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| Chemical Characterization of Cellulose-degrading Streptomyces and Its Alkaline Extraction Fraction During Cellulose Degradation |
| Received:April 12, 2014 |
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| KeyWord:Streptomyces sp.;cellulose;alkaline extraction component;structural characteristics |
| Author Name | Affiliation | E-mail | | ZHANG Wei | College of Resources and Environmental Sciences, Jilin Agricultural University, Changchun 130118, China | | | DOU Sen | College of Resources and Environmental Sciences, Jilin Agricultural University, Changchun 130118, China | dousen@tom.com |
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| Abstract: |
| Streptomyces are Gram-positive filamentous bacteria that live in the superficial layer of soil where they can degrade cellulose. They play important roles in producing the currently known antibiotics and many other bioactive molecules useful to human health and agriculture. However, little is known about the characteristics of mycelia and alkaline extraction of Streptomyces sp. during cellulose degradation. In the present study, sodium carboxymethyl cellulose(CMC) was used as a unique carbon source for the isolated strain Streptomyces sp. F in the liquid culture condition during the 60 day period. Carbon distribution, elemental compositions, thermostability and infrared structure of the alkali extraction of the harvested cells were further explored. The results showed that sodium carboxymethyl cellulose could be used as a unique carbon and energy source for the growth of strain Streptomyces sp. F. There was a significant increase in the production rate of harvested cells(α=0.05) during incubation. At the end of incubation(60 d), this production rate reached at 7.29%. Though the elemental composition was similar between the "mycelia" of harvested cells at different culture time and the humic acid(HA) of black soil, the mycelia showed different characteristics from these of the soil HA, with lower degree of crystallinity, greater thermal stability, weaker aromaticity, and higher aliphatic carbon chain and oxygen-containing functional group content. Compared with HA from black soil, Streptomyces had more "water-soluble component" groups and "alkali-soluble acid-insoluble groups(the equivalent of humic acid)" but less "alkali-soluble component groups(the equivalent of humic and fulvic acid)". These results suggest that both the "water-soluble component" and "alkali-soluble acid-insoluble fraction " were related with the breakdown of sodium carboxymethyl cellulose and the biological synthesis in "mycelia", and that the "alkali-soluble acid-insoluble groups" characteristics of the "mycelia" was distinct from the humic acid of the real black soil(HA). |
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