Projects / Programmes source: ARRS

Investigation of mechanims of plant extracts impact on growth and metabolism of gut microorganisms

Research activity

Code Science Field Subfield
4.02.00  Biotechnical sciences  Animal production   

Code Science Field
B400  Biomedical sciences  Zootechny, animal husbandry, breeding 
plant extracts, gastrointestinal tract, microorganisms, food and feed additives, antibiotics
Evaluation (rules)
source: COBISS
Researchers (15)
no. Code Name and surname Research area Role Period No. of publications
1.  19485  PhD Tomaž Accetto  Animal production  Researcher  2007 - 2009  159 
2.  13654  PhD Jerneja Ambrožič Avguštin  Biochemistry and molecular biology  Researcher  2007 - 2009  233 
3.  08320  PhD Gorazd Avguštin  Animal production  Principal Researcher  2007 - 2009  351 
4.  21437  PhD Tadej Čepeljnik  Biotechnology  Researcher  2007  51 
5.  11765  PhD Lijana Fanedl  Animal production  Researcher  2007 - 2009  98 
6.  23439  PhD Gregor Gorenc  Animal production  Junior researcher  2007 
7.  25515  PhD Sebastijan Hobor  Biotechnology  Researcher  2009  14 
8.  28504  Nina Klemenčič  Animal production  Junior researcher  2007 
9.  24296  PhD Darja Kušar  Veterinarian medicine  Junior researcher  2007 - 2008  179 
10.  08404  PhD Romana Marinšek Logar  Animal production  Researcher  2007 - 2009  501 
11.  03098  PhD Franc-Viktor Nekrep  Animal production  Researcher  2007 - 2008  196 
12.  29429  PhD Katarina Rajapakse  Biotechnology  Junior researcher  2008 - 2009  17 
13.  19104  PhD Blaž Stres  Animal production  Researcher  2008  348 
14.  28851  PhD Maša Vodovnik  Animal production  Researcher  2007 - 2009  99 
15.  17864  PhD Maša Zorec  Animal production  Researcher  2007 - 2009  68 
Organisations (1)
no. Code Research organisation City Registration number No. of publications
1.  0481  University of Ljubljana, Biotechnical Faculty  Ljubljana  1626914  64,118 
Some plant extracts are already used as feed additives in the developed European countries (developed in terms of the state of the animal breeding technology) in order to enhance animal performance. The market for so called natural phytoactive compounds and their use will presumably grow substantially since the ban on the use of some growth enhancers, predominately feed antibiotics in EU, in 2006. The mechanisms of action of the phytoactive compounds remain unknown in vast majority, however, as well as possible side effects and the emergence of resistance towards them. Within the proposed project we intend to investigate the mechanism of action of some of the plant extracts on growth and metabolism of gut microorganisms. As investigation objects bacterial species are going to be used that represent on one hand the most prominent and abundant microbial populations in the animal gut and were at the same time found to be acceptable to the plant extracts effects during the preliminary studies. Growth of chosen bacteria in the presence of certain plant extracts is going to be analyzed from various points of view and subsequently metabolism is going to be studied via gene and protein expression. A combination of microbiological, biochemical and genetic and molecular biological approaches will hopefully make possible the elucidation of the action of some plant extracts in at least some of the model cases.
Significance for science
Ruminants have the ability to convert the low-quality product into nutritionally rich food for human consumption. The complex microbial communities in the rumen make that conversion possible. The rate of productivity in ruminant breeding systems is determined by the efficiency of rumen microbial fermentations, and in intensive animal production systems optimization means among others also manipulation of rumen fermentation. The most effective direct manipulation is achieved by by rumen microbial symbionts modifiers. The first successfully used rumen modifiers include antibiotics such as monensin, but their use is prohibited since 1st January 2006 in the European Community because of the possibility of their accumulation in milk and meat, and fear of selection and transfer of antibiotic resistances to pathogenic bacterial species. Plant secondary metabolites appear to be appropriate replacement for antibiotic feed additives, since they have been used for centuries in medicine and constitute a reservoir of potentially useful bioactive substances. Unlike the ruminant microbial fermentation which takes place before the actual stomach in monogastric herbivores such as rabbits, the major microbial degradation takes place in the caecum. The content and digestibility of feed proteins are the most important factors in rabbits feeding formulas which may influence with the addition of certain antinutritivnimi factors such as tannins and some other feed additives. To obtain a permission for the commercial use of selected plant extracts and its bioactive components in animal nutrition it is necessary to understand the mechanisms the underlay the sensitivity of the main microbial groups in the gut towards these substances, the minimum inhibitory concentration, the mechanisms of their action, and more. The most appropriate approach to assessing the suitability of plant extracts as alternative feed additives include molecular biology techniques in combination with traditional microbiological and biochemical methods. A relatively small proportion of bioactive plant extracts or components have been previously analysed in biological as well as chemical sense. Given the importance of manipulation of fermentation in the digestive tract of ruminants and monogastric animals using natural ingredients, we have analyzed the effect of garlic extract and its components, as well as cinamaldehyde and eugenol from cinnamon, which have shown potential as alternatives to feed antibiotics, on selected bacterial and archaeal rumen strains in pure cultures, and on the composition of the microbial community from the dual flow reactor systems and in vivo animal gut samples. We have also analyzed the impact of tannins on the microbial community from the caecum of rabbits. In this project we have examined the manner and scope of activity of plant extracts at the cellular and microbial community level in terms of identifying target species. We came across significant discoveries that not only represent a novelty in Slovenian terms but also globally.
Significance for the country
Among the main objectives of the project group J4-9409 “The study of the impact mechanism of plant extracts on growth and metabolism of microorganisms from the digestive tract” is the support of the educational process at the graduate as well as postgraduate level, in accordance with the mission of the institution to which they belong. Thus, graduate students of Food technology, Biotechnology, Microbiology and Zootechnics as well as postgraduate students of Interdisciplinary doctoral programmes Biosciences, Biomedicine and Environmental protection can experience an insider view and even direct involvement into the results of our studies. At the same time the proposed research programme provides possibilities for acquiring new skills in one of the most important areas, i.e. production and supply of safe food, which falls within the first priority set by the Research Agency of the Republic of Slovenia i.e. Research in genomics and biotechnology for health, food quality and safety and sustainable development. This kind of production should be based on safe resources regarding health and should be implemented in the paradigm of sustainable production. The results of this research will contribute to greater awareness, better nutrition and therefore health status of the population in Slovenia. Research that we conducted with plant extracts is also interesting for Slovenian producers of plant extracts, feed as well as domestic animals breeders, as our research results provide the first scientific findings that may explain the in vivo activity of natural plant extracts in animal nutrition. They also show their potential as feed additives to improve the quality and stability of animal products and open possibilities for creating or marketing of such functional foods. There are also important findings regarding their use for minimizing the effects on the environment. They also offer insights that may in future represent a good basis for their use in human nutrition.
Most important scientific results Annual report 2008, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2008, final report, complete report on dLib.si
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