Butyric acid production from brown algae using Clostridium tyrobutyricum strains

Abstract

Butyric acid was produced from brown algae (Laminaria japonica) even without pretreatment by the enriched cultures using a tidal flat sediment sample from Ganghwa Island, South Korea as an inoculum. The structure of the microbial community in butyric acid-producing cultures suggested that Clostridium spp. were major producers of butyric acid using brown algae. To evaluate butyric acid-producing ability of Clostridium strains using brown algae without pretreatment, 13 strains of C. tyrobutyricum were selected and cultivated in the mineral base medium containing brown algae. Butyric acid was produced in a range of 0.2 ~ 1.8 g/L by the tested strains. Among them, C. tyrobutyricum DSM 664 (1.8 g/L) and C. tyrobutyricum DSM 1460 (1.7 g/L) showed the highest butyric acid production after 48 hours from 40 g/L brown algae. As mannitol was detected as a main carbohydrate, both strains were tested for butyric acid production using mannitol as a carbon source. As a result, C. tyrobutyricum DSM 664 and DSM 1460 produced 5.7 g/L and 7.3 g/L of butyric acid, respectively, in the mineral medium containing mannitol 20 g/L, suggesting that those two strains are candidates for butyric acid production using brown algae without pretreatment.