Modulation of lipase B from Candida antarctica properties via covalent immobilization on eco-friendly support for enzymatic kinetic resolution of rac-indanyl acetate.

In this study, the modulation of enzymatic biocatalysts were developed by the use of lipase B from Candida antarctica covalently immobilized on an eco-friendly support, cashew apple bagasse, activated with 10% glycidol-ethylenediamine-glutaraldehyde (GEG) under different immobilization strategies (5 mM or 100 mM ionic strength and in absence or presence of 0.5% (v/v) Triton X-100). The biocatalysts were characterized for thermal and organic solvents stabilities and compared with the soluble enzyme. The biocatalysts were then applied to the hydrolysis of the rac-indanyl acetate (2:1 ratio enzyme/substrate) at pH 7.0 and 30 °C for 24 h. For all the strategies evaluated, GEG promoted kinetic resolution of rac-indanyl acetate with maximum conversion (50%) and led to (R)-indanol with excellent enantiomeric excess (97%), maintaining the maximum conversion for five consecutive cycles of hydrolysis. Therefore, the use of cashew apple bagasse has proved to be a promising eco-friendly support for enzyme immobilization, since it resulted in stable biocatalysts for enzymatic kinetic resolution.

The Bioconversion of Pretreated Cashew Apple Bagasse into Ethanol by SHF and SSF Processes.

Ethanol production from acidic-alkaline pretreated cashew apple bagasse (CAB-OH) was investigated using separated hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes. First, a screening of Kluyveromyces strains was conducted by SHF and a maximum ethanol concentration of 24.1 g L(-1) was obtained using Kluyveromyces marxianus ATCC36907, which presented similar profiles when compared to results obtained by a Saccharomyces strain. The effect of temperature on ethanol production conducted by SHF using K. marxianus ATCC36907 was investigated, and the maximum ethanol yield (YE/G) was obtained at 40 °C (0.46 g g(-1)) using a synthetic medium. In the SHF using CAB-OH hydrolysate, the maximum ethanol concentration obtained was 24.9 g L(-1), 5.92 g L(-1) h(-1) of productivity, and ethanol yield of 0.43 g g(-1) at 40 °C. Afterwards, K. marxianus ATCC36907 was used in the bioconversion of CAB-OH by SSF, and an ethanol concentration of 41.41 ± 0.2 g L(-1) was obtained using 10 % CAB-OH at 40 °C, 150 rpm and 24 h, resulting in a Y'E/G of 0.50 gE gG (-1) and an efficiency of 98.4 %, in the process conducted with cellobiase supplementation. SHF and SSF processes using CAB-OH and K. marxianus ATCC36907 can be used to ethanol production, but the SSF process required only one step to achieve the same production.