Effects of Copper, Manganese, and Glucose on the Induction of Ligninolytic Enzymes Produced by Pleurotus ostreatus during Fungal Pretreatment of Switchgrass

2019 ◽  
Vol 62 (6) ◽  
pp. 1673-1681
Author(s):  
Shelyn Slavens ◽  
Stephen M. Marek ◽  
Mark R. Wilkins

Abstract. produces laccase and manganese peroxidase (MnP) to selectively degrade lignin and can be used as a biological pretreatment of lignocellulose biomass to enhance ethanol production. Exogenous copper and manganese have been reported to increase production of laccase and MnP, respectively. The effects of supplementing copper, manganese, or glucose to switchgrass inoculated with on ligninolytic enzyme activity were evaluated. Solutions of copper, manganese, glucose, or water were added with and without fungal inoculum at 75% moisture for 40 d at 28°C. Ligninolytic enzyme activities and biomass compositions were determined after the pretreatments. Simultaneous saccharification and fermentations (SSF) were conducted with the pretreated biomass. There were no significant differences between the supplement solutions on laccase activity, but MnP activities in copper-treated samples were significantly reduced. Fungal-pretreated samples had significantly less glucan, xylan, and lignin recoveries and significantly greater extractable sugars than non-inoculated controls. Ethanol yields during SSF corresponded with lignin degradation in the fungal-inoculated samples. Water-treated (control solution), fungal-inoculated samples showed the greatest lignin degradation and ethanol yields, while the copper-treated, fungal-inoculated samples had the lowest lignin degradation and ethanol yield. Manganese-treated and glucose-treated, fungal-inoculated samples had similar intermediate lignin contents and ethanol yields. Ethanol yield during SSF was significantly increased by fungal pretreatment compared to no pretreatment. Water alone was more effective than the copper, manganese, and glucose solutions added to the fungal pretreatments. Fungal pretreatment with provided significant lignin degradation to increase ethanol yield from switchgrass biomass. Keywords: Bioenergy, Biological pretreatment, Lignin.

2008 ◽  
Vol 54 (4) ◽  
pp. 305-313 ◽  
Author(s):  
Sarika Kuhar ◽  
Lavanya M. Nair ◽  
Ramesh Chander Kuhad

Phanerochaete chrysosporium , Pycnoporus cinnabarinus ,and fungal isolates RCK-1 and RCK-3 were tested for their lignin degradation abilities when grown on wheat straw (WS) and Prosopis juliflora (PJ) under solid-state cultivation conditions. Fungal isolate RCK-1 degraded more lignin in WS (12.26% and 22.64%) and PJ (19.30% and 21.97%) and less holocellulose in WS (6.27% and 9.39%) and PJ (3.01% and 4.58%) after 10 and 20 days, respectively, than other fungi tested. Phanerochaete chrysosporium caused higher substrate mass loss and degraded more of holocellulosic content (WS: 55.67%; PJ: 48.89%) than lignin (WS: 18.89%; PJ: 20.20%) after 20 days. The fungal pretreatment of WS and PJ with a high-lignin-degrading and low-holocellulose-degrading fungus (fungal isolate RCK-1) for 10 days resulted in (i) reduction in acid load for hydrolysis of structural polysaccharides (from 3.5% to 2.5% in WS and from 4.5% to 2.5% in PJ), (ii) an increase in the release of fermentable sugars (from 30.27 to 40.82 g·L–1in WS and from 18.18 to 26.00 g·L–1in PJ), and (iii) a reduction in fermentation inhibitors (total phenolics) in acid hydrolysate of WS (from 1.31 to 0.63 g·L–1) and PJ (from 2.05 to 0.80 g·L–1). Ethanol yield and volumetric productivity from RCK-1-treated WS (0.48 g·g–1and 0.54 g·L–1·h–1, respectively) and PJ (0.46 g·g–1and 0.33 g·L–1·h–1, respectively) were higher than untreated WS (0.36 g·g–1and 0.30 g·L–1·h–1, respectively) and untreated PJ (0.42 g·g–1and 0.21 g·L–1·h–1, respectively).


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Miguel Sanchis-Sebastiá ◽  
Borbála Erdei ◽  
Krisztina Kovacs ◽  
Mats Galbe ◽  
Ola Wallberg

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.


