scholarly journals Process Design and Economics of On-Site Cellulase Production on Various Carbon Sources in a Softwood-Based Ethanol Plant

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Zsolt Barta ◽  
Krisztina Kovacs ◽  
Kati Reczey ◽  
Guido Zacchi
Keyword(s):  
Carbon Source ◽  
Enzyme Production ◽  
Ethanol Yield ◽  
Liquid Fraction ◽  
Carbon Sources ◽  
Cellulase Production ◽  
Raw Material ◽  
Steam Pretreatment ◽  
Whole Process ◽  
Feasible Alternative

On-site cellulase enzyme fermentation in a softwood-to-ethanol process, based on SO2-catalysed steam pretreatment followed by simultaneous saccharification and fermentation, was investigated from a techno-economic aspect using Aspen Plus© and Aspen Icarus Process Evaluator© softwares. The effect of varying the carbon source of enzyme fermentation, at constant protein and mycelium yields, was monitored through the whole process. Enzyme production step decreased the overall ethanol yield (270 L/dry tonne of raw material in the case of purchased enzymes) by 5–16 L/tonne. Capital cost was found to be the main cost contributor to enzyme fermentation, constituting to 60–78% of the enzyme production cost, which was in the range of 0.42–0.53 SEK/L ethanol. The lowest minimum ethanol selling prices (4.71 and 4.82 SEK/L) were obtained in those scenarios, where pretreated liquid fraction supplemented with molasses was used as carbon source. In some scenarios, on-site enzyme fermentation was found to be a feasible alternative.

scholarly journals Wild type Bacillus subtilis treated with ethyl methyl sulphonate produced catabolite insensitive mutants with improved cellulase production

2021 ◽  
Author(s):  
Oladipo Olaniyi
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Enzyme Production ◽  
Cellulase Activity ◽  
Cellulase Production ◽  
Minimal Salt Medium ◽  
Salt Medium ◽  
Production Medium ◽  
Wild Type ◽  
Ethyl Methyl

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

Fuel Ethanol Production from Wet Oxidised Corn Stover by S. Cerevisiae

2011 ◽  
Vol 343-344 ◽  
pp. 963-967 ◽  
Author(s):  
Zhang Qiang ◽  
Anne Belinda Thomsen
Keyword(s):  
Ethanol Production ◽  
Corn Stover ◽  
Simultaneous Saccharification And Fermentation ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Liquid Fraction ◽  
Raw Material ◽  
Wet Oxidation ◽  
Inhibition Effect ◽  
Simultaneous Saccharification

In order to find out appropriate process for ethanol production from corn stover, wet oxidation（195°C，15 minutes）and simultaneous saccharification and fermentation (SSF) was carried out to produce ethanol. The results showed that the cellulose recovery of 92.9% and the hemicellulose recovery of 74.6% were obtained after pretreatment. 86.5% of cellulose was remained in the solid cake . After 24h hydrolysis at 50°C using cellulase（Cellubrix L）,the achieved conversion of cellulose to glucose was 64.8%. Ethanol production was evaluated from dried solid cake and the hydrolysate was employed as liquid fraction . After 142 h of SSF with substrate concentration of 8% (W/V), ethanol yield of 73.1 % of the theoretical based on glucose in the raw material was obtained by S. cerevisiae(ordinary baker’ yeast) . The corresponding ethanol concentration and volumetric productivity were 17.2g/L and 0.121g/L.h respectively. The estimated total ethanol production was 257.7 kg/ton raw material by assuming consumption of both C-6 and C-5. No obvious inhibition effect occurred during SSF. These instructions give you the basic guidelines for preparing papers for WCICA/IEEE conference proceedings.

scholarly journals The Carbon Source Controls the Secretion and Yield of Polysaccharide-Hydrolyzing Enzymes of Basidiomycetes

2021 ◽  
Author(s):  
Eka Metreveli ◽  
Tamar Khardziani ◽  
Vladimir Elisashvili
Keyword(s):  
Carbon Source ◽  
Carbon Sources ◽  
Schizophyllum Commune ◽  
Cellulase Production ◽  
Crystalline Cellulose ◽  
Irpex Lacteus ◽  
Xylanase Production ◽  
Hydrolyzing Enzymes ◽  
Pycnoporus Coccineus ◽  
Polymeric Substrates

In the present study, the polysaccharide-hydrolyzing secretomes of Irpex lacteus BCC104, Pycnoporus coccineus BCC310, and Schizophyllum commune 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. A synergistic 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.

scholarly journals Introducing low-quality feedstocks in bioethanol production: efficient conversion of the lignocellulose fraction of animal bedding through steam pretreatment

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Miguel Sanchis-Sebastiá ◽  
Borbála Erdei ◽  
Krisztina Kovacs ◽  
Mats Galbe ◽  
Ola Wallberg
Keyword(s):  
Residence Time ◽  
Ethanol Yield ◽  
Environmental Benefits ◽  
Raw Material ◽  
Steam Pretreatment ◽  
Bioethanol Production ◽  
Ethanol Yields ◽  
Conversion Efficiencies ◽  
Animal Bedding ◽  
Simultaneous Saccharification

