1.Evaluation of different methods for immobilization of Candida antarctica lipase B (CalB lipase) in polyurethane foam and its application in the production of geranyl propionate.
Nicoletti G1, Cipolatti EP, Valério A, Carbonera NG, Soares NS, Theilacker E, Ninow JL, de Oliveira D. Bioprocess Biosyst Eng. 2015 Sep;38(9):1739-48. doi: 10.1007/s00449-015-1415-6. Epub 2015 Jun 3.
With the aim of studying the best method for the interaction of polyurethane (PU) foam and Candida antarctica lipase B, different methods of CalB immobilization were studied: adsorption (PU-ADS), bond (using polyethyleneimine) (PU-PEI), ionic adsorption by PEI with cross-linking with glutaraldehyde (PU-PEI-GA) and entrapment (PU). The characterization of immobilized enzyme derivatives was performed by apparent density and Fourier transform infrared spectroscopy. The free enzyme and enzyme preparations were evaluated at different pH values and temperatures. The highest enzyme activity was obtained using the PU method (5.52 U/g). The methods that stood out to compare the stabilities and kinetic parameters were the PU and PU-ADS. Conversions of 83.5 and 95.9 % for PU and PU-ADS derivatives were obtained, in 24 h reaction, using citronella oil and propionic acid as substrates.
2.Chemical composition of the essential oil from Pulicaria vulgaris var. graeca (Sch.-Bip.) Fiori (Asteraceae) growing wild in Sicily and its antimicrobial activity.
Casiglia S1, Riccobono L1, Bruno M1, Senatore F2, Senatore F3. Nat Prod Res. 2016;30(3):259-67. doi: 10.1080/14786419.2015.1055267. Epub 2015 Jul 16.
In this study the chemical composition of the essential oil from aerial parts of Pulicaria vulgaris var. graeca (Sch.-Bip.) Fiori collected in Sicily was evaluated by GC and GC-MS. The main components of P. vulgaris var. graeca oil were hexadecanoic acid (21.7%), β-caryophyllene (14.3%) and geranyl propionate (8.2%). The comparison with other studied oils of genus Pulicaria is discussed. Antibacterial activity against several bacteria, including some ones infesting historical art craft, was also determined.
3.Solvent-free geranyl oleate production by enzymatic esterification.
Paroul N1, Grzegozeski LP, Chiaradia V, Treichel H, Cansian RL, Oliveira JV, de Oliveira D. Bioprocess Biosyst Eng. 2011 Mar;34(3):323-9. doi: 10.1007/s00449-010-0475-x. Epub 2010 Oct 28.
This work reports the optimization of geranyl propionate production by esterification of geraniol and propionic acid in a solvent-free system using a commercial lipase as catalyst. For this purpose, a sequential strategy was performed applying two experimental designs. The operating conditions that optimized geranyl propionate production were determined to be 40 °C, geraniol to propionic acid molar ratio of 3:1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the optimum reaction parameters, a kinetic study was carried out evaluating the influence of substrates molar ratio, enzyme concentration and temperature on reaction conversion. Results obtained in this step allow to conclude that an excess of alcohol (acid to alcohol molar ratio of 1:6), relatively low enzyme concentration (5 wt%), temperature of 40 °C and substrates molar ratio of 1:1 afforded nearly complete reaction conversion after 30 min of reaction.
4.Concentration, characterization and application of lipases from Sporidiobolus pararoseus strain.
Smaniotto A1, Skovronski A1, Rigo E1, Tsai SM2, Durrer A2, Foltran LL2, Paroul N1, Di Luccio M3, Oliveira JV3, de Oliveira D3, Treichel H4. Braz J Microbiol. 2014 May 19;45(1):294-302. eCollection 2014.
Lipases produced by a newly isolated Sporidiobolus pararoseus strain have potential catalytic ability for esterification reactions. After production, the enzymatic extracts (conventional crude and precipitated, 'CC' and 'CP', and industrial crude and precipitated, 'IC' e 'IP') were partially characterized. The enzymes presented, in general, higher specificity for short chain alcohols and fatty acids. The precipitated extract showed a good thermal stability, higher than that for crude enzymatic extracts. The 'CC' and 'CP' enzymes presented high activities after exposure to pH 6.5 and 40 °C. On the other hand, the 'IC' and 'IP' extracts kept their activities in a wide range of pH memory but presented preference for higher reaction temperatures. Preliminary studies of application of the crude lipase extract in the enzymatic production of geranyl propionate using geraniol and propionic acid as substrates in solvent-free system led to a reaction conversion of 42 ± 1.