Biohydrogen production from seagrass (SG) has gained much attention due to their chemical composition (carbohydrate rich biomass). In this study, an attempt was made to enhance the biohydrogen production from sea grass through novel ozone coupled rotor-stator homogenization (ORSH). The efficiency of the homogenization pretreatment was evaluated in terms of seagrass lysis and biohydrogen generation. Initially, sea grass was subjected to rotor-stator homogenization (RSH) to optimize its power input (5.4-19.1 W) and energy spent (0-1285 kJ/kg TS). RSH consumes specific energy of 510 kJ/kg TS to achieve seagrass lysis of 10.45%, whereas ORSH achieved 23.7% of seagrass lysis at less energy (212.4 kJ/kg TS) input. The outcome of the present study reveals ORSH reduced 58.3% of energy input and increased 55.9% of SG lysis when compared with RSH. Hence, a considerable amount of energy could be saved through this combinative pretreatment. Biohydrogenesis was done to evaluate and compare the biohydrogen production potential of ORSH sample. Higher ultimate biohydrogen production was achieved by ORSH (90.7 mL/g COD) than RSH (39.6 mL/g COD). A higher energy ratio of 1.17 could be achieved through ORSH. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.