Effective Substrate Loading for Saccharification of Corn Cob and Concurrent Production of Lignocellulolytic Enzymes by Fusarium oxysporum and Sporothrix carnis

2020 ◽  
Vol 8 (2) ◽  
pp. 109-115
Author(s):  
Folasade M. Olajuyigbe ◽  
Cornelius O. Fatokun ◽  
Oluwatosin I. Oni

Background: One of the critical challenges of cost-effective bioethanol production from lignocellulosic biomass is the decreasing yield of reducing sugars caused by increasing substrate loading. Hence, it is crucial to determine the best substrate concentration for efficient saccharification of lignocellulosic wastes. Objective: This paper reports the saccharification of corn cob by two lignocellulolytic fungi (Fusarium oxysporum and Sporothrix carnis) and concurrent production of lignocellulolytic enzymes at varying substrate concentrations. Methods: F. oxysporum and S. carnis were cultivated on corn cob based media at 30°C and 160 rpm for 144 h. The lignocellulosic composition of corn cob was determined. Saccharification of varying concentrations of substrate was determined by evaluating the release of reducing sugar while the production of cellulase and xylanase was monitored. Results: Cellulose, hemicellulose and lignin contents of corn cob were 37.8±1.56%, 42.2±1.68% and 12.7±1.23%, respectively. Yields of reducing sugar by F. oxysporum and S. carnis were 5.03 µmol/mL and 6.16 µmol/mL; and 6.26 µmol/mL and 6.58 μmol/mL at 10.0 and 25.0% substrate concentration, respectively. The production of cellulase and xylanase was exponential as corn cob concentration increased from 0.5% to 10.0% yielding 586.93 U/mL and 1559.18 U/mL from F. oxysporum, with 590.7 U/mL and 1573.95 U/mL from S. carnis, respectively. Conclusion: The study shows that the most efficient saccharification of corn cob by F. oxysporum and S. carnis was achieved at 10.0% substrate concentration. This suggests that two separate saccharification processes at this concentration will result in higher yields of enzyme and reducing sugars than a single process involving higher concentration.

1988 ◽  
Vol 20 (11-12) ◽  
pp. 117-123 ◽  
Author(s):  
D. van der Kooij ◽  
W. A. M. Hijnen

A K.pneumoniae strain, isolated from a water treatment system, was tested in growth measurements for its ability to multiply at substrate concentrations of a few micrograms per liter. The organism multiplied on mixtures of carbohydrates and amino acids at a substrate concentration of 1 µg of C of each compound per liter. Tests with individual compounds revealed that especially carbohydrates were utilized at low concentrations. The Ks values obtained for maltose and maltopentaose were 53 µg of C/l and 114 µg of C per liter, respectively. The significance of the growth of K.pneumoniae at low substrate concentrations is discussed.


2016 ◽  
Vol 27 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Elsa Cherian ◽  
M. Dharmendira Kumar ◽  
G. Baskar

Purpose – The purpose of this paper is to optimize production of cellulase enzyme from agricultural waste by using Aspergillus fumigatus JCF. The study also aims at the production of bioethanol using cellulase and yeast. Design/methodology/approach – Cellulase production was carried out using modified Mandel’s medium. The optimization of the cellulase production was carried out using Plackett-Burman and Response surface methodology. Bioethanol production was carried out using simultaneous saccharification and fermentation. Findings – Maximum cellulase production at optimized conditions was found to be 2.08 IU/ml. Cellulase was used for the saccharification of three different feed stocks, i.e. sugar cane leaves, corn cob and water hyacinth. Highest amount of reducing sugar was released was 29.1 gm/l from sugarcane leaves. Sugarcane leaves produced maximum bioethanol concentration of 9.43 g/l out of the three substrates studied for bioethanol production. Originality/value – The present study reveals that by using the agricultural wastes, cellulase production can be economically increased thereby bioethanol production.


