Displaying publications 1 - 20 of 62 in total

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  1. Crude cellulase from oil palm empty fruit bunch by Trichoderma asperellum UPM1 and Aspergillus fumigatus UPM2 for fermentable sugars production
    Ibrahim MF, Razak MN, Phang LY, Hassan MA, Abd-Aziz S
    Appl Biochem Biotechnol, 2013 Jul;170(6):1320-35.
    PMID: 23666614 DOI: 10.1007/s12010-013-0275-2
    Cellulase is an enzyme that converts the polymer structure of polysaccharides into fermentable sugars. The high market demand for this enzyme together with the variety of applications in the industry has brought the research on cellulase into focus. In this study, crude cellulase was produced from oil palm empty fruit bunch (OPEFB) pretreated with 2% NaOH with autoclave, which was composed of 59.7% cellulose, 21.6% hemicellulose, and 12.3% lignin using Trichoderma asperellum UPM1 and Aspergillus fumigatus UPM2. Approximately 0.8 U/ml of FPase, 24.7 U/ml of CMCase and 5.0 U/ml of β-glucosidase were produced by T. asperellum UPM1 at a temperature of 35 °C and at an initial pH of 7.0. A 1.7 U/ml of FPase, 24.2 U/ml of CMCase, and 1.1 U/ml of β-glucosidase were produced by A. fumigatus UPM2 at a temperature of 45 °C and at initial pH of 6.0. The crude cellulase was best produced at 1% of substrate concentration for both T. asperellum UPM1 and A. fumigatus UPM2. The hydrolysis percentage of pretreated OPEFB using 5% of crude cellulase concentration from T. asperellum UPM1 and A. fumigatus UPM2 were 3.33% and 19.11%, with the reducing sugars concentration of 1.47 and 8.63 g/l, respectively.
    Matched MeSH terms: Cellulase/biosynthesis*
  2. Fulltext Optimisation of Simultaneous Saccharification and Fermentation (SSF) for Biobutanol Production Using Pretreated Oil Palm Empty Fruit Bunch
    Md Razali NAA, Ibrahim MF, Kamal Bahrin E, Abd-Aziz S
    Molecules, 2018 Aug 03;23(8).
    PMID: 30081514 DOI: 10.3390/molecules23081944
    This study was conducted in order to optimise simultaneous saccharification and fermentation (SSF) for biobutanol production from a pretreated oil palm empty fruit bunch (OPEFB) by Clostridium acetobutylicum ATCC 824. Temperature, initial pH, cellulase loading and substrate concentration were screened using one factor at a time (OFAT) and further statistically optimised by central composite design (CCD) using the response surface methodology (RSM) approach. Approximately 2.47 g/L of biobutanol concentration and 0.10 g/g of biobutanol yield were obtained after being screened through OFAT with 29.55% increment (1.42 fold). The optimised conditions for SSF after CCD were: temperature of 35 °C, initial pH of 5.5, cellulase loading of 15 FPU/g-substrate and substrate concentration of 5% (w/v). This optimisation study resulted in 55.95% increment (2.14 fold) of biobutanol concentration equivalent to 3.97 g/L and biobutanol yield of 0.16 g/g. The model and optimisation design obtained from this study are important for further improvement of biobutanol production, especially in consolidated bioprocessing technology.
    Matched MeSH terms: Cellulase
  3. Fulltext Production of chitosan oligosaccharides using β-glycosidic degrading enzyme: optimization using response surface methodology
    Yusof Nurhayati, Abdul Manaf Ali
    Malaysian Journal of Applied Sciences, 2020;5(2):30-44.
    MyJurnal
    Many researchers have focused chitosan as a source of potential bioactive material during the past few decades. However, chitosan has several drawbacks to be utilised in biological applications, including poor solubility under physiological conditions. Therefore, a new interest has recently emerged on partially hydrolysed chitosan, chitosan oligosaccharides (COS). In this study, degradation of chitosan was performed by Cellulase from Trichoderma reesei® 1.5L and Response Surface Methodology (RSM) were employed to optimize the hydrolysis temperature, pH, enzyme concentration and substrate concentration. Optimization of cellulase T. reesei® using central composite design (CCD) was to obtain optimum parameters and all the factors showed significant effects (p˂0.05). The maximum response, Celluclast® activity (1.268 U) was obtained by assaying the process at 49.79oC, pH 4.5, 3% (v/w) of enzyme concentration and 25% (w/v) concentration of chitosan for 24 hours.
