The MarPlast project has develop methods for utilizing marine bacteria for production of biodegradable bioplastics from biomasses which are currently less utilized. The utility of petroleum-based plastic has made it an indispensable material, and the consumption of plastics has increased dramatically since the 1950s. The result of this is evident as pollution of nature and the oceans. Microplastics, which are formed during decomposition, have additional consequences as it may be ingested by plankton and other small animals, and thereby enter the food chain. A sustainable solution will therefore be to replace some of the petroleum-based plastics with biodegradable alternatives from renewable sources. Many bacteria have the ability to convert different carbon sources into the polymer polyhydroxyalkanoate (PHA) which is a fully biodegradable bioplastic. Different types of bacteria can make slightly different PHA building blocks that determine the characteristics of the bioplastics. It is the bacterium's own enzymes as well as carbon sources in the growth medium that determine which PHAs are produced. We have investigated several hundreds of marine bacteria and our best PHA producers identified are members of the Halomonadaceae family (Halomonas sp and Cobetia sp), the Vibrionaceae family (Photobacterium sp) and the Pseudomonadaceae family. These bacteria can make slightly different types of PHA that will have an impact on the bioplastic's properties in terms of elasticity and strength. All of them can make bioplastics from simple carbon sources such as glucose, but more importantly we have managed to produce relatively good amounts of PHA from a fish oil derived from a category 2 rest raw material from the aquaculture industry (product from ensilage of diseased and self-dead fish). MarPlast has also identified promising candidates that produce large quantities of PHA by consuming glycerol found in residual material from the biodiesel production. We have also investigated the genomes of the bacteria and characterized enzymes required for polymerization of PHA. This knowledge can be used to tailor a bioplastic with desired properties. The focus of the project has also been on developing "green" methods for extracting PHA. The project has been a collaboration between researchers at the universities in Tromsø (Norway), Umeå (Sweden) and Bucharest (Romania).
In MarPlast we have develop and provided tools (bacteria, enzymes, pathways and methods) to enable efficient production and extraction of sustainable and biodegradable bioplastics from low-cost unexploited biomass using marine bacteria. The project has been an international collaboration between the universities in Tromsø (UiT, Norway), Umeå (UmU, Sweden) and Bucharest (UB, Romania). Our research has been interdisciplinary merging the fields of microbiology, biotechnology and chemistry. The research field will benefit greatly from our findings and new ideas will arise based on our discoveries. In the long term, the industry and society will also benefit from having more knowledge in this field, and new environmental friendly bioplastic can emerge together with new jobs related to its production. Our bacteria with their unique bioplastic-producing abilities and enzymes are good tools in the quest for even better plastics that is degradable and non-fossil.
Plastics are cheap, lightweight, and durable materials, which have resulted in their use in an enormous range of products and mass production has steadily increased since around the 1950s. However, the limited degradability of most plastics has led to an accumulation of large amounts in Nature, in particular in the sea. The exposure to sunlight causes a disintegration of plastics into nanoparticles, which are ingested by marine organisms and has been shown to enter our food chain. The long-term effect of this is not fully understood, but the steady increase in microplastic concentration could result in dramatic effects on the vulnerable wildlife of the oceans and marine food supplies. It is therefore of immediate importance to develop novel types of polymeric materials that can be sustainably produced to address these environmental concerns. MARPLAST focuses on Polyhydroxyalkanoates (PHAs), a class of biodegradable bioplastics which are considered to be feasible replacements for current petroleum-based plastics. PHAs are polymers occurring in nature, produced among others by bacteria, and with properties similar to oil-derived polypropylene and polyesters, rendering them useful as an attractive biodegradable replacement. However, the naturally occurring PHA production pathways are not sufficiently understood, and currently known technologies for production are too costly to allow for a full-scale replacement. MARPLAST aims to develop and provide tools (bacteria, enzymes, and pathways) to enable efficient production of sustainable and biodegradable bioplastics from low-cost unexploited biomass. Focus will be on PHA-producing cold-adapted marine bacteria, with a range of properties that make them especially suitable for industrial applications. MARPLAST will utilize expertise from the Univ of Tromsø (Norway), Univ of Bucharest (Romania) and Umeå University (Sweden) to make important progress and contributions to the transition to a bio-based European economy.