[en] Full text: Micro-instabilities, such as Ion Temperature Gradient modes (ITG) and Collisionless Trapped Electrons Modes (CTEM), are commonly held responsible for anomalous transport observed in tokamaks. While there have been a wide range of nonlinear studies on ITG turbulence, very little is known about the nonlinear physics of CTEM. This work presents the first linear and nonlinear simulations of ITG-CTEM turbulence performed with the global PIC code ORB5. The originality of this code is the use of a field-aligned Fourier technique and a noise-control algorithm that allows long, statistically converged simulations. The code, originally written using the adiabatic electrons assumption, has been extended to study TEM turbulence. The model, which assumes drift-kinetic trapped electrons and adiabatic passing electrons will be discussed. In particular, the role of the trapped-passing boundary will be examined. A linear benchmark of ORB5 against other gyrokinetic codes will be shown. Then, nonlinear simulations, motivated by [3], will focus on the role of zonal flows on heat transport. (author)