Journal articles on the topic 'Cellulase'
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1
Ilić, Nevena, Marija Milić, Sunčica Beluhan, and Suzana Dimitrijević-Branković. "Cellulases: From Lignocellulosic Biomass to Improved Production." Energies 16, no. 8 (April 21, 2023): 3598. http://dx.doi.org/10.3390/en16083598.
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Cellulases are enzymes that are attracting worldwide attention because of their ability to degrade cellulose in the lignocellulosic biomass and transform it into highly demanded bioethanol. The enzymatic hydrolysis of cellulose by cellulases into fermentable sugars is a crucial step in biofuel production, given the complex structure of lignocellulose. Due to cellulases’ unique ability to hydrolyze the very recaltricant nature of lignocellulosic biomass, the cellulase market demand is rapidly growing. Although cellulases have been used in industrial applications for decades, constant effort is being made in the field of enzyme innovation to develop cellulase mixtures/cocktails with improved performance. Given that the main producers of cellulases are of microbial origin, there is a constant need to isolate new microorganisms as potential producers of enzymes important for biofuel production. This review provides insight into current research on improving microbial cellulase production as well as the outlook for the cellulase market with commercial cellulase preparation involved in industrial bioethanol production.
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Tokuda, Gaku, and Hirofumi Watanabe. "Hidden cellulases in termites: revision of an old hypothesis." Biology Letters 3, no. 3 (March 20, 2007): 336–39. http://dx.doi.org/10.1098/rsbl.2007.0073.
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The intestinal flagellates of termites produce cellulases that contribute to cellulose digestion of their host termites. However, 75% of all termite species do not harbour the cellulolytic flagellates; the endogenous cellulase secreted from the midgut tissue has been considered a sole source of cellulases in these termites. Using the xylophagous flagellate-free termites Nasutitermes takasagoensis and Nasutitermes walkeri , we successfully solubilized cellulases present in the hindgut pellets. Zymograms showed that the hindguts of these termites possessed several cellulases and contained up to 59% cellulase activity against crystalline cellulose when compared with the midgut. Antibiotic treatment administered to N. takasagoensis significantly reduced cellulase activity in the hindgut, suggesting that these cellulases were produced by symbiotic bacteria.
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Liu, Jun, and Huiren Hu. "The role of cellulose binding domains in the adsorption of cellulases onto fibers and its effect on the enzymatic beating of bleached kraft pulp." BioResources 7, no. 1 (January 11, 2012): 878–92. http://dx.doi.org/10.15376/biores.7.1.878-892.
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The adsorption of cellulases onto fibers may be one of the most important factors affecting the enzymatic reaction between cellulases and fibers. This study investigated the adsorption kinetics involved, using isothermal adsorption equations. Cellulose binding domains (CBDs) were isolated from a commercial cellulase, and their role in the adsorption and enzymatic reaction was evaluated. Approximately 13% to 24% of the refining energy was saved after northern bleached softwood kraft pulp samples were pretreated with full cellulase, CBDs, or cellulase lacking CBDs under optimal conditions. The absence of CBDs in cellulase resulted in less effective enzyme adsorption and hydrolysis of the fibers. These data suggest that pretreatment of northern bleached softwood kraft pulp with CBDs may not only improve the beating degree of the pulp and reduce refining energy consumption but also improve the tensile index of the handsheet. Analysis of the degree of cellulose crystallinity and fiber surface morphology by X-ray diffraction and scanning electron microscopy revealed that the CBDs in cellulase help modify the crystalline area and facilitate the enzymatic degradation of cellulose. The adsorption parameters of the cellulases calculated from isothermal adsorption experiments confirmed the role of CBDs in the adsorption of cellulases onto fibers.
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Brumm, Phillip, Phillip Brumm, Dan Xie, Dan Xie, Larry Allen, Larry Allen, David A. Mead, and David A. Mead. "Hydrolysis of Cellulose by Soluble Clostridium Thermocellum and Acidothermus Cellulolyticus Cellulases." Journal of Enzymes 1, no. 1 (April 26, 2018): 5–19. http://dx.doi.org/10.14302/issn.2690-4829.jen-18-2025.
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The goal of this work was to clone, express, characterize and assemble a set of soluble thermostablecellulases capable of significantly degrading cellulose. We successfully cloned, expressed, and purified eleven Clostridium thermocellum (Cthe) cellulases and eight Acidothermuscellulolyticus(Acel) cellulases. The performance of the nineteen enzymes was evaluated on crystalline (filter paper) and amorphous (PASC) cellulose. Hydrolysis products generated from these two substrates were converted to glucose using beta-glucosidase and the glucose formed was determined enzymatically. Ten of the eleven Cthe enzymes were highly active on amorphous cellulose. The individual enzymes all produced <10% reducing sugar equivalents from filter paper. Combinations of Cthe cellulases gave higher conversions, with the combination of CelE, CelI, CelG, and CelK converting 34% of the crystalline cellulose. All eight Acel cellulases showed endo-cellulase activity and were highly active on PASC. Only Acel_0615 produced more than 10% reducing sugar equivalents from filter paper, and a combination of six Acel cellulases produced 32% conversion. Acel_0617, a GH48 exo-cellulase, and Acel_0619, a GH12 endo-cellulase, synergistically stimulated cellulose degradation by the combination of Cthe cellulases to almost 80%. Addition of both Acel enzymes to the Cthe enzyme mix did not further stimulate hydrolysis. Cthe CelG and CelI stimulated cellulose degradation by the combination of Acel cellulases to 66%.
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Feng, Yue, Hui-Qin Liu, Run-Cang Sun, and Jian-Xin Jiang. "Enzymatic hydrolysis of cellulose from steam-pretreated Lespedeza stalk (Lespedeza crytobotrya) with four Trichoderma cellulases." BioResources 6, no. 3 (June 7, 2011): 2776–89. http://dx.doi.org/10.15376/biores.6.3.2776-2789.
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The hydrolytic potential of cellulases produced by Trichoderma viride, Trichoderma pseudokoningii, Trichoderma koningii, and Trichoderma reesei with addition of exogenous β-glucosidase was evaluated on cellulose of steam-pretreated Lespedeza. The T. viride enzyme achieved the highest glucose conversion (90.09%), while T. pseudokoningii cellulase achieved the highest ratio of cellobiose to glucose (4.94%) at the end of hydrolysis. Enzymatic adsorption on the substrate was evaluated on filter paper activity and β-glucosidase activity in the corresponding digest with the obtained T. cellulases. T. viride cellulase possessed an efficient adsorption-desorption on the substrate and reached the highest FPA difference (0.72 U/mL) among enzyme activities, indicating to its excellent hydrolysis capability. However, β-glucosidase in T. viride cellulase system showed close bonding on the substrate, suggesting that efficiencies of adsorption-desorption on the cellulose are different between the entire cellulase system and β-glucosidase. T. viride cellulase, with active endogenous β-glucosidase (1.60 U/mL), has compatible synergism with the additional exogenous β-glucosidase.
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Aro, Nina, Marja Ilmén, Anu Saloheimo, and Merja Penttilä. "ACEI of Trichoderma reesei Is a Repressor of Cellulase and Xylanase Expression." Applied and Environmental Microbiology 69, no. 1 (January 2003): 56–65. http://dx.doi.org/10.1128/aem.69.1.56-65.2003.
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ABSTRACT We characterized the effect of deletion of the Trichoderma reesei (Hypocrea jecorina) ace1 gene encoding the novel cellulase regulator ACEI that was isolated based on its ability to bind to and activate in vivo in Saccharomyces cerevisiae the promoter of the main cellulase gene, cbh1. Deletion of ace1 resulted in an increase in the expression of all the main cellulase genes and two xylanase genes in sophorose- and cellulose-induced cultures, indicating that ACEI acts as a repressor of cellulase and xylanase expression. Growth of the strain with a deletion of the ace1 gene on different carbon sources was analyzed. On cellulose-based medium, on which cellulases are needed for growth, the Δace1 strain grew better than the host strain due to the increased cellulase production. On culture media containing sorbitol as the sole carbon source, the growth of the strain with a deletion of the ace1 gene was severely impaired, suggesting that ACEI regulates expression of other genes in addition to cellulase and xylanase genes. A strain with a deletion of the ace1 gene and with a deletion of the ace2 gene coding for the cellulase and xylanase activator ACEII expressed cellulases and xylanases similar to the Δace1 strain, indicating that yet another activator regulating cellulase and xylanase promoters was present.
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Nicomrat, Duongruitai, and Jirasak Tharajak. "Synergistic Effects of Cellulase-Producing Microorganisms for Future Bioconversion of Lignocellulosic Biomass." Applied Mechanics and Materials 804 (October 2015): 255–58. http://dx.doi.org/10.4028/www.scientific.net/amm.804.255.
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Lignocellulosic biomass can nowadays be bioconverted to value-added biofuels by numerous cellulases purified from diverse microbes. In nature, complex microbial communities produce multifunctional cellulase systems with broader substrate utilization and act sequentially in the synergistic action by subsequently converting cellulose into an utilizable energy source and glucose. This research was to apply cellulase producing isolates based on their possible synergistic action to degrade complex cellulose containing biomass. In the study, the microorganism species, isolated species from durian peels after macerated for 3 days and shown for their high biodegradation activity, Bacillus spp. (B12, B13, and B16) and Pseudomonas spp., (B23 and B55), could express high cellulase activity on carboxymethylcellulose (CMC) and filter paper (FP). Bacillus spp. B13 and B16 showed high cellulase activity on soluble cellulose of CMC while B12 and B55 displayed high cellulase activity on crystalline insoluble cellulose of FP. To observe the synergistic effect of the cellulase-producing consortia, co-cultures of B12,B23 and F23 were grew well on both CMC and FP. Therefore, these findings of synergistic effects of microbial consortia could bring us a future work to develop high efficient cellulase producing systems for further industry application.
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Singh, Nivisti, Bishop Bruce Sithole, and Roshini Govinden. "Optimisation of β-Glucosidase Production in a Crude Aspergillus japonicus VIT-SB1 Cellulase Cocktail Using One Variable at a Time and Statistical Methods and its Application in Cellulose Hydrolysis." International Journal of Molecular Sciences 24, no. 12 (June 9, 2023): 9928. http://dx.doi.org/10.3390/ijms24129928.
