In vitro degradation of ß-amyloid fibrils by microbial keratinase.

INTRODUCTION: Amyloid fibrils are misfolded, protease-resistant forms of normal proteins. They are infectious such as prions or noninfectious such as ß-amyloid (Aß) fibrils causing Alzheimer's disease (AD). Prions and amyloids are structurally similar, possessing cross ß-pleated sheet-like structures. As microbial keratinase could degrade prions, we tested keratinase activity on Aß fibrils. METHODS: Lysozyme treated with urea generates Aß fibrils demonstrated by immunoblotting with anti-Aß antibody, high-performance liquid chromatography, and Congo red absorption spectroscopy. Two keratinases, Ker1 and Ker2, were purified from an actinomycete Amycolatopsis sp. MBRL 40 and incubated with Aß fibrils. RESULTS: Soluble Ker1 and Ker1 reconstituted on neutral/cationic liposomes degraded Aß fibrils efficiently. Ker 2 was less potent. DISCUSSION: Drugs that target AD inhibit acetylcholinesterase or formation of Aß fibrils and downstream effects. These drugs have side effects and do not benefit globally in cognition. Keratinases are novel molecules for drug development against AD.

Biocontrol and plant growth promoting activities of a Streptomyces corchorusii strain UCR3-16 and preparation of powder formulation for application as biofertilizer agents for rice plant.

Streptomyces corchorusii strain UCR3-16, obtained from rice rhizospheric soils showed antifungal activities against 6 major rice fungal pathogens by diffusible and volatile compounds production. The strain was found positive for production of fungal cell wall degrading enzymes such as chitinase, ß-1,3-glucanase, ß-1,4-glucanase, lipase and protease. The strain was also positive for plant growth promoting traits. It produced up to 30.5µg/ml of IAA and solubilized a significant amount of inorganic phosphate (up to 102µg/ml). It also produced 69% siderophore units. The strain also produced ammonia and gave positive result for ACC deaminase activity. Highest vigor index of inoculated seedlings was observed when rice seeds were treated with cell suspension of UCR3-16 corresponding to 4.5×10(8)cfu/ml. Bioinoculant-treated seeds also showed similar results under pathogen challenged conditions. In pot trial experiments, UCR3-16-treated rice plants showed significantly increased growth and grain yield production. Powder formulation of the strain was developed using talcum and corn starch as carriers and the shelf-lives were monitored. Talcum formulation showed higher cell-count than corn starch even after 6 months of storage, and optimum condition for storage of the powder formulation were found to be at 4°C. Pot trial experiments using talcum powder formulation also showed significant positive effects on growth of rice plants. Field trial using talcum powder formulation also exhibited significant enhancement in shoot length and weight of shoot and root, and total grain yield and weight of grains in rice plants. Talcum formulation also significantly reduced the sheath blight disease in rice leaves.