YEAST GROWTH AND PROTEIN QUALITY CULTIVATED IN LIGNOCELLULOSE MATERIAL

摘要

Oil palm fronds (OPF) and palm oil mill effluent (POME) had been used as cultivation media to study their influences on growth and protein quality of yeasts S. cerevisiae ITM 3010 and C. utilis ITM 1017. Two different methods using acid hydrolysis treatment and enzymatic treatment had been applied on OPF. Cultivations were carried out in 250 ml Erlenmeyer flasks at 30℃, 100 rpm for 72 hours. Yeast growth was monitored for every 12 hours interval. Harvested cell was ruptured by mechanical method using glass beads and cell extract were analyzed for protein and amino acid concentration. Results showed that only OPF medium treated with cellulase allowed yeasts growth as no growth was observed in acid hydrolyzed medium due to the presence of inhibitors. However, yeasts growth observed in OPF medium (S. cerevisiae, 1.42 g/l; C. utilis, 1.67 g/l) was relatively lower than in POME medium (S. cerevisiae, 2.60 g/l; C. utilis, 3.90 g/l). Cell extract of S. cerevisiae from OPF medium contained relatively higher level of amino acids as compared to extract obtained from POME medium. However, maximum level of lysine was observed in cell extract of C. utilis (10.68 g/100g protein) cultivated in POME medium whereas maximum level of glutamic acid was observed in cell extract of C. utilis (9.83 g/100g protein) from OPF medium.