Predominant secretion of cellobiohydrolases and endo-β-1,4-glucanases in nutrient-limited medium by Aspergillus spp. isolated from subtropical field

2020 ◽  
Vol 168 (3) ◽  
pp. 243-256 ◽  
Author(s):  
May Thin Kyu ◽  
Shunsuke Nishio ◽  
Koki Noda ◽  
Bay Dar ◽  
San San Aye ◽  
...  
Keyword(s):  
Rice Straw ◽  
Plant Biomass ◽  
Cellulose Degradation ◽  
Industrial Wastes ◽  
Added Value ◽  
Crystalline Cellulose ◽  
Cellulolytic Activity ◽  
Biological Degradation ◽  
Industry Waste ◽  
Degradation Intermediates

Abstract Biological degradation of cellulose from dead plants in nature and plant biomass from agricultural and food-industry waste is important for sustainable carbon recirculation. This study aimed at searching diverse cellulose-degrading systems of wild filamentous fungi and obtaining fungal lines useful for cellooligosaccharide production from agro-industrial wastes. Fungal lines with cellulolytic activity were screened and isolated from stacked rice straw and soil in subtropical fields. Among 13 isolated lines, in liquid culture with a nutrition-limited cellulose-containing medium, four lines of Aspergillus spp. secreted 50–60 kDa proteins as markedly dominant components and gave clear activity bands of possible endo-β-1,4-glucanase in zymography. Mass spectroscopy (MS) analysis of the dominant components identified three endo-β-1,4-glucanases (GH5, GH7 and GH12) and two cellobiohydrolases (GH6 and GH7). Cellulose degradation by the secreted proteins was analysed by LC-MS-based measurement of derivatized reducing sugars. The enzymes from the four Aspergillus spp. produced cellobiose from crystalline cellulose and cellotriose at a low level compared with cellobiose. Moreover, though smaller than that from crystalline cellulose, the enzymes of two representative lines degraded powdered rice straw and produced cellobiose. These fungal lines and enzymes would be effective for production of cellooligosaccharides as cellulose degradation-intermediates with added value other than glucose.

scholarly journals Inactivation of Cellobiose Dehydrogenases Modifies the Cellulose Degradation Mechanism of Podospora anserina

2016 ◽  
Vol 83 (2) ◽  
Author(s):  
Narumon Tangthirasunun ◽  
David Navarro ◽  
Sona Garajova ◽  
Didier Chevret ◽  
Laetitia Chan Ho Tong ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Degradation ◽  
Degradation Mechanism ◽  
Podospora Anserina ◽  
Cellulosic Biomass ◽  
Striking Difference ◽  
Crystalline Cellulose ◽  
Minor Role ◽  
Wild Type ◽  
Content Type

ABSTRACT Conversion of biomass into high-value products, including biofuels, is of great interest to developing sustainable biorefineries. Fungi are an inexhaustible source of enzymes to degrade plant biomass. Cellobiose dehydrogenases (CDHs) play an important role in the breakdown through synergistic action with fungal lytic polysaccharide monooxygenases (LPMOs). The three CDH genes of the model fungus Podospora anserina were inactivated, resulting in single and multiple CDH mutants. We detected almost no difference in growth and fertility of the mutants on various lignocellulose sources, except on crystalline cellulose, on which a 2-fold decrease in fertility of the mutants lacking P. anserina CDH1 (PaCDH1) and PaCDH2 was observed. A striking difference between wild-type and mutant secretomes was observed. The secretome of the mutant lacking all CDHs contained five beta-glucosidases, whereas the wild type had only one. P. anserina seems to compensate for the lack of CDH with secretion of beta-glucosidases. The addition of P. anserina LPMO to either the wild-type or mutant secretome resulted in improvement of cellulose degradation in both cases, suggesting that other redox partners present in the mutant secretome provided electrons to LPMOs. Overall, the data showed that oxidative degradation of cellulosic biomass relies on different types of mechanisms in fungi. IMPORTANCE Plant biomass degradation by fungi is a complex process involving dozens of enzymes. The roles of each enzyme or enzyme class are not fully understood, and utilization of a model amenable to genetic analysis should increase the comprehension of how fungi cope with highly recalcitrant biomass. Here, we report that the cellobiose dehydrogenases of the model fungus Podospora anserina enable it to consume crystalline cellulose yet seem to play a minor role on actual substrates, such as wood shavings or miscanthus. Analysis of secreted proteins suggests that Podospora anserina compensates for the lack of cellobiose dehydrogenase by increasing beta-glucosidase expression and using an alternate electron donor for LPMO.

