Improvement of carboxymethyl cellulase production from <i>Chaetomium cellulolyticum</i> NRRL 18756 by mutation and optimization of solid state fermenttion

Abstract

Cellulase producing fungus Chaetomium cellulolyticum NRRL 18756 was subjected to various doses of gamma irradiation to enhance the production of the industrially important enzyme carboxymethyl cellulase (CMCase). Among all the mutants tested, M-7 obtained through 0.5 KGy irradiation showed highest extracellular CMCase production which is 1.6-fold higher than that of the wild type. Optimal conditions for the production of CMCase by the mutant fungal strain using solid-state fermentation were examined. The optimized medium consisted of sugarcane bagasse supplemented with 1% (w/w) peptone, 2.5mM MgSO4, and 0.05% (v/w) Tween 80. Optimal moisture content and initial pH was 40% (v/w) and 5.0-6.5, respectively. The medium was fermented at 40° C for 4 days. The resulting CMCase yield was 4.0-fold more than that of the wild type strain grown on the basal wheat bran medium. Some characteristics of partially purified CMCase from the mutant and wild type of C. cellulolyticum were investigated. The partially purified mutant CMCase was more stable than the wild type CMCase. Thus, the higher thermostability of mutant CMCase makes it a potential candidate for commercial and industrial process. Key words: Chaetomium cellulolyticum; Carboxymethyl cellulase; Mutation; Optimization; Solid state fermentation DOI: http://dx.doi.org/10.3329/bjb.v40i2.9769 Bangladesh J. Bot. 40(2): 139-147, 2011 (December)

Synthesis and investigations on tellurium myconanoparticles

“…Gamma rays are short wave, high-energy electromagnetic radiations capable of ionizing other atoms [ 15 ]. Gamma irradiation of potassium tellurite/broth culture mixture improved TeNPs production at 1 kGy.…”

Cost‐effective cellulase production, improvement strategies, and future challenges

“…It is claimed by many researchers that strain improvement can be achieved by mutagenic agents for microbial cellulase production (El‐Ghonemy, Ali, El‐Bondkly, Moharam, & Talkhan, 2014; Li et al, 2010). For enhanced cellulase production, several mutagenic agents like ultraviolet (UV) irradiation, gamma irradiation (Co60 γ‐rays), ethyl‐methane sulphonate (EMS), and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine have been enacted on various strains of fungus (El‐Ghonemy, Ali, & Moharam, 2014; Fawzi & Hamdy, 2011; Mostafa, 2014). A transformed strain of A. oryzae NRRL 3484 having more noteworthy yielding of extracellular cellulase by utilizing a multistep change system was created by Dhillon, Kaur, Brar, and Verma (2012).…”

“…SU‐M15) than wild type strain fermented onto wheat bran medium. When Chaetomiumcellulolyticum NRRL 18756 was treated with several doses of gamma light (0.5 KGy) exhibited maximum production of CMCaseup to 1.6‐fold more than wild type strains (Fawzi & Hamdy, 2011). Shafique, Bajwa, and Shafique (2011) examined T. Viride FCBP‐142, a wild type strain was adopted to develop hyperproducer strain for cellulases production and exposed to mutation with UV and EMS.…”

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“…Various pretreatment technologies examined the changes in lignocellulosic structure primarily in cellulose and hemicellulose during the most commonly applied pretreatment, technologies including dilute acid pretreatment, and alkaline pretreatment (Taherzadeh and Karimi,2008). Fawzi and Hamdy (2011) used HCl for pretreatment sugar-cane bagasse for producing CMCase by Chaetomium cellulolyticum NRRL 18756.…”