2018 ◽  
Vol 61 (6) ◽  
pp. 1997-2006 ◽  
Author(s):  
Mengxing Li ◽  
Stephen M. Marek ◽  
Jiaqi Peng ◽  
Zhongdong Liu ◽  
Mark R. Wilkins

Abstract. The white-rot fungus is capable of selectively degrading lignin over polymeric sugars. Solid-state cultivation and subsequent simultaneous saccharification and fermentation for ethanol production were performed. Effects of moisture content (MC) and fungus inoculum on biomass degradation, ligninolytic enzyme, and ethanol production were evaluated. First, fungal pretreatment was performed with varied MC and inoculum levels and sampled every 20 days. The highest xylose yield observed was 15.6% for samples with 75% MC and 5 mL inoculum at fungal pretreatment of 40 days. The highest lignin degradation of 52% and highest ethanol yield of 31% (based on the glucan present in the raw switchgrass) were achieved for 80-day fungal-treated samples with 75% MC and 5 mL inoculum. Keywords: KLywords. Bioenergy, Fungal pretreatment, Oyster mushroom, Perennial grass.


2017 ◽  
Vol 85 (2) ◽  
Author(s):  
. ISROI

Pleurotus floridanus have ability on lignin degradation by producing ligninolytic enzyme and prefer to degrade lignin than carbohydrate (hemicellulose and cellulose). Oil palm empty fruit bunches has been pretreated using P. floridanus.  Addition of cation (Cu2+) on biological pretreatment reduced lignin content and increased digestibility of the empty fruit bunches. P. floridanus reduce lignin and hemicellulose content from 23.9% to 10.1% and from 20.8% to 16.9%, respectively. P. floridanus did not degrade cellulose. Cellulose content of empty fruit bunches increase from 40.4% to 51.7%. Crystallinity of empty fruit bunches reduced after biological pretreatment. Crystallinity presented as LOI (lateral order index) of un-treated and biological pretreated oil palm empty fruit bunches are 2.08 and 1.44. Digestibility of the empty fruit bunches increased from 17.2% to 60.3% by biological pretreatment.[Key words:  biological pretreatment, oil palm empty fruit bunches, Pleurotus floridanus, biofuel, white-rot fungi, lignocellulose]AbstrakPleurotus floridanus memiliki kemampuan untuk mendegradasi lignin dengan memproduksi enzim ligninolitik dan lebih memilih untuk mendegradasi lignin daripada karbohidrat (hemiselulosa dan selulosa). Kemampuan unik P. floridanus ini dimanfaatkan dalam pretreatment biologi tandan kosong kelapa sawit. Penambahan kation (Cu2+) pada pretreatment biologi menurunkan kandungan lignin dan meningkatkan digestibiliti tandan kosong kelapa sawit. Perlakuan P. floridanus mengurangi kandungan lignin dan hemiselulosa dari 23,9% menjadi 10,1% dan dari 20,8% menjadi 16,9%. Perlakuan P. floridanus tidak menurunkan kandungan selulosa. Kandungan selulosa tandan kosong kelapa sawit meningkat dari 40,4% menjadi 51,7%. Kristalinitas tandan kosong menurun setelah pretreatment biologi. Kristalinitas yang dinyatakan dalam LOI (LOI, Lateral Order Index) adalah 2,08 untuk tandan kosong tanpa pretreatment biologi dan 1,44 untuk tandan kosong dengan pretreatment biologi. Digestibiliti itandan kosong meningkat dari 17,2% menjadi 60,3%.[Kata kunci: Pretreatment biologi, tandan kosong kelapa sawit, jamur pelapuk putih, lignoselulosa, Pleurotus floridanus]


2019 ◽  
Vol 1 ◽  
pp. 153-160
Author(s):  
I J Ona ◽  
H O Agogo ◽  
M S Iorungwa

