Abstract Aureobasidium is omnipresent and can be isolated from air, water bodies, soil, wood, and other plant materials, as well as inorganic materials such as rocks and marble. A total of 32 species of this fungal genus have been identified at the level of DNA, of which Aureobasidium pullulans is best known. Aureobasidium is of interest for a sustainable economy because it can be used to produce a wide variety of compounds, including enzymes, polysaccharides, and biosurfactants. Moreover, it can be used to promote plant growth and protect wood and crops. To this end, Aureobasidium cells adhere to wood or plants by producing extracellular polysaccharides, thereby forming a biofilm. This biofilm provides a sustainable alternative to petrol-based coatings and toxic chemicals. This and the fact that Aureobasidium biofilms have the potential of self-repair make them a potential engineered living material avant la lettre.
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Eight new primer sets were designed for PCR detection of (i) mono-oxygenase and dioxygenase gene sequences involved in initial attack of bacterial aerobic BTEX degradation and of (ii) catechol 2,3-dioxygenase gene sequences responsible for meta-cleavage of the aromatic ring. The new primer sets allowed detection of the corresponding genotypes in soil with a detection limit of 10(3)-10(4) or 10(5)-10(6) gene copies g(-1) soil, assuming one copy of the gene per cell. The primer sets were used in PCR to assess the distribution of the catabolic genes in BTEX degrading bacterial strains and DNA extracts isolated from soils sampled from different locations and depths (vadose, capillary fringe and saturated zone) within a BTEX contaminated site. In both soil DNA and the isolates, tmoA-, xylM- and xylE1-like genes were the most frequently recovered BTEX catabolic genes. xylM and xylE1 were only recovered from material from the contaminated samples while tmoA was detected in material from both the contaminated and non-contaminated samples. The isolates, mainly obtained from the contaminated locations, belonged to the Actinobacteria or Proteobacteria (mainly Pseudomonas). The ability to degrade benzene was the most common BTEX degradation phenotype among them and its distribution was largely congruent with the distribution of the tmoA-like genotype. The presence of tmoA and xylM genes in phylogenetically distant strains indicated the occurrence of horizontal transfer of BTEX catabolic genes in the aquifer. Overall, these results show spatial variation in the composition of the BTEX degradation genes and hence in the type of BTEX degradation activity and pathway, at the examined site. They indicate that bacteria carrying specific pathways and primarily carrying tmoA/xylM/xylE1 genotypes, are being selected upon BTEX contamination.
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Closed loop or ‘circular’ production systems known as Circular Economy and Cradle to Cradle represent a unique opportunity to radically revise the currently wasteful system of production. One of the challenges of such systems is that circular products need to be both produced locally with minimum environmental footprint and simultaneously satisfy demand of global consumers. This article presents a literature review that describes the application of circular methodologies to education for sustainability, which has been slow to adopt circular systems to the curriculum. This article discusses how Bachelor and Master-level students apply their understanding of these frameworks to corporate case studies. Two assignment-related case studies are summarized, both of which analyze products that claim to be 'circular'. The students' research shows that the first case, which describes the impact of a hybrid material soda bottle, does not meet circularity criteria. The second case study, which describes products and applications of a mushroom-based material, is more sustainable. However, the students' research shows that the manufacturers have omitted transport from the environmental impact assessment and therefore the mushroom materials may not be as sustainable as the manufacturers claim. As these particular examples showed students how green advertising can be misleading, applying “ideal” circularity principles as part of experiential learning could strengthen the curriculum. Additionally, this article recommends that sustainable business curriculum should also focus on de-growth and steady-state economy, with these radical alternatives to production becoming a central focus of education of responsible citizens. https://doi.org/10.1016/j.jclepro.2019.02.005 LinkedIn: https://www.linkedin.com/in/helenkopnina/
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