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Enhancement of Cellulose Degradation by Cattle Saliva.

Seki Y, Kikuchi Y, Kimura Y, Yoshimoto R, Takahashi M, Aburai K, Kanai Y, Ruike T, Iwabata K, Sugawara F, Sakai H, Abe M, Sakaguchi K - PLoS ONE (2015)

Bottom Line: Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose.Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva.We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect.

View Article: PubMed Central - PubMed

Affiliation: Research Institute for Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.

ABSTRACT
Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale.

No MeSH data available.


Related in: MedlinePlus

Removal of protein in cattle saliva.(a) Protein concentration in cattle saliva treated with methanol or acetone. Protein concentration was measured using Bradford protein assay. (b) Enhancement effect of cattle saliva treated with methanol or acetone. Cattle saliva treated with methanol or acetone used in the cellulose degradation assay. The reaction condition follows the basic experimental protocol. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).
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pone.0138902.g004: Removal of protein in cattle saliva.(a) Protein concentration in cattle saliva treated with methanol or acetone. Protein concentration was measured using Bradford protein assay. (b) Enhancement effect of cattle saliva treated with methanol or acetone. Cattle saliva treated with methanol or acetone used in the cellulose degradation assay. The reaction condition follows the basic experimental protocol. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).

Mentions: In order to remove proteins in cattle saliva, we treated cattle saliva with methanol and acetone. Methanol and acetone often denature and insolubilize protein and usually use for removal of protein. Meanwhile, various kinds of organic substances, except for protein, can be dissolved in methanol and acetone. We measured the protein concentration in cattle saliva treated with methanol or acetone by Bradford protein assay (Fig 4A). Proteins in cattle saliva treated with methanol contained more than treated with acetone. The rate of dissolved protein in untreated cattle saliva, cattle saliva treated with methanol and acetone were 100%, 38% and 11%, respectively. Based on the result of protein concentration in cattle saliva treated with methanol and acetone, we tested cattle saliva treated with methanol and acetone in the cellulose degradation assay (Fig 4B). The amount of glucose produced lower in cattle saliva treated with methanol or acetone than in untreated cattle saliva. The enhancement effect decreased corresponding decrease of the protein amount in cattle saliva. These results also suggested that the substance responsible for enhancement effect probably non-enzymatic protein.


Enhancement of Cellulose Degradation by Cattle Saliva.

Seki Y, Kikuchi Y, Kimura Y, Yoshimoto R, Takahashi M, Aburai K, Kanai Y, Ruike T, Iwabata K, Sugawara F, Sakai H, Abe M, Sakaguchi K - PLoS ONE (2015)

Removal of protein in cattle saliva.(a) Protein concentration in cattle saliva treated with methanol or acetone. Protein concentration was measured using Bradford protein assay. (b) Enhancement effect of cattle saliva treated with methanol or acetone. Cattle saliva treated with methanol or acetone used in the cellulose degradation assay. The reaction condition follows the basic experimental protocol. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581621&req=5

pone.0138902.g004: Removal of protein in cattle saliva.(a) Protein concentration in cattle saliva treated with methanol or acetone. Protein concentration was measured using Bradford protein assay. (b) Enhancement effect of cattle saliva treated with methanol or acetone. Cattle saliva treated with methanol or acetone used in the cellulose degradation assay. The reaction condition follows the basic experimental protocol. All experiments were performed in triplicate and average mean values were plotted. Error bars indicate ± standard deviations. Values labeled with asterisk are statistically different as established by Student's t-test (P < 0.05).
Mentions: In order to remove proteins in cattle saliva, we treated cattle saliva with methanol and acetone. Methanol and acetone often denature and insolubilize protein and usually use for removal of protein. Meanwhile, various kinds of organic substances, except for protein, can be dissolved in methanol and acetone. We measured the protein concentration in cattle saliva treated with methanol or acetone by Bradford protein assay (Fig 4A). Proteins in cattle saliva treated with methanol contained more than treated with acetone. The rate of dissolved protein in untreated cattle saliva, cattle saliva treated with methanol and acetone were 100%, 38% and 11%, respectively. Based on the result of protein concentration in cattle saliva treated with methanol and acetone, we tested cattle saliva treated with methanol and acetone in the cellulose degradation assay (Fig 4B). The amount of glucose produced lower in cattle saliva treated with methanol or acetone than in untreated cattle saliva. The enhancement effect decreased corresponding decrease of the protein amount in cattle saliva. These results also suggested that the substance responsible for enhancement effect probably non-enzymatic protein.

Bottom Line: Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose.Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva.We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect.

View Article: PubMed Central - PubMed

Affiliation: Research Institute for Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.

ABSTRACT
Saccharification of cellulose is a promising technique for producing alternative source of energy. However, the efficiency of conversion of cellulose into soluble sugar using any currently available methodology is too low for industrial application. Many additives, such as surfactants, have been shown to enhance the efficiency of cellulose-to-sugar conversion. In this study, we have examined first whether cattle saliva, as an additive, would enhance the cellulase-catalyzed hydrolysis of cellulose, and subsequently elucidated the mechanism by which cattle saliva enhanced this conversion. Although cattle saliva, by itself, did not degrade cellulose, it enhanced the cellulase-catalyzed degradation of cellulose. Thus, the amount of reducing sugar produced increased approximately 2.9-fold by the addition of cattle saliva. We also found that non-enzymatic proteins, which were present in cattle saliva, were responsible for causing the enhancement effect. Third, the mechanism of cattle saliva mediated enhancement of cellulase activity was probably similar to that of the canonical surfactants. Cattle saliva is available in large amounts easily and cheaply, and it can be used without further purification. Thus, cattle saliva could be a promising additive for efficient saccharification of cellulose on an industrial scale.

No MeSH data available.


Related in: MedlinePlus