The production of ethanol from cassava flour using Zymomonas mobilis a gram negative bacterium was conducted at 30oC, 33oC, 35oC and 37oC. The fermentation reaction was also carried out at different substrate concentrations; 5% W/V, 7% W/V and 10% W/V. The microorganism Zymomonas mobilis was detected in palm wine, isolated and identified. It was found to be gram negative, oxidase negative, catalase positive, anaerobic and plump rods with an unusual width. Results obtained from the simultaneous saccharification and fermentation reactions carried out with Zymomonas mobilis showed that maximum theoretical ethanol yield of 63% was obtained for 7% W/V cassava flour at 35oC. This was followed by a theoretical yield of 56.23 and 54.12 for 5% W/V and 10% W/V cassava flour, respectively. Fermentations at 30oC and 33 oC gave similar results with 7% W/V cassava producing higher ethanol yield when compared to 5% W/V and 10% W/V. Fermentation reactions at 37oC gave the lowest ethanol yields. The optimum pH for the simultaneous saccharification and fermentation of cassava was found to be pH of 6.


2021 ◽  
Author(s):  
Caroline Hartmann ◽  
Roselei Claudete Fontana ◽  
Félix Gonçalves de Siqueira ◽  
Marli Camassola

Abstract Biological pretreatment was investigated to increase ethanol production from lignocellulosic biomass, like sugarcane bagasse. Enzyme secretion, changes in substrate composition, enzymatic hydrolysis and ethanol yield after pretreatment by different basidiomycetes were evaluated. Analysis by Fourier transform infrared spectroscopy showed that P. pulmonarius PS2001 and T. villosa 82I6 promoted more extensive selective modifications in the lignin content. Glucose release during enzymatic hydrolysis of samples pretreated with P. pulmonarius PS2001 for 35, 42 and 49 days and with T. villosa 82I6 for 21, 28 and 49 days were higher than the control (48.5±2.38 mg/g), i.e. 68.4 ±0.7, 76.3 ±1.6 and 76.5±2.1 mg/g and 70.9±8.3, 77.8±5.8 and 77.6±4.2 mg/g, respectively. During the fermentation of hydrolysates of samples pretreated with T. villosa 82I6 for 28 and 49 days, a maximum ethanol yield of 19.1±2.8 and 20.2±0.5 mg/g, respectively, was achieved. A positive effect of biological pretreatment on hydrolysis and fermentation was demonstrated.


Nativa ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 352
Author(s):  
Adriano Mendes Lourenço ◽  
Aline Torquato Tavares ◽  
Tiago Alves Ferreira ◽  
Danilo Alves da Silva Porto Lopes ◽  
João Victor Gonçalves Carline ◽  
...  

A batata-doce (Ipomoea batatas (L.) Lam.) tem sido reportada como uma das espécies de planta com grande capacidade de converter biomassa em matéria prima para produção de etanol. O objetivo do trabalho foi avaliar o potencial de clones de batata-doce para produção de etanol. Foram avaliados 60 clones de batata-doce para produtividade de raízes, teor de amido nas raízes, produtividade de amido, coloração da casca e da polpa e o rendimento de etanol. O clone BDTO#122,32 e as cultivares Ana Clara e Carolina Vitória com média de 46,77; 42,75 e 41,25 t ha-¹, respectivamente, foram os que mais conseguiram acumular biomassa na forma de raiz. Os clones que apresentam as maiores médias de produtividade de amido por hectare foram BDTO#144.22 e BDTO#100.23, com valores de 15,46 e 14,16% t ha-1, com rendimentos de etanol de 8,33 e 7,63 m³ ha-¹. Os clones BDTO#144.22 e BDTO#100.23 apresentaram as maiores médias de produtividade de amido por hectare e rendimento de etanol, sendo, portanto, os mais promissores para a produção de etanol.Palavras-chave: Ipomoea batatas (L.) Lam, melhoramento genético, seleção, biocombustível. POTENTIAL OF EXPERIMENTAL CLONES OF SWEET POTATO FOR ETHANOL PRODUCTION ABSTRACT:Sweet potato (Ipomoea batatas (L.) Lam.) Has been reported as one of the plant species with great ability to convert biomass into feedstock for ethanol production. The objective of this work was to evaluate the potential of sweet potato clones for ethanol production. Twenty-six sweet potato clones were evaluated for root productivity, root starch content, starch yield, bark and pulp color, and ethanol yield. Clone BDTO # 122.32 and cultivars Ana Clara and Carolina Vitória averaging 46.77; 42.75 and 41.25 t ha-1, respectively, were the ones that were able to accumulate biomass in the root form. The clones presenting the highest starch productivity per hectare were BDTO # 144.22 and BDTO # 100.23, with values of 15.46 and 14.16% t ha-1, with ethanol yields of 8.33 and 7.63 m³ ha-¹. The clones BDTO # 144.22 and BDTO # 100.23 showed the highest averages of starch productivity per hectare and yield of ethanol, thus being the most promising for the production of ethanol.Keywords: Ipomoea potatoes (L.) Lam, breeding, selection, biofuel.