scholarly journals Metabolic Engineering of Clostridium cellulolyticum for Production of Isobutanol from Cellulose

2011 ◽  
Vol 77 (8) ◽  
pp. 2727-2733 ◽  
Author(s):  
Wendy Higashide ◽  
Yongchao Li ◽  
Yunfeng Yang ◽  
James C. Liao
Keyword(s):  
Metabolic Engineering ◽  
Consolidated Bioprocessing ◽  
Cellulose Degradation ◽  
Crystalline Cellulose ◽  
Cellulolytic Activity ◽  
Keto Acid ◽  
Acid Biosynthesis ◽  
Content Type ◽  
Clostridium Cellulolyticum ◽  
Alcohol Synthesis

ABSTRACTProducing biofuels directly from cellulose, known as consolidated bioprocessing, is believed to reduce costs substantially compared to a process in which cellulose degradation and fermentation to fuel are accomplished in separate steps. Here we present a metabolic engineering example for the development of aClostridium cellulolyticumstrain for isobutanol synthesis directly from cellulose. This strategy exploits the host's natural cellulolytic activity and the amino acid biosynthesis pathway and diverts its 2-keto acid intermediates toward alcohol synthesis. Specifically, we have demonstrated the first production of isobutanol to approximately 660 mg/liter from crystalline cellulose by using this microorganism.

scholarly journals Production of a β-Glucosidase-Rich Cocktail From Talaromyces Amestolkiae Using Raw Glycerol: Its Role for Lignocellulose Wastes Valorization

2021 ◽  
Author(s):  
Juan Méndez-Liter ◽  
Laura I. De Eugenio ◽  
Neumara L.S. Hakalin ◽  
Alicia Prieto ◽  
Maria Jesus Martinez
Keyword(s):  
Circular Economy ◽  
Plant Biomass ◽  
Raw Materials ◽  
Industrial Wastes ◽  
Cellulolytic Activity ◽  
Chemical Production ◽  
Raw Glycerol ◽  
Major Bottleneck ◽  
Beta Glucosidase ◽  
Pretreated Wheat Straw

As β-glucosidases represent the major bottleneck for industrial degradation of plant biomass, great efforts are being devoted both to discover novel and robust versions of these enzymes, as well as to develop efficient and inexpensive ways to produce them. In this work, raw glycerol from chemical production of biodiesel was tested as carbon source for the fungus Talaromyces amestolkiae with the aim of producing enzyme cocktails rich in this activity. Approximately 11 U/mL β-glucosidase were detected in these cultures, constituting the major cellulolytic activity. Proteomic analysis revealed BGL-3 as the most abundant protein and the main β-glucosidase. This enzyme crude was successfully used to supplement a basal commercial cellulolytic cocktail (Cellu-clast 1.5L) for saccharification of pretreated wheat straw, corroborating that even hardly exploitable industrial wastes, such as glycerol, can be used as secondary raw materials to produce valuable enzymatic preparations in a framework of circular economy

scholarly journals Production of a β-glucosidase-Rich Cocktail from Talaromyces Amestolkiae using Raw Glycerol: Its Role for Lignocellulose Wastes Valorization

