Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

PRODUCTION OF CELLULASE FROM PALM OIL INDUSTRIAL SOLID WASTE BY ACTINOMYCETES ISOLATE 12.3.A

HAMKA NURKAYA, O. WATHANACHAIYINGYONG, MARWATI, S. CHAIYANAN AND S. CHAIYANAN

Abstract

This research aimed at utilization of palm oil industrial solid waste for enzyme cellulose production. The abundant waste of palm oil industry is oil palm empty fruit bunch (OPEFB) which composed of lignocellulosic material. A potential of using OPEFB and its acid pretreatment residue to accelerate cellulase production by cellulolytic microorganism was tested. The high cellulase producing actinomycetes isolate 12.3.A that was isolated from the oil palm plantation area in Phetchaburi, Thailand was used in this study. The isolate 12.3.A was preliminary appointed to be Streptomyces hirsutus from the result of 16S-rRNA gene analysis. The optimal conditions for cellulase production of S. hirsutus isolate 12.3.A were similar for both substrates. The best yields were derived from culturing the cells at pH 7, 30°C, and substrate concentration at 1% for 6 days. The highest cellulase activities from OPEFB and the acid residue were 0.71 U/mL and 0.56 U/mL, respectively. The suitable nitrogen sources for the culture medium made of OPEFB was ammonium sulfate, while peptone was for the residue. The zymogram assay with polyacrylamide amended with carboxymethylcellulose (CMC) demonstrated that the isolate 12.3.A produced 2 CMCases (endo-β-glucanases) which had optimal conditions for the activity at pH 6.5 and 45oC. The pretreatment should loosen the complex structure of lignocellulosic component of OPEFB for facilitating the attack of cellulose by microbial cellulase. Acid hydrolysis pretreatment extracted all hemicellulose out and increased the percentage of cellulose of the residue. However, this increased the percentage of lignin as well. Therefore, the acid hydrolysis pretreatment of the OPEFB did not assist the acceleration of the microbial cellulase production. However, OPEFB and its acid hydrolysis residue may act as good substrates for cellulase production of S. hirsutus isolate 12.3.A.