    Matched MeSH terms: Cellulase
  4. Fulltext Enhancement of Versatile Extracellular Cellulolytic and Hemicellulolytic Enzyme Productions by Lactobacillus plantarum RI 11 Isolated from Malaysian Food Using Renewable Natural Polymers
    Mohamad Zabidi NA, Foo HL, Loh TC, Mohamad R, Abdul Rahim R
    Molecules, 2020 Jun 03;25(11).
    PMID: 32503356 DOI: 10.3390/molecules25112607
    Lactobacillus plantarum RI 11 was reported recently to be a potential lignocellulosic biomass degrader since it has the capability of producing versatile extracellular cellulolytic and hemicellulolytic enzymes. Thus, this study was conducted to evaluate further the effects of various renewable natural polymers on the growth and production of extracellular cellulolytic and hemicellulolytic enzymes by this novel isolate. Basal medium supplemented with molasses and yeast extract produced the highest cell biomass (log 10.51 CFU/mL) and extracellular endoglucanase (11.70 µg/min/mg), exoglucanase (9.99 µg/min/mg), β-glucosidase (10.43 nmol/min/mg), and mannanase (8.03 µg/min/mg), respectively. Subsequently, a statistical optimization approach was employed for the enhancement of cell biomass, and cellulolytic and hemicellulolytic enzyme productions. Basal medium that supplemented with glucose, molasses and soybean pulp (F5 medium) or with rice straw, yeast extract and soybean pulp (F6 medium) produced the highest cell population of log 11.76 CFU/mL, respectively. However, formulated F12 medium supplemented with glucose, molasses and palm kernel cake enhanced extracellular endoglucanase (4 folds), exoglucanase (2.6 folds) and mannanase (2.6 folds) specific activities significantly, indicating that the F12 medium could induce the highest production of extracellular cellulolytic and hemicellulolytic enzymes concomitantly. In conclusion, L. plantarum RI 11 is a promising and versatile bio-transformation agent for lignocellulolytic biomass.
    Matched MeSH terms: Cellulase/metabolism*
  5. Fulltext Prospecting Agro-waste Cocktail: Supplementation for Cellulase Production by a Newly Isolated Thermophilic B. licheniformis 2D55
    Kazeem MO, Shah UKM, Baharuddin AS, AbdulRahman NA
    Appl Biochem Biotechnol, 2017 Aug;182(4):1318-1340.
    PMID: 28176140 DOI: 10.1007/s12010-017-2401-z
    Bacteria isolated from thermophilic environment that can produce cellulase as well as utilise agro-waste biomass have a high potential for developing thermostable cellulase required in the biofuel industry. The cost for cellulase represents a significant challenge in converting lignocellulose to fermentable sugars for biofuel production. Among three potential bacteria examined, Bacillus licheniformis 2D55 (accession no. KT799651) was found to produce the highest cellulolytic activity (CMCase 0.33 U/mL and FPase 0.09 U/mL) at 18-24 h fermentation when grown on microcrystalline cellulose (MCC) as a carbon source in shake flask at 50 °C. Cellulase production process was further conducted on the untreated and NaOH pretreated rice straw (RS), rice husk (RH), sugarcane bagasse (BAG) and empty fruit bunch (EFB). Untreated BAG produced the highest FPase (0.160 U/mL), while the highest CMCase (0.150 U/mL) was supported on the pretreated RH. The mixture of untreated BAG and pretreated RH as agro-waste cocktail has remarkably improved CMCase (3.7- and 1.4-fold) and FPase (2.5- and 11.5-fold) compared to the untreated BAG and pretreated RH, respectively. The mechanism of cellulase production explored through SEM analysis and the location of cellulase enzymes of the isolate was also presented. Agro-waste cocktail supplementation provides an alternative method for an efficient production of cellulase.
    Matched MeSH terms: Cellulase/biosynthesis*
  6. Fulltext Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches
    Woon JS, Mackeen MM, Illias RM, Mahadi NM, Broughton WJ, Murad AMA, et al.
    PeerJ, 2017;5:e3909.