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Pulp and paper mill sludge (PPMS) is currently disposed of into landfills which are reaching their maximum capacity. Valorisation of PPMS by enzymatic hydrolysis using cellulases is an alternative strategy. Existing commercial cellulases are expensive and contain low titres of β-glucosidases. In this study, β-glucosidase production was optimised by Aspergillus japonicus VIT-SB1 to obtain higher β-glucosidase titres using the One Variable at a Time (OVAT), Plackett Burman (PBD), and Box Behnken design (BBD)of experiments and the efficiency of the optimised cellulase cocktail to hydrolyse cellulose was tested. β-Glucosidase production was enhanced from 0.4 to 10.13 U/mL, representing a 25.3-fold increase in production levels after optimisation. The optimal BBD production conditions were 6 days of fermentation at 20 °C, 125 rpm, 1.75% soy peptone, and 1.25% wheat bran in (pH 6.0) buffer. The optimal pH for β-glucosidase activity in the crude cellulase cocktail was (pH 5.0) at 50 °C. Optimal cellulose hydrolysis using the crude cellulase cocktail occurred at longer incubation times, and higher substrate loads and enzyme doses. Cellulose hydrolysis with the A. japonicus VIT-SB1 cellulase cocktail and commercial cellulase cocktails resulted in glucose yields of 15.12 and 12.33 µmol/mL glucose, respectively. Supplementation of the commercial cellulase cocktail with 0.25 U/mg of β-glucosidase resulted in a 19.8% increase in glucose yield.
9
Hwang, In Sun, Eom-Ji Oh, Han Beoyl Lee, and Chang-Sik Oh. "Functional Characterization of Two Cellulase Genes in the Gram-Positive Pathogenic Bacterium Clavibacter michiganensis for Wilting in Tomato." Molecular Plant-Microbe Interactions® 32, no. 4 (April 2019): 491–501. http://dx.doi.org/10.1094/mpmi-08-18-0227-r.
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Diverse plant pathogens secrete cellulases to degrade plant cell walls. Previously, the plasmid-borne cellulase gene celA was shown to be important for the virulence of the gram-positive bacterium Clavibacter michiganensis in tomato. However, details of the contribution of cellulases to the development of wilting in tomato have not been well-determined. To better understand the contribution of cellulases to the virulence of C. michiganensis in tomato, a mutant lacking cellulase activity was generated and complemented with truncated forms of certain cellulase genes, and virulence of those strain was examined. A celA mutant of the C. michiganensis type strain LMG7333 lost its cellulase activity and almost all its ability to cause wilting in tomato. The cellulase catalytic domain and cellulose-binding domain of CelA together were sufficient for both cellulase activity and the development of wilting in tomato. However, the expansin domain did not affect virulence or cellulase activity. The celA ortholog of Clavibacter sepedonicus restored the full virulence of the celA mutant of C. michiganensis. Another cellulase gene, celB, located in the chromosome, carries a single-base deletion in most C. michiganensis strains but does not carry a functional signal peptide in its N terminus. Nevertheless, an experimentally modified CelB protein with a CelA signal peptide was secreted and able to cause wilting in tomato. These results indicate that cellulases are major virulence factors of C. michiganensis that causes wilting in tomato. Furthermore, there are natural variations among cellulase genes directly affecting their function.
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Zhou, Qingxin, Jintao Xu, Yanbo Kou, Xinxing Lv, Xi Zhang, Guolei Zhao, Weixin Zhang, Guanjun Chen, and Weifeng Liu. "Differential Involvement of β-Glucosidases from Hypocrea jecorina in Rapid Induction of Cellulase Genes by Cellulose and Cellobiose." Eukaryotic Cell 11, no. 11 (September 21, 2012): 1371–81. http://dx.doi.org/10.1128/ec.00170-12.
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ABSTRACTAppropriate perception of cellulose outside the cell by transforming it into an intracellular signal ensures the rapid production of cellulases by cellulolyticHypocrea jecorina. The major extracellular β-glucosidase BglI (CEL3a) has been shown to contribute to the efficient induction of cellulase genes. Multiple β-glucosidases belonging to glycosyl hydrolase (GH) family 3 and 1, however, exist inH. jecorina. Here we demonstrated that CEL1b, like CEL1a, was an intracellular β-glucosidase displayingin vitrotransglycosylation activity. We then found evidence that these two major intracellular β-glucosidases were involved in the rapid induction of cellulase genes by insoluble cellulose. Deletion ofcel1aandcel1bsignificantly compromised the efficient gene expression of the major cellulase gene,cbh1. Simultaneous absence of BglI, CEL1a, and CEL1b caused the induction of the cellulase gene by cellulose to further deteriorate. The induction defect, however, was not observed with cellobiose. The absence of the three β-glucosidases, rather, facilitated the induced synthesis of cellulase on cellobiose. Furthermore, addition of cellobiose restored the productive induction on cellulose in the deletion strains. The results indicate that the three β-glucosidases may not participate in transforming cellobiose beyond hydrolysis to provoke cellulase formation inH. jecorina. They may otherwise contribute to the accumulation of cellobiose from cellulose as inducing signals.
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Kudanga, T., and E. Mwenje. "Extracellular cellulase production by tropical isolates of Aureobasidium pullulans." Canadian Journal of Microbiology 51, no. 9 (September 1, 2005): 773–76. http://dx.doi.org/10.1139/w05-053.
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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.
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Hall, J., G. W. Black, L. M. A. Ferreira, S. J. Millward-Sadler, B. R. S. Ali, G. P. Hazlewood, and H. J. Gilbert. "The non-catalytic cellulose-binding domain of a novel cellulase from Pseudomonas fluorescens subsp. cellulosa is important for the efficient hydrolysis of Avicel." Biochemical Journal 309, no. 3 (August 1, 1995): 749–56. http://dx.doi.org/10.1042/bj3090749.
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A genomic library of Pseudomonas fluorescens subsp. cellulosa DNA, constructed in lambda ZAPII, was screened for carboxymethyl-cellulase activity. The pseudomonad insert from a recombinant phage which displayed elevated cellulase activity in comparison with other cellulase-positive clones present in the library, was excised into pBluescript SK- to generate the plasmid pC48. The nucleotide sequence of the cellulase gene, designated celE, revealed a single open reading frame of 1710 bp that encoded a polypeptide, defined as endoglucanase E (CelE), of M(r) 59663. The deduced primary structure of CelE revealed an N-terminal signal peptide followed by a 300-amino-acid sequence that exhibited significant identity with the catalytic domains of cellulases belonging to glycosyl hydrolase Family 5. Adjacent to the catalytic domain was a 40-residue region that exhibited strong sequence identity to non-catalytic domains located in two other endoglucanases and a xylanase from P. fluorescens. The C-terminal 100 residues of CelE were similar to Type-I cellulose-binding domains (CBDs). The three domains of the cellulase were joined by linker sequences rich in serine residues. Analysis of the biochemical properties of full-length and truncated derivatives of CelE confirmed that the enzyme comprised an N-terminal catalytic domain and a C-terminal CBD. Analysis of purified CelE revealed that the enzyme had an M(r) of 56000 and an experimentally determined N-terminal sequence identical to residues 40-54 of the deduced primary structure of full-length CelE. The enzyme exhibited an endo mode of action in hydrolysing a range of cellulosic substrates including Avicel and acid-swollen cellulose, but did not attack xylan or any other hemicelluloses. A truncated form of the enzyme, which lacked the C-terminal CBD, displayed the same activity as full-length CelE against soluble cellulose and acid-swollen cellulose, but exhibited substantially lower activity than the full-length cellulase against Avicel. The significance of these data in relation to the role of the CBD is discussed.
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Metreveli, Eka, Tamar Khardziani, and Vladimir Elisashvili. "The Carbon Source Controls the Secretion and Yield of Polysaccharide-Hydrolyzing Enzymes of Basidiomycetes." Biomolecules 11, no. 9 (September 10, 2021): 1341. http://dx.doi.org/10.3390/biom11091341.
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In the present study, the polysaccharide-hydrolyzing secretomes of Irpex lacteus (Fr.) Fr. (1828) BCC104, Pycnoporus coccineus (Fr.) Bondartsev and Singer (1941) BCC310, and Schizophyllum commune Fr. (1815) BCC632 were analyzed in submerged fermentation conditions to elucidate the effect of chemically and structurally different carbon sources on the expression of cellulases and xylanase. Among polymeric substrates, crystalline cellulose appeared to be the best carbon source providing the highest endoglucanase, total cellulase, and xylanase activities. Mandarin pomace as a growth substrate for S. commune allowed to achieve comparatively high volumetric activities of all target enzymes while wheat straw induced a significant secretion of cellulase and xylanase activities of I. lacteus and P. coccineus. An additive effect on the secretion of cellulases and xylanases by the tested fungi was observed when crystalline cellulose was combined with mandarin pomace. In I. lacteus the cellulase and xylanase production is inducible in the presence of cellulose-rich substrates but is suppressed in the presence of an excess of easily metabolizable carbon source. These enzymes are expressed in a coordinated manner under all conditions studied. It was shown that the substitution of glucose in the inoculum medium with Avicel provides accelerated enzyme production by I. lacteus and higher cellulase and xylanase activities of the fungus. These results add new knowledge to the physiology of basidiomycetes to improve cellulase production.
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Wu, Bin, Yue Zhao, and Pei Ji Gao. "A new approach to measurement of saccharifying capacities of crude cellulase." BioResources 1, no. 2 (October 3, 2006): 189–200. http://dx.doi.org/10.15376/biores.1.2.189-200.
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A practical, quantitative approach has been designed, which makes it possible to accurately estimate the saccharifying activities of crude cellulase preparations for insoluble cellulosics. The challenge in activity determination imposed by changes in hydrolysis time and concentration of cellulase and cellulosics on the assay could be overcome by selection of the specific conversion percentage of cellulose as a function of cellulase concentration, that is, the hydrolysis percentage of filter paper by unit cellulase per minute, as the objective function with respect to different concentrations of crude cellulase. A rational and governing equation for crude cellulase assay was derived , and reliable results for quantitatively estimating the saccharifying activities of crude cellulases during the progress of hydrolysis of several cellulosic substrates were obtained.
