A Proposal to Make Bioplastics from Seaweed (AMSEN)
Like the other AMSEN students attending the network’s annual meeting in March 2012, Naomi Shifeta of the University of Namibia (UNAM) was asked to give a brief PowerPoint presentation about her research topic. She was expected to defend her choice of topic, its value to society, and her proposed research methodology.
At dinner the night before her talk, she was so nervous she could speak only in whispers and barely touched her food. As one of the newest and youngest AMSEN students, and only the second woman to be accepted into the program, she had little experience speaking in public; nor did she know any of the senior faculty members from four countries who had assembled for the meeting. Two of her own advisors and traveling companions, Erold Naomab and Diina Shuuluka, were also new to the program. They kept her company at dinner, and tried to ease her anxiety. They knew she had heard tough questions tossed by faculty members at some of the more advanced students, and they tried to play that down.
“You’re going to be fine,” said the soft-spoken Dr. Naomab. “They know this is just a proposal, and they know you have just begun to sort things out. They won’t grill you about the kinds of details expected from the students who are well into their research.” Naomi nodded and attempted a smile.
By the next day, Naomi’s jitters had given way to renewed confidence and an obvious passion for her topic – making bioplastics from the red seaweed that washes onto the beaches of southwestern Africa. She spoke with a firm voice, a bright smile, and great enthusiasm; only a few pauses hinted at the terrors of the evening before.
Like many other young RISE students, she conveyed a zealous commitment to the values of her generation: sustainability, care for the environment, outcomes with the potential to help the poor and the needy. As she described her proposal, each of these elements became clear, as did her obvious love of research.
Most plastics manufactured today, she told the faculty, students, and others AMSEN participants who assembled in Nairobi, are carbon-based polymers derived primarily from the world’s steadily dwindling stocks of non-renewable petroleum. These plastics have the advantage of durability, but their dark flipside is the tendency to resist degradation in the soil or water for many years. They constitute a major cause of pollution, degrading the quality of the environment and threatening countless wildlife that accidentally ingest plastics. Worldwide, about 1 million tons of petroleum-based plastics are produced and used annually, including an estimated trillion plastic bags handed out by grocery and other stores.
Biomass-based plastics, or bioplastics, by contrast, are derived from renewable bio-resources, many of which can be broken down into simple compounds by the action of naturally occurring micro-organisms such as bacteria, fungi, and algae. “My research,” said Naomi, “aims to explore the potential for large-scale production of bioplastics.”
She was born in the tiny town of Oshakati, near the Angolan border far to the north of Windhoek, where the main university campus is located. Nonetheless, she was able to go to high school in Windhoek after her father moved there, and found her first mentor. “I had a great biology teacher in high school,” she said. “She fired up my interest, and because of that, I was always first in biology.” She went on to UNAM, where she majored in both biology and chemistry. After graduation, she was working as a lab technician and tutoring undergraduates when Dr. Naomab, then her advisor, urged her to apply to AMSEN. Frank Kavishe, the Namibian node director for AMSEN, asked Dr. Shuuluka to co-supervise her, and she began her studies in February 2012.
She has learned the fundamentals of her new field quickly. She told her audience that many kinds of bioplastics are already in use, made from such raw materials as vegetable oils, corn starch, sugar cane, pea starch, cellulose, and bacterial sludge. They find applications in blister wraps and foils for fruit and vegetables, organic waste bags, packaging “peanuts,” cutlery, pots, jars, drinking straws, bottles, ball-point pens, diapers, tire components, and drug capsules for pharmaceuticals.
Even though biopolymers have been adapted to some applications for half a century, especially those based on cellulose, there remain challenges to scaling up their use. For example, some people caution that they are likely to compete for resources with biofuels; this might raise prices, undermining one strong advantage of bioplastics. Others fear that millions of acres of forest and savannah might be sacrificed for planting bio-crops. Still others warn of the risk of excess planting of corn or other bio-crops that require heavy use of fossil fuels, pesticides and fertilizers. Finally, some bioplastics do not degrade quickly without the use of industrial-scale composters.
However, Naomi pointed out that the seaweed she studies, a common red algae named Gracilaria gracilis, avoids many of these disadvantages. Gracilaria grows abundantly along the western Namibian and South African coast (as it does in many other locations around the world). There it is nourished by the nutrient-rich upwelling of the Benguela current, bypassing any need for agricultural inputs such as fertilizer. She will harvest her samples from Luderitz Bay, a highly productive environment near the southern end of the Namib Desert. The alga’s natural polysaccharides, or long-chained sugars, which can be used to make bioplastics, degrade readily after use. These polysaccharides are already used to make agar, a biopolymer with broad uses as a Jello-like food and highly valued qualities as a biological substrate for growing and testing drugs. The potential markets for Gracilaria bioplastics are many, including food technology, biotechnology, microbiology, and the general plastics industry.
The aim of Naomi’s research is to create from this alga a specific biodegradable bioplastic that will have comparable tensile strength and chemical resistance to the petroleum-based plastics in use today. This work will include harvesting Gracilaria from the field, extracting its agar, manufacturing the bioplastic, and testing its biodegradability, tensile strength, and general chemical resistance.
She will be closely assisted by Diina Shuuluka, who is based at UNAM’s Sam Nujoma Marine and Coastal Resources Research Centre (SANUMARC) at Henties Bay. As an expert in marine botany and algae biochemistry, Dr. Shuuluka was trained by renowned seaweed scientist Prof. John Bolton.
Like Naomi, Dr. Shuuluka glows with enthusiasm for her work, and honors the mentors who guided her. “I came into the study of algae from my background in chemistry because of Prof. Keto Mshigeni. I think he has something contagious, and I caught it. I definitely share his love for the field, and I love to do research.” Prof. Mshigeni, who helped design the University of Namibia and served as its academic pro vice-chancellor from 1995 to 2000, has returned to his native Tanzania, where he is director of the Tanzanian Academy of Sciences and vice-chancellor of the Hubert Kairuki Memorial University, a private medical school.
Because of his influence, UNAM also has a program on mushroom research, which is his second great passion. “We now have seven priority areas at SANUMARC,” said Dr. Shuuluka. “And I hope to bring more young students into these fields. Especially more young women, like Naomi.”
By the time of the AMSEN party and dance on the final evening, Naomi had fully recovered her confidence. After snake dancing around the buffet with faculty and fellow students, she broke away to join the band, seizing the microphone and singing the Namibian national anthem to loud applause.