1979 ◽  
Vol 179 (3) ◽  
pp. 697-700 ◽  
Author(s):  
N Gains

By using a standard graphical method values of Km and V may be found that are independent of the conditions and assumptions that the total substrate concentration approximates to its free concentration and that Km is much larger than the enzyme concentration. The procedure is also applicable to the determination of equilibrium binding parameters of a ligand to a macromolecule.


2008 ◽  
Vol 43 (8) ◽  
pp. 1017-1023 ◽  
Author(s):  
Daniel Oliveira Jordão do Amaral ◽  
Marleide Magalhães de Andrade Lima ◽  
Luciane Vilela Resende ◽  
Márcia Vanusa da Silva

The objective of this work was to determine the transcript profile of tomato plants (Lycopersicon esculentum Mill.), during Fusarium oxysporum f. sp. lycopersici infection and after foliar application of salicylic acid. The suppression subtractive hybridization (SSH) technique was used to generate a cDNA library enriched for transcripts differentially expressed. A total of 307 clones was identified in two subtractive libraries, which allowed the isolation of several defense-related genes that play roles in different mechanisms of plant resistance to phytopathogens. Genes with unknown roles were also isolated from the two libraries, which indicates the possibility of identifying new genes not yet reported in studies of stress/defense response. The SSH technique is effective for identification of resistance genes activated by salicylic acid and F. oxysporum f. sp. lycopersici infection. Not only the application of this technique enables a cost effective isolation of differentially expressed sequences, but also it allows the identification of novel sequences in tomato from a relative small number of sequences.


2019 ◽  
Vol 11 (2) ◽  
pp. 503-510 ◽  
Author(s):  
Prachi Singh ◽  
Jyoti Singh ◽  
Rahul Singh Rajput ◽  
Anukool Vaishnav ◽  
Shatrupa Ray ◽  
...  

Fusarium wilt is one of the major diseases of tomato causing extensive loss of production. Exploration of agriculturally important microbes (AIMs) for management of the tomato wilt is an ecofriendly and cost effective approach. In the present study, a total 30 Trichoderma and 30 bacterial isolates were screened in the laboratory for their biocontrol activity against Fusarium oxysporum f.sp. lycopersici (FOL). Out of all the isolates tested, Trichoderma asperellum BHU P-1 and Ochrobactrum sp. BHU PB-1 were found to show maximum inhibition of FOL in dual culture assay. Both the microbes also exhibited plant growth promoting activities such as phosphate solubilisation, production of siderophore, hydrogen cyanide (HCN), indole acetic acid (IAA) and protease activity. These microbes could be evaluated further in greenhouse and field studies for their potential use in management of Fusarium wilt of tomato.


2021 ◽  
Vol 5 (2) ◽  
pp. 289-294
Author(s):  
Zeenat Ibrahim Saulawa ◽  
Lawal Nura ◽  
Muntari Bala ◽  
Abdullahi A. Iman

The effectiveness of alkaline hydrogen peroxide as a suitable choice of pretreatment for the conversion of millet husk to reducing sugars using cellulase enzyme for hydrolysis and subsequent ethanol production was determined. The effects of three variables on reducing sugar production from millet husk were determined using one factor at a time (OFAT) method namely; peroxide concentration, pretreatment time and pretreatment temperature. From the results, it was observed that a significant (P<0.05) amount of reducing sugars were lost during pretreatment of millet husk. The untreated group which was only physically pretreated (milled) however yielded a significantly higher (P<0.05) reducing sugar concentration of 10.67mg/ml after enzymatic hydrolysis while the highest reducing sugar concentration of 4.82mg/ml was obtained using 0.375%v/v peroxide concentration for 60minutes at 250C. Therefore, pretreatment of biomass with alkaline hydrogen peroxide may be more suitable for feedstock with high lignin contents than millet husk.


