Cellulases of Humicola insolens and Humicola grisea

Hayashida, Shinsaku; Ohta, Kazuyoshi; Mo, Kaiguo

doi:10.1016/0076-6879(88)60134-0

Cited by 19 publications

(7 citation statements)

References 7 publications

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“…Yoshioka and Hayashida (271) purified cellulases from a strain of H. insolens grown on wheat bran. From 2.5 g of culture extract protein, 9, 11, and 18 mg, respectively, of pure endoglucanase, exoglucanase, and ␤-glucosidase were obtained (110,113,271).…”

Section: Cellulasementioning

confidence: 99%

Thermophilic Fungi: Their Physiology and Enzymes

Maheshwari

Bharadwaj

Bhat

2000

Microbiol Mol Biol Rev

658

380

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SUMMARY Thermophilic fungi are a small assemblage in mycota that have a minimum temperature of growth at or above 20°C and a maximum temperature of growth extending up to 60 to 62°C. As the only representatives of eukaryotic organisms that can grow at temperatures above 45°C, the thermophilic fungi are valuable experimental systems for investigations of mechanisms that allow growth at moderately high temperature yet limit their growth beyond 60 to 62°C. Although widespread in terrestrial habitats, they have remained underexplored compared to thermophilic species of eubacteria and archaea. However, thermophilic fungi are potential sources of enzymes with scientific and commercial interests. This review, for the first time, compiles information on the physiology and enzymes of thermophilic fungi. Thermophilic fungi can be grown in minimal media with metabolic rates and growth yields comparable to those of mesophilic fungi. Studies of their growth kinetics, respiration, mixed-substrate utilization, nutrient uptake, and protein breakdown rate have provided some basic information not only on thermophilic fungi but also on filamentous fungi in general. Some species have the ability to grow at ambient temperatures if cultures are initiated with germinated spores or mycelial inoculum or if a nutritionally rich medium is used. Thermophilic fungi have a powerful ability to degrade polysaccharide constituents of biomass. The properties of their enzymes show differences not only among species but also among strains of the same species. Their extracellular enzymes display temperature optima for activity that are close to or above the optimum temperature for the growth of organism and, in general, are more heat stable than those of the mesophilic fungi. Some extracellular enzymes from thermophilic fungi are being produced commercially, and a few others have commercial prospects. Genes of thermophilic fungi encoding lipase, protease, xylanase, and cellulase have been cloned and overexpressed in heterologous fungi, and pure crystalline proteins have been obtained for elucidation of the mechanisms of their intrinsic thermostability and catalysis. By contrast, the thermal stability of the few intracellular enzymes that have been purified is comparable to or, in some cases, lower than that of enzymes from the mesophilic fungi. Although rigorous data are lacking, it appears that eukaryotic thermophily involves several mechanisms of stabilization of enzymes or optimization of their activity, with different mechanisms operating for different enzymes.

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Section: Cellulasementioning

confidence: 99%

Thermophilic Fungi: Their Physiology and Enzymes

Maheshwari

Bharadwaj

Bhat

2000

Microbiol Mol Biol Rev

658

380

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“…In contrast, dimeric enzymes with native molecular masses of about 200 kDa were found in Paecilomyces thermophila (Yang et al, 2008) and Thermomyces lanuginosus (Lin et al, 1999). Apparent molecular masses ranging from 40 to 250 kDa were reported for -D-glucosidases from other fungal sources (Hayashida et al, 1988;Masheshwari et al, 2000;Bhatia et al, 2002;Yoon et al, 2008).…”

Section: Enzyme Purification and Molecular Propertiesmentioning

confidence: 83%

“…The -D-glucosidase from H. grisea var. thermoidea showed a carbohydrate content of about 43%, elevated when compared to the contents estimated for the intracellular enzymes from H. insolens (Hayashida et al, 1988;Rao and Murthy, 1988) and S. thermophilum (Zanoelo et al, 2004). Interestingly, a 2-fold-lower value was determined for the intracellular enzyme purified from the same strain of H. grisea var.…”

Section: Enzyme Purification and Molecular Propertiesmentioning

confidence: 89%

“…The enzyme also showed high apparent affinities for pNP-Fuc (K M =0.05 0.005 mM) and pNPGlc (K M =0.12 0.01 mM). Greater maximal velocities and affinities for synthetic substrates rather than natural ones are kinetic features shared by -D-glucosidases from several fungal sources (Hayashida et al, 1988;Venturi et al, 2002;Zanoelo et al, 2004;Yang et al, 2008;Yoon et al, 2008).…”

