EJPAU 2008. Rodziewicz A. , Łaba W. BIODEGRADATION OF FEATHER KERATIN BY <I>BACILLUS CEREUS</I> IN PURE CULTURE AND COMPOST

Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.

2008
Volume 11
Issue 2

Topic:

Biotechnology

ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES

Rodziewicz A. , Łaba W. 2008. BIODEGRADATION OF FEATHER KERATIN BY BACILLUS CEREUS IN PURE CULTURE AND COMPOST, EJPAU 11(2), #03.
Available Online: http://www.ejpau.media.pl/volume11/issue2/abs-03.html

BIODEGRADATION OF FEATHER KERATIN BY BACILLUS CEREUS IN PURE CULTURE AND COMPOST

Anna Rodziewicz, Wojciech Łaba
Department of Biotechnology and Food Microbiology, Wrocław University of Environmental and Life Sciences, Poland

ABSTRACT

The cultures of Bacillus cereus B5esz strain in feather keratin-containing media showed, that proteinceaous substrate was gradually degraded and next used as a carbon and nitrogen source. This strain biosynthesised extracellular enzymes, such as: keratinases, proteases and others. As a result, increases in soluble protein and amino groups concentration were observed, together with the release of inorganic sulphur compounds and medium alkalinization. This coincided also with increasing concentrations of thiol compounds. An excess of cystine-derived sulphur was accumulated in inorganic sulphates (IV and VI) or thiosulphates. The investigated bacterial strain in twelve-day cultures decomposed 70 % of feather keratin. Inoculation of feather-containing compost with B. cereus, initially resulted in predominance of spore-forming and thermophilic bacteria. After six weeks of composting, yeast or filamentous fungi were eliminated. Bacterial inoculum slightly accelerated the mineralization of feathers and increased the fertilizer value of the compost. Electron microscopy visualization of feather keratin fibres after composting, showed enhanced degradation of the feather structures. The degradation of feather keratin structures was conspicuous both in the medium and compost. The feathers were covered with a complex microbial matrix.

Key words: Bacillus cereus, keratinolysis, feather keratin, composting.

Anna Rodziewicz
Department of Biotechnology and Food Microbiology,
Wrocław University of Environmental and Life Sciences, Poland
Norwida 25, 50-375 Wrocław, Poland
email: Anna.Rodziewicz@wnoz.up.wroc.pl

Wojciech Łaba
Department of Biotechnology and Food Microbiology,
Wrocław University of Environmental and Life Sciences, Poland
Chełmońskiego 37/41
51-630 Wrocław
Poland

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