2021 ◽  
Author(s):  
Juan Antonio Méndez-Líter ◽  
Laura Isabel de Eugenio ◽  
Neumara Hakalin ◽  
Alicia A Prieto ◽  
María Jesús Martínez
Keyword(s):  
Carbon Source ◽  
Plant Biomass ◽  
Carbon Sources ◽  
Industrial Wastes ◽  
Cellulolytic Activity ◽  
Chemical Production ◽  
Commercial Preparation ◽  
Enzymatic Production ◽  
Raw Glycerol ◽  
Pretreated Wheat Straw

Abstract Background: As β-glucosidases represent the major bottleneck for industrial degradation of plant biomass, great efforts are being devoted both to discover novel and robust versions of these enzymes, as well as to develop efficient and inexpensive ways to produce them. In this work, raw glycerol from chemical production of biodiesel was tested as carbon source for the fungus Talaromyces amestolkiae with the aim of producing enzyme cocktails rich in this activity. Results: When using raw glycerol as sole carbon source, approximately 11 U/mL β-glucosidase were detected in these cultures, constituting the major cellulolytic activity. Besides, it was detected that the enzymatic production started when glycerol was completely depleted, which implicates that it was produced under carbon starvation stimuli. Proteomic analysis of the produced crudes revealed BGL-3 as the most abundant protein and the main b-glucosidase. This enzymatic cocktail was successfully used to supplement a basal commercial cellulolytic cocktail (Celluclast 1.5L) for saccharification of different pretreated wheat straw, and improving the yield that the commercial preparation can reach alone.Conclusions: This study corroborates that even hardly exploitable industrial wastes, such as glycerol, can be used by Talaromyces amestolkiae as carbon sources to produce very valuable enzymatic preparations for the production of biofuels and other bioproducts in a framework of circular economy.

In vitro assembly and cellulolytic activity of a β-glucosidase-integrated cellulosome complex

2019 ◽  
Vol 366 (17) ◽  
Author(s):  
Katsuaki Hirano ◽  
Tsubasa Saito ◽  
Suguru Shinoda ◽  
Mitsuru Haruki ◽  
Nobutaka Hirano
Keyword(s):  
Protein Interactions ◽  
Plant Biomass ◽  
Product Inhibition ◽  
Maximum Activity ◽  
Crystalline Cellulose ◽  
Type I ◽  
Enzyme Complex ◽  
Cellulolytic Activity ◽  
In Vitro Assembly

ABSTRACT The cellulosome is a supramolecular multi-enzyme complex formed by protein interactions between the cohesin modules of scaffoldin proteins and the dockerin module of various polysaccharide-degrading enzymes. In general, the cellulosome exhibits no detectable β-glucosidase activity to catalyze the conversion of cellobiose to glucose. Because β-glucosidase prevents product inhibition of cellobiohydrolase by cellobiose, addition of β-glucosidase to the cellulosome greatly enhances the saccharification of crystalline cellulose and plant biomass. Here, we report the in vitro assembly and cellulolytic activity of a β-glucosidase-coupled cellulosome complex comprising the three major cellulosomal cellulases and full-length scaffoldin protein of Clostridium (Ruminiclostridium) thermocellum, and Thermoanaerobacter brockii β-glucosidase fused to the type-I dockerin module of C. thermocellum. We show that the cellulosome complex composed of nearly equal numbers of cellulase and β-glucosidase molecules exhibits maximum activity toward crystalline cellulose, and saccharification activity decreases as the enzymatic ratio of β-glucosidase increases. Moreover, β-glucosidase-coupled and β-glucosidase-supplemented cellulosome complexes similarly exhibit maximum activity toward crystalline cellulose (i.e. 1.7-fold higher than that of the β-glucosidase-free cellulosome complex). These results suggest that the enzymatic ratio of cellulase and β-glucosidase in the assembled complex is crucial for the efficient saccharification of crystalline cellulose by the β-glucosidase-integrated cellulosome complex.

