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Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites.

Ben Guerrero E, Arneodo J, Bombarda Campanha R, Abrão de Oliveira P, Veneziano Labate MT, Regiani Cataldi T, Campos E, Cataldi A, Labate CA, Martins Rodrigues C, Talia P - PLoS ONE (2015)

Bottom Line: In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan.Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed.This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biotecnología, CICVyA, CNIA, INTA Castelar, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, Provincia de Buenos Aires, Argentina.

ABSTRACT
Saccharum officinarum bagasse (common name: sugarcane bagasse) and Pennisetum purpureum (also known as Napier grass) are among the most promising feedstocks for bioethanol production in Argentina and Brazil. In this study, both biomasses were assessed before and after acid pretreatment and following hydrolysis with Nasutitermes aquilinus and Cortaritermes fulviceps termite gut digestome. The chemical composition analysis of the biomasses after diluted acid pretreatment showed that the hemicellulose fraction was partially removed. The (hemi) cellulolytic activities were evaluated in bacterial culture supernatants of termite gut homogenates grown in treated and untreated biomasses. In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan. Several protein bands with (hemi) cellulolytic activity were detected in zymograms and two-dimensional gel electrophoresis. Some proteins of these bands or spots were identified as xylanolytic peptides by mass spectrometry. Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed. This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.

No MeSH data available.


Related in: MedlinePlus

Zymogram.(A) SDS-PAGE-CMC lane 1 GE–C. fulviceps, lane 2 GE—N. aquilinus, lane 3 SN—cultures from N. aquilinus, lane 4 negative control, medium CMC. (B) SDS-PAGE-xylan line 1 SN—cultures from N. aquilinus P. purpureum, lane 2 negative control, medium PP. The arrows show the bands analyzed by de novo sequencing peptide identification.
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pone.0136573.g004: Zymogram.(A) SDS-PAGE-CMC lane 1 GE–C. fulviceps, lane 2 GE—N. aquilinus, lane 3 SN—cultures from N. aquilinus, lane 4 negative control, medium CMC. (B) SDS-PAGE-xylan line 1 SN—cultures from N. aquilinus P. purpureum, lane 2 negative control, medium PP. The arrows show the bands analyzed by de novo sequencing peptide identification.

Mentions: To further identify cellulases and hemicellulases in N. aquilinus and C. fulviceps, we analyzed GE and SN from both insects. The zymograms of GE-CMC consistently showed the presence of at least one endoglucanase in each termite species, with molecular weights of 45 kDa and 40 kDa (N. aquilinus and C. fulviceps, respectively) (Fig 4A, lane 1 and 2). In the SN-CMC from cultures from N. aquilinus, six relevant protein bands (around 45–130 kDa) with cellulolytic activity were observed (Fig 4A, lane 3). When xylan was used as substrate for zymography, several distinct xylanolytic protein bands were detected in SN from cultures of N. aquilinus endosymbionts grown on untreated PP (Fig 4B). However, no activity was observed in the SN from cultures from C. fulviceps bacterial cultures grown on CMC, xylan and untreated SOB. The detected molecular weights are comparable to those reported for endoglucanases and xylanases from insects [45–47]. Separation of these proteins by 2D-gel electrophoresis in SN-CMC cultures from N. aquilinus has allowed the identification of about eight relevant proteins stained with Coomassie blue (Fig 5).


Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites.

Ben Guerrero E, Arneodo J, Bombarda Campanha R, Abrão de Oliveira P, Veneziano Labate MT, Regiani Cataldi T, Campos E, Cataldi A, Labate CA, Martins Rodrigues C, Talia P - PLoS ONE (2015)

Zymogram.(A) SDS-PAGE-CMC lane 1 GE–C. fulviceps, lane 2 GE—N. aquilinus, lane 3 SN—cultures from N. aquilinus, lane 4 negative control, medium CMC. (B) SDS-PAGE-xylan line 1 SN—cultures from N. aquilinus P. purpureum, lane 2 negative control, medium PP. The arrows show the bands analyzed by de novo sequencing peptide identification.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4552170&req=5

pone.0136573.g004: Zymogram.(A) SDS-PAGE-CMC lane 1 GE–C. fulviceps, lane 2 GE—N. aquilinus, lane 3 SN—cultures from N. aquilinus, lane 4 negative control, medium CMC. (B) SDS-PAGE-xylan line 1 SN—cultures from N. aquilinus P. purpureum, lane 2 negative control, medium PP. The arrows show the bands analyzed by de novo sequencing peptide identification.
Mentions: To further identify cellulases and hemicellulases in N. aquilinus and C. fulviceps, we analyzed GE and SN from both insects. The zymograms of GE-CMC consistently showed the presence of at least one endoglucanase in each termite species, with molecular weights of 45 kDa and 40 kDa (N. aquilinus and C. fulviceps, respectively) (Fig 4A, lane 1 and 2). In the SN-CMC from cultures from N. aquilinus, six relevant protein bands (around 45–130 kDa) with cellulolytic activity were observed (Fig 4A, lane 3). When xylan was used as substrate for zymography, several distinct xylanolytic protein bands were detected in SN from cultures of N. aquilinus endosymbionts grown on untreated PP (Fig 4B). However, no activity was observed in the SN from cultures from C. fulviceps bacterial cultures grown on CMC, xylan and untreated SOB. The detected molecular weights are comparable to those reported for endoglucanases and xylanases from insects [45–47]. Separation of these proteins by 2D-gel electrophoresis in SN-CMC cultures from N. aquilinus has allowed the identification of about eight relevant proteins stained with Coomassie blue (Fig 5).

Bottom Line: In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan.Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed.This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biotecnología, CICVyA, CNIA, INTA Castelar, Dr. N. Repetto y Los Reseros s/n, (1686) Hurlingham, Provincia de Buenos Aires, Argentina.

ABSTRACT
Saccharum officinarum bagasse (common name: sugarcane bagasse) and Pennisetum purpureum (also known as Napier grass) are among the most promising feedstocks for bioethanol production in Argentina and Brazil. In this study, both biomasses were assessed before and after acid pretreatment and following hydrolysis with Nasutitermes aquilinus and Cortaritermes fulviceps termite gut digestome. The chemical composition analysis of the biomasses after diluted acid pretreatment showed that the hemicellulose fraction was partially removed. The (hemi) cellulolytic activities were evaluated in bacterial culture supernatants of termite gut homogenates grown in treated and untreated biomasses. In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan. Several protein bands with (hemi) cellulolytic activity were detected in zymograms and two-dimensional gel electrophoresis. Some proteins of these bands or spots were identified as xylanolytic peptides by mass spectrometry. Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed. This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.

No MeSH data available.


Related in: MedlinePlus