Biologically active compounds of semi-metals

Řezanka, Tomáš; Sigler, Karel

doi:10.1016/j.phytochem.2007.09.018

Cited by 97 publications

(52 citation statements)

References 156 publications

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“…It has been described as another limiting factor for enzymatic hydrolysis of rice straw hydrolysis (Ma et al 2009). It was reported that the silicon deposits in cell walls and acts as another physical barrier for enzymatic hydrolysis (Řezanka and Sigler 2008). The silicon content was identified by the chemical analysis for ash using the XRF test, which revealed the presence of 6.8% silica.…”

Section: Chemical Compositionmentioning

confidence: 99%

“…Table 5 shows EDX analysis of test points 1, 2, and 3. The presence of silica on this cell layer will probably affect enzymatic hydrolysis negatively (Řezanka and Sigler 2008). Morphology SEM micrographs reveal the physical changes in the surface structure of untreated and pretreated SPB via microwave-acid pretreatment at different magnification (Fig.…”

Section: Chemical Compositionmentioning

confidence: 99%

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Microwave-assisted Dilute Acid Pretreatment and Enzymatic Hydrolysis of Sago Palm Bark

Ethaib¹,

Omar²,

Kamal³

et al. 2016

BioResources

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aMaximizing the amount of monomeric sugar yield from lignocellulosic materials requires an effective pretreatment process and identification of an optimal enzyme loading for cost-effectiveness. In this work, a microwave-diluted sulfuric acid pretreatment was applied prior to enzymatic hydrolysis of sago palm bark (SPB). Characterization of the solid fraction was completed before and after the pretreatment process. Analysis of SPB ash showed a presence of 6.8% silica. There was a 32% reduction in lignin content, an increased crystallinity from 29% to 47%, and clear damage and fragmentation to the surface structure of SPB after the pretreatment. Inhibitors were not detectable in the liquor after the microwave-acid pretreatment. The enzymatic hydrolysis of SPB was employed by adding 6 to 42 FPU/g of cellulase and 50 U/g of β-glucosidase to identify the optimal cellulase loading at fixed β-glucosidase loading. The maximum total monomeric sugar yield and total reducing sugar (using DNS method) at 77 mg/g and 378 mg/g were achieved using 24 FPU/g of cellulose, respectively. Thus, this enzyme loading can be recommended for further microwave-acid pretreatment and enzymatic hydrolysis of SPB.

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Section: Chemical Compositionmentioning

confidence: 99%

Section: Chemical Compositionmentioning

confidence: 99%

Microwave-assisted Dilute Acid Pretreatment and Enzymatic Hydrolysis of Sago Palm Bark

Ethaib¹,

Omar²,

Kamal³

et al. 2016

BioResources

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“…As(III) is reported to be ~100 times more toxic as compared to As(V) [3, 4]. As(V) causes harm to the cells by being analogous to phosphorous, replacing the latter in many chemical reactions [5]. As(III), on the other hand, affects activity of many enzymes by reacting with their sulfhydryl groups [6].…”

Section: Introductionmentioning

confidence: 99%

Arsenic-Redox Transformation and Plant Growth Promotion by Purple Nonsulfur Bacteria Rhodopseudomonas palustris CS2 and Rhodopseudomonas faecalis SS5

