Application of palm pressed fiber as a carrier for ethanol production by Candida shehatae TISTR5843

Abstract

Palm pressed fiber (PPF) is a clean and renewable lignocellulosic material. The PPF and delignified PPF (DPPF) were used as a carrier for immobilization of Candida shehatae TISTR5843 in bioethanol production. PPF was pre-treated by milling to obtain small particles, whereas DPPF was the delignification of PPF using NaClO2. C. shehatae TISTR5843 was grown in modified yeast extractmalt (YM) medium at 30 ± 2ºC on an orbital shaker at 150 rpm for batch and repeated batch fermentation. In the batch system, immobilized cells on a small size, less than 0.5 mm, of DPPF (sDPPF) gave the maximum ethanol production of 11.5 g L -1 at 24 hrs cultivation period. The ethanol concentration and ethanol yield of sDPPF were 6.2% and 6.8% higher (ethanol production 11.5 g L -1 , ethanol yield 0.47 g g -1 ) than those of free cells (ethanol production 10.8 g L -1 , ethanol yield 0.44 g g -1 ) after 36 hrs of cultivation. In contrast, the small size of PPF (sPPF) was selected as a carrier in repeated batch fermentation for cost effectiveness. The ethanol productivity of immobilized yeast cells in repeated batch fermentations was 45.2-51.6% greater than that obtained from batch fermentations. The immobilized cells on sPPF improved the ethanol production and could be reused 4 times with retaining the activity of 93%. In conclusion, PPF is a potential carrier in the immobilization system. The pre-treatment of PPF increases the surface area that enhances cell adsorption and ethanol production by C. shehatae TISTR5843.

Development of corn silk as a biocarrier for <i>Zymomonas mobilis</i> biofilms in ethanol production from rice straw

“…Therefore, the removal of lignin through chemical processes tends to deform the rigid structure of corn silk and enhances opportunities for bacterial cell immobilization on the structure of cellulose and hemicelluloses by increasing the porosity of the supporting material. This is in agreement with reports which showed yeast cells favor cell adhesion to lignocellulosic supports treated by delignification (Riansa-ngawong et al, 2012). This work also documented increases in the immobilized cell concentrations for Z. mobilis biofilms on delignified corn silk and increased ethanol productivity in fermentations.…”

“…However, natural carriers are more available, cost effective, maintain viable cells for several cycles of operations, and are easily separated in the downstream process. Chitosan, sawdust, rice husk, rice straw, sorghum bagasse, thin shell silk cocoon and palm pressed fiber have been used as natural carriers for many yeast applications in ethanol productions (Kopsahelis et al, 2007;Rattanapan et al, 2011;Riansa-ngawong et al, 2012;Yu et al, 2007). The potential of Z. mobilis cell immobilization on natural carriers for the fermentation of lignocellulosic material has not yet been reported.…”

Sodium Hydroxide-Steam Explosion Treated Oil Palm Empty Fruit Bunch: Ethanol Production and Co-Fermentation with Cane Molasses

“…8). This result is consistent with previous reports where, for example, ethanol production by Candida shehatae was increased in the presence of palm-pressed fiber (PPF), a solid waste extracted from OPEFB through decortation, and the C. shehatae cells were immobilized on the PPF (Riansa-ngawong et al 2012). The pretreatment of the PPF by size reduction and delignification improved its immobilization support.…”

Sugarcane Bagasse as a Carrier for the Immobilization of Saccharomyces cerevisiaein Bioethanol Production

“…In this study, 2.5 g of the sugarcane bagasse was used as a carrier to absorb 50 mL cells suspension, or known as biocatalyst. This was because a higher cell density inside the carrier can certainty cause an increase of sugar consumption, ethanol productivity, and ethanol yield [17]. The best ratio between the carrier and the volume of cell suspension Fermentation using immobilized yeast.…”