Section: Substrate Specificity and Kinetic Parameters Of The Purifiedmentioning

confidence: 97%

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Purification and biochemical properties of a glucose-stimulated β-D-glucosidase produced by Humicola grisea var. thermoidea grown on sugarcane bagasse

et al. 2010

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The effect of several carbon sources on the production of mycelial-bound beta-glucosidase by Humicola grisea var. thermoidea in submerged fermentation was investigated. Maximum production occurred when cellulose was present in the culture medium, but higher specific activities were achieved with cellobiose or sugarcane bagasse. Xylose or glucose (1%) in the reaction medium stimulated beta-glucosidase activity by about 2-fold in crude extracts from mycelia grown in sugarcane bagasse. The enzyme was purified by ammonium sulfate precipitation, followed by Sephadex G-200 and DEAE-cellulose chromatography, showing a single band in PAGE and SDS-PAGE. The beta-glucosidase had a carbohydrate content of 43% and showed apparent molecular masses of 57 and 60 kDa, as estimated by SDS-PAGE and gel filtration, respectively. The optimal pH and temperature were 6.0 and 50 degrees C, respectively. The purified enzyme was thermostable up to 60 min in water at 55 degrees C and showed half-lives of 7 and 14 min when incubated in the absence or presence of 50 mM glucose, respectively, at 60 degrees C. The enzyme hydrolyzed p-nitrophenyl-beta-D-glucopyranoside, p-nitrophenyl-beta-D-galactopyranoside, p-nitrophenyl-beta-D-fucopyranoside, p-nitrophenyl-beta-D-xylopyranoside, o-nitrophenyl-beta-D-galactopyranoside, lactose, and cellobiose. The best synthetic and natural substrates were p-nitrophenyl-beta-D-fucopyranoside and cellobiose, respectively. Purified enzyme activity was stimulated up to 2-fold by glucose or xylose at concentrations from 25 to 200 mM. The addition of purified or crude beta-glucosidase to a reaction medium containing Trichoderma reesei cellulases increased the saccharification of sugarcane bagasse by about 50%. These findings suggest that H. grisea var. thermoidea beta-glucosidase has a potential for biotechnological applications in the bioconversion of lignocellulosic materials.

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“…Among most widely studied organisms having notably high cellulolytic activity, include various fungal species like Humicola, Trichoderma, Penicillium and Aspergillus. Some bacterial species include; Pseudomonas, Bacilli, Actinomycetes, streptomycetes, Cellumonas, Streptomyces and Actinomucor [48]- [50]. Because of the ability of fungi to consume cellulose for energy consumption, only certain species could be used practically for cellulose hydrolysis.…”

Section: Cellulase Producing Organismsmentioning

confidence: 99%

Cellulase Production from Species of Fungi and Bacteria from Agricultural Wastes and Its Utilization in Industry: A Review

Imran¹,

Anwar²,

Irshad³

et al. 2016

AER

102

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In energy deficient world, cellulases play a major role for the production of alternative energy resources utilizing lignocellulosic waste materials for bioethanol and biogas production. This study highlights fungal and bacterial strains for the production of cellulases and its industrial applications. Solid State Fermentation (SSF) is more suitable process for cellulase production as compared to submerge fermentation techniques. Fungal cellulosomes system for the production of cellulases is more desirable and resistant to harsh environmental conditions. Trichoderma species are considered as most suitable candidate for cellulase production and utilization in industry as compared to Aspergillus and Humicola species. However, genetically modified strains of Aspergillus have capability to produce cellulase in relatively higher amount. Bacterial cellulase are more resistant to alkaline and thermophile conditions and good candidate in laundries. Cellulases are used in variety of industries such as textile, detergents and laundries, food industry, paper and pulp industry and biofuel production. Thermally stable modified strains of fungi and bacteria are good future prospect for cellulase production.

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Cellulases of Humicola insolens and Humicola grisea

Cited by 19 publications

References 7 publications

Thermophilic Fungi: Their Physiology and Enzymes

Thermophilic Fungi: Their Physiology and Enzymes

Purification and biochemical properties of a glucose-stimulated β-D-glucosidase produced by Humicola grisea var. thermoidea grown on sugarcane bagasse

Cellulase Production from Species of Fungi and Bacteria from Agricultural Wastes and Its Utilization in Industry: A Review

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