Cellulase complex of a mesophilic Streptomyces strain

1980 ◽  
Vol 26 (2) ◽  
pp. 183-189 ◽  
Author(s):  
M. Ishaque ◽  
D. Kluepfel

Various cellulolytic streptomycetes were isolated from natural environments. The cellulase production of one of these mesophilic Streptomyces strains, identified as S. flavogriseus was studied. When grown as a submerged culture with 1% microcrystalline cellulose (Avicel) as substrate, the strain produced considerable amounts of β-1, 4-glucan glucanohydrolase (EC 3.2.1.4; CM cellulase) in the extracellular supernatant and exhibited good overall cellulolytic activity as measured using filter paper (FP cellulase) and cotton as substrates. The maximum enzyme yields were obtained after 72 h of incubation at 30 °C. The optimal conditions for the FP cellulase activity were found at pH 5.6 and 40 °C. All β-glucosidase and cellobiase activities were found in the mycelial fraction of the culture and could be obtained in soluble form by sonication.

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Ega Soujanya Lakshmi ◽  
Manda Rama Narasinga Rao ◽  
Muddada Sudhamani

ABSTRACT Thirty seven different colonies were isolated from decomposing logs of textile industries. From among these, a thermotolerant, grampositive, filamentous soil bacteria Streptomyces durhamensis vs15 was selected and screened for cellulase production. The strain showed clear zone formation on CMC agar plate after Gram’s iodine staining.  Streptomyces durhamensis vs15 was further confirmed for cellulase production by estimating the reducing sugars through dinitrosalicylic acid (DNS) method. The activity was enhanced by sequential mutagenesis using three mutagens of ultraviolet irradiation (UV), N methyl-N’-nitro-N-nitrosoguanidine (NTG) and Ethyl methane sulphonate (EMS). After mutagenesis, the cellulase activity of GC23 (mutant) was improved to 1.86 fold compared to the wild strain (vs15). Optimal conditions for the production of cellulase by the GC 23 strain were evaluated using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Effect of pH, temperature, duration of incubation, , and substrate concentration on cellulase production were evaluated. Optimal conditions for the production of cellulase enzyme using Carboxy Methyl Cellulase as a substrate are 55 oC of temperature, pH of 5.0 and incubation for 40 h. The cellulase activity of the mutant Streptomyces durhamensis GC23 was further optimised to 2 fold of the activity of the wild type by RSM and ANN.  


2005 ◽  
Vol 51 (9) ◽  
pp. 773-776 ◽  
Author(s):  
T Kudanga ◽  
E Mwenje

Cellulase production by Aureobasidium pullulans from the temperate regions has remained speculative, with most studies reporting no activity at all. In the current study, tropical isolates from diverse sources were screened for cellulase production. Isolates were grown on a synthetic medium containing cell walls of Msasa tree (Brachystegia sp.) as the sole carbon source, and their cellulolytic activities were measured using carboxymethyl cellulose and α-cellulose as substrates. All isolates studied produced carboxymethyl cellulase (endoglucanase) and alpha-cellulase (exoglucanase) activity. Endoglucanase-specific activities of ten selected isolates ranged from 2.375 to 12.884 µmol glucose·(mg protein)–1·h–1, while activities on α-cellulose (exoglucanase activity) ranged from 0.293 to 22.442 µmol glucose·(mg protein)–1·day–1. Carboxymethyl cellulose induced the highest cellulase activity in the selected isolates, while the isolates showed variable responses to nitrogen sources. The current study indicates that some isolates of A. pullulans of tropical origin produce significant extracellular cellulolytic activity and that crude cell walls may be good inducers of cellulolytic activity in A. pullulans.Key words: Aureobasidium pullulans, plant cell wall, cellulases, endoglucanase, exoglucanase.


1971 ◽  
Vol 17 (1) ◽  
pp. 31-37 ◽  
Author(s):  
R. E. Smith ◽  
T. S. Neudoerffer

A bacterial contaminant from a cellulase-producing culture of Trichurus cylindricus was subjected to physiological and biochemical tests, and identified as a member of the genus Micrococcus, subgroup 6 (Baird-Parker). It appeared either to stimulate cellulase production by the fungus, or to increase cellulase activity. The amino acid and protein content of the Micrococcus suggested that it might be useful as a feed supplement. In a preliminary trial, rats accepted freeze-dried cells as a partial source of energy, and grew at a normal rate. No toxic effects of the diet were noted.


