ORIGINAL ARTICLE
Year : 2014  |  Volume : 13  |  Issue : 2  |  Page : 121-129

β-Glucosidase production by mixed culture using crude hemicellulose from rice straw black liquor and peat moss as an inert support


1 Department of Microbial Chemistry, National Research Center, Cairo, Egypt
2 Natural and Microbial Products, National Research Center, Cairo, Egypt
3 Green Chemistry, National Research Center, Cairo, Egypt

Correspondence Address:
Mohamed A Farid
Department of Natural and Microbial Products, National Research Center, Dokki, Cairo
Egypt
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1687-4315.147074

Rights and Permissions

Background and objectives Rice straw black liquor (RSBL) has no commercial significance and causes environmental pollution because of its poor disposal, although it holds promise as a cheap substrate for the production of β-glucosidase. The objective of the present work was to improve and optimize the cultural conditions of mixed cultures of Trichoderma reesei NRRL 6165 and Aspergillus niger NRC 9A under solid-state fermentation (SSF) for the production of β-glucosidase using crude hemicellulose (CHC) prepared from RSBL and peat moss as an inert support. Materials and methods Mixed cultures of the mycelial fungi T. reesei NRRL 11236 and T. reesei NRRL 6165 and A. niger strains (NRC 5A, NRC 7A, and NRC 9A) were evaluated for their ability to produce β-glucosidase using CHC prepared from RSBL and peat moss as an inert support under SSF. Optimization of initial pH (4-8), supplementation with different concentrations of corn steep liquor and ammonium sulfate, the initial moisture content (63.6-87.4% v/w), inoculum size and ratio of microorganisms, CHC/peat moss ratio, and incubation time (0-14 day) were studied. The extracted enzyme was assayed using p-nitrophenyl-β-d-glucopyranoside as a substrate. Data analysis was performed by one-way analysis of variance using computer software Minitab 16. Results and conclusion Mixed cultures of the mycelial fungi T. reesei NRRL 11236 and T. reesei NRRL 6165 and A. niger strains (NRC 5A, NRC 7A, and NRC 9A) were evaluated for their ability to produce β-glucosidase using CHC prepared from RSBL and peat moss as an inert support under SSF. The most potent coculture composed of A. niger NRC 9A (192.39 ± 7.37 U/g CHC) and T. reesei NRRL 6165 (12.56 ± 0.42 U/g CHC) was used in a mixed culture to enhance β-glucosidase production by coculturing under SSF. In mixed culture, β-glucosidase of the coculture (265.32 ± 0.25 U/g CHC) was nearly 1.3-fold and 10.6-fold than that of monocultures of A. niger NRC 9A and T. reesei NRRL 6165, respectively. Optimization of the environmental and culture parameters, different solid supports, concentration of nitrogen sources (ammonium sulfate and corn steep liquor), initial pH value, CHC/peat moss ratio, inoculum size and ratios of the two strains, moisture content, and incubation time exhibited a significant increase (466 ± 5.42 U/g CHC) in β-glucosidase production compared with before optimization. The study demonstrated that a substrate that does not find any commercial significance and causes environmental pollution because of its poor disposal holds promise as a cheap substrate for the production of β-glucosidase.


[FULL TEXT] [PDF]*
Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)
 

 Article Access Statistics
    Viewed1767    
    Printed32    
    Emailed0    
    PDF Downloaded182    
    Comments [Add]    

Recommend this journal