    PMID: 29038760 DOI: 10.7717/peerj.3909
    BACKGROUND: Aspergillus niger, along with many other lignocellulolytic fungi, has been widely used as a commercial workhorse for cellulase production. A fungal cellulase system generally includes three major classes of enzymes i.e., β-glucosidases, endoglucanases and cellobiohydrolases. Cellobiohydrolases (CBH) are vital to the degradation of crystalline cellulose present in lignocellulosic biomass. However, A. niger naturally secretes low levels of CBH. Hence, recombinant production of A. niger CBH is desirable to increase CBH production yield and also to allow biochemical characterisation of the recombinant CBH from A. niger.

    METHODS: In this study, the gene encoding a cellobiohydrolase B (cbhB) from A. niger ATCC 10574 was cloned and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant CBHB was purified and characterised to study its biochemical and kinetic characteristics. To evaluate the potential of CBHB in assisting biomass conversion, CBHB was supplemented into a commercial cellulase preparation (Cellic(®) CTec2) and was used to hydrolyse oil palm empty fruit bunch (OPEFB), one of the most abundant lignocellulosic waste from the palm oil industry. To attain maximum saccharification, enzyme loadings were optimised by response surface methodology and the optimum point was validated experimentally. Hydrolysed OPEFB samples were analysed using attenuated total reflectance FTIR spectroscopy (ATR-FTIR) to screen for any compositional changes upon enzymatic treatment.

    RESULTS: Recombinant CBHB was over-expressed as a hyperglycosylated protein attached to N-glycans. CBHB was enzymatically active towards soluble substrates such as 4-methylumbelliferyl-β-D-cellobioside (MUC), p-nitrophenyl-cellobioside (pNPC) and p-nitrophenyl-cellobiotrioside (pNPG3) but was not active towards crystalline substrates like Avicel(®) and Sigmacell cellulose. Characterisation of purified CBHB using MUC as the model substrate revealed that optimum catalysis occurred at 50 °C and pH 4 but the enzyme was stable between pH 3 to 10 and 30 to 80 °C. Although CBHB on its own was unable to digest crystalline substrates, supplementation of CBHB (0.37%) with Cellic(®) CTec2 (30%) increased saccharification of OPEFB by 27%. Compositional analyses of the treated OPEFB samples revealed that CBHB supplementation reduced peak intensities of both crystalline cellulose Iα and Iβ in the treated OPEFB samples.

    DISCUSSION: Since CBHB alone was inactive against crystalline cellulose, these data suggested that it might work synergistically with other components of Cellic(®) CTec2. CBHB supplements were desirable as they further increased hydrolysis of OPEFB when the performance of Cellic(®) CTec2 was theoretically capped at an enzyme loading of 34% in this study. Hence, A. niger CBHB was identified as a potential supplementary enzyme for the enzymatic hydrolysis of OPEFB.

    Matched MeSH terms: Cellulase; Cellulases
  7. Fulltext Growth, substrate consumption, and product formation kinetics of Phanerochaete chrysosporium and Schizophyllum commune mixed culture under solid-state fermentation of fruit peels
    Olorunnisola KS, Jamal P, Alam MZ
    3 Biotech, 2018 Oct;8(10):429.
    PMID: 30305998 DOI: 10.1007/s13205-018-1452-3
    Kinetic analysis of solid-state fermentation (SSF) of fruit peels with Phanerochaete chrysosporium and Schizophyllum commune mixed culture was studied in flask and 7 kg capacity reactor. Modified Monod kinetic model suggested by Haldane sufficiently described microbial growth with co-efficient of determination (R2) reaching 0.908 at increased substrate concentration than the classical Monod model (R2 = 0.932). Leudeking-Piret model adequately described product synthesis in non-growth-dependent manner (R2 = 0.989), while substrate consumption by P. chrysosporium and S. commune fungal mixed culture was growth-dependent (R2 = 0.938). Hanes-Woolf model sufficiently represented α-amylase and cellulase enzymes synthesis (R2 = 0.911 and 0.988); α-amylase had enzyme maximum velocity (Vmax) of 25.19 IU/gds/day and rate constant (Km) of 11.55 IU/gds/day, while cellulase enzyme had Vmax of 3.05 IU/gds/day and Km of 57.47 IU/gds/day. Product yield in the reactor increased to 32.65 mg/g/day compared with 28.15 mg/g/day in shake flask. 2.5 cm media thickness was adequate for product formation within a 6 day SSF in the tray reactor.
