A Novel Bacterial Polymeric Silk-Like Protein from a Petroleum Origin Bacillus sp. strain NE: Isolation and Characterization

This paper explores a novel silk-like protein (named Bacillus NE silk (BNES)) isolated from a petroleum origin bacterial strain belongs to the genus Bacillus. The successful characterizations for its chemical structure determination and protein composition have been performed. The results demonstrate that BNES protein is a new type of silk-like protein and has a prospective for applying as a new bacterial silk-like biomaterial. The amino acids constituents of silk-like protein showed that (Ala-Pro-Gly) rich-block protein, are the main major amino acids, while the protein M-wt., was recorded around>similar to 400kDa, which excelled those similar of natural silk. The degummed or purified silk-like protein was successfully electro-spinned for wet-electrospun silk-like nanofibers using electrospinning technique. Silk-like nanofibers gave an adequate and uniform ribbon-shape structure with average diameter of nanofiber around 110nm. Meanwhile, the block silk-like protein exhibited high thermal degradation monitored at 140-373 degrees C, which close those of natural silkworm silk. The purified silk-like protein showed no toxic effect against Vero kidney normal cell-line even after 48h of incubation, using MTT-assay test. The obtained results demonstrate that, silk-like protein from wild type bacterial origin has potential for use as novel fibrous biomaterials for biomedical and environmental applications.