlorella sorokiniana, engineered to express SNRK 2 (SNF related kinase) from the green alga Picochlorum soloecismus, an enzyme involved in sugar metabolism, with the goal of improving photosynthetic efficiency and biomass production. This gene was not codon-optimized, and was also expressed on a plasmid under the control of native Chlorella regulatory sequences. This study had the same goals as the testing proposed in the first TERA. Interestingly, the modified strain described in this application was first tested in a 50 L indoor minipond inside a greenhouse, and was found to have significantly increased carbohydrate accumulation compared to wild type.
These TERAs proposed outdoor experimentation under essentially identical conditions and procedures. Each test was proposed to take place in a total of 6 miniponds, each of which had a working volume of between 800 and 1,000 liters and a surface area of approximately 4.2 m2. The miniponds were set on raised stands and were placed within secondary containment constructed of a wooden frame acting as a berm that was overlaid with an industrial liner. The miniponds were also said to be contained within a 9m x 11m perimeter that was underlined by a mesh‐reinforced, puncture‐resistant, UV‐resistant pond liner. Each test was planned to last for 60 days, during which time samples were to be taken from the miniponds to evaluate biomass accumulation of the modified strains compared to the wild type controls. The experiments also featured monitoring protocols, using water traps at various distances from the miniponds to detect any possible spread from the experimental ponds: sampling was to take place weekly, with more frequent monitoring and other mitigation steps to be taken if any dispersal was detected.
I don’t know if these tests were carried out, but since they were to be conducted by an academic group, results would likely be published eventually. Overall, these TERAs represent a sound, thoughtful approach to proposals for outdoor testing of genetically modified algae, with plans for monitoring that should produce useful data on the environmental impacts of such testing. The submissions themselves were thorough in providing the necessary information for EPA to conduct its risk assessment.
There have been other recent TERAs for outdoor experimentation using modified microalgae, which is hopefully indicative of increased interest in developing industrial uses of geneticaly-improved algae strains, as well as evidence that the tools to improve such strains are becoming more accessible. I hope to discuss these other algae TERAs in future blog posts.
D. Glass Associates, Inc. is a consulting company specializing in government and regulatory affairs support for renewable fuels and industrial biotechnology. David Glass, Ph.D. is a veteran of over thirty-five years in the biotechnology industry, with expertise in industrial biotechnology regulatory affairs, U.S. and international renewable fuels regulation, patents, technology licensing, and market and technology assessments. More information on D. Glass Associates’ regulatory affairs consulting capabilities, and links to some of Dr. Glass’s prior presentations on biofuels and biotechnology regulation, are available at www.dglassassociates.com. The views expressed in this blog are those of Dr. Glass and D. Glass Associates and do not represent the views of any other organization with which Dr. Glass is affiliated.
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