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Ramalingam, Subramanian, and Dhanashekar Revathi. "De-Escalation of Saccharification Costs through Enforcement of Immobilization of Cellulase Synthesized by Wild Trichoderma viride." Catalysts 12, no. 6 (June 15, 2022): 659. http://dx.doi.org/10.3390/catal12060659.
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The economic uncertainty associated with cellulosic bioethanol can be overcome through the inclusion of cheap substrates and methodologies that can extend the shelf life of cellulolytic enzymes. In this study, wild Trichoderma viride was used to produce cellulases, media formulation studies were conducted to enhance the cellulase production further and immobilization strategies were tested for stable cellulase–iron oxide magnetic nanoparticle coupling. Out of the seven different production media designed, media containing glucose, wheat bran, cellulose and corn steep liquor supported the highest biomass growth (60 Packed cell volume) and cellulase formation (7.4 U/mL), and thus was chosen for the fiscal analysis at a larger scale (1000 m3). The profitability of the cellulase production process was assessed to be 20.86%, considering both the capital expenditure and operating expenses. Further, the effect of cost of different carbon sources, nitrogen sources and cellulase yields on the annual operating costs was explored, which led to the choice of delignified sugarcane bagasse, corn steep liquor and productivity levels to be respective decisive factors of the overall cost of the cellulase production. Likewise, the break-even period of such a large-scale operation was gauged given the market price of cellulases at USD 17 for 105 U of cellulases. Moreover, enzyme immobilization led to enhanced cellulase shelf life and ultimately contributed toward saccharification cost reduction.
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Janatunaim, Rifqi Zahroh, Radhiyah Mardhiyah Hamid, Ghea Putri Christy, Yekti Asih Purwestri, and Woro Anindito Sri Tunjung. "Identification of BSA B1 Bacteria and Its Potency of Purified Cellulase to Hydrolyze Chlorella zofingiensis." Indonesian Journal of Biotechnology 20, no. 1 (November 8, 2016): 77. http://dx.doi.org/10.22146/ijbiotech.15277.
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Cellulase has been widely used as biocatalyst in industries. Production of cellulase from microorganismshas many advantages such as short production time and less expense. Our previous study indicated that oneof cellulolytic bacteria from digestive tract of milkfish (Chanos chanos), namely BSA B1, showed the highestcellulase activity. The objective of this study was to determine the phylogenetic of BSA B1 strain using 16SrRNA gene sequence. Furthermore, this study also determine the specific activity of purified cellulase from BSAB1 strain and its potency to hydrolyze Chlorella zofingiensis cellulose. Cellulase was purified using ammoniumsulphate precipitation, dialysis, and ion exchange chromatography. The purified cellulase was used to hydrolyzecellulose of C. zofingiensis. The result demonstrated that BSA B1 strain was closely related with Bacillus aeriusand Bacillus licheniformis. The specific activity of the crude enzyme was 1.543 U mL-1; after dialysis was 4.384 UmL-1; and after chromatography was 7.543 U mL-1. Purified cellulase exhibited activity in hydrolyzed both CMCand C. zofingiensis. Compared to commercial cellulase, purified cellulase had lower activity in hydrolyzed CMCbut higher activity in hydrolyzed C. zofingiensis. Ethanol dehydration could potentially increase the reducingsugar yield in cellulose hydrolysis when used appropriately. Morphology of C. zofingiensis cell has changedafter incubation with cellulases and ethanol dehydration indicated degradation of cell wall.
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Legodi, L. M., D. La Grange, E. L. Jansen van Rensburg, and I. Ncube. "Isolation of Cellulose Degrading Fungi from Decaying Banana Pseudostem and Strelitzia alba." Enzyme Research 2019 (July 25, 2019): 1–10. http://dx.doi.org/10.1155/2019/1390890.
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Cellulases are a group of hydrolytic enzymes that break down cellulose to glucose units. These enzymes are used in the food, beverage, textile, pulp, and paper and the biofuel industries. The aim of this study was to isolate fungi from natural compost and produce cellulases in submerged fermentation (SmF). Initial selection was based on the ability of the fungi to grow on agar containing Avicel followed by cellulase activity determination in the form of endoglucanase and total cellulase activity. Ten fungal isolates obtained from the screening process showed good endoglucanase activity on carboxymethyl cellulose-Congo Red agar plates. Six of the fungal isolates were selected based on high total cellulase activity and identified as belonging to the genera Trichoderma and Aspergillus. In SmF of synthetic media with an initial pH of 6.5 at 30°C Trichoderma longibrachiatum LMLSAUL 14-1 produced total cellulase activity of 8 FPU/mL and endoglucanase activity of 23 U/mL whilst Trichoderma harzianum LMLBP07 13-5 produced 6 FPU/mL and endoglucanase activity of 16 U/mL. The produced levels of both cellulases and endoglucanase by Trichoderma species were higher than the levels for the Aspergillus fumigatus strains. Aspergillus fumigatus LMLPS 13-4 produced higher β-glucosidase 38 U/mL activity than Trichoderma species.
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Poomai, Nutt, Wilailak Siripornadulsil, and Surasak Siripornadulsil. "Cellulase Enzyme Production from Agricultural Waste by Acinetobacter sp. KKU44." Advanced Materials Research 931-932 (May 2014): 1106–10. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.1106.
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Due to a high ethanol demand, the approach for effective ethanol production is important and has been developed rapidly worldwide. Several agricultural wastes are highly abundant in celluloses and the effective cellulase enzymes do exist widely among microorganisms. Accordingly, the cellulose degradation using microbial cellulase to produce a low-cost substrate for ethanol production has attracted more attention. In this study, the cellulase producing bacterial strain has been isolated from rich straw and identified by 16S rDNA sequence analysis as Acinetobacter sp. KKU44. This strain is able to grow and exhibit the cellulase activity. The optimal temperature for its growth and cellulase production is 37 °C. The optimal temperature of bacterial cellulase activity is 60 °C. The cellulase enzyme from Acinetobacter sp. KKU44 is heat-tolerant enzyme. The bacterial culture of 36 h. showed highest cellulase activity at 120 U/mL when grown in LB medium containing 2% (w/v). The capability of Acinetobacter sp. KKU44 to grow in cellulosic agricultural wastes as a sole carbon source and exhibiting the high cellulase activity at high temperature suggested that this strain could be potentially developed further as a cellulose degrading strain for a production of low-cost substrate used in ethanol production.
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Pratama, Rahadian, I. Made Artika, Tetty Chaidamsari, Herti Sugiarti, and Soekarno Mismana Putra. "Isolation and Molecular Cloning of Cellulase Gene from Bovine Rumen Bacteria." Current Biochemistry 1, no. 1 (September 2, 2017): 29–36. http://dx.doi.org/10.29244/cb.1.1.29-36.
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Cellulases are the enzymes that hydrolyze cellulosic biomass and are produced by the microorganisms that grow over cellulosic matters. The objective of this research was to isolate and clone cellulase gene from cellulose-degrading bacteria of bovine rumen. Cellulose-degrading bacteria was isolated from rumen fluid using a selective medium. Total RNA was isolated from selected colony having cellulose degrading activity and was used as a template for cDNA construction using reverse transcriptase polymerase chain reaction (RT-PCR) technique. The resulted cDNA was employed as a template for PCR amplification of cellulase gene using specific primers. The cellulase gene candidate obtained was cloned into the pGEM-T-Easy vector followed by determination of its nucleotide sequence. The sequence was then aligned with sequences of cellulase genes from GenBank. Results showed that a number of isolates of rumen bacteria exhibit cellulase activity and the CR-8 isolate was selected for further analysis. The successful isolation of total RNA from CR-8 was indicated by the presence of two intense bands of ribosomal RNA (23S and 16S). The reverse transcription process was successful and the amplification of cellulase gene using the specific primers F1 and R1 resulted in a DNA fragment of 1900 bp as a candidate of cellulase gene. The fragment was successfully cloned into the pGEM-T-Easy vector, and the resulted recombinant plasmid was successfully introduced into the E. coli cells. Nucleotide sequence analysis suggested that the cloned gene is cellulase gene and shares 99% homology with the endo-1,6-beta-glucanase of T. harzianum.
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Chen, Yudian, Yushan Gao, Zancheng Wang, Nian Peng, Xiaoqin Ran, Tingting Chen, Lulu Liu, and Yonghao Li. "The Influence of Trctf1 Gene Knockout by CRISPR–Cas9 on Cellulase Synthesis by Trichoderma reesei with Various Soluble Inducers." Fermentation 9, no. 8 (August 10, 2023): 746. http://dx.doi.org/10.3390/fermentation9080746.
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Knockout of the transcriptional repressor Trctf1 is known to enhance the yield of cellulose-induced cellulase synthesis in Trichoderma reesei. However, different inducers possess distinct induction mechanisms, and the effect of Trctf1 on cellulase synthesis with soluble inducers remains unknown. To evaluate the effect of the Trctf1 gene on cellulase synthesis and develop a high-yielding cellulase strain, we established a CRISPR–Cas9 genome editing system in T. reesei Rut C30 using codon-optimized Cas9 protein and in vitro transcribed RNA. This study demonstrated that T. reesei ΔTrctf1 with the Trctf1 gene knocked out showed no statistically significant differences in cellulase, cellobiohydrolase, endoglucanase, and β−glucosidase production when induced with MGD (the mixture of glucose and sophorose). However, when induced with lactose, the activities of these enzymes increased by 20.2%, 12.4%, and 12.9%, respectively, with no statistically significant differences in β−glucosidase activity. The hydrolysis efficiency on corn stover of cellulases produced by T. reesei ΔTrctf1 under different inducers was not significantly different from that of wild-type cellulases, indicating that Trctf1 gene deletion has little effect on the cellulase cocktail. These findings contribute to a better understanding of the molecular mechanisms underlying the regulation of T. reesei cellulase synthesis by different soluble inducers, as well as the construction of high-yield cellulase gene−engineered strains.