1979 ◽  
Vol 25 (7) ◽  
pp. 858-860 ◽  
Author(s):  
N. Daigneault-Sylvestre ◽  
D. Kluepfel

A method for the rapid screening of cellulolytic streptomycetes and their mutants is reported. The technique consists of a plate assay on media containing filter paper fibres as cellulose substrate. The cellulolytic activity is detected and measured by the formation of clearing zones around the streptomycete colonies. The sensitivity of the method is increased considerably by subjecting the plates to an additional incubation period at 43 °C in the presence of a buffer at pH 5.3. By replicating these colonies on other Petri plates containing the appropriate media, it is possible to assess rapidly, not only the degree of catabolic repression of the cellulase production by glucose, but also, in a semiquantitative way, the amount of enzymes produced.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1360
Author(s):  
Ekaterina Budenkova ◽  
Stanislav Sukhikh ◽  
Svetlana Ivanova ◽  
Olga Babich ◽  
Vyacheslav Dolganyuk ◽  
...  

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.


2021 ◽  
Author(s):  
Oladipo Olaniyi

Abstract The goal of this present investigation was to mutagenize Bacillus subtilis with Ethyl Methyl Sulphonate (EMS), screen the mutants for cellulase production and evaluate the influence of different glucose concentrations on their cellulase production potentials. The wild type B. subtilis was treated with 20, 40, 60 and 80 µl of EMS and the mutants generated were screened for cellulase production in minimal salt medium containing carboxylmethylcellulose (CMC) as the carbon source. Quantitatively, cellulase activity and protein contents were determined by dinitrosalicylic acid and Lowry methods respectively. Seven mutants were developed from each of the EMS concentration bringing the total to twenty-eight from all the concentrations. Approximately 14 and 57% of the mutants developed from 40 and 60µl of EMS had higher cellulase activities than the wild type, while none of the mutants developed from 20 and 80 µl of EMS had better activities than the wild type. The supplementation of 0.2, 0.5, 1.0 and 1.5% glucose in enzyme production medium caused approximately 100, 14, 29 and 14% cellulase repression respectively in the mutants developed from 60µl EMS. Mutants MSSS02 and MSSS05 were considered as catabolite insensitive mutants because their cellulase production were enhanced in comparison to wild type.


Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 575-575 ◽  
Author(s):  
Neelima Garg ◽  
Om Prakash ◽  
B. K. Pandey ◽  
B. P. Singh ◽  
G. Pandey

Indian gooseberry (Emblica officinalis Gaertn.) is a medicinal plant with high nutraceutical value. During November and December 2003, soft rot was noticed on harvested and stored (20 ± 5°C and 65 ± 5% relative humidity) fruits at the experimental farm in Rehmanhera, Lucknow, India (26°50′N, 80°54′E). These fruits had numerous, minute brown necrotic lesions showing white mycelial growth. A pronounced halo of water-soaked, faded tissue surrounded the lesion between the fringe of mycelium and healthy tissues. The rotted surface was covered with a black, powdery layer of spores. On Czapek yeast extract agar, fungal colonies were blackish grey, moderately dense, and covered the entire petri dish. The fungus produced aseptate mycelium. The sporangial heads were 30 to 50 μm in diameter with sporangiospores found linearly within cylindrical sacs (merosporangia) borne on spicules around the columella. Sporangiospores, spherical to cylindrical in shape and borne in chains, measured 3.0 to 5.0 μm long. The fungus was morphologically and physiologically identified as Syncephalastrum racemosum Schr. (2). For pathogenicity tests, healthy fruits (10 replicates) were surface sterilized and punctured inoculated aseptically with 1.0 × 106 conidia and incubated at 20 ± 5°C Typical symptoms of the disease appeared after 4 days. The fungus exhibited a strong level of cellulolytic activity as indicated by prolific growth on Indian gooseberry fiber waste under solid-state fermentation conditions. The level of cellulase activity (1) was 21 filter paper activity unit per ml at 72 hr in culture supernatant of basal medium having carboxymethyl cellulose as the carbon source. The fungus showed resistance to tannins (as much as 2%), since it could grow well in liquid growth medium (Czapek Dox broth) with 2% tannins and aonla juice with 1.8% tannins. Since Indian gooseberry is rich in fiber (2.5 to 3.4%) and tannins (1.5 to 2.0%), this may be an important pathogen. To our knowledge, this is the first report of the occurrence of Syncephalastrum racemosum on Indian gooseberry fruits. References: (1) T. K. Ghose. Pure Appl. Chem. 59(2):257, 1987. (2) J. I. Pitt and A. D. Hocking. Fungi and Food Spoilage. Academic Press. North Ryde, Australia, 1985.


