Improving the digestibility of lignocellulosic material by using enzymatic extracts from fungi
Influence of the nitrogen sources on the lignolytic enzyme activity.

The STSM of Hasliza Abu Hassim (Ghent University) was held from end October 2011 till end 2011 at the Research Centre of Animal and Veterinary Sciences, University of Tras-os-Montes e Alto Douro, 5001-911 Vila Real, Portugal. Host was Prof. Miguel Antonio Machado Rodrigues

Purpose of the visit

The aim of the short term scientific mission (STSM) was to gather information on enzyme extraction from white rot fungi (WRF) and determination of its enzyme activities. During this stay, we optimized the protocol for enzyme activities determination, using the methodology of the research group in the host institute (Rodrigues et al., 2008) as a starting point. 

Description of the work carried out during the visit

During the stay, the beneficiary performed experiments to produce enzyme extracts, in solid state fermentation, of oil palm fronds (OPF) cultivated with ofWRF. In this experiment, 3 strains of WRF (Ceriporiopsis subvermispora, Ganoderma lucidum and Lentinula edodes) were used as case study. To optimize the enzyme extraction protocol, the influence of two different nitrogen sources were also evaluated. The enzyme activity, particularly the lignolytic enzymes (e.g. laccase, lignin peroxidase and manganese peroxidase) were determined as described by Dias et al. (2003).
The extraction procedures leading to higher lignolytic activity were further used for pre-treatment of OPF with these enzyme extracts. After that, determination of the effectiveness of the pre-treatment with enzyme extracts were determined on 4 levels, 1) dry matter losses; 2) extent of lignin degradation; 3) extent of cellulose degradation based on enzyme assays; and 4) extent of microbial fermentation as described below. The first level was determined at UTAD whereas the other three levels will be determined at UGent.

Description of the main results obtained
During the STSM it was possible to learn all the methods for enzyme activities determination. The preliminary results obtained from this study indicated that there is an influence of the nitrogen sources on the lignolytic enzyme activity. Furthermore, the activity level indicates that the application of the enzyme extracts on OPF will promote changes on the cell wall hydrolysis. 

Future collaboration with host institution

The start of the collaboration between Universidade de Trás-os-Montes e Alto Douro (host institute) and Ghent University was successful. The host institute has shown a strong will to assist and collaborate in the activities above mentioned in the future.

Projected publication/articles resulting or to result from the STSM

It is planned to disseminate the present and future results at least in a conference abstract. Possible publication in a peer-review journal such as “Animal Feed Science and Technology” will also be considered. Financial support from the COST Action Feed for Health will be acknowledged in the final submitted manuscripts.

Hasliza Abu Hassim STSM
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