Artificial lichens and the integration of products with high added value to a biorefinery

Abstract

The use of microbial communities has been considered one of the new exponents in the field of bioprocess engineering. Lichen-type biofilms, composed of microalgae and filamentous fungi, are an example of a symbiotic relationship able to sum the biotechnological potentials of each species present in the structure. Considering the fact that filamentous fungi, such as Mucor circinelloides, and microalgae, such as Chlorella vulgaris, are already consolidated in the context of production of lipids and other value-added metabolites, we propose herein to study the interaction of the aforementioned species in a lichenized form. Also included in this proposal is the use of the microalgae Nephroselmis viridis, recently isolated in Brazilian waters, which is also reported as a producer of high value metabolites, such as lipids and carotenoids. The current doctoral proposal aims (i) the study of interaction and formation of structures of the lichen form between M. circinelloides/C. vulgaris and M. circinelloides/N. viridis, followed by (ii) optimization of the culture medium with determination of the most appropriate conditions for formation of lichen-like structures, i.e., that promote high values of cellular integration in submerged lichen medium, with (iii) integration of this structure to the production of polyunsaturated lipids and carotenoids. Finally, the growth capacity of the submerged structure will be tested (iv) using co-products typical of the bioethanol and biodiesel industries. This proposal is linked to the thematic project "From the cellular plant to the integrated biodiesel-bioethanol biorefinery: a systemic approach applied to complex problems in micro and macro scales" (BIOEN FAPESP 2016/10636-8), with the involvement of the following institutions UFSCAR, EEL/ USP, UNICAMP, and EMBRAPA. In the linked thematic project, the challenges for the viability of integrated biorefineries have been addressed considering the system in all its dimensions. In particular the present proposal takes in consideration the consolidated experience of the Biocatalysis Laboratory at EEL/USP in axenic cultivation of the fungus M. circinelloides and microalgae, providing the necessary base for the formation of artificial lichens capable of integrating products of high added value to a G1-G2 biorefinery. (AU)