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Thoresen, Mariska, Samkelo Malgas, Mpho Mafa, and Brett Pletschke. "Revisiting the Phenomenon of Cellulase Action: Not All Endo- and Exo-Cellulase Interactions Are Synergistic." Catalysts 11, no. 2 (January 27, 2021): 170. http://dx.doi.org/10.3390/catal11020170.
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The conventional endo–exo synergism model has extensively been supported in literature, which is based on the perception that endoglucanases (EGs) expose or create accessible sites on the cellulose chain to facilitate the action of processive cellobiohydrolases (CBHs). However, there is a lack of information on why some bacterial and fungal CBHs and EGs do not exhibit synergism. Therefore, the present study evaluated and compared the synergistic relationships between cellulases from different microbial sources and provided insights into how different GH families govern synergism. The results showed that CmixA2 (a mixture of TlCel7A and CtCel5A) displayed the highest effect with BaCel5A (degree of synergy for reducing sugars and glucose of 1.47 and 1.41, respectively) in a protein mass ratio of 75–25%. No synergism was detected between CmixB1/B2 (as well as CmixC1/C2) and any of the EGs, and the combinations did not improve the overall cellulose hydrolysis. These findings further support the hypothesis that “not all endo-to exo-cellulase interactions are synergistic”, and that the extent of synergism is dependent on the composition of cellulase systems from various sources and their compatibility in the cellulase cocktail. This method of screening for maximal compatibility between exo- and endo-cellulases constitutes a critical step towards the design of improved synergistic cellulose-degrading cocktails for industrial-scale biomass degradation.
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Doan, Chien Thang, Thi Ngoc Tran, Thi Phuong Pham, Thi Thanh Thao Tran, Ba Phong Truong, Thi Tinh Nguyen, The Manh Nguyen, Thi Quynh Hoa Bui, Anh Dzung Nguyen, and San-Lang Wang. "Production, Purification, and Characterization of a Cellulase from Paenibacillus elgii." Polymers 16, no. 14 (July 17, 2024): 2037. http://dx.doi.org/10.3390/polym16142037.
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Cellulases are one of the most essential natural factors for cellulose degradation and, thus, have attracted significant interest for various applications. In this study, a cellulase from Paenibacillus elgii TKU051 was produced, purified, and characterized. The ideal fermentation conditions for cellulase productivity were 2% carboxymethyl cellulose (CMC) as the growth substrate, pH = 8, temperature of 31 °C, and 4 days of culturing. Accordingly, a 45 kDa cellulase (PeCel) was successfully purified in a single step using a High Q column with a recovery yield of 35% and purification of 42.2-fold. PeCel has an optimal activity at pH 6 and a temperature of 60 °C. The activity of cellulase was significantly inhibited by Cu2+ and enhanced by Mn2+. The PeCel-catalyzed products of the CMC hydrolysis were analyzed by high-performance liquid chromatography, which revealed chitobiose and chitotriose as the major products. Finally, the clarity of apple juice was enhanced when treated with PeCel.
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Mizuno, Masahiro, Shuji Kachi, Eiji Togawa, Noriko Hayashi, Kouichi Nozaki, Toshiyuki Itoh, and Yoshihiko Amano. "Structure of Regenerated Celluloses Treated with Ionic Liquids and Comparison of their Enzymatic Digestibility by Purified Cellulase Components." Australian Journal of Chemistry 65, no. 11 (2012): 1491. http://dx.doi.org/10.1071/ch12342.
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In this study, regenerated celluloses were prepared from microcrystalline cellulose (MCC) by treatment with three ionic liquids (ILs) having 1-ethyl-3-methylimidazolium (Emim) as the cation, and the IL N-(2-methoxyethyl)-N,N-diethyl-N-methylammonium alanine ([N221ME][Ala]), where the amino acid moiety is the anion. The crystal form of cellulose was transformed from cellulose I to cellulose II by dissolution with an IL and regeneration with anti-solvent. However, the crystallinity of the regenerated cellulose was different; the disordered chain region was increased in the order of [N221ME][Ala] < [Emim][OAc] < [Emim][DEP] < [Emim][Cl]. The monocomponent cellulase, especially endoglucanase, showed high hydrolyzing activity for regenerated cellulose compared with untreated cellulose. Furthermore, the degree of increase of hydrolyzing activity was almost coincident with the order of crystallinity. For the effective hydrolysis of cellulose treated with an IL, it is necessary to prepare the cellulase mixture containing an adequate ratio of each cellulase component according to crystal allomorph and the crystallinity of regenerated cellulose.
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Rusdianti, Reni, Azizah Azizah, Esti Utarti, Hidayat Teguh Wiyono, and Kahar Muzakhar. "Cheap Cellulase Production by Aspergillus sp. VTM1 Through Solid State Fermentation of Coffee Pulp Waste." Key Engineering Materials 884 (May 2021): 159–64. http://dx.doi.org/10.4028/www.scientific.net/kem.884.159.
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Coffee pulp biomass waste can easily be found anywhere in Indonesia, considering it is the fourth world's largest coffee exporter. The utilization of coffee pulp is very limited and is categorized as a source of pollutants in water bodies and soils. In contrast, coffee pulp waste is very potential because 63% of the main compound is cellulose. Microbial utilization of this waste for enzyme production purposes, especially cellulase, is a breakthrough that may lead to reduce production costs. Initial investigations showed that Aspergillus sp. VTM1 through solid-state fermentation (SSF) could produce cellulases. Optimal cellulase could be produced if 10 g coffee pulp with 10% moisture is inoculated using 108 spores/mL of Aspergillus sp. VTM1 for 48 hours at 30 °C. Hydrolysis of 1% carboxymethyl cellulose (CMC) substrate in 50 mM acetate buffer pH 5 by this cellulase showed that the enzyme activity reached up to 1.18 U/mL. The optimum pH of the enzyme was 5 and stable at 3-3.5 and 4-7. The success of the first step of this investigation will be a cheap way of producing cellulases.
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Wang, Hongliang, Fabio Squina, Fernando Segato, Andrew Mort, David Lee, Kirk Pappan, and Rolf Prade. "High-Temperature Enzymatic Breakdown of Cellulose." Applied and Environmental Microbiology 77, no. 15 (June 17, 2011): 5199–206. http://dx.doi.org/10.1128/aem.00199-11.
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ABSTRACTCellulose is an abundant and renewable biopolymer that can be used for biofuel generation; however, structural entrapment with other cell wall components hinders enzyme-substrate interactions, a key bottleneck for ethanol production. Biomass is routinely subjected to treatments that facilitate cellulase-cellulose contacts. Cellulases and glucosidases act by hydrolyzing glycosidic bonds of linear glucose β-1,4-linked polymers, producing glucose. Here we describe eight high-temperature-operating cellulases (TCel enzymes) identified from a survey of thermobacterial and archaeal genomes. Three TCel enzymes preferentially hydrolyzed soluble cellulose, while two preferred insoluble cellulose such as cotton linters and filter paper. TCel enzymes had temperature optima ranging from 85°C to 102°C. TCel enzymes were stable, retaining 80% of initial activity after 120 h at 85°C. Two modes of cellulose breakdown, i.e., with endo- and exo-acting glucanases, were detected, and with two-enzyme combinations at 85°C, synergistic cellulase activity was observed for some enzyme combinations.
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Hetzler, Stephan, Daniel Bröker, and Alexander Steinbüchel. "Saccharification of Cellulose by Recombinant Rhodococcus opacus PD630 Strains." Applied and Environmental Microbiology 79, no. 17 (June 21, 2013): 5159–66. http://dx.doi.org/10.1128/aem.01214-13.
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ABSTRACTThe noncellulolytic actinomyceteRhodococcus opacusstrain PD630 is the model oleaginous prokaryote with regard to the accumulation and biosynthesis of lipids, which serve as carbon and energy storage compounds and can account for as much as 87% of the dry mass of the cell in this strain. In order to establish cellulose degradation inR. opacusPD630, we engineered strains that episomally expressed six different cellulase genes fromCellulomonas fimiATCC 484 (cenABC,cex,cbhA) andThermobifida fuscaDSM43792 (cel6A), thereby enablingR. opacusPD630 to degrade cellulosic substrates to cellobiose. Of all the enzymes tested, five exhibited a cellulase activity toward carboxymethyl cellulose (CMC) and/or microcrystalline cellulose (MCC) as high as 0.313 ± 0.01 U · ml−1, but recombinant strains also hydrolyzed cotton, birch cellulose, copy paper, and wheat straw. Cocultivations of recombinant strains expressing different cellulase genes with MCC as the substrate were carried out to identify an appropriate set of cellulases for efficient hydrolysis of cellulose byR. opacus. Based on these experiments, the multicellulase gene expression plasmid pCellulose was constructed, which enabledR. opacusPD630 to hydrolyze as much as 9.3% ± 0.6% (wt/vol) of the cellulose provided. For the direct production of lipids from birch cellulose, a two-step cocultivation experiment was carried out. In the first step, 20% (wt/vol) of the substrate was hydrolyzed by recombinant strains expressing the whole set of cellulase genes. The second step was performed by a recombinant cellobiose-utilizing strain ofR. opacusPD630, which accumulated 15.1% (wt/wt) fatty acids from the cellobiose formed in the first step.
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Rohman, M. Saifur, Endang Pamulatsih, Yudi Kusnadi, Triwibowo Yuwono, and Erni Martani. "An Active of Extracellular Cellulose Degrading Enzyme from Termite Bacterial Endosimbiont." Indonesian Journal of Biotechnology 20, no. 1 (November 8, 2016): 62. http://dx.doi.org/10.22146/ijbiotech.15273.
