International Journal of Current Microbiology and Applied Sciences |
ISSN: 2319-7706 Volume 2 Number 9 (2013) pp. 174-187 |
Utilization of fortified rice husk for the fermentative production of xylanase by Trichoderma sp. |
K.Balakrishnan1
*, Rahul Kumar1
, R Agalya Devi1
, S. Jayasri2
and B.Nishabalu2 |
1Technology Business Incubator, BIT Sathyamangalam, Erode District 638401, Tamil Nadu, India 2Department of Biotechnology, BIT Sathyamangalam, Erode District 638401, Tamil Nadu, India *Corresponding author e-mail:rainbalu@gmail.com |
ABSTRACT |
Mineral salt agar plates containing rice husk powder were used for the isolation of xylanase producing microorganisms. Two of the fungal isolates namely Trichoderma sp. and Neurospora sp. showed better xylanase activities. Trichoderma sp. produced maximum xylanase activity (22.5 U/ gds 72 h) when
grown in solid substrate than that in submerged cultivation (2.62 U/mL in 96 h). It was further revealed that carboxy methyl cellulose (CMC) as additional carbon
source produced maximum rise in xylanase activity (107 U/gds, 72 h) in solid
culturing. Similarly the nitrogen sources (casein acid hydrolysate, yeast extract & corn steep solid) supplemented also gave enhanced enzyme activities. Synergistic
effect of CMC & corn steep solid resulted in enhanced xylanase activity as high as 570 U/gds in 72 h. The same further enhanced to 722 U/gds when this combination was altered by replacing pressmud extract (PE) with a combination of PE: Corn
steep liquor (2:8). The crude xylanase activity was more pronounced at 50°C and at pH 5. Enzyme was stable at 40 to 70°C. Ca2+ Cu
2+ and Fe2+ acted as strong
inhibitors for xylanase activity. Three phase partition resulted in 7 fold rise in
enzyme activity i.e. 5985 U/mg |
Keywords |
Rice husk; Trichoderma
sp.; SSF; Pressmud Neurospora
sp.; Xylanase. |