    Matched MeSH terms: Cellulase
  8. Fulltext Agricultural residues for cellulolytic enzyme production by Aspergillus niger: effects of pretreatment
    Salihu A, Abbas O, Sallau AB, Alam MZ
    3 Biotech, 2015 Dec;5(6):1101-1106.
    PMID: 28324400 DOI: 10.1007/s13205-015-0294-5
    Different agricultural residues were considered in this study for their ability to support cellulolytic enzyme production by Aspergillus niger. A total of eleven agricultural residues including finger millet hulls, sorghum hulls, soybean hulls, groundnut husk, banana peels, corn stalk, cassava peels, sugarcane bagasse, saw dust, rice straw and sheanut cake were subjected to three pretreatment (acid, alkali and oxidative) methods. All the residues supported the growth and production of cellulases by A. niger after 96 h of incubation. Maximum cellulase production was found in alkali-treated soybean hulls with CMCase, FPase and β-glucosidase yields of 9.91 ± 0.04, 6.20 ± 0.13 and 5.69 ± 0.29 U/g, respectively. Further studies in assessing the potential of soybean hulls are being considered to optimize the medium composition and process parameters for enhanced cellulase production.
    Matched MeSH terms: Cellulase
  9. Fulltext Enzyme aided extraction of sulfated polysaccharides from Turbinaria turbinata brown seaweed
    Hammed, A. M., Jaswir, I., Simsek, S., Alam, Z., Amid, A.
    International Food Research Journal, 2017;24(4):1660-1666.
    MyJurnal
    This study involves extraction of sulfated polysaccahride (SP) from brown seaweed (Turbinaria turbinata). Eight processing conditions affecting enzyme aided extraction (EAE) were screened using Plackett-Burman design. Three significant factors (hydrolysis time, enzyme concentration and extraction stage) were optimized using Faced Centred Central Composite Design in Random Surface Methods. Micrograph obtained using Field Emission Scanning Electron Microscopy revealed that cellulase degradation ruptured the seaweed cell matrix thus caused increase in the release of SP. The optimum conditions for extraction of SP from T. turbinata are: extraction stage of 2, hydrolysis time of 19.5 h and enzyme concentration of 1.5 μl/ml to produce 25.13% yield. The SP obtained from cellulase treated T. turbinata is a suitable anti-inflammatory agent for pharmaceutical applications.
    Matched MeSH terms: Cellulase
  10. Fulltext Valorizing guava (Psidium guajava L.) seeds through germination-induced carbohydrate changes
    Ling CX, Chang YP
    J Food Sci Technol, 2017 Jun;54(7):2041-2049.
    PMID: 28720961 DOI: 10.1007/s13197-017-2641-5
    Guava seeds are produced as a waste product by the guava processing industry. Their high carbohydrate contents may suit the carbohydrate needs of the feed sector but their high dietary fiber content limits their feed value. The feed values of fruit seeds can be improved through germination, which involves the mobilization of nutrients through seed enzymes and alters the seed carbohydrate composition. The changes of selected carbohydrates in guava (Psidium guajava L.) seeds brought by germination to those in red bean (Vigna angularis) and winter wheat (Triticum aestivum L.) were compared. The contents of soluble carbohydrates, digestible starch, resistant starch and cellulose in the seeds were determined. The radial diffusion method was used to detect carbohydrate-degrading enzymes in the seed extracts. Guava seeds were rich in cellulose (402.2 mg/g), which decreased progressively during germination, probably through the action of cellulase. Winter wheat contained the highest starch content (412.2 mg/g) and also distinct quantities of α-amylase and cellulase. The starch contents of all the seeds decreased, but the soluble carbohydrate contents in red beans and guava seeds increased significantly by the end of germination, suggesting the transient oversupply of reserve metabolites. The content of hydrolyzed polysaccharides increased in the germinated seeds with detectable amounts of cellulose-degrading enzymes present, indicating improved value as feed. Further research is warranted to explore the potential of guava seeds as a source of low-cost animal feed supplements.
    Matched MeSH terms: Cellulase
  11. Ultrasound mediated enzymatic hydrolysis of cellulose and carboxymethyl cellulose
    Sulaiman AZ, Ajit A, Chisti Y
    Biotechnol Prog, 2013 Nov-Dec;29(6):1448-57.
