Johan Baars started his academic career as a microbiologist at Radboud University in Nijmegen (Netherlands). He obtained his Ph.D. in 1996 investigating nitrogen metabolism of Agaricus bisporus. From there he moved to the Mushroom Experimental Station in Horst (Netherlands) to join in on a project involving the construction of a genomic map of the white button mushroom Agaricus bisporus. In 2001 he became a researcher at the department “Genetics, breeding and bioactive components” of WUR-PPO-Paddenstoelen. In this position he worked in projects aimed at cultivation and breeding of mushrooms (mainly Agaricus bisporus and Pleurotus ostreatus). During that period he obtained a plant patent for a sporeless strain of Oyster mushroom which is now marketed in the European Union by the name of SPOPPO.

In 2006 he became a researcher at WUR Plant Breeding, Mushroom Research Group. In this position he worked on projects aimed at cultivation and breeding of mushrooms, on crop protection using natural products and participated in a EU funded project that tries to find solutions for Trichoderma green mould or virus X infections in the mushroom industry. Furthermore, he is involved in projects that focus on the utilization of nutrients from substrates, both for Agaricus bisporus and white rot fungi.

In 2013 he was posted in a part time position as researcher at CNC, one of the largest producers of mushroom substrate in the Netherlands.