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Cellulase is an ezyme that specifically cleaves the 1,4-β-glycosidic bond of cellulose to produce thesmall fragments of simple carbohydrate. This work was aimed to characterize the extracellular cellulase fromPaenibacillus spp., which was previously isolated from macro termites, Odontotermes bhagwatii in our laboratory.Two Paenibacillus isolates were used in this experiment, namely Paenibacillus cellulositrophicus SBT1 andPaenibacillus, sp. SBT8. Analysis of the total proteins in the supernatants showed that P. cellulositrophicus SBT1and Paenibacillus sp. SBT8 roughly produced as much as 18.6 mg/l and 24.8 mg/l of extracellular cellulases,respectively. Enzymatic assay showed that SBT1 and SBT8 cellulase exhibited enzymatic acitivity of 0.17 U/mg and 0.12 U/mg, respectively. Temperature dependencies analysis indicated that both cellulases exhibitedmaximum activity at 35oC. At the temperature higher than 55oC, the enzymatic activities of both cellulases wereroughly 20% reduced compared to the maximum activity. SBT1 and SBT8 cellulases were both active at acidicpH. At basic pH (pH 8) the enzymatic activities of both cellulases were reduced roughly 30% compared to thatof acidic pH. Supplementing of Mg2+, Zn2+, and Ca2+ in range of 1-10 mM increased the enzymatic activity ofboth cellulases roughly 33 to 50%.
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Contreras, Francisca, Subrata Pramanik, Aleksandra M. Rozhkova, Ivan N. Zorov, Olga Korotkova, Arkady P. Sinitsyn, Ulrich Schwaneberg, and Mehdi D. Davari. "Engineering Robust Cellulases for Tailored Lignocellulosic Degradation Cocktails." International Journal of Molecular Sciences 21, no. 5 (February 26, 2020): 1589. http://dx.doi.org/10.3390/ijms21051589.
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Lignocellulosic biomass is a most promising feedstock in the production of second-generation biofuels. Efficient degradation of lignocellulosic biomass requires a synergistic action of several cellulases and hemicellulases. Cellulases depolymerize cellulose, the main polymer of the lignocellulosic biomass, to its building blocks. The production of cellulase cocktails has been widely explored, however, there are still some main challenges that enzymes need to overcome in order to develop a sustainable production of bioethanol. The main challenges include low activity, product inhibition, and the need to perform fine-tuning of a cellulase cocktail for each type of biomass. Protein engineering and directed evolution are powerful technologies to improve enzyme properties such as increased activity, decreased product inhibition, increased thermal stability, improved performance in non-conventional media, and pH stability, which will lead to a production of more efficient cocktails. In this review, we focus on recent advances in cellulase cocktail production, its current challenges, protein engineering as an efficient strategy to engineer cellulases, and our view on future prospects in the generation of tailored cellulases for biofuel production.
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Lian, Ling-Dan, Ling-Yan Shi, Jing Zhu, Rui Liu, Liang Shi, Ang Ren, Han-Shou Yu, and Ming-Wen Zhao. "GlSwi6 Positively Regulates Cellulase and Xylanase Activities through Intracellular Ca2+ Signaling in Ganoderma lucidum." Journal of Fungi 8, no. 2 (February 14, 2022): 187. http://dx.doi.org/10.3390/jof8020187.
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Ganoderma lucidum is a white-rot fungus that produces a range of lignocellulolytic enzymes to decompose lignin and cellulose. The mitogen-activated protein kinase (MAPK) pathway has been implicated in xylanases and cellulases production. As the downstream transcription factor of Slt2-MAPK, the function of Swi6 in G. lucidum has not been fully studied. In this study, the transcription factor GlSwi6 in G. lucidum was characterized and shown to significantly positively regulate cellulases and xylanases production. Knockdown of the GlSwi6 gene decreased the activities of cellulases and xylanases by approximately 31%~38% and 54%~60% compared with those of the wild-type (WT) strain, respectively. Besides, GlSwi6 can be alternatively spliced into two isoforms, GlSwi6A and GlSwi6B, and overexpression of GlSwi6B increased the activities of cellulase and xylanase by approximately 50% and 60%, respectively. Further study indicates that the existence of GlSwi6B significantly increased the concentration of cytosolic Ca2+. Our study indicated that GlSwi6 promotes the activities of cellulase and xylanase by regulating the Ca2+ signaling. These results connected the GlSwi6 and Ca2+ signaling in the regulation of cellulose degradation, and provide an insight for further improvement of cellulase or xylanase activities in G. lucidum as well as other fungi.
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Mingardon, Florence, Ang�lique Chanal, Ana M. L�pez-Contreras, Cyril Dray, Edward A. Bayer, and Henri-Pierre Fierobe. "Incorporation of Fungal Cellulases in Bacterial Minicellulosomes Yields Viable, Synergistically Acting Cellulolytic Complexes." Applied and Environmental Microbiology 73, no. 12 (April 27, 2007): 3822–32. http://dx.doi.org/10.1128/aem.00398-07.
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ABSTRACT Artificial designer minicellulosomes comprise a chimeric scaffoldin that displays an optional cellulose-binding module (CBM) and bacterial cohesins from divergent species which bind strongly to enzymes engineered to bear complementary dockerins. Incorporation of cellulosomal cellulases from Clostridium cellulolyticum into minicellulosomes leads to artificial complexes with enhanced activity on crystalline cellulose, due to enzyme proximity and substrate targeting induced by the scaffoldin-borne CBM. In the present study, a bacterial dockerin was appended to the family 6 fungal cellulase Cel6A, produced by Neocallimastix patriciarum, for subsequent incorporation into minicellulosomes in combination with various cellulosomal cellulases from C. cellulolyticum. The binding of the fungal Cel6A with a bacterial family 5 endoglucanase onto chimeric miniscaffoldins had no impact on their activity toward crystalline cellulose. Replacement of the bacterial family 5 enzyme with homologous endoglucanase Cel5D from N. patriciarum bearing a clostridial dockerin gave similar results. In contrast, enzyme pairs comprising the fungal Cel6A and bacterial family 9 endoglucanases were substantially stimulated (up to 2.6-fold) by complexation on chimeric scaffoldins, compared to the free-enzyme system. Incorporation of enzyme pairs including Cel6A and a processive bacterial cellulase generally induced lower stimulation levels. Enhanced activity on crystalline cellulose appeared to result from either proximity or CBM effects alone but never from both simultaneously, unlike minicellulosomes composed exclusively of bacterial cellulases. The present study is the first demonstration that viable designer minicellulosomes can be produced that include (i) free (noncellulosomal) enzymes, (ii) fungal enzymes combined with bacterial enzymes, and (iii) a type (family 6) of cellulase never known to occur in natural cellulosomes.
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Malik, Muhammad Saqib, Abdul Rehman, Irfan Ullah Khan, Taj Ali Khan, Muhammad Jamil, Eui Shik Rha, and Muhammad Anees. "Thermo-neutrophilic cellulases and chitinases characterized from a novel putative antifungal biocontrol agent: Bacillus subtilis TD11." PLOS ONE 18, no. 1 (January 27, 2023): e0281102. http://dx.doi.org/10.1371/journal.pone.0281102.
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Cellulose and chitin are the most abundant naturally occurring biopolymers synthesized in plants and animals and are used for synthesis of different organic compounds and acids in the industry. Therefore, cellulases and chitinases are important for their multiple uses in industry and biotechnology. Moreover, chitinases have a role in the biological control of phytopathogens. A bacterial strain Bacillus subtilis TD11 was previously isolated and characterized as a putative biocontrol agent owing to its significant antifungal potential. In this study, cellulase and chitinase produced by the strain B. subtilis TD11 were purified and characterized. The activity of the cellulases and chitinases were optimized at different pH (2 to 10) and temperatures (20 to 90°C). The substrate specificity of cellulases was evaluated using different substances including carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), and crystalline substrates. The cellulase produced by B. subtilis TD11 had a molecular mass of 45 kDa while that of chitinase was 55 kDa. The optimal activities of the enzymes were found at neutral pH (6.0 to 7.0). The optimum temperature for the purified cellulases was in the range of 50 to 70°C while, purified chitinases were optimally active at 50°C. The highest substrate specificity of the purified cellulase was found for CMC (100%) followed by HEC (>50% activity) while no hydrolysis was observed against the crystalline substrates. Moreover, it was observed that the purified chitinase was inhibitory against the fungi containing chitin in their hyphal walls i.e., Rhizoctonia, Colletotrichum, Aspergillus and Fusarium having a dose-effect relationship.
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Arsov, Alexander, Kaloyan Petrov, and Penka Petrova. "Enhanced Activity by Genetic Complementarity: Heterologous Secretion of Clostridial Cellulases by Bacillus licheniformis and Bacillus velezensis." Molecules 26, no. 18 (September 16, 2021): 5625. http://dx.doi.org/10.3390/molecules26185625.
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To adapt to various ecological niches, the members of genus Bacillus display a wide spectrum of glycoside hydrolases (GH) responsible for the hydrolysis of cellulose and lignocellulose. Being abundant and renewable, cellulose-containing plant biomass may be applied as a substrate in second-generation biotechnologies for the production of platform chemicals. The present study aims to enhance the natural cellulase activity of two promising 2,3-butanediol (2,3-BD) producers, Bacillus licheniformis 24 and B. velezensis 5RB, by cloning and heterologous expression of cel8A and cel48S genes of Acetivibrio thermocellus. In B. licheniformis, the endocellulase Cel8A (GH8) was cloned to supplement the action of CelA (GH9), while in B. velezensis, the cellobiohydrolase Cel48S (GH48) successfully complemented the activity of endo-cellulase EglS (GH5). The expression of the natural and heterologous cellulase genes in both hosts was demonstrated by reverse-transcription PCR. The secretion of clostridial cellulases was additionally enhanced by enzyme fusion to the subtilisin-like signal peptide, reaching a significant increase in the cellulase activity of the cell-free supernatants. The results presented are the first to reveal the possibility of genetic complementation for enhancement of cellulase activity in bacilli, thus opening the prospect for genetic improvement of strains with an important biotechnological application.
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Ndukwe, Nelly A., J. Boitumelo M. Sibiya, and J. Pieter H. Van Wyk. "Saccharification of Sawdust with Aspergillus Niger Cellulase." Journal of Solid Waste Technology and Management 46, no. 3 (August 1, 2020): 321–27. http://dx.doi.org/10.5276/jswtm/2020.321.
