2012|13 Annual Report Fraunhofer IGB

9 0 Initial situation and project aim The processing of prawns, crabs and shrimps results in the accumulation of large quantities of shell waste that contains chitin. Every year over six million metric tons of these crusta- cean shells land in the waste, with an estimated several hun- dred thousand tons of these being within the EU alone [1]. A use has already been found for a small part of this biogenic resource and in Asia, for example, it is utilized for the produc- tion of chitosan for the use in biomedical applications or as a food additive [2]. Because of the higher proportions of cal- cium carbonate, the utilization of European shells is less eco- nomical and not very common. Nevertheless, proper disposal of the shell waste – material which poses a contamination risk – is complex and costly owing to EU and country-speciﬁc regulations. In the EU-funded ChiBio project, an international team of re- searchers under the direction of the Fraunhofer BioCat project group in Straubing is working on new processes for develop- ing the shell waste accumulating in the EU as a raw mate- rial’s source for specialty chemicals. ChiBio is adopting the approach of a bioreﬁnery in order to use the biogenic waste material in a holistic way, in other words materially and ener- getically. Stabilization of the shells and mobilization of chitin In a ﬁrst process step, methods are being developed to pre- treat and stabilize the waste shells thereby making them stor- age-stable and transportable. A further important process step is the mobilization of chitin, an N-containing biopolymer. ChiBio, under the direction of the Letterkenny Institute of Technology, is developing process solutions for mild (benign) mobilization of the chitin, protein and lipid fractions using sus- tainable chemical, microbiological and enzymatic methods. Enzymatic cleavage of chitin A further fundamental process step is the cleavage of the chi- tin or of the chitosan obtained through deacetylation into its monomeric sugar units N-acetylglucosamine and glucosamine, respecitively. Chemo-catalytic methods used in this context are not particularly sustainable. ChiBio is therefore develop- ing biocatalytic digestion methods and for this purpose is us- ing chitin-degrading enzymes from prokaryotic and eukaryotic organisms such as strains of Trichoderma, Aspergillus, Bacillus and Aeromonas. Of particular use here is the expertise of our Norwegian partner Prof. Dr. Vincent Eijsink (UMB) in dealing with enzymes from the CBM33 family. These enzymes signiﬁ- cantly increase the rates of chitin degradation [3], but in some cases still need to be optimized. This work is being comple- mented by our own chitinases and also chitin-deacetylases at the Fraunhofer IGB in Stuttgart [4]. Intensive work is current- ly underway to match the enzyme cocktails in the best way possible and to adapt them to industrial process conditions and/or production methods on an industrial scale. CHEMISTRY CHIBIO – CHITIN FROM FISHERY WASTE AS A RAW MATERIAL FOR THE PRODUCTION OF SPECIALTY CHEMICALS Dr. rer. nat. Lars O. Wiemann, Prof. Dr. rer. nat. Volker Sieber 1

2012|13 Annual Report Fraunhofer IGB

Pages