An expansin from the marine bacterium Hahella chejuensis acts synergistically with xylanase and enhances xylan hydrolysis

Lee, Hee Jin; Kim, In Jung; Kim, Jihyun F.; Choi, In Geol; Kim, Kyoung Heon

doi:10.1016/j.biortech.2013.09.086

Cited by 21 publications

(17 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Binding parameters were B max 0.33 µmol/g Avicel, and K d 2.97 µM, almost identical to the reported parameters found for BsEXLX1 [10]. Treatment of filter paper strips with bacterial expansins decreases their breaking force under tension [10], [14]. To determine whether PcExl1 produces the same effect, filter paper strips were incubated in the presence of the protein for one hour and the tensile force required to break them was measured.…”

Section: Resultssupporting

confidence: 75%

“…Finally, because of opposing results in the literature on the existence of synergism between bacterial expansins and cellulases and/or xylanases [6], [14], [26], we looked for synergism between PcExl1 and these enzymes. Reactions with 0.25 U of endocellulase from T. reesei failed to produce reducing sugars with 2.5 mg Avicel as a substrate even at long incubation times, either in the presence or absence of PcExl1 (Figure 6), whereas the same amount of enzyme produced 2.5 mM of glucose equivalents using carboxymethyl cellulose in three hours (not shown), indicating that the enzyme was active.…”

Section: Resultsmentioning

confidence: 99%

“…Because expansins act on cellulose to loosen plant cell walls, they have been seen as a potential additive alongside hydrolytic activities to make processes more efficient. Indeed, reports indicate that production of reducing sugars by either cellulases or xylanases in reactions containing expansins from B. subtilis [26], [30] or H. chejuensis [14], [27] is increased. This is not the case for PcExl1, that even at very high concentration or long incubation time (640 µg/ml; 96 h, data not shown) did not generate an increase in the production of reducing sugars in combination with a cellulase, and only a modest increment was observed at early times of incubation times in combination with a xylanase.…”

Section: Discussionmentioning

confidence: 99%

“…Finally, expansins are attractive proteins for potential biotechnological applications, specifically for the production of biofuels from lignocellulose. On this respect, there are contradicting results in the literature on the existence of synergism between bacterial expansins and cellulases or xylanases [6], [14].…”

Section: Introductionmentioning

confidence: 88%

See 3 more Smart Citations

PcExl1 a Novel Acid Expansin-Like Protein from the Plant Pathogen Pectobacterium carotovorum, Binds Cell Walls Differently to BsEXLX1

et al. 2014

View full text Add to dashboard Cite

Microbial expansins act on plant cell walls similarly to plant expansins, albeit their loosening activity levels are tenfold lesser compared to plant expansins. We report the characterization of an expansin-like gene from the plant pathogen Pectobacterium carotovorum, named exl1. PcExl1 is an acidic protein that binds cellulose (Avicel), and weakens filter paper. The acidic nature of PcExl1 confers different binding properties when compared to Bacillus subtilis BsEXLX1, which is a basic protein. PcExl1 binding to wheat cell wall increased when acidic components were depleted, reaching a similar level to the binding to Avicel, indicating that cellulose is the target of PcExl1.

show abstract

Section: Resultssupporting

confidence: 75%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 88%

See 2 more Smart Citations

PcExl1 a Novel Acid Expansin-Like Protein from the Plant Pathogen Pectobacterium carotovorum, Binds Cell Walls Differently to BsEXLX1

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Interestingly, a recombinant swollenin from A. fumigatus produced in A. oryzae was reported not to bind to xylan [34]. Contrarily, most bacterial expansins are reported to bind on xylan [21, 26, 54, 64, 65]. …”

Section: Discussionmentioning

confidence: 99%

Functional characterization of the native swollenin from Trichoderma reesei: study of its possible role as C1 factor of enzymatic lignocellulose conversion