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Accumulated sawdust is a major waste product produced by numerous active sawmills around the Lagos Lagoon in Nigeria. The potential of this wood waste as a resource for bio-product development through the hydrolysis of its cellulose component into glucose, a fermentable sugar is not yet appreciated. Not only is the environment exposed to this organic pollutant but the health of humans is also at risk. The cellulose content of wood sawdust from five different tropical tree species dumped along the Lagos lagoon has been saccharified with cellulase from Aspergillus niger. In order to increase the amount of fermentable sugars released from the cellulose content the various sawdust samples have been delignified with the Kraft process and hydrogen peroxide treatment prior to A. niger cellulase catalyzed degradation at incubation temperatures of 30 0C, 400C, 500C and 600C, respectively. The delignification process was successful by triggering an increase in sugar formation during cellulase catalyze hydrolyses of all waste cellulose materials with different amounts of sugar produced from the various celluloses.
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Gamathiya, Niha B. "Isolation, Screening and Production of Bacterial Cellulase from Cow Dung." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (July 25, 2021): 2176–87. http://dx.doi.org/10.22214/ijraset.2021.36762.
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Cellulases are the most important industrial enzyme due to their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing and agriculture. The present study was carried out to isolate and characterize cellulase producing microorganisms from different cow dung samples. Four different cow dung samples were collected from variety of cows namely Gir, Holstein, Jersey and Desi and isolation and screening was done to check cellulase producing microorganisms. The obtained 11 isolates were screened for their cellulase activity by using CMC (carboxymethyl cellulose) agar medium. In the current study, 10 cellulase producing isolates were obtained and were characterized morphologically from which 8 isolates were found Gram negative and 2 were found Gram positive. All the 10 cellulase producers were further confirmed for their cellulase producing ability by performing turbidity test. Out of these 10 isolates, GN4 and HN2 with optical density 0.35 and 0.28, respectively were found to be best cellulase producer and were selected for cellulase enzyme production and other further studies. Botssh the isolates were tested for their enzymatic activities by performing DNSA method and protein estimation by Lowry’s method. Cellulase activities were found to be 7.33 µg/ml/min and 3.66 µg/ml/min and the total protein concentrations were found to be 40 µg/ml and 32 µg/ml for GN4 and HN2, respectively. Thus, dungs cow dung can be considered as the excellent source for cellulase producing bacteria.
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Hildebrand, Amanda, Edyta Szewczyk, Hui Lin, Takao Kasuga, and Zhiliang Fan. "Engineering Neurospora crassa for Improved Cellobiose and Cellobionate Production." Applied and Environmental Microbiology 81, no. 2 (November 7, 2014): 597–603. http://dx.doi.org/10.1128/aem.02885-14.
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ABSTRACTWe report engineeringNeurospora crassato improve the yield of cellobiose and cellobionate from cellulose. A previously engineered strain ofN. crassa(F5) with six of seven β-glucosidase (bgl) genes knocked out was shown to produce cellobiose and cellobionate directly from cellulose without the addition of exogenous cellulases. In this study, the F5 strain was further modified to improve the yield of cellobiose and cellobionate from cellulose by increasing cellulase production and decreasing product consumption. The effects of two catabolite repression genes,cre-1andace-1, on cellulase production were investigated. The F5 Δace-1mutant showed no improvement over the wild type. The F5 Δcre-1and F5 Δace-1Δcre-1strains showed improved cellobiose dehydrogenase and exoglucanase expression. However, this improvement in cellulase expression did not lead to an improvement in cellobiose or cellobionate production. The cellobionate phosphorylase gene (ndvB) was deleted from the genome of F5 Δace-1Δcre-1to prevent the consumption of cellobiose and cellobionate. Despite a slightly reduced hydrolysis rate, the F5 Δace-1Δcre-1ΔndvBstrain converted 75% of the cellulose consumed to the desired products, cellobiose and cellobionate, compared to 18% converted by the strain F5 Δace-1Δcre-1.
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Rohrmann, S., and H. P. Molitoris. "Screening for wood-degrading enzymes in marine fungi." Canadian Journal of Botany 70, no. 10 (October 1, 1992): 2116–23. http://dx.doi.org/10.1139/b92-263.
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Forty marine and 15 terrestrial fungi in the Ascomycetes, Basidiomycetes, and Deuteromycetes were screened for presence and relative amount of enzymes involved in wood degradation (cellulases and redox enzymes) using seawater and deionized water media. Distribution of cellulases, laccase, tyrosinase, and peroxidase among marine and terrestrial groups of fungi was investigated. β-Glucosidase (C4) and endoglucanase (C3) were the most frequent enzymes (80 – 100% of the strains) of cellulose metabolism. Acid-swollen cellulose (C1) was generally more easily degraded than microcrystalline-dyed Avicel® (C2).All groups of strains showed relatively high percentages of cellulases C1, C3, C4, whereas production of cellulase C2 was lower. In comparison with Sporotrichum pulverulentum, a strongly cellulolytic terrestrial Deuteromycete, about 25% of the marine fungi tested showed the same high cellulase activity. Peroxidase was formed by nearly all strains tested at least on seawater medium; tyrosinase was the least frequent enzyme (20 – 35%). The presence of laccase was different among the various fungal systematic groups, reaching its highest percentages in the marine and terrestrial Basidiomycetes and the marine Ascomycetes, which mostly belong to the ecological groups of white-rot and soft-rot fungi, respectively. Enzymes involved in wood degradation were demonstrated in large number and sometimes considerable amounts in wood-inhabiting marine fungi. Key words: marine fungi, wood degradation, cellulase, phenoloxidases, screening, ecology.
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Beyisa Benti Diro, Tadessa Daba, and Temam Gemeda Genemo. "Production and characterization of cellulase from mushroom (Pleurotus ostreatus) for effective degradation of cellulose." International Journal of Biological and Pharmaceutical Sciences Archive 2, no. 1 (August 30, 2021): 135–50. http://dx.doi.org/10.53771/ijbpsa.2021.2.1.0066.
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Cellulases are a group of hydrolytic enzymes capable of hydrolyzing the most abundant organic polymer that means cellulose to smaller sugar components including glucose subunits. The aim of this study was to screen cellulase producing oyster mushroom collected from Eucalyptus tree bark to evaluate the in vitro production of cellulase by Pleurotus ostreatus using different lignocellulosic substrates, and to characterize the cellulase produced with respect to changes in pH, temperature, and concentration of substrates. A total of ten mushroom specimens were randomly collected from Eucalyptus tree bark in the premise of Holetta Agricultural Research Center campus. All of the collected mushroom specimens were identified morphologically and biochemically as Pleurotus ostreatus and also screened for their ability to produce cellulase by detecting and measuring zone of hydrolysis on commercial media containing Carbxymethyl Cellulose (CMC) as the sole carbon source. These mushroom specimens were cultivated using both solid state fermentation and submerged fermentation systems supplemented with different lignocellulosic substrates (wheat straw, teff straw, bean straw, wood fiber and Eucalyptus tree bark) to identify the most suitable medium for the production of cellulase. The highest enzyme production was obtained on bean straw and wheat straw which resulted in 0.191 U/ml, 0.868 U/ml and 0.389 U/ml; and 0.216 U/ml, 0.444 U/ml, and 0.245 U/ml of FPase, CMCase, and β-glucosidase in solid state fermentation. The lowest values were, however, obtained in media containing wood fiber in both solid state fermentation and submerged fermentation. Comparison of the lignocellulosic substrates revealed that wheat straw was selected for further growth parameter optimization. The production of cellulase was higher at the 5th day of incubation period, and the optimum pH and incubation temperature required for maximum cellulase production were 4 and 30°C, respectively. Sucrose and Yeast extract at 1% concentration were found to be the most preferred carbon and nitrogen sources for cellulase production by Pleurotus ostreatus. The optimum pH and temperature for cell_free cellulase activity on were found to be 4 and 50°C, respectively. Generally the cellulases produced by Pleurotus ostreatus were stable and active at temperatures ranging from 20-50°C. These characteristics hopefully would make this enzyme potentially attractive in a variety of industrial applications including animal feed treatments. There was a linear relationship between cellulase and its substrate concentration for there was an increase in activity with increase in substrate concentration. The relationship between rate of reaction and substrate concentration depended on the affinity of the enzyme for its substrate. Finally the cellulase was tested for its ability to saccharify agricultural wastes and the results showed the highest release of sugars from wheat straw.
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GHAZANFAR, MISBAH, MUHAMMAD IRFAN, MUHAMMAD NADEEM, HAFIZ ABDULLAH SHAKIR, MUHAMMAD KHAN, SHAUKAT ALI, SHAGUFTA SAEED, and TAHIR MEHMOOD. "ISOLATION OF CELLULOLYTIC BACTERIA FROM SOIL AND VALORIZATION OF DIFFERENT LIGNOCELLULOSIC WASTES FOR CELLULASE PRODUCTION BY SUBMERGED FERMENTATION." Cellulose Chemistry and Technology 55, no. 7-8 (September 30, 2021): 821–28. http://dx.doi.org/10.35812/cellulosechemtechnol.2021.55.69.
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Cellulases are known to convert cellulose into monomeric or dimeric structures, hence playing an important role in bioethanol production, along with their applications in textile and paper industries. This study was directed towards the isolation and screening of cellulase producing bacteria from different soil samples on CMC (carboxymethyl cellulose) agar plates, followed by Gram’s iodine staining. Six strains showed clear zones of hydrolysis on CMC agar plates. Isolates were identified as Bacillus megaterium, Pseudomonas stutzeri, Bacillus aerius, Bacillus paralichniformis, Bacillus flexus, and Bacillus wiedmanni by 16S rRNA gene sequencing. These strains were cultivated by submerged fermentation for cellulase production using various lignocellulosic wastes, such as corn cob, rice husk, wheat straw, seed pods of Bombax ceiba and eucalyptus leaves. Results showed that Pseudomonas stutzeri is the best cellulase producer among these strains. It offered the highest cellulase activity of 170.9±4.1 (IU/mL/min) in media containing eucalyptus leaves after 24 h of incubation at 37 °C, followed by Bacillus paralichniformis, Bacillus wiedmanni, Bacillus flexus, Bacillus aerius and Bacillus megaterium. These bacterial strains and lignocellulosic wastes could be potentially used for industrial exploitation, particularly in biofuels and textiles.
