scholarly journals Matrix Discriminant Analysis Evidenced Surface-Lithium as an Important Factor to Increase the Hydrolytic Saccharification of Sugarcane Bagasse

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3614
Author(s):  
Ana Sílvia de Almeida Scarcella ◽  
Alexandre Favarin Somera ◽  
Christiane da Costa Carreira Nunes ◽  
Eleni Gomes ◽  
Ana Claudia Vici ◽  
...  

Statistical evidence pointing to the very soft change in the ionic composition on the surface of the sugar cane bagasse is crucial to improve yields of sugars by hydrolytic saccharification. Removal of Li+ by pretreatments exposing -OH sites was the most important factor related to the increase of saccharification yields using enzyme cocktails. Steam Explosion and Microwave:H2SO4 pretreatments produced unrelated structural changes, but similar ionic distribution patterns. Both increased the saccharification yield 1.74-fold. NaOH produced structural changes related to Steam Explosion, but released surface-bounded Li+ obtaining 2.04-fold more reducing sugars than the control. In turn, the higher amounts in relative concentration and periodic structures of Li+ on the surface observed in the control or after the pretreatment with Ethanol:DMSO:Ammonium Oxalate, blocked -OH and O− available for ionic sputtering. These changes correlated to 1.90-fold decrease in saccharification yields. Li+ was an activator in solution, but its presence and distribution pattern on the substrate was prejudicial to the saccharification. Apparently, it acts as a phase-dependent modulator of enzyme activity. Therefore, no correlations were found between structural changes and the efficiency of the enzymatic cocktail used. However, there were correlations between the Li+ distribution patterns and the enzymatic activities that should to be shown.

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 20
Author(s):  
Matan Mussel ◽  
Peter J. Basser ◽  
Ferenc Horkay

Incremental changes in ionic composition, solvent quality, and temperature can lead to reversible and abrupt structural changes in many synthetic and biopolymer systems. In the biological milieu, this nonlinear response is believed to play an important functional role in various biological systems, including DNA condensation, cell secretion, water flow in xylem of plants, cell resting potential, and formation of membraneless organelles. While these systems are markedly different from one another, a physicochemical framework that treats them as polyelectrolytes, provides a means to interpret experimental results and make in silico predictions. This article summarizes experimental results made on ion-induced volume phase transition in a polyelectrolyte model gel (sodium polyacrylate) and observations on the above-mentioned biological systems indicating the existence of a steep response.


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.


2021 ◽  
pp. 213-222
Author(s):  
Dandan Wu ◽  
Xiaoxia Zhu ◽  
Lu Tan ◽  
Haiqin Zhang ◽  
Lina Sha ◽  
...  

The genera of the tribe Triticeae (family Poaceae), constituting many economically important plants with abundant genetic resources, carry genomes such as St, H, P, and Y. The genome symbol of <i>Roegneria</i> C. Koch (Triticeae) is StY. The St and Y genomes are crucial in Triticeae, and tetraploid StY species participate extensively in polyploid speciation. Characterization of St and Y nonhomologous chromosomes in StY-genome species could help understand variation in the chromosome structure and differentiation of StY-containing species. However, the high genetic affinity between St and Y genome and the deficiency of a complete set of StY nonhomologous probes limit the identification of St and Y genomes and variation of chromosome structures among <i>Roegneria</i> species. We aimed to identify St- and Y-enhanced repeat clusters and to study whether homoeologous chromosomes between St and Y genomes could be accurately identified due to high affinity. We employed comparative genome analyses to identify St- and Y-enhanced repeat clusters and generated a FISH-based karyotype of <i>R. grandis</i> (Keng), one of the taxonomically controversial StY species, for the first time. We explored 4 novel repeat clusters (StY_34, StY_107, StY_90, and StY_93), which could specifically identify individual St and Y nonhomologous chromosomes. The clusters StY_107 and StY_90 could identify St and Y addition/substitution chromosomes against common wheat genetic backgrounds. The chromosomes V_St, VII_St, I_Y, V_Y, and VII_Y displayed similar probe distribution patterns in the proximal region, indicating that the high affinity between St and Y genome might result from chromosome rearrangements or transposable element insertion among V_St/Y, VII_St/Y, and I_Y chromosomes during allopolyploidization. Our results can be used to employ FISH further to uncover the precise karyotype based on colinearity of Triticeae species by using the wheat karyotype as reference, to analyze diverse populations of the same species to understand the intraspecific structural changes, and to generate the karyotype of different StY-containing species to understand the interspecific chromosome variation.


