In the present study, an attempt was made to examine the potential of mesophilic bacteria in degradation of poly lactic acid (PLA) plastic. A total of five isolates (MS1 to MS5) were screened from compost sample at mesophilic temperature. The degradation of PLA was studied by weight loss of PLA film, pH of the medium and change in toe levels. The weight loss of PLA film ranged from 10% to 45.5% with different isolates indicating the effect of compost mesophiles on the degradation of PLA. The scanning electron micrographs showed that the bacilli were able to adhere on the polymer surface and the film found to be rough with irregular holes on comparison with uninoculated PLA film. Based on the zone of hydrolysis on emulsified PLA agar plates, the isolate MS-2 was selected for further identification. Biochemical characteristics and 16Sr RNA based phylogenetic analysis revealed the isolated organisms Bacillus amyloliliquefaciens. The results showed the proteasetype of PLA depolymerase in Bacillus amyloliliquefaciens and it may be utilised for the degradation PLA plastic under mesophilic conditions