scholarly journals Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9246-9261
Author(s):  
Asma Zafar ◽  
Muhammad Nauman Aftab ◽  
Anam Asif ◽  
Ahmet Karadag ◽  
Liangcai Peng ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Biomass Saccharification ◽  
Biofuel Industry ◽  
Clostridium Clariflavum ◽  
Successful Expression

Successful expression of a novel cellobiohydrolase enzyme from Clostridium clariflavum with efficient saccharification potential of plant biomass for the biofuel industry.

scholarly journals Correction: Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry

RSC Advances ◽  
2021 ◽  
Vol 11 (19) ◽  
pp. 11387-11387
Author(s):  
Asma Zafar ◽  
Muhammad Nauman Aftab ◽  
Anam Asif ◽  
Ahmet Karadag ◽  
Liangcai Peng ◽  
...  
Keyword(s):  
Biomass Saccharification ◽  
Biofuel Industry ◽  
Clostridium Clariflavum

Correction for ‘Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry’ by Asma Zafar et al., RSC Adv., 2021, 11, 9246–9261, DOI: 10.1039/D1RA00545F.

scholarly journals Myceliophthora thermophila Xyr1 is predominantly involved in xylan degradation and xylose catabolism

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Carolina dos Santos Gomes ◽  
Daniel Falkoski ◽  
Evy Battaglia ◽  
Mao Peng ◽  
Maira Nicolau de Almeida ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Strain Improvement ◽  
Basic Knowledge ◽  
Myceliophthora Thermophila ◽  
Wild Type ◽  
Degrading Enzymes ◽  
Biomass Saccharification ◽  
Regulatory Systems ◽  
Genes Encoding ◽  
Pentose Transport

Abstract Background Myceliophthora thermophila is a thermophilic ascomycete fungus that is used as a producer of enzyme cocktails used in plant biomass saccharification. Further development of this species as an industrial enzyme factory requires a detailed understanding of its regulatory systems driving the production of plant biomass-degrading enzymes. In this study, we analyzed the function of MtXlr1, an ortholog of the (hemi-)cellulolytic regulator XlnR first identified in another industrially relevant fungus, Aspergillus niger. Results The Mtxlr1 gene was deleted and the resulting strain was compared to the wild type using growth profiling and transcriptomics. The deletion strain was unable to grow on xylan and d-xylose, but showed only a small growth reduction on l-arabinose, and grew similar to the wild type on Avicel and cellulose. These results were supported by the transcriptome analyses which revealed reduction of genes encoding xylan-degrading enzymes, enzymes of the pentose catabolic pathway and putative pentose transporters. In contrast, no or minimal effects were observed for the expression of cellulolytic genes. Conclusions Myceliophthora thermophila MtXlr1 controls the expression of xylanolytic genes and genes involved in pentose transport and catabolism, but has no significant effects on the production of cellulases. It therefore resembles more the role of its ortholog in Neurospora crassa, rather than the broader role described for this regulator in A. niger and Trichoderma reesei. By revealing the range of genes controlled by MtXlr1, our results provide the basic knowledge for targeted strain improvement by overproducing or constitutively activating this regulator, to further improve the biotechnological value of M. thermophila.

scholarly journals Structural basis for glucose tolerance in GH1 β-glucosidases

2014 ◽  
Vol 70 (6) ◽  
pp. 1631-1639 ◽  
Author(s):  
Priscila Oliveira de Giuseppe ◽  
Tatiana de Arruda Campos Brasil Souza ◽  
Flavio Henrique Moreira Souza ◽  
Leticia Maria Zanphorlin ◽  
Carla Botelho Machado ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Active Site ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Product Inhibition ◽  
Structural Basis ◽  
Clear Correlation ◽  
Biomass Saccharification ◽  
Glucose Tolerant ◽  
Shed Light

Product inhibition of β-glucosidases (BGs) by glucose is considered to be a limiting step in enzymatic technologies for plant-biomass saccharification. Remarkably, some β-glucosidases belonging to the GH1 family exhibit unusual properties, being tolerant to, or even stimulated by, high glucose concentrations. However, the structural basis for the glucose tolerance and stimulation of BGs is still elusive. To address this issue, the first crystal structure of a fungal β-glucosidase stimulated by glucose was solved in native and glucose-complexed forms, revealing that the shape and electrostatic properties of the entrance to the active site, including the +2 subsite, determine glucose tolerance. The aromatic Trp168 and the aliphatic Leu173 are conserved in glucose-tolerant GH1 enzymes and contribute to relieving enzyme inhibition by imposing constraints at the +2 subsite that limit the access of glucose to the −1 subsite. The GH1 family β-glucosidases are tenfold to 1000-fold more glucose tolerant than GH3 BGs, and comparative structural analysis shows a clear correlation between active-site accessibility and glucose tolerance. The active site of GH1 BGs is located in a deep and narrow cavity, which is in contrast to the shallow pocket in the GH3 family BGs. These findings shed light on the molecular basis for glucose tolerance and indicate that GH1 BGs are more suitable than GH3 BGs for biotechnological applications involving plant cell-wall saccharification.

