Dr. Marian P. De Leon is the Director of the University of the Philippines Los Baños (UPLB) Museum of Natural History and concurrently serves as Assistant to the Vice Chancellor for Research and Extension. She is a University Researcher and Curator of the UPLB MNH Microbial Culture Collection.

A pioneer in cave microbiology, Dr. De Leon has extensively explored cave microorganisms for potential applications in antibiotics, enzymes, and pigments. Her groundbreaking research has been published internationally, fostering collaborations with global experts. She leads the DOST-PCAARRD funded program Center for Caves Ecosystem Research (CAVES), a Niche Center for Regional R&D in CALABARZON.

Dr. De Leon was appointed as a Visiting Associate Professor at Osaka University in 2018 and was conferred as a Certified Biosafety Officer by the National Training Center for Biosafety and Biosecurity and the US Department of State Biosecurity Engagement Program in 2018. Recognized by the Philippine Academy of Microbiology as a Registered Microbiologist, she holds leadership positions in the National Research Council of the Philippines, Philippine Society for Microbiology, and the Philippine Network of Microbial Culture Collections.

Dr. De Leon earned her BS in Food Technology (Microbiology) and MS in Food Science (Biochemistry) from UPLB, followed by a PhD in Engineering (Material and Life Science) from Osaka University. She was a Post-Doctoral Fellow at UP NSRI and DA-BAR.