Eibinger

Sigl

Sattelkow

et al. 2016

Biotechnol Biofuels

View full text Add to dashboard Cite

BackgroundThrough binding to cellulose, expansin-like proteins are thought to loosen the structural order of crystalline surface material, thus making it more accessible for degradation by hydrolytic enzymes. Swollenin SWO1 is the major expansin-like protein from the fungus Trichoderma reesei. Here, we have performed a detailed characterization of a recombinant native form of SWO1 with respect to its possible auxiliary role in the enzymatic saccharification of lignocellulosic substrates.ResultsThe swo1 gene was overexpressed in T. reesei QM9414 Δxyr1 mutant, featuring downregulated cellulase production, and the protein was purified from culture supernatant. SWO1 was N-glycosylated and its circular dichroism spectrum suggested a folded protein. Adsorption isotherms (25 °C, pH 5.0, 1.0 mg substrate/mL) revealed SWO1 to be 120- and 20-fold more specific for binding to birchwood xylan and kraft lignin, respectively, than for binding to Avicel PH-101. The SWO1 binding capacity on lignin (25 µmol/g) exceeded 12-fold that on Avicel PH-101 (2.1 µmol/g). On xylan, not only the binding capacity (22 µmol/g) but also the affinity of SWO1 (Kd = 0.08 µM) was enhanced compared to Avicel PH-101 (Kd = 0.89 µM). SWO1 caused rapid release of a tiny amount of reducing sugars (<1 % of total) from different substrates (Avicel PH-101, nanocrystalline cellulose, steam-pretreated wheat straw, barley β-glucan, cellotetraose) but did not promote continued saccharification. Atomic force microscopy revealed that amorphous cellulose films were not affected by SWO1. Also with AFM, binding of SWO1 to cellulose nanocrystallites was demonstrated at the single-molecule level, but adsorption did not affect this cellulose. SWO1 exhibited no synergy with T. reesei cellulases in the hydrolysis of the different celluloses. However, SWO1 boosted slightly (1.5-fold) the reducing sugar release from a native grass substrate.ConclusionsSWO1 is a strongly glycosylated protein, which has implications for producing it in heterologous hosts. Although SWO1 binds to crystalline cellulose, its adsorption to xylan is much stronger. SWO1 is not an auxiliary factor of the enzymatic degradation of a variety of cellulosic substrates. Effect of SWO1 on sugar release from intact plant cell walls might be exploitable with certain (e.g., mildly pretreated) lignocellulosic feedstocks.

show abstract

Design of an enzyme cocktail consisting of different fungal platforms for efficient hydrolysis of sugarcane bagasse: Optimization and synergism studies

Arias

Modesto

Polikarpov

et al. 2016

Biotechnology Progress

View full text Add to dashboard Cite

Lignocellulosic materials represent a very important and promising source of renewable biomass. In order to turn them into fermentable sugars, synergism among the different enzymes that carry out bioconversion of these materials is one of the main factors that should be considered. Experimental mixture design was performed to optimize the proportion of enzymes produced by native strains of Trichoderma harzianum IOC 3844, Penicillium funiculosum ATCC 11797, and Aspergillus niger ATCC 1004, resulting in a proportion of 15, 50, and 35%, respectively. This mixture was able to hydrolyze 25 g/L of pretreated sugarcane bagasse with 91% of yield after 48 h of enzymatic reaction. Synergism along the hydrolysis process, besides the influence of lignin, hemicellulose, and solids loading, were also studied. Response surface methodology (RSM) based on Central Composite Rotatable Design was used to optimize solids and protein loadings to increase glucose release and enzymatic hydrolysis yield. The optimum solid and protein loadings established with RSM were 196 g/L and 24 mg/g cellulose, respectively, and under these conditions (94.1 ± 8) g/L of glucose were obtained, corresponding to a hydrolysis yield of 64%. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1222-1229, 2016.

show abstract

An expansin from the marine bacterium Hahella chejuensis acts synergistically with xylanase and enhances xylan hydrolysis

Cited by 21 publications

References 28 publications

PcExl1 a Novel Acid Expansin-Like Protein from the Plant Pathogen Pectobacterium carotovorum, Binds Cell Walls Differently to BsEXLX1

PcExl1 a Novel Acid Expansin-Like Protein from the Plant Pathogen Pectobacterium carotovorum, Binds Cell Walls Differently to BsEXLX1

Functional characterization of the native swollenin from Trichoderma reesei: study of its possible role as C1 factor of enzymatic lignocellulose conversion

Design of an enzyme cocktail consisting of different fungal platforms for efficient hydrolysis of sugarcane bagasse: Optimization and synergism studies

Contact Info

Product

Resources

About