一株放线菌对丝素纤维的降解作用

Degradation of Fibroin Fibre by an Actinomycetes Strain

探讨了一株从土壤中分离到的放线菌(C3菌株)对丝素纤维的降解特性。结果表明,C3菌株在28～37℃范围内对蚕丝纤维均具有较强的降解活性;培养基中的碳源能抑制C3菌株的降解活性,而氮源基本无影响,即在缺乏碳源和氮源或单独缺乏碳源的培养基中降解活性增强。在以丝素粉作为唯一碳源和氮源的色氨酸培养基中,C3菌株在28℃下培养6 d左右降解速度最大,并延续至第12天左右。电镜观察表明,培养基中接种C3菌株14 d时,菌丝体已经大量繁殖,丝素纤维出现降解凹陷,部分丝素纤维出现断裂;培养42 d时,丝素纤维已完全降解。

The degradation characteristics of fibroin fibre by the strain C3, an actinomycetes isolated from soil, were discussed in detail in this paper. The results indicated that the strain C3 showed excellent degradation activity for silk fibroin at the temperatures ranging from 28 ℃ to 37 ℃. The degradation activity was inhibited when the carbon and nitrogen sources existed or only carbon source existed in the culture medium. The fibroin-degrading activity reached the maximum level 6 days after cultivation at 28 ℃ in the tryptophan medium containing fibroin powder as the sole carbon and nitrogen sources, and lasted in the following 6 days. Observed under the scanning electron microscope （SEM）, the mycelia of strain C3 has greatly occurred in the 14th day after the cultivation, and the features such as hollow and rupture has been found on the surface of fibroin fibre. The fibroin fibre was degraded completely 42 days after the cultivation.