    PMID: 23926080 DOI: 10.1002/btpr.1786
    A recombinant Trichoderma reesei cellulase was used for the ultrasound-mediated hydrolysis of soluble carboxymethyl cellulose (CMC) and insoluble cellulose of various particle sizes. The hydrolysis was carried out at low intensity sonication (2.4-11.8 W cm(-2) sonication power at the tip of the sonotrode) using 10, 20, and 40% duty cycles. [A duty cycle of 10%, for example, was obtained by sonicating for 1 s followed by a rest period (no sonication) of 9 s.] The reaction pH and temperature were always 4.8 and 50°C, respectively. In all cases, sonication enhanced the rate of hydrolysis relative to nonsonicated controls. The hydrolysis of CMC was characterized by Michaelis-Menten kinetics. The Michaelis-Menten parameter of the maximum reaction rate Vmax was enhanced by sonication relative to controls, but the value of the saturation constant Km was reduced. The optimal sonication conditions were found to be a 10% duty cycle and a power intensity of 11.8 W cm(-2) . Under these conditions, the maximum rate of hydrolysis of soluble CMC was nearly double relative to control. In the hydrolysis of cellulose, an increasing particle size reduced the rate of hydrolysis. At any fixed particle size, sonication at a 10% duty cycle and 11.8 W cm(-2) power intensity improved the rate of hydrolysis relative to control. Under the above mentioned optimal sonication conditions, the enzyme lost about 20% of its initial activity in 20 min. Sonication was useful in accelerating the enzyme catalyzed saccharification of cellulose.
    Matched MeSH terms: Cellulase/chemistry*
  12. Draft genome sequence of Parvularcula flava strain NH6-79 T, revealing its role as a cellulolytic enzymes producer
    Abdul Karim MH, Lam MQ, Chen SJ, Yahya A, Shahir S, Shamsir MS, et al.
    Arch Microbiol, 2020 Nov;202(9):2591-2597.
    PMID: 32607725 DOI: 10.1007/s00203-020-01967-z
    To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 β-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and β-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and β-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.
    Matched MeSH terms: Cellulase/genetics; Cellulase/metabolism
  13. Genome analysis of cellulose and hemicellulose degrading Micromonospora sp. CP22
    Chen SJ, Lam MQ, Thevarajoo S, Abd Manan F, Yahya A, Chong CS
    3 Biotech, 2020 Apr;10(4):160.
    PMID: 32206494 DOI: 10.1007/s13205-020-2148-z
    In this study, a bacterial strain CP22 with ability to produce cellulase, xylanase and mannanase was isolated from the oil palm compost. Based on the 16S rRNA gene analysis, the strain was affiliated to genus Micromonospora. To further investigate genes that are related to cellulose and hemicellulose degradation, the genome of strain CP22 was sequenced, annotated and analyzed. The de novo assembled genome of strain CP22 featured a size of 5,856,203 bp with G + C content of 70.84%. Detailed genome analysis on lignocellulose degradation revealed a total of 60 genes consisting of 47 glycoside hydrolase domains and 16 carbohydrate esterase domains predicted to be involved in cellulolytic and hemicellulolytic deconstruction. Particularly, 20 genes encode for cellulases (8 endoglucanases, 3 exoglucanases and 9 β-glucosidases) and 40 genes encode for hemicellulases (15 endo-1,4-β-xylanase, 3 β-xylosidase, 3 α-arabinofuranosidase, 10 acetyl xylan esterase, 6 polysaccharide deacetylase, 1 β-mannanase, 1 β-mannosidase and 1 α-galactosidase). Thirty-two genes encoding carbohydrate-binding modules (CBM) from six different families (CBM2, CBM4, CBM6, CBM9, CBM13 and CBM22) were present in the genome of strain CP22. These CBMs were found in 27 cellulolytic and hemicellulolytic genes, indicating their potential role in enhancing the substrate-binding capability of the enzymes. CBM2 and CBM13 are the major CBMs present in cellulases and hemicellulases (xylanases and mannanases), respectively. Moreover, a GH10 xylanase was found to contain 3 CBMs (1 CBM9 and 2 CBM22) and these CBMs were reported to bind specifically to xylan. This genome-based analysis could facilitate the exploration of this strain for lignocellulosic biomass degradation.
    Matched MeSH terms: Cellulase; Cellulases
  14. Simultaneous production of cellulase and reducing sugar through modification of compositional and structural characteristic of sugarcane bagasse
    Yoon LW, Ngoh GC, Chua AS
    Enzyme Microb Technol, 2013 Sep 10;53(4):250-6.
