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

• Wiboon Riansa-ngawong ^[1] ; Maneewan Suwansaard ^[2] ; Poonsuk Prasertsan ^[1]
  1. [1] Prince of Songkla University

     Prince of Songkla University

     Tailandia

     
  2. [2] Bowling Green State University

     Bowling Green State University

     City of Bowling Green, Estados Unidos

     
• Localización: Electronic Journal of Biotechnology, ISSN-e 0717-3458, Vol. 15, Nº. 6, 2012, págs. 1-1
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • 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 extract- malt (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.