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Aims:  To characterize a new feather‐degrading bacterium. Methods and Results:  The strain kr10 producing a high keratinolytic activity when cultured on native feather broth was identified as Microbacterium sp., based on phenotypical characteristics and 16S rDNA sequence. The bacterium presented optimum growth and feather‐degrading activity at pH 7·0 and 30°C. Complete feather degradation was achieved during cultivation. The keratinase was partially purified by gel filtration chromatography. It was optimally active at pH 7·0 and 55°C. The enzyme was inhibited by 1,10‐phenanthroline, EDTA, p‐chloromercuribenzoic acid, 2‐mercaptoethanol and metal ions like Hg2+, Cu2+ and Zn2+. Significance and Impact of the Study:  A new Microbacterium sp. strain was characterized presenting high feather‐degrading activity, which appears to be associated to a metalloprotease‐type keratinase. This micro‐organism has enormous potential for use in biotechnological processes involving keratin hydrolysis.

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The effect of alkaline treatment on the ultrastructure of C-type starch granules was investigated during the alkaline extraction of Araucaria angustifolia (pinhao) starch. The efficiency in protein removal was evaluated using intrinsic fluorescence and Kjeldahl's method. In parallel, morphological changes of starch granules were observed using scanning electron microscopy and atomic force microscopy. The starch crystallinity was monitored by wide-angle X-ray scattering and the lamellar structure was studied by small-angle X-ray scattering (SAXS). The paracrystalline model was employed to interpret the SAXS curves. It was found that the granular organization was significantly altered when alkaline solutions were used during the extraction. A partial degradation of B-type allomorph of starch and a significant compression of semicrystalline growth rings were observed.