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Wymelenberg, Amber Vanden, Stuart Denman, Diane Dietrich, Jennifer Bassett, Xiaochun Yu, Rajai Atalla, Paul Predki, Ulla Rudsander, Tuula T. Teeri, and Daniel Cullen. "Transcript Analysis of Genes Encoding a Family 61 Endoglucanase and a Putative Membrane-Anchored Family 9 Glycosyl Hydrolase from Phanerochaete chrysosporium." Applied and Environmental Microbiology 68, no. 11 (November 2002): 5765–68. http://dx.doi.org/10.1128/aem.68.11.5765-5768.2002.
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ABSTRACT Phanerochaete chrysosporium cellulase genes were cloned and characterized. The cel61A product was structurally similar to fungal endoglucanases of glycoside hydrolase family 61, whereas the cel9A product revealed similarities to Thermobifida fusca Cel9A (E4), an enzyme with both endo- and exocellulase characteristics. The fungal Cel9A is apparently a membrane-bound protein, which is very unusual for microbial cellulases. Transcript levels of both genes were substantially higher in cellulose-grown cultures than in glucose-grown cultures. These results show that P. chrysosporium possesses a wide array of conventional and unconventional cellulase genes.
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Restaino, Odile Francesca, Sabrina Cuomo, Sergio D’Ambrosio, Valentina Vassallo, Seyedeh Fatemeh Mirpoor, Concetta Valeria L. Giosafatto, Raffaele Porta, and Chiara Schiraldi. "Cellulose from Posidonia oceanica Sea Balls (Egagropili) as Substrate to Enhance Streptomyces roseochromogenes Cellulase Biosynthesis." Fermentation 9, no. 2 (January 21, 2023): 98. http://dx.doi.org/10.3390/fermentation9020098.
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Enhancing Streptomyces cellulase production by supplying lignocellulose biomasses has been poorly investigated so far. In this research the biosynthesis of Streptomyces roseochromogenes ATCC13400 cellulases was increased for the first time by addition of a cellulose fraction (2.5 g·L−1) to the growth medium, isolated from the marine origin Posidonia oceanica sea balls, generally called egagropili.. In shake flasks the cellulase production increased of 4.3 folds, compared to the control, up to 268 U·L−1 in 72 h, with a productivity of 3.7 U·L−1·h−1, while in batch it was further enhanced up to 347 U·L−1 in 45 h with a doubled productivity of 7.7 U·L−1·h−1 A downstream protocol was set up by coupling two ultrafiltration steps on 10 and 3 kDa membranes to recover the enzymes from the supernatant. A pool of three cellulases, having molecular weights between 115 and 47 kDa, was recovered. The optimal conditions for their enzymatic activity were 60 °C and pH 5.0, and they showed CMCase, FPase and β-glucosidase action. In conclusion, S. roseochromogenes might be considered a new cell factory for cellulase biotechnological production that might be enhanced by using the cellulose from egagropili, a well-known marine origin plant waste, as the substrate.
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Bhatt, Puja, Garima Bista, Mukesh Yadav, Sujeeta Maharjan, Pravesh Paudel, Usha Lamsal, Sanoj Katharia, and Jarina Joshi. "Production of Cellulase from the Municipal Waste Residue by a Novel Cellulolytic Fungi." Journal of Nepal Biotechnology Association 4, no. 1 (March 22, 2023): 52–57. http://dx.doi.org/10.3126/jnba.v4i1.53446.
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Cellulases catalyze the hydrolysis of 1,4-β-D-glycosidic linkages in cellulose and play a significant role in nature by recycling polysaccharide debris. This enzyme has enormous potential in industries such as textile wet processing, bio-stoning of denim fabric, biopolishing of textile fibres, softening of garments and removal of excess dye from the fabrics. Therefore, the research focused on obtaining new cellulose-producing microorganisms with higher specific activities and greater efficiency. By identifying a good strain, improving the production medium and using an alternative carbon source such as waste residue, this study aimed to lower the manufacturing cost of cellulase. This study was designed to assess the cellulase production by fungi isolated from water, soil, straw, dung, leaf and goat manure. In the present research, cellulase-producing fungal isolates obtained from waste samples were identified by morphological and microscopic features. On Congo red test, the largest zone of hydrolysis was found as 1.2 cm. From the morphological and microscopic test, the fungal strain was expected as Aspergillus sp. The assay of the enzyme cellulase was performed by measuring the release amount of reducing sugar. Optimization of process parameters was carried out for the isolate to maximize enzyme yield. On optimization, isolated fungal species showed maximum enzyme activity at a temperature of 30 °C and pH 6. Under optimized conditions of temperature and pH, agitation at 200 rpm with a 1 L/m air flow rate showed better cellulase activity. Cellulase production from Aspergillus sp. can be an advantage as the enzyme production rate is normally higher as compared to other fungi.
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Zhang, Zhengjian, Qilian Zhang, Yunzhi Chen, and Zhihong Li. "Poly(dimethyldiallylammonium chloride) (polyDADMAC) assisted cellulase pretreatment for microfibrillated cellulose (MFC) preparation and MFC analysis." Holzforschung 72, no. 7 (July 26, 2018): 531–38. http://dx.doi.org/10.1515/hf-2017-0152.
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AbstractMicrofibrillated cellulose (MFC) preparation was investigated by means of cellulase pretreatment aided by poly(dimethyldiallylammonium chloride) (polyDADMAC) as an additive. The effect of polyDADMAC on the adsorption of cellulase onto the cellulose fibers, and the properties of MFC and MFC films are described. The additive improved the adsorption of cellulase onto cellulose fibers. Compared to the control, at an addition level of polyDADMAC of 0.789 ml g−1, the crystallinity, aspect ratio, the specific surface area of MFC and, the elongation at break and tensile strength of MFC films are increased, while the oxygen permeability coefficient of the MFC films is decreased. The optimal conditions for preparation of MFC by cellulase pretreatment were: pulp consistency 10%, cellulase dosage 10 µ g−1, pretreatment time 16 h and 0.789 ml g−1polyDADMAC. In summary, polyDADMAC-assisted cellulase pretreatment enhances the efficiency of the cellulase pretreatment of cellulose fibers and improves the performance of MFC and the MFC films.
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Kim, Sang Jin, Kyung-Chul Shin, Dae Wook Kim, Yeong-Su Kim, and Chang-Su Park. "Cloning and Characterization of Cellulase from Paenibacillus peoriae MK1 Isolated from Soil." Fermentation 9, no. 10 (September 27, 2023): 873. http://dx.doi.org/10.3390/fermentation9100873.
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An isolated bacterium from soil that highly hydrolyzes cellulose was identified as Paenibacillus peoriae and named P. peoriae MK1. The cellulase from P. peoriae MK1 was cloned and expressed in Escherichia coli. The purified recombinant cellulase, a soluble protein with 13.2-fold purification and 19% final yield, displayed a specific activity of 77 U/mg for CM-cellulose and existed as a metal-independent monomer of 65 kDa. The enzyme exhibited maximum activity at pH 5.0 and 40 °C with a half-life of 9.5 h in the presence of Ca2+ ion. The highest activity was observed toward CM-cellulose as an amorphous substrate, followed by swollen cellulose, and sigmacell cellulose and α-cellulose as crystalline substrates. The enzyme and substrate concentrations for the hydrolysis of CM-cellulose were optimized to 133 U/mL and 20 g/L CM-cellulose, respectively. Under these conditions, CM-cellulose was hydrolyzed to reducing sugars composed mostly of oligosaccharides by cellulase from P. peoriae MK1 as an endo-type cellulase with a productivity of 11.1 g/L/h for 10 min. Our findings will contribute to the industrial usability of cellulase and the research for securing cellulase sources.
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Deng, Yijie, and Shiao Y. Wang. "Sorption of Cellulases in Biofilm Enhances Cellulose Degradation by Bacillus subtilis." Microorganisms 10, no. 8 (July 26, 2022): 1505. http://dx.doi.org/10.3390/microorganisms10081505.
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Biofilm commonly forms on the surfaces of cellulosic biomass but its roles in cellulose degradation remain largely unexplored. We used Bacillus subtilis to study possible mechanisms and the contributions of two major biofilm components, extracellular polysaccharides (EPS) and TasA protein, to submerged biofilm formation on cellulose and its degradation. We found that biofilm produced by B. subtilis is able to absorb exogenous cellulase added to the culture medium and also retain self-produced cellulase within the biofilm matrix. The bacteria that produced more biofilm degraded more cellulose compared to strains that produced less biofilm. Knockout strains that lacked both EPS and TasA formed a smaller amount of submerged biofilm on cellulose than the wild-type strain and also degraded less cellulose. Imaging of biofilm on cellulose suggests that bacteria, cellulose, and cellulases form cellulolytic biofilm complexes that facilitate synergistic cellulose degradation. This study brings additional insight into the important functions of biofilm in cellulose degradation and could potentiate the development of biofilm-based technology to enhance biomass degradation for biofuel production.
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Patel, Milind A., Mark S. Ou, Roberta Harbrucker, Henry C. Aldrich, Marian L. Buszko, Lonnie O. Ingram, and K. T. Shanmugam. "Isolation and Characterization of Acid-Tolerant, Thermophilic Bacteria for Effective Fermentation of Biomass-Derived Sugars to Lactic Acid." Applied and Environmental Microbiology 72, no. 5 (May 2006): 3228–35. http://dx.doi.org/10.1128/aem.72.5.3228-3235.2006.
