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BACKGROUND This study investigated the use of core–shell biocatalysts, synthesized using recombinant lipase B from Candida antarctica (CALB), for the production of isopropyl palmitate and the optimization of this biocatalytic route. RESULTS: Initially, three distinct core–shell biocatalysts, were evaluated for the production of isopropyl palmitate and the CALB‐P(S‐co‐DVB)/P(S‐co‐DVB) biocatalyst (biocatalyst made of polystyrene‐co‐divinylbenzene core–shell particles) was the most suitable biocatalyst for this purpose. The effect of organic solvents – n‐hexane, isooctane, n‐heptane and cyclohexane – in the ester conversion was evaluated, and the most suitable solvent was the isooctane. The optimal reaction conditions were pursued conducting an optimization statistical analysis. The most suitable reaction conditions were identified: reaction temperature, 55°C; substrate molar ratio, 1:1.42 (palmitic acid: isopropyl alcohol); biocatalyst content, 24% w/w. Finally, the reuse of the biocatalyst was evaluated and the relative enzymatic activity remained up to 50% after the fourth cycle. CONCLUSION: Results were compared with commercial biocatalyst and the home‐made enzymatic biocatalyst (CALB‐P(S‐co‐DVB/PS‐co‐DVB) showed promise for application in the synthesis of isopropyl palmitate. The optimization study improved reaction conversion from 30% to 78%. The home‐made biocatalysts exhibited better performance for the synthesis of isopropyl palmitate compared with the commercial Novozym 435, using the same enzymatic activity. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The oleaginous yeast Moniliella spathulata R25L270 was the first yeast able to grow and produce extracellular lipase using Macaúba (Acrocomia aculeate) cake as substrate. The novel lipase was recently identified, and presented promising features for biotechnological applications. The M. spathulata R25L270 lipase efficiently hydrolyzed vegetable and animal oils, and showed selectivity for generating cis-5,8,11,15,17-eicosapentaenoic acid from sardine oil. The enzyme can act in a wide range of temperatures (25-48 °C) and pH (6.5-8.4). The present study deals with the immobilization of M. spathulata R25L270 lipase on hydrophobic, covalent and ionic supports to select the most active biocatalyst capable to obtain omega-3 fatty acids (PUFA) from sardine oil. Nine immobilized agarose derivatives were prepared and biochemically characterized for thermostability, pH stability and catalytic properties (KM and Vmax). Ionic supports improved the enzyme-substrate affinity; however, it was not an effective strategy to increase the M. spathulata R25L270 lipase stability against pH and temperature. Covalent support resulted in a biocatalyst with decreased activity, but high thermostability. The enzyme was most stabilized when immobilized on hydrophobic supports, especially Octyl-Sepharose. Compared with the free enzyme, the half-life of the Octyl-Sepharose derivative at 60 °C increased 10-fold, and lipase stability under acidic conditions was achieved. The Octyl-Sepharose derivative was selected to obtain omega-3 fatty acids from sardine oil, and the maximal enzyme selectivity was achieved at pH 5.0. [ABSTRACT FROM AUTHOR]

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]

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]

The oleaginous yeast Moniliella spathulata R25L270 was the first yeast able to grow and produce extracellular lipase using Macaúba ( Acrocomia aculeate ) cake as substrate. The novel lipase was recently identified, and presented promising features for biotechnological applications. The M. spathulata R25L270 lipase efficiently hydrolyzed vegetable and animal oils, and showed selectivity for generating cis -5,8,11,15,17-eicosapentaenoic acid from sardine oil. The enzyme can act in a wide range of temperatures (25-48 °C) and pH (6.5-8.4). The present study deals with the immobilization of M. spathulata R25L270 lipase on hydrophobic, covalent and ionic supports to select the most active biocatalyst capable to obtain omega-3 fatty acids (PUFA) from sardine oil. Nine immobilized agarose derivatives were prepared and biochemically characterized for thermostability, pH stability and catalytic properties (K M and V max ). Ionic supports improved the enzyme-substrate affinity; however, it was not an effective strategy to increase the M. spathulata R25L270 lipase stability against pH and temperature. Covalent support resulted in a biocatalyst with decreased activity, but high thermostability. The enzyme was most stabilized when immobilized on hydrophobic supports, especially Octyl-Sepharose. Compared with the free enzyme, the half-life of the Octyl-Sepharose derivative at 60 °C increased 10-fold, and lipase stability under acidic conditions was achieved. The Octyl-Sepharose derivative was selected to obtain omega-3 fatty acids from sardine oil, and the maximal enzyme selectivity was achieved at pH 5.0., Competing Interests: The authors declare that they have no competing interests.