Obituary Notice: Mark Hildebrand, Leading Algal Biofuel Scientist

Note: Story updated Sept. 4 to add memorial details

Mark Hildebrand, a research molecular biologist at Scripps Institution of Oceanography at the University of California San Diego, died Aug. 9 after a battle with cancer lasting more than four years. He was 59.

Hildebrand was a leader of the national research effort to develop fuels from algae and his laboratory had been ranked by the U.S. Department of Energy as the top algae biofuel program in the United States.

The director of the Marine Biology Research Division at Scripps since 2012, Hildebrand was also a founding member of the California Center for Algae Biotechnology, and a world leader in algal research. His lab is credited with developing many of the advanced genetic tools now commonly used in the research of marine microorganisms called diatoms, said Stephen Mayfield, the director of the center and a close collaborator. 

“His worked spanned from basic studies on diatom metabolisms, to the production of biofuels and even nanotechnology using diatom silica cell walls,” said Mayfield. “For more than 30 years, Mark was at the forefront of algae research. His recent studies on diatom genomics and metabolic analysis of lipid production have paved the way for the development of products using diatoms, including biofuels.”

Born in 1958, Hildebrand obtained his BS in chemistry from SUNY Syracuse in 1980 and his PhD in biochemistry from the University of Arizona in 1987. His PhD thesis concerned the biochemistry of isolated chloroplasts from tobacco plants. Because of his expertise in the molecular biology of photosynthetic organisms, he was hired at Scripps in 1987 as a postgraduate research biologist to work on the biology of diatoms.

Hildebrand’s branch of molecular biology was just emerging at the time. Researchers were excited about cloning and sequencing genes, said emeritus Scripps Oceanography marine biologist Vic Vacquier, a longtime colleague of Hildebrand’s. Diatoms are single-cell algae with intricate cell envelopes incorporating silica and are responsible for about 20 percent of worldwide carbon fixation by photosynthesis. Hildebrand was the first to show that diatoms had plasmids, DNA segments that later proved to be important tools for gene manipulations.

“Mark was fascinated by the mechanism by which diatoms build the precise nanoscale repeating lace-like patterns of their silicon walls and he talked often about the idea that such regularly repeating structures might be used to store digital information,” said Vacquier.

Hildebrand’s reputation grew rapidly from his research discoveries, his leadership, and service to the field. His research attracted a group of superior graduate students and postdoctorals who broadened the scope of diatom biology at Scripps, Vacquier said.

“He cared deeply for science and for his students, co-workers, and colleagues and is fondly remembered by them for his enthusiasm for science and courage in the face of a difficult diagnosis,” said Hildebrand’s student Sarah Smith. “Mark is also remembered for his artistic senses; both his appreciation for the intricate beauty of a diatom frustule and for his self-taught musical talents on the guitar.”

Hildebrand's lab covered all fields of modern experimental biology, from ultrastructure of cell walls, to gene transformation of diatom cells, to genome sequencing. Several of his research papers described the increases in triacylglycerol (TAG), a potential biofuel, when diatoms are starved for silicon. Because a large volume of the diatom cell can be occupied by the TAG droplet, the Hildebrand lab and others understood the future potential importance of algal biofuels, and thus a sizable portion of the lab was devoted to diatom biofuel research. He and his students and postdocs showed use of different pathways for lipid synthesis.

Their foundational work on lipid synthesis led to the top ranking from the Department of Energy in 2013.

“Mark was a fantastic resource for UC San Diego and the world of algae, and his work has set a standard that will hold for years to come,” said Mayfield.

Hildebrand is survived by sisters Susan Donovan of Portland, Maine; Gail Fensom of Newburyport, Massachusetts; and Wendy Gray of Okeechobee, Florida, as well as several nieces, grandnieces, and grandnephews.

Colleagues will host a celebration of life for Hildebrand at 3 p.m. Sept. 28 at the Martin Johnson House on the Scripps Oceanography campus. Also at 1:30 p.m. Sept. 30, a spiritual ceremony will be held at the Self Realization Fellowship Temple, 3072 First Ave., San Diego.

Tributes to Mark Hildebrand

"We are saddened to hear of Mark’s passing and send our deepest condolences to his family.  Mark touched many lives both personally and scientifically. He was a compassionate leader and gracious colleague. Mark’s generosity in helping our lab with research needs and his contributions to the genetics and bioengineering of Thalassiosira pseudonana will leave a legacy of excellence in the field. Thank you Mark.

– Nitin S. Baliga, Monica V. Orellana, Jacob J. Valenzuela/Baliga group (Institute for Systems Biology)

"I first met and had the honor and pleasure to collaborate with Mark when he was a post doc with Ben Volcani. It was clear from the get-go that Mark was an outstanding scientist and also a wonderful and thoughtful Mensch. He has always been the nicest person. We had the opportunity to catch up on each other's research and life when we met. When my daughter Julia became interested in marine biology, he accepted her as an intern in his lab, and Mark took time out of his busy days to explain the big picture and the details of the research to her. She still talks about that time and the awesome research goals, over 6 years later. She is a huge fan of Mark and loved Mark’s team in the lab. Mark has inspired a next generation of curious minds that will carry on his pioneering research."
 
– Julian Schroeder, UC San Diego

“Mark was an outstanding scientist; he was a world expert in diatom biology and made significant novel contributions about how they make their silica shells and how they produce lipids relevant for biofuel production, among many other topics. But above all, he was a good person, and a great colleague and mentor. He showed enormous courage fighting disease, staying optimistic, active and productive until his last day, and I will also always admire him for that. I will deeply miss him.”

– Martin Tresguerres, Scripps Institution of Oceanography at UC San Diego