2011 ◽  
Vol 236-238 ◽  
pp. 1005-1013
Author(s):  
Zhi Xi Hang ◽  
Qing Long Rao ◽  
Shi Yuan Yu

The influence of pH and dissolved oxygen tension (DOT) on mycelium growth and cellulase production by Trichoderma reesei was studied in this paper. The experiments were carried out with a cellulose of 10 g/l in a 10 L steam sterilizable bioreactor. The results have shown that H+ concentration was highly fluctuated in the growing and metabolizing periods of mycelium, which went against mycelium growth and cellulase production. Controlling pH to 4.8 was favorable to mycelium growth and cellulase production; the maximum mycelium mass concentration was increased from 2.60 g/l to 2.77 g/l; the maximum filter paper activity was raised from 1.87 IU/ml to 2.79 IU/ml. Meanwhile, the growth and metabolism of mycelium demand an appropriate dissolved oxygen tension (DOT). When the velocity of aeration was increased from 0.4 to 0.5vvm to improve the condition of dissolving oxygen, the mycelium mass concentration was increased from 2.77 g/l to 2.98g/l, and the filter paper activity was raised from 2.79 IU/ml to 2.98 IU/ml.


1978 ◽  
Vol 56 (16) ◽  
pp. 1974-1981 ◽  
Author(s):  
W. H. Miele ◽  
A. E. Linkins

The antheridial strain of the dioecious water mold Achlya bisexualis was grown in chemically defined media using glucose, cellobiose, and selected polysaccharides as carbon sources. Growth and cellulase levels were measured with media containing glucose, cellobiose, and cellulose. Evaluation of cellulase activity in the medium by viscometric and reducing sugar generation assays suggests that cellulase plays a significant role in degrading cellulose for uptake and catabolism by A. bisexualis. Cellulase in glucose-grown cultures exists as a soluble extracellular enzyme complex, while in cellulose-grown cultures much of the enzyme is absorbed to the cellulose. Elution of the cellulose substrate after 96 h growth with NaCl-fortified buffer releases absorbed cellulase in a soluble form. The absorption of cellulase to the substrate and possibly the cell walls of A. bisexualis could account for the rapid loss in dry weight of A. bisexualis during culture on cellulose in a closed system. Scanning electron microscopic (SEM) examination of the walls of A. bisexualis shows disruption in cellulose cultures, which is not evident for glucose-or cellobiose-grown hyphae. Transmission electron microscopic (TEM) photomicrographs show a significant reduction in the wall thickness of cellulose-grown hyphae as compared with glucose-grown samples. This evidence suggests that the enzyme(s) produced during growth on cellulose is (are) capable of binding as an active hydrolase to walls of A. bisexualis or to the cellulosic substrate.


2011 ◽  
Vol 94 (2) ◽  
pp. 660-663
Author(s):  
Chi Zhang ◽  
Jun Yang ◽  
Ling Qiao

Abstract Microcrystalline cellulose (MCC) is suspected to be a new adulteration in pasteurized milk in China, yet an efficient method for MCC detection in dairy has not been established. This study presents a novel procedure to detect and estimate MCC in pasteurized milk using dialysis, cellulase hydrolysis, and a reducing sugar assay. The background value of reducing sugar was eliminated by dialysis, and cellulase activity toward MCC was stable in dialyzed milk. A criterion for MCC detection and an empirical formula for MCC estimation were summarized based on the reducing sugar variation after hydrolysis. The detection sensitivity was below 0.5 g/L. Reducing sugar distribution after cellulase-catalyzed hydrolysis was examined by HPLC, and revealed that most of the detected sugar was glucose. This paper describes a practical method for detection of MCC in pasteurized milk that might benefit dairy QC.


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