Contract number

J4-2549

Department:

Department of Biology

Type of project

ARRS projects

Type of project

Basic research project

Role

Lead

Duration

01.09.2020 - 31.08.2023

Total

1.4 FTE

Project manager at BF

Gostinčar Cene

ABSTRACT

Pollution with plastic polymers has become one of the most urgent problems of modern times. Objects made from recalcitrant plastic materials are produced in ever growing quantities, currently approaching around 400 million tons per year. Efforts directed into establishing the circular economy of plastics are hindered by the associated costs, large diversity of plastic materials, complex mixtures of different polymers and mixed material products. In the meantime plastics, including microplastics are accumulating in all, even the most distant environments on the planet. The negative implications of this pollution for the ecosystems and human health are only beginning to be understood, but are predicted to have a long-term impact. Even if we stopped all plastic production, the remnants of inappropriate storage in the past would remain a global environmental burden for decades if not centuries to come. 

Microbial hydrolases capable of modifying or degrading plastics have emerged recently as a potential technology for plastic biodepolymerization, allowing for a completely biological recycling of plastics. Employing microbes to convert plastic waste into harmless small molecules or even into high value products would provide an alternative to conventional recycling or incineration and would open new possibilities for remediation where plastic collection is not feasible. Despite a handful of achievements, approaches using microorganisms for achieving biodegradation of otherwise non-biodegradable polymers are still at laboratory scale. Besides the insufficient knowledge on microbial degraders, one of the reasons for this is a lack of well-defined, standardised and optimised methods for screening and analysing the microbial degradation of plastics. 

Fungi, with their abundance and huge diversity of extracellular enzymes, are able to degrade some of the most complex organic materials known. However, the diversity of known enzymes and microbes acting on synthetic polymers is very limited. The advances in recent years have provided us with new strains from previously overlooked habitats, which were so far neglected as potential sources of novel enzymes. Among them are polyextremotolerant fungi, versatile species found in some of the most unexpected parts of the planet and capable of degrading a wide spectrum of different food sources. Our preliminary results indicate that some of these fungi harbour previously unobserved capabilities for degradation of plastic polymers. This includes (to the best of our knowledge) the best available indication of polypropylene biodegradation to date.

The primary objectives of the proposed research are as follows: 

  1. To determine the potential for biodegradation of 5-15 polyextremotolerant fungi of different plastic polymers. Five promising candidates have already been identified through preliminary screening.
  2. To design and standardise the methodology for screening and testing of plastic biodegradation to increase the impact of the study and contribute to later studies.
  3. To screen 400 strains of polyextremotolerant fungi for additional plastic degraders, using the largest collection of fungi from extreme environments in the world, managed by members of the project consortium.
  4. To identify plastic degradation mechanisms of five selected polyextremotolerant fungi through genomics, transcriptomics and heterologous expression.
  5. To test the performance of a consortium of best plastic degraders in a pilot degradation of a complex plastic mixture.

Microbial degradation of plastic should form a part of solution for the ever-growing plastic production and its increasing environmental burden. This project will use the dark matter of fungal diversity from extreme environments to identify new species and their mechanisms for the degradation of plastic polymers.

 

THE PHASES OF THE PROJECT AND THEIR REALIZATION

  1. Results of plastic degradation analyses with 10-15 fungi and 5 polymers. 
  2. Established Methodology for screening and testing of plastic degradation.
  3. Additional potential plastic degraders identified by screening of a collection o polyextremotolerant fungi.
  4. At least one biodegradation-associated gene per polymer identified and expressed in a heterologous system.
  5. Biodegradation of mixed plastic polymers with a fungal consortium in a pilot experiment finished.
  6. At least one scientific article on the methodology of testing submitted; at least one scientific article or potentially a patent application submitted on the final outcome of the project.

Citations for bibliographic records

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