Abstract Background Animal bedding remains an underutilized source of raw material for bioethanol production, despite the economic and environmental benefits of its use. Further research concerning the optimization of the production process is needed, as previously tested pretreatment methods have not increased the conversion efficiency to the levels necessary for commercialization of the process. Results We propose steam pretreatment of animal bedding, consisting of a mixture of straw and cow manure, to deliver higher ethanol yields. The temperature, residence time and pH were optimized through response-surface modeling, where pretreatment was evaluated based on the ethanol yield obtained through simultaneous saccharification and fermentation of the whole pretreated slurry. The results show that the best conditions for steam pretreatment are 200 °C, for 5 min at pH 2, at which an ethanol yield of about 70% was obtained. Moreover, the model also showed that the pH had the greatest influence on the ethanol yield, followed by the temperature and then the residence time. Conclusions Based on these results, it appears that steam pretreatment could unlock the potential of animal bedding, as the same conversion efficiencies were achieved as for higher-quality feedstocks such as wheat straw.

scholarly journals Co-inducible catabolism of 1-naphthol via synergistic regulation of the initial hydroxylase genes in Sphingobium sp. strain B2

2021 ◽  
Author(s):  
Junwei Huang ◽  
Dian Chen ◽  
Xiangkun Kong ◽  
Shurui Wu ◽  
Kai Chen ◽  
...  
Keyword(s):  
Carbon Source ◽  
Organic Pollutant ◽  
Carbon Sources ◽  
Transcriptional Regulators ◽  
Raw Material ◽  
Toxic Compound ◽  
Catabolic Genes ◽  
Growth Substrates ◽  
Synergistic Regulation ◽  
Metabolic Mechanism

1-Naphthol, a widely used raw material for organic synthesis, is also a well-known organic pollutant. Due to its high toxicity, 1-naphthol is rarely used by microorganisms as the sole carbon source for growth. In this study, catabolism of 1-naphthol by Sphingobium sp. strain B2 was found to be greatly enhanced by additional supplementation with primary carbon sources (e.g., glucose, maltose and sucrose), and 1-naphthol was even used as the carbon source for growth when strain B2 cells had been pre-induced by both 1-naphthol and glucose. A distinct two-component flavin-dependent monooxygenase NdcA1A2 was found to be responsible for the initial hydroxylation of 1-naphthol to 1,2-dihydroxynaphthalene, a more toxic compound. Transcriptional levels of ndcA1A2 genes were significantly up-regulated when strain B2 cells were cultured with both 1-naphthol and glucose as compared to cells cultured with sole 1-naphthol or glucose. Two transcriptional regulators, the activator NdcS and the inhibitor NdcR were found to play key roles in the synergistic regulation of the transcription of the 1-naphthol initial catabolic genes ndcA1A2. Importance Co-metabolism is a widely observed phenomenon, especially in the field of microbial catabolism of highly toxic xenobiotics. However, the mechanisms of co-metabolism are ambiguous and the roles of the obligately co-existing growth substrates remain largely unknown. In this study, we revealed that the roles of the co-existing primary carbon sources (e.g. glucose) in the enhanced catabolism of the toxic compound 1-naphthol in Sphingobium sp. strain B2 was not solely because they were used as growth substrates to support cell growth, but more importantly they acted as “co-inducers” to interact with two transcriptional regulators, the activator NdcS and the inhibitor NdcR, to synergistically regulate the transcription of the 1-naphthol initial catabolic genes ndcA1A2. Our findings provide new insights into the co-metabolic mechanism of highly toxic compounds in microorganisms.

scholarly journals The Carbon Source Controls the Secretion and Yield of Polysaccharide-Hydrolyzing Enzymes of Basidiomycetes

Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1341
Author(s):  
Eka Metreveli ◽  
Tamar Khardziani ◽  
Vladimir Elisashvili
Keyword(s):  
Carbon Source ◽  
Carbon Sources ◽  
Schizophyllum Commune ◽  
Cellulase Production ◽  
Crystalline Cellulose ◽  
Irpex Lacteus ◽  
Xylanase Production ◽  
Hydrolyzing Enzymes ◽  
Pycnoporus Coccineus ◽  
Polymeric Substrates

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.

scholarly journals Optimization of Cellulase Production from Bacteria Isolated from Soil

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sonia Sethi ◽  
Aparna Datta ◽  
B. Lal Gupta ◽  
Saksham Gupta
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Pseudomonas Fluorescens ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Fermentation Medium ◽  
Cellulase Production ◽  
Culture Conditions ◽  
Optimum Conditions ◽  
E Coli

Cellulase-producing bacteria were isolated from soil and identified as Pseudomonas fluorescens, Bacillus subtilIs, E. coli, and Serratia marcescens. Optimization of the fermentation medium for maximum cellulase production was carried out. The culture conditions like pH, temperature, carbon sources, and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40°C at pH 10 with glucose as carbon source and ammonium sulphate as nitrogen source, and coconut cake stimulates the production of cellulase. Among bacteria, Pseudomonas fluorescens is the best cellulase producer among the four followed by Bacillus subtilis, E. coli, and Serratia marscens.