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ABSTRACT Biomass-derived sugars, such as glucose, xylose, and other minor sugars, can be readily fermented to fuel ethanol and commodity chemicals by the appropriate microbes. Due to the differences in the optimum conditions for the activity of the fungal cellulases that are required for depolymerization of cellulose to fermentable sugars and the growth and fermentation characteristics of the current industrial microbes, simultaneous saccharification and fermentation (SSF) of cellulose is envisioned at conditions that are not optimal for the fungal cellulase activity, leading to a higher-than-required cost of cellulase in SSF. We have isolated bacterial strains that grew and fermented both glucose and xylose, major components of cellulose and hemicellulose, respectively, to l(+)-lactic acid at 50�C and pH 5.0, conditions that are also optimal for fungal cellulase activity. Xylose was metabolized by these new isolates through the pentose-phosphate pathway. As expected for the metabolism of xylose by the pentose-phosphate pathway, [13C]lactate accounted for more than 90% of the total 13C-labeled products from [13C]xylose. Based on fatty acid profile and 16S rRNA sequence, these isolates cluster with Bacillus coagulans, although the B. coagulans type strain, ATCC 7050, failed to utilize xylose as a carbon source. These new B. coagulans isolates have the potential to reduce the cost of SSF by minimizing the amount of fungal cellulases, a significant cost component in the use of biomass as a renewable resource, for the production of fuels and chemicals.
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Mostafa, Yasser S., Saad A. Alamri, Mohamed Hashem, Nivien A. Nafady, Kamal A. M. Abo-Elyousr, and Zakaria A. Mohamed. "Thermostable cellulase biosynthesis from Paenibacillus alvei and its utilization in lactic acid production by simultaneous saccharification and fermentation." Open Life Sciences 15, no. 1 (April 10, 2020): 185–97. http://dx.doi.org/10.1515/biol-2020-0019.
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AbstractCellulosic date palm wastes may have beneficial biotechnological applications for eco-friendly utilization. This study reports the isolation of thermophilic cellulase-producing bacteria and their application in lactic acid production using date palm leaves. The promising isolate was identified as Paenibacillus alvei by 16S rRNA gene sequencing. Maximum cellulase production was acquired using alkaline treated date palm leaves (ATDPL) at 48 h and yielded 4.50 U.mL-1 FPase, 8.11 U.mL-1 CMCase, and 2.74 U.mL-1 β-glucosidase. The cellulase activity was optimal at pH 5.0 and 50°C with good stability at a wide temperature (40-70°C) and pH (4.0-7.0) range, demonstrating its suitability in simultaneous saccharification and fermentation. Lactic acid fermentation was optimized at 4 days, pH 5.0, 50°C, 6.0% cellulose of ATDPL, 30 FPU/ g cellulose, 1.0 g. L-1 Tween 80, and 5.0 g. L-l yeast extract using Lactobacillus delbrueckii. The conversion efficiency of lactic acid from the cellulose of ATDPL was 98.71%, and the lactic acid productivity was 0.719 g. L-1 h-1. Alkaline treatment exhibited a valuable effect on the production of cellulases and lactic acid by reducing the lignin content and cellulose crystallinity. The results of this study offer a credible procedure for using date palm leaves for microbial industrial applications.
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Schmoll, Monika, André Schuster, Roberto do Nascimento Silva, and Christian P. Kubicek. "The G-Alpha Protein GNA3 of Hypocrea jecorina (Anamorph Trichoderma reesei) Regulates Cellulase Gene Expression in the Presence of Light." Eukaryotic Cell 8, no. 3 (January 9, 2009): 410–20. http://dx.doi.org/10.1128/ec.00256-08.
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ABSTRACT Although the enzymes enabling Hypocrea jecorina (anamorph Trichoderma reesei) to degrade the insoluble substrate cellulose have been investigated in some detail, little is still known about the mechanism by which cellulose signals its presence to the fungus. In order to investigate the possible role of a G-protein/cyclic AMP signaling pathway, the gene encoding GNA3, which belongs to the adenylate cyclase-activating class III of G-alpha subunits, was cloned. gna3 is clustered in tandem with the mitogen-activated protein kinase gene tmk3 and the glycogen phosphorylase gene gph1. The gna3 transcript is upregulated in the presence of light and is almost absent in the dark. A strain bearing a constitutively activated version of GNA3 (gna3QL) exhibits strongly increased cellulase transcription in the presence of the inducer cellulose and in the presence of light, whereas a gna3 antisense strain showed delayed cellulase transcription under this condition. However, the gna3QL mutant strain was unable to form cellulases in the absence of cellulose. The necessity of light for stimulation of cellulase transcription by GNA3 could not be overcome in a mutant which expressed gna3 under control of the constitutive gpd1 promoter also in darkness. We conclude that the previously reported stimulation of cellulase gene transcription by light, but not the direct transmission of the cellulose signal, involves the function and activation of GNA3. The upregulation of gna3 by light is influenced by the light modulator ENVOY, but GNA3 itself has no effect on transcription of the light regulator genes blr1, blr2, and env1. Our data for the first time imply an involvement of a G-alpha subunit in a light-dependent signaling event in fungi.
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Ezea, Ifeanyi Boniface, Yoshinori Murata, and James Chukwuma Ogbonna. "Simultaneous production of cellulase and amylase by Aspergillus fumigatus IB-A1." Bio-Research 20, no. 1 (March 1, 2022): 1426–33. http://dx.doi.org/10.4314/br.v20i1.4.
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Utilization of agricultural wastes for production of useful metabolites requires hydrolysis using both cellulase and amylase enzymes. We isolated Aspergillus fumigatus IB-A1 and evaluated its ability to simultaneously produce both cellulase and amylase. Although the isolate could produce both cellulase and amylase from either soluble starch or carboxymethyl cellulose, amylase activity was higher with soluble starch while cellulase activity was higher when carboxymethyl cellulose was used as the sole carbon source. With a mixture of carboxymethyl cellulose and soluble starch, both the amylase and cellulase activities increased with increase in the ratio of soluble starch. The optima ratio of carboxymethyl cellulose to soluble starch for cellulase and amylase activities were 0.7:0.3, and 0.4 to 0.6 respectively. For practical application, the optimum ratio of carboxymethyl cellulose to soluble starch in the production medium depends on the relative composition of cellulose and starch in the substrate to be hydrolyzed. The isolate was also able to efficiently produce both amylase and cellulase from cassava peel. With 10 g/L cassava peel, the cellulase and amylase activities were 6.122± 0.320 U/ml/min and 4.342± 0.210 U/ml/min respectively. When the cells were immobilized on loofa sponge and subjected to alternating air phase- liquid phase culture, cellulase and amylase production from cassava peel increased to 8.106± 0.620 U/ml/min and 5.206± 1.24 U/ml/min respectively. The optimum ratio of the air phase to the liquid phase was 3 hours of air phase to 21 hours of liquid phase.
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Zhang, Jiaqi, Yingying Liu, Junxing Hu, Guangxian Leng, Xining Liu, Zailin Cui, Wenzhen Wang, Yufang Ma, and Shanshan Sha. "Cellulase Promotes Mycobacterial Biofilm Dispersal in Response to a Decrease in the Bacterial Metabolite Gamma-Aminobutyric Acid." International Journal of Molecular Sciences 25, no. 2 (January 15, 2024): 1051. http://dx.doi.org/10.3390/ijms25021051.
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Biofilm dispersal contributes to bacterial spread and disease transmission. However, its exact mechanism, especially that in the pathogen Mycobacterium tuberculosis, is unclear. In this study, the cellulase activity of the M. tuberculosis Rv0062 protein was characterized, and its effect on mycobacterial biofilm dispersal was analyzed by observation of the structure and components of Rv0062-treated biofilm in vitro. Meanwhile, the metabolite factors that induced cellulase-related biofilm dispersal were also explored with metabolome analysis and further validations. The results showed that Rv0062 protein had a cellulase activity with a similar optimum pH (6.0) and lower optimum temperature (30 °C) compared to the cellulases from other bacteria. It promoted mycobacterial biofilm dispersal by hydrolyzing cellulose, the main component of extracellular polymeric substrates of mycobacterial biofilm. A metabolome analysis revealed that 107 metabolites were significantly altered at different stages of M. smegmatis biofilm development. Among them, a decrease in gamma-aminobutyric acid (GABA) promoted cellulase-related biofilm dispersal, and this effect was realized with the down-regulation of the bacterial signal molecule c-di-GMP. All these findings suggested that cellulase promotes mycobacterial biofilm dispersal and that this process is closely associated with biofilm metabolite alterations.
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Thi Thao, Nguyen, Do Thi Huyen, and Truong Nam Hai. "Prediction of cellulolytic and hemicellulolytic bacterial diversity in the gut of Coptotermes gestroi in the Southern Vietnam." Vietnam Journal of Biotechnology 17, no. 3 (November 28, 2020): 537–44. http://dx.doi.org/10.15625/1811-4989/17/3/15708.
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In lower termite such as Coptotermes gestroi, cellulose and hemicellulose are hydrolysed by cellulases and hemicellulases secreted from bacteria, archaea, protozoa and fungy in the hindgut. In which, majority of the enzymes are contributed by protozoa. From the metagenomic DNA data (125,423 open reading frames -ORFs) of free-living bacteria in the gut of C. gestroi harvested in Southern Vietnam and by MEGA 4.0 software, 100.340 ORFs were classified into 1,368 species, 628 genera, 217 families, 97 orders, 41 classes and 22 phyla (Do et al., 2014). Among these, 2,131 ORFs (2,12%) belong to 24 bacterial species (account 1,75% bacterial species), 11 families, 9 orders, 8 classes and 5 phyla were predicted have ability to produce cellulases; 679 ORFs belong to 18 bacterial species 8 families, 6 orders, 5 classes, 4 phyla were predicted have ability to produce hemicellulase. Majority of cellulase producers were species which of Firmicutes (15/24 species), accumulated in class Clostridia, order Clostridiales. The most abundant cellulase producer was Pseudomonas fluorescens (1,258 ORFs) of order Pseudomonadaceae. Out of the 18 hemicellulase producers, the most abundant species was Clostridium thermocellum (113 ORFs) in the phylum Firmicutes, followed by 3 species belonging to the phylum Bacteroidetes. The species predicted to produce both cellulase, hemicellulase were C. thermocellum, Ruminococcusns flavefaciens and Bacillus subtilis. Our study provides a data of gut cellulose and hemicellulose - degrading bacteria composition of C. gestroi