Penicillium subrubescens is a promising alternative for Aspergillus niger in enzymatic plant biomass saccharification

2016 ◽  
Vol 33 (6) ◽  
pp. 834-841 ◽  
Author(s):  
Miia R. Mäkelä ◽  
Sadegh Mansouri ◽  
Ad Wiebenga ◽  
Johanna Rytioja ◽  
Ronald P. de Vries ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Plant Biomass ◽  
Promising Alternative ◽  
Biomass Saccharification

scholarly journals Colocalization and Disposition of Cellulosomes in Clostridium clariflavum as Revealed by Correlative Superresolution Imaging

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Lior Artzi ◽  
Tali Dadosh ◽  
Elad Milrot ◽  
Sarah Moraïs ◽  
Smadar Levin-Zaidman ◽  
...  
Keyword(s):  
Cell Surface ◽  
Bacterial Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Soluble Sugars ◽  
Attractive Alternative ◽  
Cellulolytic Bacteria ◽  
Extracellular Medium ◽  
Bacterial Cell Surface ◽  
Clostridium Clariflavum

ABSTRACTCellulosomes are multienzyme complexes produced by anaerobic, cellulolytic bacteria for highly efficient breakdown of plant cell wall polysaccharides.Clostridium clariflavumis an anaerobic, thermophilic bacterium that produces the largest assembled cellulosome complex in nature to date, comprising three types of scaffoldins: a primary scaffoldin, ScaA; an adaptor scaffoldin, ScaB; and a cell surface anchoring scaffoldin, ScaC. This complex can contain 160 polysaccharide-degrading enzymes. In previous studies, we proposed potential types of cellulosome assemblies inC. clariflavumand demonstrated that these complexes are released into the extracellular medium. In the present study, we explored the disposition of the highly structured, four-tiered cell-anchored cellulosome complex of this bacterium. Four separate, integral cellulosome components were subjected to immunolabeling: ScaA, ScaB, ScaC, and the cellulosome’s most prominent enzyme, GH48. Imaging of the cells by correlating scanning electron microscopy and three-dimensional (3D) superresolution fluorescence microscopy revealed that some of the protuberance-like structures on the cell surface represent cellulosomes and that the components are highly colocalized and organized by a defined hierarchy on the cell surface. The display of the cellulosome on the cell surface was found to differ between cells grown on soluble or insoluble substrates. Cell growth on microcrystalline cellulose and wheat straw exhibited dramatic enhancement in the amount of cellulosomes displayed on the bacterial cell surface.IMPORTANCEConversion of plant biomass into soluble sugars is of high interest for production of fermentable industrial materials, such as biofuels. Biofuels are a very attractive alternative to fossil fuels, both for recycling of agricultural wastes and as a source of sustainable energy. Cellulosomes are among the most efficient enzymatic degraders of biomass known to date, due to the incorporation of a multiplicity of enzymes into a potent, multifunctional nanomachine. The intimate association with the bacterial cell surface is inherent in its efficient action on lignocellulosic substrates, although this property has not been properly addressed experimentally. The dramatic increase in cellulosome performance on recalcitrant feedstocks is critical for the design of cost-effective processes for efficient biomass degradation.

scholarly journals Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Paolo Longoni ◽  
Sadhu Leelavathi ◽  
Enrico Doria ◽  
Vanga Siva Reddy ◽  
Rino Cella
Keyword(s):  
Cell Wall ◽  
Large Scale ◽  
Plant Biomass ◽  
Cellulosic Biomass ◽  
Nuclear Transformation ◽  
Recombinant Enzymes ◽  
Cell Wall Degrading Enzymes ◽  
Leaf Extracts ◽  
Degrading Enzymes ◽  
Biomass Saccharification

Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

ESTIMATION OF ABOVE GROUND BIOMASS OF THE THREE SITES (GRAZED SITE, PROTECTED SITE AND SEED SOWN SITE) FOR COMPARING THEIR PRODUCTIVITY IN KASHMIR VALLEY

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
AFSHAN ANJUM BABA ◽  
SYED NASEEM UL-ZAFAR GEELANI ◽  
ISHRAT SALEEM ◽  
MOHIT HUSAIN ◽  
PERVEZ AHMAD KHAN ◽  
...  
Keyword(s):  
Protected Areas ◽  
Aboveground Biomass ◽  
Plant Biomass ◽  
Summer Season ◽  
Above Ground Biomass ◽  
Spring Season ◽  
Kashmir Valley ◽  
Ground Biomass ◽  
Maximum Value ◽  
Protected Site

The plant biomass for protected areas was maximum in summer (1221.56 g/m2) and minimum in winter (290.62 g/m2) as against grazed areas having maximum value 590.81 g/m2 in autumn and minimum 183.75 g/m2 in winter. Study revealed that at Protected site (Kanidajan) the above ground biomass ranged was from a minimum (1.11 t ha-1) in the spring season to a maximum (4.58 t ha-1) in the summer season while at Grazed site (Yousmarag), the aboveground biomass varied from a minimum (0.54 t ha-1) in the spring season to a maximum of 1.48 t ha-1 in summer seasonandat Seed sown site (Badipora), the lowest value of aboveground biomass obtained was 4.46 t ha-1 in spring while as the highest (7.98 t ha-1) was obtained in summer.

REED - PLANT BIOMASS - AS RENEWABLE AND LOW-POLLUTING ENERGY RESOURCE

2011 ◽  
Vol 10 (8) ◽  
pp. 1053-1057
Author(s):  
Gavril Budau ◽  
Mihaela Campean ◽  
Camelia Cosereanu ◽  
Dumitru Lica
Keyword(s):  
Plant Biomass ◽  
Energy Resource
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