scholarly journals Peran Mikroba Dekomposer Selulolitik dari Sarang Rayap dalam Menurunkan Kandungan Selulosa Limbah Pertanian Berselulosa Tinggi

SoilREns ◽  
2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Mieke Rochimi Setiawati ◽  
Nizar Ulfah ◽  
Pujawati Suryatmana ◽  
Reginawanti Hindersah
Keyword(s):  
Rice Straw ◽  
Oil Palm ◽  
Cellulose Degradation ◽  
Agricultural Waste ◽  
Block Design ◽  
Organic Fertilizer ◽  
Added Value ◽  
Cellulose Content ◽  
Cellulosic Material ◽  
Empty Fruit Bunches

Agricultural waste is rich in cellulosic material that is difficult to degrade but can be decomposed by cellulase enzymes. Cellulosic material is an organic component abundantly in nature in the form of cellulose and hemicellulose polymer. Utilization of microbes in the process of waste bioconversion can be done to get added value from the waste material into other products such as organic fertilizer. Cellulase-producing microbes can be isolated from various sources, one of which is from termite nests. The use of microbes from termite nests as decomposers for composting high-yielding agricultural waste was carried out in this study. Cellulolytic microbial isolates (combination of bacteria and fungi and without decomposers) were applied to agricultural wastes high in cellulose content: rice straw, bagasse, and oil palm empty fruit bunches. Randomized Block Design was applied and each treatment was and repeated 3 times. The composting process was carried out for 1 month indoors. The results showed that cellulolytic microbial consortium obtained from termite nests reduced the compost cellulose content of bagasse agricultural waste in one month. Whereas rice straw and oil palm empty fruit bunches showed a tendency to decrease cellulose content because cellulose degradation by decomposer microbes still continues after one month of incubation.

scholarly journals Expression of a Cellobiose Phosphorylase fromThermotoga maritimainCaldicellulosiruptor besciiImproves the Phosphorolytic Pathway and Results in a Dramatic Increase in Cellulolytic Activity

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Sun-Ki Kim ◽  
Michael E. Himmel ◽  
Yannick J. Bomble ◽  
Janet Westpheling
Keyword(s):  
Extracellular Enzymes ◽  
Plant Biomass ◽  
Rational Approach ◽  
Crystalline Cellulose ◽  
Synergistic Activity ◽  
Cellulolytic Activity ◽  
Glycosyl Hydrolases ◽  
Content Type ◽  
Biomass Deconstruction ◽  
Cellobiose Phosphorylase

ABSTRACTMembers of the genusCaldicellulosiruptorhave the ability to deconstruct and grow on lignocellulosic biomass without conventional pretreatment. A genetically tractable species,Caldicellulosiruptor bescii, was recently engineered to produce ethanol directly from switchgrass.C. besciicontains more than 50 glycosyl hydrolases and a suite of extracellular enzymes for biomass deconstruction, most prominently CelA, a multidomain cellulase that uses a novel mechanism to deconstruct plant biomass. Accumulation of cellobiose, a product of CelA during growth on biomass, inhibits cellulase activity. Here, we show that heterologous expression of a cellobiose phosphorylase fromThermotoga maritimaimproves the phosphorolytic pathway inC. besciiand results in synergistic activity with endogenous enzymes, including CelA, to increase cellulolytic activity and growth on crystalline cellulose.IMPORTANCECelA is the only known cellulase to function well on highly crystalline cellulose and it uses a mechanism distinct from those of other cellulases, including fungal cellulases. Also unlike fungal cellulases, it functions at high temperature and, in fact, outperforms commercial cellulase cocktails. Factors that inhibit CelA during biomass deconstruction are significantly different than those that impact the performance of fungal cellulases and commercial mixtures. This work contributes to understanding of cellulase inhibition and enzyme function and will suggest a rational approach to engineering optimal activity.

