Acid hydrolysis behaviour of microbial cellulose II

Shibazaki, Hideki; Kuga, Shigenori; Onabe, Fumihiko; Brown, R. Malcolm

doi:10.1016/0032-3861(96)81623-5

Cited by 29 publications

(23 citation statements)

References 15 publications

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“…Based on the LODP behavior, higher plant native, mercerized and regenerated celluloses have been reported to have different crystal sizes along the cellulose chain directions, DP 200-300, DP 40-90 and DP 30-60, respectively (Nickerson and Harble 1947;Battista 1950;Rånby 1952;Nelson and Tripp 1953;Millett et al 1954;Battista et al 1956;Sharples 1958;Chang 1971;Fischer et al 1978;Fan et al 1987;Shibazaki et al 1995Shibazaki et al , 1997Håkansson and Ahlgren 2005;Einfeldt et al 2005). Such structures of periodic cellulose crystalline regions or inversely the presence of periodic distribution of disordered or para-crystalline regions in celluloses are possible to show LODP behavior not only by dilute acid hydrolysis at high temperatures but also other conditions such as alkali hydrolysis, radical cleavage and thermal degradation, where the glycoside bonds of cellulose have a chance to be hydrolyzed or cleaved.…”

Section: Introductionmentioning

confidence: 97%

Degrees of polymerization (DP) and DP distribution of dilute acid-hydrolyzed products of alkali-treated native and regenerated celluloses

2008

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Three groups of cellulose II samples, 20% NaOH-treated native celluloses (M-native celluloses), commercial regenerated celluloses and those treated with 20% NaOH (M-regenerated celluloses), were subjected to dilute acid hydrolysis at 105°C to obtain so-called leveling-off degrees of polymerization (LODP). Molecular mass parameters of the acidhydrolyzed products were analyzed by SEC-MALLS using 1% LiCl/DMAc as an eluent. The LODP values were in the order of M-native celluloses % M-regenerated celluloses [ regenerated celluloses. The LODP values of M-regenerated celluloses are 1.5-1.7 times as much as those of the regenerated celluloses; the cellulose II crystallites in regenerated celluloses increase in size to the longitudinal direction by the alkali treatment and the successive acid hydrolysis at 105°C. This increase in the longitudinal crystal sizes might primarily occur during acid hydrolysis. All the acid-hydrolyzed products had bimodal SEC elution patterns, i.e. the predominant high-molecular-mass and minor low-molecular-mass components, the latter of which corresponded to DP 20.

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Section: Introductionmentioning

confidence: 97%

Degrees of polymerization (DP) and DP distribution of dilute acid-hydrolyzed products of alkali-treated native and regenerated celluloses

2008

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“…According to Steinbüchel et al (32), bacterial cellulose is relatively purer than plant cellulose, which is often associated with hemicelluloses, lignin, and waxy materials. Previous studies have shown that bacterial cellulose produced by A. xylinum was hydrolyzed by cellulase from Trichoderma and chemical agents such as sodium hydroxide and hydrochloric acid (13,24,29,30). The present study evaluated the effectiveness of selected enzymatic and chemical treatments that have been or have the potential to be used by the food industry to control cellulose-producing bacterial pathogens such as STEC.…”

Section: Discussionmentioning

confidence: 99%

Inactivation of Shiga Toxin-Producing Escherichia coli (STEC) and Degradation and Removal of Cellulose from STEC Surfaces by Using Selected Enzymatic and Chemical Treatments

Park

Chen

2011

Appl Environ Microbiol

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Some Shiga toxin-producing Escherichia coli (STEC) strains produce extracellular cellulose, a long polymer of glucose with ␤-1-4 glycosidic bonds. This study evaluated the efficacies of selected enzymatic and chemical treatments in inactivating STEC and degrading/removing the cellulose on STEC surfaces. Six celluloseproducing STEC strains were treated with cellulase (0.51 to 3.83 U/15 ml), acetic and lactic acids (2 and 4%), as well as an acidic and alkaline sanitizer (manufacturers' recommended concentrations) under appropriate conditions. Following each treatment, residual amounts of cellulose and surviving populations of STEC were determined. Treatments with acetic and lactic acids significantly (P < 0.05) reduced the populations of STEC, and those with lactic acid also significantly decreased the amounts of cellulose on STEC. The residual amounts of cellulose on STEC positively correlated to the surviving populations of STEC after the treatments with the organic acids (r ‫؍‬ 0.64 to 0.94), and the significance of the correlations ranged from 83 to 99%. Treatments with cellulase and the sanitizers both degraded cellulose. However, treatments with cellulase had no influence on the fate of STEC, and those with the sanitizers reduced STEC cell populations to undetectable levels. Thus, the correlations between the residual amounts of cellulose and the surviving populations of STEC caused by these two treatments were not observed. The results suggest that the selected enzymatic and chemical agents degraded and removed the cellulose on STEC surfaces, and the treatments with organic acids and sanitizers also inactivated STEC cells. The amounts of cellulose produced by STEC strains appear to affect their susceptibilities to certain sanitizing treatments.Shiga toxin-producing Escherichia coli (STEC) strains are enteropathogens producing one or more toxins related to the Shiga toxins of Shigella dysenteriae serotype 1 (15,19,20). The pathogens cause human illness ranging from mild diarrhea to severe hemorrhagic colitis and hemolytic uremic syndrome (3,11,16,21). The reservoirs of STEC are ruminants such as cattle, sheep, goats, etc., but cattle have been identified as the predominant source of STEC (1, 17). STEC infection can be transmitted through contaminated foods, especially raw and undercooked foods of animal origin (6,17,18,33).Cells of certain STEC strains produce cellulose as an extracellular component (5, 45). The cellulose is a long polymer of glucose, which is insoluble and inelastic, and has a high tensile strength (23, 44). The polymer forms subfibrils and crystallizes into microfibrils (12). The fibrils subsequently build insoluble layered sheets and form hydrogen-bonding networks (23). Cellulose-producing and other bacteria can be entrapped in the networks formed by the cellulose polymers (23, 41).Cellulose is viscous and hydrophilic and protects bacterial cells from changes in moisture content, acidity, and toxin content in various environments (23). Bacterial cellulose has the capability to hold water ...

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“…The products were filtered and washed thoroughly with water. The SEC was performed with tetrahydrofuran as the eluent to determine the average molar weight (Mw) of the cellulose trinitrate obtained from the enzymatic hydrolyzates [21]. The Mw of the acid hydrolyzates of Cladophora CMFs was measured in the same manner.…”

Section: Determination Of Molecular Weightmentioning

confidence: 99%

Enzymatically Produced Nano-ordered Elements Containing Cellulose Iβ Crystalline Domains of Cladophora Cellulose

Hayashi

Kondo

2014

Handbook of Polymer Nanocomposites. Processing, Performance and Application

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Acid hydrolysis behaviour of microbial cellulose II

Cited by 29 publications

References 15 publications

Degrees of polymerization (DP) and DP distribution of dilute acid-hydrolyzed products of alkali-treated native and regenerated celluloses

Degrees of polymerization (DP) and DP distribution of dilute acid-hydrolyzed products of alkali-treated native and regenerated celluloses

Inactivation of Shiga Toxin-Producing Escherichia coli (STEC) and Degradation and Removal of Cellulose from STEC Surfaces by Using Selected Enzymatic and Chemical Treatments

Enzymatically Produced Nano-ordered Elements Containing Cellulose Iβ Crystalline Domains of Cladophora Cellulose

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