2006 ◽  
Vol 58 (3) ◽  
pp. 179-182 ◽  
Author(s):  
Jelena Vukojevic ◽  
Mirjana Stajic ◽  
Sonja Duletic-Lausevic ◽  
Jasmina Simonic

The effect of initial medium pH on biomass, extracellular and intracellular polysaccharide, and ligninolytic enzyme production by Ganoderma lucidum was investigated at different pH values after 7 and 14 days of cultivation. Maximal production of biomass was recorded at pH 4.5 and 5.0; maximal production of extracellular polysaccharides at pH 7.0 and 3.0; and maximal production of intracellular polysaccharides at pH 7.0 and 5.5. Ligninolytic enzymes were not produced at any pH of the medium. Maximal biomass production was obtained on the 11th day of cultivation; maximal extracellular polysaccharide production on the 7th day; and maximal intracellular polysaccharide production on the 6th and 10th day of cultivation. .


2021 ◽  
pp. 8-19
Author(s):  
Gautam Degweker ◽  
Arvind Lali

Rapid and high yield conversion of xylose to ethanol remains a signi cant bottleneck in the cost-effective production of ethanol using mixed sugars derived from lignocellulosic biomass (LBM). The present study attempts to circumvent this by separate continuous fermentation of glucose and xylose using high cell densities of a Saccharomyces cerevisiae mutant (ICT-1) and a Scheffersomyces stipitis mutant (M1CD), respectively with the help of external micro ltration membrane assisted cell recycle. Different cell densities and aeration rates for xylose fermentation were studied for optimizing continuous fermentation. Consistent high ethanol yields and productivities of 0.46 g/g and 5.19 g/L/h with glucose; and 0.38 g/g and 1.62 g/L/h with xylose; were achieved in simple media. This provided an average ethanol yield of 0.44 g/g on combined sugars, and average productivity of 3.4 g/L/h which is higher than typical molasses-based batch ethanol fermentation. The study thus highlights the potential of high cell density recycle strategy as an effective approach for separate ethanol fermentation of LBM derived sugars.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8662-8676
Author(s):  
Maria Mushtaq ◽  
Muhammad Javaid Asad ◽  
Muhammad Zeeshan Hyder ◽  
Syed Muhammad Saqlan Naqvi ◽  
Saad Imran Malik ◽  
...  

Utilization of biomass for production of second generation bioethanol was considered as a way to reduce burdens of fossil fuel in Pakistan. The materials wheat straw, rice straw, cotton stalk, corn stover, and peel wastes were used in this experiment. Various parameters, such as acidic and alkali pretreatment, enzymatic hydrolysis by cellulases, and effect of proteases inhibitors on ethanol production, were examined. Fermentation was completed by the yeasts Saccharomyces cerevisiae and Clostridium thermocellum separately, and their ethanol production were compared and maximum ethanol yield was obtained with wheat straw i.e.,11.3 g/L by S. cerevisiae and 8.5 g/L by C. thermocellum. Results indicated that a higher quantity of sugar was obtained from wheat straw (19.6 ± 1.6 g/L) followed by rice straw (17.6 ± 0.6 g/L) and corn stover (16.1 ± 0.9 g/L) compared to the other evaluated biomass samples. A higher yield of ethanol (11.3 g/L) was observed when a glucose concentration of 21.7 g/L was used, for which yeast fermentation efficiency was 92%. Results also revealed the increased in ethanol production (93%) by using celluases in combination with recombinant Serine protease inhibitors from C. thermocellum. It is expected that the use of recombinant serpins with cellulases will play a major role in the biofuel production by using agricultural biomass. This will also help in the economics of the biofuel.


Sign in / Sign up

Export Citation Format

Share Document