    PMID: 23931690 DOI: 10.1016/j.enzmictec.2013.05.005
    This study examined the potential of untreated and alkali-pretreated sugarcane bagasse (SCB) in cellulase, reducing sugar (RS) and fungal biomass production via solid state fermentation (SSF) using Pycnoporus sanguineus. The impact of the composition, structure and cellulase adsorption ability of SCB on the production of cellulase, RS and fungal biomass was investigated. From the morphological and compositional analyses, untreated SCB has relatively more structural changes with a higher percentage of depolymerisation on the cellulose, hemicellulose and lignin content compared to alkali-pretreated SCB. Thus, untreated SCB favoured the production of cellulase and fungal biomass whereas alkali-pretreated SCB yielded a higher amount of RS. The composition and morphology of untreated SCB did not encourage RS production and this suggested that RS produced during SSF might be consumed in a faster rate by the more abundantly grown fungus. Besides that, alkali-pretreated SCB with higher cellulase adsorption ability could have adsorbed the cellulase produced and resulted in a lower cellulase titre. In short, the production of specific bioproducts via SSF is dependent on the structure and composition of the substrate applied.
    Matched MeSH terms: Cellulase/biosynthesis*
  15. Fulltext Additives for cellulase enhancement
    Eugene M. Obeng, Chan, Yi Wei, Siti Nurul Nadzirah Adam, Clarence M. Ongkudon
    Borneo International Journal of Biotechnology, 2020;1(1):1-18.
    MyJurnal
    Cellulases have been vital for the saccharification of lignocellulosic biomass into reduced sugars to produce biofuels and other essential biochemicals. However, the sugar yields achievable for canonical cellulases (i.e. endoglucanases, exoglucanases and β-glucosidases) have not been convincing in support of the highly acclaimed prospects and end-uses heralded. The persistent pursuit of the biochemical industry to obtain high quantities of useful chemicals from lignocellulosic biomass has resulted in the supplementation of cellulose-degrading enzymes with other biological complementation. Also, chemical additives (e.g. salts, surfactants and chelating agents) have been employed to enhance the stability and improve the binding and overall functionality of cellulases to increase product titre. Herein, we report the roadmap of cellulase-additive supplementations and the associated yield performances.
    Matched MeSH terms: Cellulase; Cellulases
  16. Fulltext Characterisation of an antarctic yeast, glaciozyma antarctica pi12
    Teoh, Chul Peng, Koh, Soon Peng, Clemente Michael Wong Vui Ling
    Borneo International Journal of Biotechnology, 2020;1(1):89-102.
    MyJurnal
    Glaciozyma antarctica PI12 is a psychrophilic yeast isolated from Antarctica. It has an optimal growth in yeast peptone dextrose (YPD) and yeast mould (YM) broth media but not in potato dextrose (PD) broth medium. Early phase G. antarctica PI12 cells had elongated-shape and became oval-shaped as they aged. G. antarctica PI12 exhibited bipolar budding and formed a chain of cells during the lag and early exponential phases. The number of chains decreased as the yeast aged. It appeared mainly as a single cell at the stationary phase, and a small number of them still produced buds. Some cells at the stationary phase entered the quiescence state (G0) as a longterm survival strategy. The G. antarctica PI12 cell size decreased when they entered the stationary phase. G. antarctica PI12 was found to produce hydrolytic enzymes, chitinase, cellulase, mannanase, and xylanase. A higher glucose concentration of 2% in the PD agar medium inhibited the activities of chitinase but not the cellulase, mananase and xylanase.
    Matched MeSH terms: Cellulase
  17. Sequential saccharification and simultaneous fermentation (sssf) of sago hampas for the production of bioethanol
    Micky Vincent, Berry Rence Anak Senawi, Ennry Esut, Norizawati Muhammad Nor, Dayang Salwani Awang Adeni
    Sains Malaysiana, 2015;44:899-904.