The impact of aerobic pretreatment of agro and industrial wastes on their biomethanation potential in Nisargruna technology

2021 ◽  
Vol 11 (5) ◽  
pp. 548-556
Author(s):  
Shubhada Nayak ◽  
Madhuri Sahasrabuddhe ◽  
Sharad Kale
Keyword(s):  
Rice Straw ◽  
Phase 1 ◽  
Industrial Wastes ◽  
Methane Formation ◽  
Municipal Solid Wastes ◽  
Metabolic Potential ◽  
Downward Displacement ◽  
Complex Polymers ◽  
The Impact ◽  
Aerobic And Anaerobic

Anaerobic digestion is among the essential biological techniques used for stabilization of organic sludge from sewage and highly concentrated efflu-ents from food processing industries. It also recycles the municipal solid wastes into compost with simultaneous production of methane. The current study was performed to estimate the biomethanation potential of various agro- and industrial wastes like Jatropha de-oil cake, prawn shells, chicken feathers, bagasse, rice straw and wheat husk by mimicking the conditions in the biphasic Nisargruna biogas plant. A small volume of samples was chemi-cally characterized and allowed to decompose under aerobic and anaerobic conditions to determine the effect of aerobic predigestion (i.e. phase 1 of Nisargruna plant) on final methane production. The biogas produced was quantified by downward displacement of water. The observations indicated that approximately 60-80% methane was produced when Jatropha de-oil cake, prawn shells and rice straw was used. Conversely, the wheat straw and sugarcane wastes showed less methane formation, which may be due to the presence of complex polymers like lignocellulose and silica that considerably reduces the metabolic potential of microorganisms.

scholarly journals β-Mannanase Production Using Coffee Industry Waste for Application in Soluble Coffee Processing

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 227 ◽  
Author(s):  
Camila Favaro ◽  
Ilton Baraldi ◽  
Fernanda Casciatori ◽  
Cristiane Farinas
Keyword(s):  
Hydrolytic Enzymes ◽  
Packed Bed ◽  
Added Value ◽  
Industrial Processes ◽  
Enzymatic Extract ◽  
Packed Bed Bioreactor ◽  
Industry Waste ◽  
Hydrolysis Of ◽  
Soluble Coffee

Soluble coffee offers the combined benefits of high added value and practicality for its consumers. The hydrolysis of coffee polysaccharides by the biochemical route, using enzymes, is an eco-friendly and sustainable way to improve the quality of this product, while contributing to the implementation of industrial processes that have lower energy requirements and can reduce environmental impacts. This work describes the production of hydrolytic enzymes by solid-state fermentation (SSF), cultivating filamentous fungi on waste from the coffee industry, followed by their application in the hydrolysis of waste coffee polysaccharides from soluble coffee processing. Different substrate compositions were studied, an ideal microorganism was selected, and the fermentation conditions were optimized. Cultivations for enzymes production were carried out in flasks and in a packed-bed bioreactor. Higher enzyme yield was achieved in the bioreactor, due to better aeration of the substrate. The best β-mannanase production results were found for a substrate composed of a mixture of coffee waste and wheat bran (1:1 w/w), using Aspergillus niger F12. The enzymatic extract proved to be very stable for 24 h, at 50 °C, and was able to hydrolyze a considerable amount of the carbohydrates in the coffee. The addition of a commercial cellulase cocktail to the crude extract increased the hydrolysis yield by 56%. The production of β-mannanase by SSF and its application in the hydrolysis of coffee polysaccharides showed promise for improving soluble coffee processing, offering an attractive way to assist in closing the loops in the coffee industry and creating a circular economy.

Biogas production from plant biomass used for phytoremediation of industrial wastes

2007 ◽  
Vol 98 (8) ◽  
pp. 1664-1669 ◽  
Author(s):  
V.K. Verma ◽  
Y.P. Singh ◽  
J.P.N. Rai
Keyword(s):  
Plant Biomass ◽  
Biogas Production ◽  
Industrial Wastes
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