Trontelj received the highest national decoration for his lifetime work in ethics and for the promotion of the international recognition of Slovenian medical expertise.
Opeka was meanwhile commended for his exceptional contribution to humanitarian work and to the social and theological discourse.
President Tuerk said that Trontelj and Opeka had each in their respective fields done a lot to improve society. "Slovenia is grateful to them for this," he said.
Trontelj, a neurology professor who has also been active in the field of medical ethics, noted that it would be often more right to give a recognition to the achievement, rather than the person. "The person behind the achievement is less important, possibly even unimportant."
Missionary Opeka offered his view of the fight against poverty, noting that this can only be done "if you are amidst poor people, rather than far from them...if you don't give them advice, but live, feel, work and rise with them".
"If there is no justice, if man is not respected and listened to, there will be no peace," Opeka said. His estimate is that more than one billion people live below the poverty line today, which he termed a disgrace for entire humanity.
Born in 1939, Trontelj graduated from the Ljubljana Faculty of Medicine and then specialised in neuropsychiatry. He earned his doctor's degree in motor neuron physiology and continued his studies in the US and Sweden.
As a neurology professor at the Ljubljana Academy of Medicine he has authored a number of articles for students and doctors, specialising on physiology and neurology. For more than 30 years he has been heading neurophysiology and neurology studies at Higher School for Medical Workers.
Clinical neurophysiology has witnessed a turbulent development in the past 40 years and Trontelj has introduced several improvements in the field of clinic electromyography, the presidential's office said in the explanation of the decoration.
At the invitation of the Kuwaiti Ministry of Health he has organised a neurophysiology department there, which has been a successful bond between Slovenian and Kuwait health care for decades.
Trontelj has also headed the National Medical Ethics Committee of Slovenia, and was appointed a Slovenian science ambassador in 2003. He was appointed to the helm of SATO in April 2008 .
Pedro Opeka was born in Buenos Aires in 1948. He joined the Lazarian missionary society in 1966. He studied theology in Ljubljana, but completed his studies at the Catholic Institute in Paris. He has been living and working in Madagascar since 1976.
He is one of the most prominent and charismatic humanitarian workers, who understands and works for the respect of human rights and decent survival of even the world's poorest people, the presidential office pointed out.
Opeka has earned international acclaim with his humanitarian project for the most marginalised group of population in Madagascar's capital of Antananarivo. He has founded several humanitarian associations, rescuing thousands of children form rubbish dumps.
His integration into the Madagascar society, his astute sense of justice and his candid, respectful, deeply ethical and religious attitude have contributed greatly to the success of his projects, the presidential office said.
He has received many awards for his work and is one of the best known Slovenians in the world. As a former student of the Ljubljana Faculty of Theology, he is representing this institution, Slovenia and its culture in the best possible was with his work.
Head of the Slovenian Bishops' Conference Alojz Uran expressed pleasure on behalf of Slovenian bishops that the state had given recognition to the missionary work of Opeka and his aides and for the Church's contribution to the poor of the third world.