Batool

Zahra

Rehman

2017

BioMed Research International

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Arsenic (As) is a well-known toxic metalloid found naturally and released by different industries, especially in developing countries. Purple nonsulfur bacteria (PNSB) are known for wastewater treatment and plant growth promoting abilities. As-resistant PNSB were isolated from a fish pond. Based on As-resistance and plant growth promoting attributes, 2 isolates CS2 and SS5 were selected and identified as Rhodopseudomonas palustris and Rhodopseudomonas faecalis, respectively, through 16S rRNA gene sequencing. Maximum As(V) resistance shown by R. faecalis SS5 and R. palustris CS2 was up to 150 and 100 mM, respectively. R. palustris CS2 showed highest As(V) reduction up to 62.9% (6.29 ± 0.24 mM), while R. faecalis SS5 showed maximum As(III) oxidation up to 96% (4.8 ± 0.32 mM), respectively. Highest auxin production was observed by R. palustris CS2 and R. faecalis SS, up to 77.18 ± 3.7 and 76.67 ± 2.8 μg mL−1, respectively. Effects of these PNSB were tested on the growth of Vigna mungo plants. A statistically significant increase in growth was observed in plants inoculated with isolates compared to uninoculated plants, both in presence and in absence of As. R. palustris CS2 treated plants showed 17% (28.1 ± 0.87 cm) increase in shoot length and 21.7% (7.07 ± 0.42 cm) increase in root length, whereas R. faecalis SS5 treated plants showed 12.8% (27.09 ± 0.81 cm) increase in shoot length and 18.8% (6.9 ± 0.34 cm) increase in root length as compared to the control plants. In presence of As, R. palustris CS2 increased shoot length up to 26.3% (21.0 ± 1.1 cm), while root length increased up to 31.3% (5.3 ± 0.4 cm), whereas R. faecalis SS5 inoculated plants showed 25% (20.7 ± 1.4 cm) increase in shoot length and 33.3% (5.4 ± 0.65 cm) increase in root length as compared to the control plants. Bacteria with such diverse abilities could be ideal for plant growth promotion in As-contaminated sites.

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“…3 General mass balance of solid-state fermentation for cellulase production using wheat bran and rice hulls as substrates another physical barrier, protecting the plant from enzymatic hydrolysis and fungal degradation. Removal of silicon can benefit the increase of acceptability of the substrates [27]. Alkali pretreatment can dissolve a significant part of silicon, and microwave pretreatment also removes a part of acid-insoluble ash [28].…”

Section: Recycle Of Fermented Residuesmentioning

confidence: 99%

Microwave Pretreatment of Substrates for Cellulase Production by Solid-State Fermentation

Zhao

Zhou

Zheng³

et al. 2009

Appl Biochem Biotechnol

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The agricultural residues, wheat bran and rice hulls, were used as substrates for cellulase production with Trichoderma sp 3.2942 by solid-state fermentation. Microwave irradiation was employed to pretreat the substrates in order to increase the susceptibility. Although the highest cellulase yield was obtained by the substrates pretreated by 450 W microwave for 3 min, pretreatment time and microwave power had no significant effect on cellulase production. The initial reducing sugar content (RSC) of substrates was decreased by microwave irradiation, but more reducing sugars were produced in later fermentation. Alkali pretreatment combined with microwave pretreatment (APCMP) of rice hulls could significantly increase cellulase yields and reducing sugar. The maximum filter paper activity, carboximethylcellulase (CMC)ase, and RSC were increased by 35.2%, 21.4%, and 13%, respectively, compared with those of untreated rice hulls. The fermented residues could produce more cellulase and reducing sugars than fresh rice hulls after they were treated by APCMP. The increased accessibility of the substrates by microwave pretreatment was mainly achieved by rupture of the rigid structure of rice hulls. However, for alkali pretreatment and APCMP, delignification and removal of ash played very important roles for increasing the acceptability of substrates.

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Biologically active compounds of semi-metals

Cited by 97 publications

References 156 publications

Microwave-assisted Dilute Acid Pretreatment and Enzymatic Hydrolysis of Sago Palm Bark

Microwave-assisted Dilute Acid Pretreatment and Enzymatic Hydrolysis of Sago Palm Bark

Arsenic-Redox Transformation and Plant Growth Promotion by Purple Nonsulfur Bacteria Rhodopseudomonas palustris CS2 and Rhodopseudomonas faecalis SS5

Microwave Pretreatment of Substrates for Cellulase Production by Solid-State Fermentation

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