Bioplastic: New hope for the Environment

Our environment is under siege. Malaysians are literally burying themselves alive by generating 18,000 tonnes of rubbish daily. If these wastes are piled up together, it is estimated to reach 16,200 meters or the height of 36 Petronas Twin Towers standing one on top of the other.

Among these, plastics contribute a significant percentile to the rubbish that is generated, contributing to 18-30% of the municipal solid waste total. Its versatility and durability is what makes it a major pollutant for our environment. Many of us wrap our rubbish in plastic bags, discard plastic shopping bags, bottles, wrappers etc. But few of us remember that it may take anywhere between 30-300 years before they actually start to degrade. One example would be that of polyethylene, which was discovered before World War II. Today, it is the world’s most voluminous plastic accumulated in landfills all over the world after being used as materials for items such as soft drink bottles and food storage containers.
       
With history as a guide, it is known that a need should arise before new technology can be developed. With the growing focus on sustainable green processes and instability of petroleum prices, mounting economical and environmental concerns are spearheading the main thrust for alternative sustainable technologies. This includes the strong R&D push for the development of bioplastics by the government in the Biotechnology policy and Budget 2006.

Bioplastics is an eco-friendly alternative to synthetic plastic. The term ‘bioplastics’ actually refer to biologically-synthesised plastics that are biodegradable and may be ecologically safe. It may degrade naturally in the environment due to the biological activities of microbes that are present in the soil. One potential form of bioplastics being developed is polyhydroxyalkanoates (PHAs) which is produced by microorganisms which serve as food storage for most bacteria. PHAs are subjected to study in many countries, including the US, Germany and Japan. In Malaysia, PHAs are being studied in the labs of Dr. Sudesh Kumar of USM for their potential commercial uses.

 
According to Dr. Sudesh, PHAs are synthesized by many types of bacteria in the presence of excess amounts of food which is a source of carbon. As vegetable oils are known as the best carbon source for certain bacteria to produce PHAs according to various studies done, Dr. Sudesh’s research delved into the viability of palm oil products in these processes. It was discovered that they can be converted into bioplastics with a conversion efficiency of more than 75% (Fig.1). In retrospect, 1 kg of palm oil can be converted into 0.75 kg of bioplastics, making them an attractive resource for the production of bioplastics due to their low price and being a renewable resource.
Fig 1. Electron micrograph of bacterial cells containing almost 90% of its dry weight bioplastics when fed with palm oil.
  


Malaysia has been making great inroads into the field of bioplastics for more than a decade. Dr. Sudesh reminisces of his active involvement in bioplastics research during his Masters in 1992 under the supervision of Assoc. Prof. Dr. Irene Tan Kit Ping and Prof. Dr. Gan Seng Neon both of UM, making them the first group to realize the potential of biologically synthesized plastics. By continuing research in Japan at the Polymer Chemistry Laboratory of RIKEN Institute, Dr. Sudesh was able to work with Prof. Dr. Yoshiharu Doi, who is one of the world famous authorities in bioplastics and later return to contribute his effort to bioplastics research in Malaysia. With great collaboration among the various universities and institutes including USM, UPM, UM, RIKEN, the potentials of bioplastics are steadily being realized at a commercial stage. Among the pioneers in bioplastics research of note, one would also come across Y. Bhg. Dato. Prof. Dr. Mohd. Isa Abd. Majid from USM and Prof. Dr. Mohd. Ali Hassan from UPM.

So, with the growing concern for the environment and the need for bioplastics, is bioplastics ready to begin its commercial debut? From the bioplastics that have been developed, two types have been slated as being superior in terms of properties and commercial viability, 3HBHx and 34HB. 3HBHx is attractive because of its properties that closely resemble Low Density Polyethylene (LDPE). On the other hand 34HB is attractive because of its excellent mechanical and biocompatible properties that makes it a highly potential bioplastic for medical devices and tissue engineering applications. Generally, the main factor here would be the cost of which the plastics may be synthesized. It is calculated that with palm oil products, it would currently cost less than RM10/kg to produce 3HBHx in Malaysia, compared to approximately RM12/kg from soybean products in Japan. Malaysian scientists are getting closer to their goal of reaching the affordable cost of approximately RM8/kg.
There is still much to be done, stipulated Dr. Sudesh. He is currently pursuing his interest in the bioplastics mechanism in hoping to harness the polymerization process of biological catalysts in cells. However, he laments on the lack of necessary facilities in Malaysia which may allow him to proceed with cutting edge research, necessitating his annual visits to the RIKEN Institute to further his work. During his recent visit, he has been able to chance upon observing the growth of polymer chains from biological catalysts using atomic force microscopy (Fig. 2). The findings has been published in Biomacromolecules and Macromolecular Bioscience.
 
 
Fig 2. Atomic force microscopy observation of the polymerization process of bioplastics molecules.
  
In addition, Dr. Sudesh is also looking into the viability of bioplastic synthesis from blue-green algae, like Spirulina (Fig. 3), which may produce their own carbon source, further reducing costs. This is generally a collaboration with the University Malaya Algae Culture Collection Center headed by Prof. Dr. Phang Siew Moi and funded in parts by Malaysia Toray Science Foundation and IRPA grant from MOSTI. Academically, Dr. Sudesh also supervises 9 postgraduate students working on various aspects of bioplastics in USM.
Fig 3. Large quantities of bioplastics particles in Spirulina platensis. The bioplastics particles appear bright orange due to staining using a special dye.
Speaking on his success at the invention exhibitions in Geneva and ITEX. Dr. Sudesh attributes them to the collaborative research with other researchers in USM and the hardworking postgraduate students. Similarly, the selection committee played a large role in scrutinizing inventions before they are sent to participate in the exhibitions and also USM’s Research and Innovation division. However, not one to rest upon his laurels, Dr. Sudesh remains true to his fundamental research in bioplastics, but then at the same time anticipates on discovering more novel inventions and to promote the university and country in international exhibitions.
 
 

For more information

http://www.usm.my/bio/asksk.htm

        By K. C. Liew for MABIC