1984 ◽  
Vol 30 (1) ◽  
pp. 143-144
Author(s):  
J C Hafkenscheid ◽  
C M van Dijk

Abstract We investigated the mechanism by which the three most commonly measured enzymes in erythrocytes are activated by their respective coenzymes by determining the catalytic activity concentrations of transketolase (EC 2.2.1.1), aspartate aminotransferase (EC 2.6.1.1), and glutathione reductase (EC 1.6.4.2) in relation to various substrate concentrations. We conclude that the underlying mechanisms by which the enzymes are activated are not the same.


2016 ◽  
Vol 3 (2) ◽  
pp. 295-304
Author(s):  
Fatema Zahan ◽  
Md Masudul Karim ◽  
Tahmina Akter ◽  
Md Alamgir Hossain

Seven potato genotypes that are available in Bangladesh, were grown at the field laboratory under the Crop Botany Department, Bangladesh Agricultural University in 2014. Reducing sugars and free asparagine were determined at freshly harvested potato tubers and those after storing at 80C for 8 months. There was no significant variation of asparagine content in all genotypes of freshly harvested tubers. But a significant difference was found in reducing sugar content. The lowest was in the samples of the genotypes Cardinal and Rumanapakri, and the highest in Hagrai. The variety Diamant appeared to contain the lowest amount of reducing sugars after 8 months storage. The results showed that freshly harvested Cardinal, Rumanapakri and Diamant after storage produced less amount of acrylamide after frying as potato chips or French fries. It may be concluded that screening potato genotypes primarily on their reducing sugar contents could be useful tool to minimize acrylamide formation in potato chips and French fries. Further investigation is needed to find out the factors affecting reducing sugar and asparagine content in potato tubers.Res. Agric., Livest. Fish.3(2): 295-304, August 2016


Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3129 ◽  
Author(s):  
Kamila Przybysz ◽  
Edyta Małachowska ◽  
Danuta Martyniak ◽  
Piotr Boruszewski ◽  
Halina Kalinowska ◽  
...  

This study showed that kraft cellulosic pulps from Miscanthus giganetus JM Greef and Deuter ex Hodk. and Renvoize, sweet sorghum and 5 other fast growing grasses may be easily enzymatically converted to glucose-rich sugar feedstocks. The scientific goal of the paper was to assess and compare the potential yield of hydrolysis and verify whether these grasses may be a source of sugars for fermentation processes. Kraft pulping was used as a pretreatment method and hydrolysis of the pulps was conducted using a commercial multienzyme preparation containing cellulases and xylanases at initial substrate concentrations of 0.476, 3.88 and 7.46% w/v, and 3 different enzyme loadings. Results showed that tall wheatgrass, striped tuber oat grass, tall fescue and smooth bromegrass may be efficiently converted to sugar feedstocks for biotechnology application, but that the simple reducing sugars yield is lower than for wood, due to lower cellulose content.


1965 ◽  
Vol 5 (18) ◽  
pp. 289 ◽  
Author(s):  
PA Wills

Tasmanian Up-to-date, Kennebec, Sebago, and Sequoia tubers were treated with low doses of gamma radiation to inhibit sprouting and were subsequently stored at 68�F or 45�F. Tubers were examined at bi-monthly intervals for some, or all, of the following biochemical constituents : dry matter, thiamin, reduced ascorbic acid, dehydroascorbic acid, total ascorbic acid, soluble reducing sugars, sucrose, total sugars, and starch. Radiation, independent of dose level, led to lower dry matter contents in the Up-to-date, Kennebec, and Sequoia tubers after four months storage, and in the Sebago tubers after six months storage at 68�F, but not at 45�F, when compared to the controls. The thiamin content of Up-to-date tubers w-as not influenced by radiation (16,000 rads). Storage w-as a more important factor than radiation in altering the ascorbic acid content of tubers. Radiation maintained, or even increased the normal level. Radiation increased the soluble reducing sugar content of Sequoia tubers, the total sugar of Sequoia and Sebago tubers, and the sucrose content of the Sebago tubers, but had little effect on the starch content of these varieties. Storage influenced some of these constituents, particularly in the Sebago variety.


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