The use of the methylotrophic yeast Pichia pastoris (Komagataella phaffi) to produce heterologous proteins has been largely reported. However, investigations addressing the potential of this yeast to produce bulk chemicals are still scarce. In this study, we have studied the use of P. pastoris as a cell factory to produce the commodity chemical 3hydroxypropionic acid (3-HP) from glycerol. 3-HP is a chemical platform which can be converted into acrylic acid and to other alternatives to petroleumbased products. To this end, the mcr gene from Chloroflexus aurantiacus was introduced into P. pastoris. This single modification allowed the production of 3-HP from glycerol through the malonyl-CoA pathway. Further enzyme and metabolic engineering modifications aimed at increasing cofactor and metabolic precursors availability allowed a 14-fold increase in the production of 3-HP compared to the initial strain. The best strain (PpHP6) was tested in a fed-batch culture, achieving a final concentration of 3-HP of 24.75 g l À1 , a product yield of 0.13 g g À1 and a volumetric productivity of 0.54 g l À1 h À1 , which, to our knowledge, is the highest volumetric productivity reported in yeast. These results benchmark P. pastoris as a promising platform to produce bulk chemicals for the revalorization of crude glycerol and, in particular, to produce 3-HP.

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l-Methionine γ-lyase (MGL) is a PLP-dependent enzyme which catalyzes the α, γ-elimination reaction in sulfur containing amino acids, such as L-methionine and L-cysteine. Its major applications are on metabolic restriction of methionine to cancer cells, food industry (cheese flavor) and for the synthesis of d and l-homoalanine. Herein, we present the immobilization and use of this new immobilized biocatalyst under batch and continuous-flow conditions. The best optimized continuousflow condition allowed 89 % conversion in 30 min of residence time with good recyclability of the biocatalyst.

Surfactin, a biosurfactant with great activity on interfaces, have been reported as a great substitute to non-renewable sources, non-biologically synthesized surfactants. It is expected to see more studies at the next years evolving its application, including on marine environments, especially ones impacted with petroleum or other contaminants. In this review we address in details the main aspects of surfactin production, including main microorganisms, cultivation modes, pathways and conditions. We address the main aspects of surfactin production by Bacillus subtilis with the different strategies explored to reach this bioprocess up to large scale, as well as the main challenges encountered. As well, is detailed its recovery and purification methods, that generally combine two or more steps as acid precipitation, solvent extraction, liquid membrane extraction, foam fractionation and membrane-based techniques. We also provide a brief summary of its potential application on marine environments, and our prospects from future application, as a brief outlook on physiochemistry characteristics of the main molecules.