    Bioethanol is a very environmentally friendly liquid biofuel that is not only renewable, but also sustainable. It is currently
    deemed as a highly suitable additive and substitute energy source to replace fossil based fuel. In this study, bioethanol
    was produced from sago hampas by using commercial amylase, cellulase and Saccharomyces cerevisiae via sequential
    saccharification and simultaneous fermentation (SSSF), a modified version of the simultaneous saccharification and
    fermentation (SSF) process. SSSF was performed on sago hampas at 2.5 and 5.0% (w/v) feedstock load for five days. The
    samples taken from the SSSF broths were analysed via high performance liquid chromatography (HPLC) for ethanol, glucose
    and acetic acid production. From the results obtained, SSSF with 5.0% sago hampas loading exhibited the highest ethanol
    production at 14.13 g/L (77.43% of theoretical ethanol yield), while SSSF using 2.5% sago hampas loading produced
    ethanol at 6.45 g/L (69.24% of theoretical ethanol yield). This study has shown that ethanol not only can be produced
    from sago hampas using different enzyme mixtures and S. cerevisiae via SSSF, but yields were also high, making this
    process highly promising for the production of cheap and sustainable ethanol as fuel.
    Matched MeSH terms: Cellulase
  18. A Weibull statistics-based lignocellulose saccharification model and a built-in parameter accurately predict lignocellulose hydrolysis performance
    Wang M, Han L, Liu S, Zhao X, Yang J, Loh SK, et al.
    Biotechnol J, 2015 Sep;10(9):1424-33.
    PMID: 26121186 DOI: 10.1002/biot.201400723
    Renewable energy from lignocellulosic biomass has been deemed an alternative to depleting fossil fuels. In order to improve this technology, we aim to develop robust mathematical models for the enzymatic lignocellulose degradation process. By analyzing 96 groups of previously published and newly obtained lignocellulose saccharification results and fitting them to Weibull distribution, we discovered Weibull statistics can accurately predict lignocellulose saccharification data, regardless of the type of substrates, enzymes and saccharification conditions. A mathematical model for enzymatic lignocellulose degradation was subsequently constructed based on Weibull statistics. Further analysis of the mathematical structure of the model and experimental saccharification data showed the significance of the two parameters in this model. In particular, the λ value, defined the characteristic time, represents the overall performance of the saccharification system. This suggestion was further supported by statistical analysis of experimental saccharification data and analysis of the glucose production levels when λ and n values change. In conclusion, the constructed Weibull statistics-based model can accurately predict lignocellulose hydrolysis behavior and we can use the λ parameter to assess the overall performance of enzymatic lignocellulose degradation. Advantages and potential applications of the model and the λ value in saccharification performance assessment were discussed.
    Matched MeSH terms: Cellulase/metabolism*
  19. Fulltext Complete genome sequence of Rhodothermaceae bacterium RA with cellulolytic and xylanolytic activities
    Liew KJ, Teo SC, Shamsir MS, Sani RK, Chong CS, Chan KG, et al.
    3 Biotech, 2018 Aug;8(8):376.
    PMID: 30105201 DOI: 10.1007/s13205-018-1391-z
    Rhodothermaceae bacterium RA is a halo-thermophile isolated from a saline hot spring. Previously, the genome of this bacterium was sequenced using a HiSeq 2500 platform culminating in 91 contigs. In this report, we report on the resequencing of its complete genome using a PacBio RSII platform. The genome has a GC content of 68.3%, is 4,653,222 bp in size, and encodes 3711 genes. We are interested in understanding the carbohydrate metabolic pathway, in particular the lignocellulosic biomass degradation pathway. Strain RA harbors 57 glycosyl hydrolase (GH) genes that are affiliated with 30 families. The bacterium consists of cellulose-acting (GH 3, 5, 9, and 44) and hemicellulose-acting enzymes (GH 3, 10, and 43). A crude cell-free extract of the bacterium exhibited endoglucanase, xylanase, β-glucosidase, and β-xylosidase activities. The complete genome information coupled with biochemical assays confirms that strain RA is able to degrade cellulose and xylan. Therefore, strain RA is another excellent member of family Rhodothermaceae as a repository of novel and thermostable cellulolytic and hemicellulolytic enzymes.
    Matched MeSH terms: Cellulase
  20. Fulltext Improvement of halophilic cellulase production from locally isolated fungal strain
    Gunny AA, Arbain D, Jamal P, Gumba RE
    Saudi J Biol Sci, 2015 Jul;22(4):476-83.
    PMID: 26150755 DOI: 10.1016/j.sjbs.2014.11.021
    Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett-Burman design and the Face Centered Central Composite Design (FCCCD). Plackett-Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization.
    Matched MeSH terms: Cellulase; Cellulases
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