THE PRODUCTION OF CELLULASE BY FUNGI ON MIXED CELLULOSIC SUBSTRATES

1960 ◽  
Vol 6 (3) ◽  
pp. 265-282 ◽  
Author(s):  
S. N. Basu ◽  
S. N. Ghose
Keyword(s):  
Filter Paper ◽  
Enzyme Production ◽  
Carbon Sources ◽  
Cellulase Production ◽  
The Other ◽  
Cellulolytic Enzyme ◽  
Other Hand

Using jute, alkali-treated jute, holocellulose from jute, and filter paper as substrates, a total of 124 fungi were tested for production of cellulolytic enzyme capable of hydrolyzing powdered filter paper and swollen cellulose. Of these, only 15 organisms failed to produce the enzyme on any substrate, and 48 produced cellulase on filter paper, so that in most species cellulase production could be induced only by mixed cellulosic substrates. Among such species were many that are ordinarily regarded as non-cellulolytic, while on the other hand comparatively little enzyme could be detected with several well-known cellulose decomposers strongly degrading cellulose in vivo. Factors stimulating enzyme production on mixed cellulosic substrates were micronutrients and hemicellulose. For most species, excluding a few of the strong cellulose decomposers, a partial loosening of the hemicellulose seemed to favor enzyme production best. Some cellulase was produced on free hemicellulose alone, but not on starch and sugars, although in presence of cellulose these substances stimulated enzyme production by a few ordinarily weak species; on strong cellulose decomposers the effect of these additional carbon sources was opposite, possibly due to a sparing action on cellulose.

scholarly journals Screening of Fungal Strains for Cellulolytic and Xylanolytic Activities Production and Evaluation of Brewers’ Spent Grain as Substrate for Enzyme Production by Selected Fungi

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4443
Author(s):  
Rossana Liguori ◽  
Anna Pennacchio ◽  
Luciana Porto de Souza Vandenberghe ◽  
Addolorata De Chiaro ◽  
Leila Birolo ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Animal Feed ◽  
Fungal Growth ◽  
Cellulase Production ◽  
Raw Material ◽  
Added Value ◽  
Xylanase Production ◽  
Solid Media ◽  
Spent Grain ◽  
Beer Production

Brewer’s spent grain (BSG), the solid residue of beer production, is attracting significant attention as raw material for the production of added value substances, since until recently it was mainly used as animal feed or deposited in landfills, causing serious environmental problems. Therefore, this work aimed at developing a bioprocess using BSG as a substrate for the production of cellulases and xylanases for waste saccharification and bioenergy production. Different fungi were analyzed for their cellulolytic and xylanolytic abilities, through a first screening on solid media by assessment of fungal growth and enzyme production on agar containing carboxylmethylcellulose or xylan as the sole carbon source, respectively. The best cellulase and xylanase producers were subjected to quantitative evaluation of enzyme production in liquid cultures. Aspergillus niger LPB-334 was selected for its ability to produce cellulase and xylanase at high levels and it was cultivated on BSG by solid state fermentation. The cellulase production reached a maximum of 118.04 ± 8.4 U/g of dry substrate after 10 days of fermentation, while a maximum xylanase production of 1315.15 ± 37.5 U/g of dry substrate was reached after 4 days. Preliminary characterization of cellulase and xylanase activities and identification of the enzymes responsible were carried out.

scholarly journals Towards Net Zero Greenhouse Gas Emissions in the Energy and Chemical Sectors in Switzerland and Beyond – A Review

2021 ◽  
Vol 75 (9) ◽  
pp. 788-799
Author(s):  
Simone Brethauer ◽  
Michael Hans-Peter Studer
Keyword(s):  
Renewable Energy ◽  
Carbon Source ◽  
Energy Demand ◽  
Nuclear Power ◽  
Carbon Sources ◽  
Energy System ◽  
Heat Pumps ◽  
Raw Material ◽  
Oil Demand ◽  
Current Energy

In today's societies, climate-damaging and finite fossil resources such as oil and natural gas serve a dual purpose as energy source and as carbon source for chemicals and plastics. To respond to the finite availability and to meet international climate goals, a change to a renewable energy and raw material basis is inevitable and represents a highly complex task. In this review, we assess possible technology paths for Switzerland to reach these goals. First, we provide an overview of Switzerland's current energy demand and discuss possible renewable technologies as well as proposed scenarios to defossilize the current energy system. In here, electric vehicles and heat pumps are key technologies, whereas mainly photovoltaics replace nuclear power to deliver clean electricity. The production of chemicals also consumes fossil resources and for Switzerland, the oil demand for imported domestically used chemicals and plastics corresponds to around 20% of the current energetic oil demand. Thus, we additionally summarize technologies and visions for a sustainable chemical sector based on the renewable carbon sources biomass, CO2 and recycled plastic. As biomass is the most versatile renewable energy and carbon source, although with a limited availability, aspects and proposed strategies for an optimal use are discussed.

Sign in / Sign up

Export Citation Format

Share Document