1988 ◽  
Vol 55 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Bernard Colas ◽  
Christine Gobin ◽  
Denis Lorient

SummaryThe effect of the covalent binding of reducing sugars such as galactose, glucose, fructose, lactose and maltose on the flow properties of casein solutions and on the voluminosity of casein molecules was investigated, voluminosity being calculated from viscosity measurements. Rheological parameters appeared to be efficient indices of structural changes occurring in proteins as a result of chemical modifications. Results showed an increase in voluminosity of casein after the binding of sugars, possibly explained by an increase in the net negative charge or by an increase in the steric hindrance of the molecule. At high concentrations (above 0·03 g/ml), viscosity of the solutions depended on the nature of the attached sugar and on the level of the modification. Thus galactose- and glucose-modified caseins were more viscous than the control. With disaccharides, the level of modification appeared to be more important than the amount of sugar bound.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4552 ◽  
Author(s):  
Merve Nazli Borand ◽  
Asli Isler Kaya ◽  
Filiz Karaosmanoglu

Pressure, temperature, and retention time are the most studied parameters in steam explosion pretreatment. However, this work aimed to fix these parameters and to evaluate the influences of several less investigated steam explosion parameters on the saccharification yield in hydrolysis. In this study, firstly, pinewood samples smaller than 200 µm were treated with steam explosion at 190 °C for 10 min. The variable parameters were biomass loading, N2 pressure, and release time. Steam-exploded samples were hydrolyzed with the Trichoderma reesei enzyme for saccharification for 72 h. The sugar content of the resultant products was analyzed to estimate the yield of sugars (such as glucose, xylose, galactose, mannose, and arabinose). The best glucose yield in the pulp was achieved with 4 g of sample, N2 pressure of 0.44 MPa, and short release time (22 s). These conditions gave a glucose yield of 97.72% in the pulp, and the xylose, mannose, galactose, and arabinose yields in the liquid fraction were found to be 85.59%, 87.76%, 86.43%, and 90.3%, respectively.


2013 ◽  
Vol 29 (4) ◽  
pp. 890-895 ◽  
Author(s):  
Fernanda M. Mendes ◽  
Debora F. Laurito ◽  
Mariana Bazzeggio ◽  
André Ferraz ◽  
Adriane M. F. Milagres

1997 ◽  
Vol 34 (6) ◽  
pp. 557-567 ◽  
Author(s):  
D. E. Swayne

To determine the association between specific structural changes in the hemagglutinin gene and pathogenicity of avian influenza viruses (AIVs), groups of 4-week-old White Plymouth Rock chickens were inoculated intravenously or intranasally with AIVs of varying pathogenicities isolated from chickens in central Mexico during 1994-1995. Mildly pathogenic (MP) viruses had a common hemagglutinin-connecting peptide sequence of Pro-Gln-Arg-Glu-Thr-Arg↓Gly and had restricted capability for replication and production of lesions in tissues. The principle targets for virus replication or lesion production were the lungs, lymphoid organs, and visceral organs containing epithelial cells, such as kidney and pancreas. Death was associated with respiratory and/or renal failure. By contrast, highly pathogenic (HP) AIVs had one substitution and the addition of two basic amino acids in the hemagglutinin connecting peptide, for a sequence of Pro-Gln-Arg-Lys-Arg-Lys-Thr-Arg↓Gly. The HP AIVs were pantropic in virus replication and lesion production ability. However, the most severe histologic lesions were produced in the brain, heart, adrenal glands, and pancreas, and failure of multiple critical organs was responsible for disease pathogenesis and death. No differences in lesion distribution patterns or in sites of AIV replication were evident to explain the variation in mortality rates for different HP AIVs, but HP AIVs that produced the highest mortality rates had more severe necrosis in heart and pancreas. The ability of individual HP AIVs to produce low or high mortality rates could not be explained by changes in sequence of the hemagglutinin-connecting peptide alone, but probably required the addition of other undetermined genomic changes.


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