Institute for Health and Bioeconomy

Publications

Production of sustainable aviation fuel precursors using the oleaginous yeast Rhodotorula toruloides PYCC 5615 cultivated on eucalyptus bark hydrolysate

Publication . Saraiva Lopes da Silva, Maria Teresa; Dutra, Francisca; Gomes, Miguel; Costa, Paula; Paradela, Filipe; Ferreira, Frederico Castelo; Torres Faria, Nuno Ricardo; Mugica, Paula; Pinheiro, Helena M.; Sá-Correia, Isabel; Gírio, Francisco; Marques, Susana

ABSTRACT: Sustainable aviation fuels (SAF) obtained from renewable sources of carbon can reduce carbon dioxide emissions and contribute for mitigating climate changes. In the present study, the yeast Rhodotorula toruloides PYCC 5615 was found to be highly promising for the bioconversion of eucalyptus bark hydrolysate and the accumulation of intracellular lipids which were further thermochemically processed to bioenergy intermediaries for SAF production. Two growth medium formulations were tested. Eucalyptus bark hydrolysate, obtained by steam explosion followed by enzymatic hydrolysis, was supplemented with yeast nitrogen base medium or with corn steep liquor and mineral medium. The latter produced the highest fatty acid content and productivity (30 % w/w and 0.11 g/ (L.h) respectively). Thereafter, the whole yeast biomass (WB) and the de-oiled biomass (DOB), obtained after lipid extraction, were processed into Bio-crude using a hydrothermal liquefaction (HTL) reactor, with a yield of approximate to 40 % (w/w). The two obtained Bio-crude fractions and the yeast lipids fraction (YL) were further upgraded by hydrodeoxygenation (HDO), to remove oxygen atoms and increase the hydrocarbon content, resulting in a Bio-crude composed of linear long-chain fatty acids suitable for processing to SAF. The best Bio-crude characteristics was observed for WB and YL fractions, with 34.8 % and 40.7 % of hydrocarbons, respectively. Both WB and YL hydrocarbons were composed of C15-C17 compounds. These results demonstrate the potential of an integrated process based on microbial oils from R. toruloides PYCC 5615 to produce SAF precursors from Eucalyptus bark residues, contributing for the sustainable jetfuel bioproduction process.

2025-06Journal article

Open access

The materials of historical monuments: characterisation of the mortars of the Roman aqueduct of Zaghouan-Carthage

Publication . Carvalho, Fernanda; Lima, Maria Margarida Rolim Augusto; Silva, Teresa; Veiga, João Pedro

ABSTRACT: The Zaghouan-Carthage Roman aqueduct was the largest built by the Roman Empire at the time, and its archaeological remains bear witness to the excellence of Roman construction. Its importance over the centuries makes it a unique case study for characterising the different types of mortar used. This work aims to study these materials, considering their functions, especially as structural elements or as render, to relate the chemical and mineralogical characteristics observed to both the function and historical context of the monument. Using a multi-analytical approach, the preservation of samples was prioritised whenever possible. The results indicate that mortars with a structural function have higher silicon contents than those used as render. In the case of water conduit coatings, the mortars were formulated with ground ceramics to develop hydraulic properties and ensure the waterproofing material. However, it was not possible to identify a characteristic pattern related to the historical construction periods.

2025-12Journal article

Open access

Keywords

Innovative Diagnostics, Therapies and Devices,Tools for Drug Discovery & Development Pipeline,Human Safety and Antimicrobial Resistance,Bioprocesses & Circular Economy, Exact and natural sciences

Funding agency

Fundação para a Ciência e a Tecnologia, I.P.
Fundação para a Ciência e a Tecnologia, I.P.

Funding programme

6817 - DCRRNI ID
Concurso para Atribuição do Estatuto e Financiamento de Laboratórios Associados (LA)

Funding Award Number

LA/P/0140/2020