We lead the synthetic biology industry, having developed and successfully commercialized the most Lab-to-Market™ ingredients. Our sustainable ingredients are used in thousands of top global brands, including our own family of consumer brands in Clean Beauty and Health markets.

Our leadership team is comprised of an exceptional group of executives who are championing a new technology and market innovation while creating significant growth opportunities as part of a company that is leading the advanced bioeconomy.

Han Kieftenbeld
Interim Chief Executive Officer and Chief Financial Officer

Mr. Kieftenbeld was appointed Interim Chief Executive Officer in June 2023. He has served as the Company’s Chief Financial Officer since March 2020, Chief Administration Officer since July 2020, and Interim Chief Accounting Officer since May 2023. Mr. Kieftenbeld has over 30 years of international business leadership, finance and operations experience in science-driven food, health, nutrition, personal care and industrial end-markets. He has extensive experience with developing talent, capital markets, complex manufacturing and supply networks, partnerships and M&A transactions with a keen focus on execution and accountability. Previously, from April 2016 to April 2019, Mr. Kieftenbeld served as Senior Vice President and Chief Financial Officer of Innophos Holdings, Inc., a leading international science-based producer of essential ingredients for health and nutrition, food and beverage and industrial brands. From June 2014 to July 2015, Mr. Kieftenbeld served as the Global Chief Financial Officer at AB Mauri, a worldwide leader in bakery ingredients. Prior to that, Mr. Kieftenbeld held finance and operations roles of increasing reach and impact, including serving as Global Chief Procurement Officer of Ingredion Incorporated, and Global Chief Financial Officer of National Starch. Mr. Kieftenbeld started his career at Unilever in the Netherlands. Mr. Kieftenbeld earned a joint Master of Business Administration degree from New York University Stern School of Business, London School of Economics and Political Science, and the HEC School of Management, Paris. He holds a Bachelor of Science degree in Business Economics and Accounting from Windesheim University in the Netherlands.

Doris Choi
General Counsel & Secretary

Doris Choi joined Amyris in December 2020 as Vice President, Senior Corporate Counsel and was appointed General Counsel and Secretary in December 2022. Prior to that, Ms. Choi served as Senior Corporate Counsel at Jazz Pharmaceuticals, a Nasdaq-listed global biopharmaceutical company. Before that, she served as Associate General Counsel and Assistant Secretary at QuinStreet, a Nasdaq-listed performance marketing technology company. Ms. Choi started her career in private practice as an associate at Latham & Watkins LLP focused on corporate and finance transactions. Ms. Choi holds a B.A. from Northwestern University, an M.A. from University of Chicago and a J.D. from Columbia University.

Michael Leavell
Senior Vice President, Research and Development

As SVP of R&D, Michael Leavell leads Amyris’ strain engineering and development pipeline which engineers millions of microorganisms per year, optimizing those that meet product requirements. Previous to leading R&D, he led the Screening and Analytical Science department which assesses the performance of the millions of engineered strains produced and identifies areas for improvement. Starting in 2015, Michael also led the development of Amyris’ zero-calorie sweetener, RebM, from project inception to first commercial production. Michael has been an employee of Amyris since 2006. He has more than 30 published scientific papers and patents. Prior to joining Amyris in 2006, Dr. Leavell received his Ph.D. in Chemistry from University of California, Berkeley, and his B.S. in Chemistry from University of Colorado, Denver.

Annie Tsong
Chief Strategy Officer & Product & Ingredients

Annie Tsong was appointed Chief Strategy and Product Officer in 2021 and is responsible for developing Amyris’ extensive pipeline of products and ingredients. She maintains the strategic portfolio by identifying the intersection between market needs and areas where Amyris’ technology offers new value.

A long-time Amyris veteran, Annie joined Amyris in 2008 in the Research and Development division, where she was central in establishing the company’s foundational microbial production platform. Subsequently, she established a Program Management Office which brought Amyris’ highest priority molecules to market by integrating activity across capabilities from upstream R&D to commercialization. Most recently, Annie turned her attention to Product Innovation, where her team established an ingredient development pipeline focused on fast-to-market opportunities that support Amyris’ strategic objectives. Annie has authored multiple landmark scientific publications in the fields of metabolic engineering and evolution of transcriptional regulation. She is an inventor on many key patents in Amyris’ IP portfolio, and a frequent speaker at international scientific conferences.

Annie holds an AB in Biochemical Sciences from Harvard University, a Ph.D. in genetics from University of California, San Francisco, and was a Miller Fellow at University of California, Berkeley.

Sola Biu
VP Global Brand Marketing & Engagement

Sola brings 17 years of Brand Marketing and Communications experience in travel, design, and finance to Amyris. She has a track record of advancing craft, innovation, and culture primarily within companies at the forefront of radically transforming societal and cultural norms. 

Most recently, she served as a Director of Brand Strategy for Robinhood instituting the brand foundations needed for the company to make finance more accessible to a new generation of investors. Prior to this, she was the Head of Airbnb’s Design Brand Marketing and Communications Group, a team focused on forging the company’s creative identity at its infancy, building its global design community, and scaling its creative and learning culture. During her tenure, she played a pivotal role in establishing design as a strategic differentiator for the company, a key contributing factor to its successful IPO in 2020. She holds a B.A. in Communications and Journalism from the University of Virginia Tech. She also serves as an advisor to the Institute of Black Imagination.