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Oranges are among the most consumed fruits in Brazil, with over 80 million tons production per year. Currently, one of the main uses of orange residues is to supplement animal feeds. However, orange residues can be used in other ways, including for obtaining enzymes. However, for the pyridoxal 5-phosphate (PLP)-dependent enzyme group, which catalyze transamination reactions, no work has been described. The use of orange-peel residues for solid-state fermentation using endophytic microorganisms is a new and interesting approach to produce these enzymes at lower cost compared to the use of purified enzymes associated to PLP co-factor. In the batch process developed in this study, it was possible to achieve a maximum conversion of 49% after 48 h of incubation, an enantiomeric excess of 99% (R)-1,2,3,4-tetra-hydro-1-naphthylamine, and productivity of 0.0102 mg biocatalyst.h−1, using the solid enzyme preparation from Alternaria arborescens as biocatalyst. In a continuous-flow system, 51% conversion and >99% ee of (R)-1,2,3,4-tetra-hydro-1-naphthylamine were achieved, with a six-fold increase productivity (0.0625 mg biocatalyst.h−1). We have screened different fungi samples for transaminase activity and we found a hit for solid-state fermentation. The endophytic fungus genetically identified as Alternaria arborescens showed promising results for the transaminase activity on the kinetic resolution of chiral amine blocks. Therefore, along with other improvement of the biocatalytic toolbox for chiral amines synthesis, we have found that the solid enzymatic preparation of the endophytic fungus Alternaria arborescens could accept bulky substrates with reasonable activity, compared to the wild-type transaminase already published over literature, and, with high enantioselectivity. [Display omitted] • First report of transaminase activity for whole cells and solid enzyme preparation of Alternaria arborescens and Sordaria sp. • Higher ω-transaminase activity on solid enzymatic preparation of A. arborescens. • High conversions in (R)-1,2,3,4-tetra-hydro-1-naphthylamine with solid enzyme preparation in a continuous-flow system. [ABSTRACT FROM AUTHOR]

Immobilized lipases are biotechnological spotlights as tools to improve and enhance enzyme applicability. Here, lipase from Rhizomucor miehei (RML) was immobilized onto core/shell supports, named poly(methyl methacrylate) (PMMA/PMMA); poly(methyl methacrylate) copolymerized with divinylbenzene (PMMA- co -DVB/PMMA- co -DVB); and polystyrene copolymerized with divinylbenzene (PS- co -DVB/PS- co -DVB), and on a commercial non-core/shell porous support (polypropylene - Accurel MP 1000). Different enzyme loadings were evaluated (400 U.g−1, 500 U.g−1, 600 U.g−1, 4000 U.g−1, and 6000 U.g−1), and the immobilized biocatalysts were used in hydrolysis (using p -nitrophenyl laurate (p -NPL) and p -nitrophenyl butyrate (p -NPB) as substrates) and in esterification reactions (using oleic acid and ethanol as substrates). The influence of pH, temperature, and buffer concentration in the hydrolysis of p -NPL was also investigated. The immobilized biocatalysts were compared to free RML and/or to commercially immobilized RML (RM-IM) and/or to Novozym 435. RML interacted differently with each support, being RML-PMMA- co -DVB/PMMA- co -DVB and RML-PMMA/PMMA the biocatalysts with the highest enzymatic activities (hydrolytic activity: >400 U.g−1, using p -NPL; esterification activity: 25,532 U.g−1). Immobilization improved the thermal and pH tolerance and buffer concentration tolerance of RML. Both free RML and the immobilized biocatalysts exhibited their maximum activity at pH 7, with the exception of RML-Accurel MP 1000, which displayed optimal performance at pH 9.0. In addition, RML-PS- co -DVB/PS- co -DVB demonstrated increased activity at 70 °C. Notably, RML-PMMA/PMMA and RML-PMMA- co -DVB/PMMA- co -DVB showcased a maximum activity of 120 U/g, and this was achieved at different temperatures, 30°C and 50°C, respectively. This diverse library of immobilized biocatalysts shows promising potential for application in various industrial processes. [Display omitted] • RML was immobilized onto four home-made hydrophobic supports. • The properties of RML biocatalysts were modulated by the immobilization conditions. • The esterification performance surpassed RM-IM and Novozym 435. • The optimal conditions to RML biocatalysts depend of the support used. [ABSTRACT FROM AUTHOR]

In order to produce carotenoids with antioxidant potential from the wild yeast Rhodotorula mucilaginosa, Sporidiobolus pararoseus and Pichia fermentans, isolated from the ecosystem of Escudo Sul-Rio Grandense (Brazil), cultivations were performed with: raw glycerol and corn steep liquor (M1), sugar cane molasses and corn steep liquor (M2) and Yeast Malt (YM) broth. Production of β -carotene more than 63% was obtained in all the experiments. The antioxidant activity of the extracts was analyzed by the methods DPPH, ABTS and FRAP. S. pararoseus is highlighted, showing 635 and 830 μg.L−1 of carotenoids in M1 and M2, respectively. The extracts of P. fermentans in M2 were promising in relation to the antioxidant activity, presented results not reported in the literature until the present moment. Based on these results and the importance of obtaining carotenoid compounds from alternative sources, the proposed means, as well as the yeasts used, were shown to be promising choices. The use of agroindustrials media and microorganisms isolated from the ecosystems intensify the importance of this study providing new sources of biocompounds from the biodiversity and biotechnological potential of Brazil. Image 1 - Yeasts were cultivated in agroindustrial byproducts; - Antioxidant capacity was determined in carotenogenic extracts of yeasts; - The main carotenoids of the extracts were identified. [ABSTRACT FROM AUTHOR]

Three commercial lipases, Lipomod 34MDP (free lipase from Candida rugosa ), Lipozyme RM IM (immobilized lipase from Rhizomucor miehei ) and Novozym 435 (immobilized lipase B from Candida antarctica ) were evaluated as catalysts in the production of biolubricant base oils. This was accomplished via the esterification of free fatty acids obtained from soybean-oil hydrolysis and different polyols (neopentyl glycol, NPG; trimethylolpropane, TMP; and pentaerythritol, PE). Reactions carried out with free C. rugosa lipase showed the highest conversions for the three polyols (97% for NPG, 100% for TMP and 55% for PE) after 24 h, while Novozym 435 and Lipozyme RM IM resulted, respectively, in 65% and 92% for NPG, 15% and 39% for TMP and 1% and 0% for PE. Then, Accurel MP1000 (a microporous polypropylene support, PP) was used to immobilize the C. rugosa lipase; enzyme loading used was 0.3 mg/g. The zymography analysis showed that the protein band of 60 KDa present in the C. rugosa lipase extract was the main protein responsible for the extract activity in the biolubricant synthesis and it was successfully immobilized onto the support. The immobilized lipase (34MDP-PP) showed conversions of 99% for NPG and 92% for TMP, after 24 h of reaction, maintaining the results obtained with the free enzyme. The 34MDP-PP could be reused for six consecutive reaction cycles without a reduction in the final conversion, using NPG and TMP as substrates. Using Lipozyme RM IM, the conversion decreased from 92 to 56% after six consecutive reactions. The soybean esters of NPG and TMP showed good viscosity indexes, higher than 200. [ABSTRACT FROM AUTHOR]