Reuse of red seaweed waste by a novel bacterium, Bacillus sp. SYR4 isolated from a sandbar

A potent bacterial strain was isolated from a sandbar and identified as Bacillus sp. SYR4 for the reuse of red seaweed waste. The isolate possessed both agarase and carrageenase activities. The optimal pH and temperature for the degradation of both agar and carrageenan by the isolate were found to be pH 7.5 and 30 °C, respectively. The effects of cations on cell growth and degradation ability of the isolate were significant in comparison with controls. The isolate produced 0.27 and 0.29 g l⁻¹of reducing sugars from 1 g l⁻¹of agar and carrageenan, respectively. When the isolate was cultivated in red seaweed powder medium for 10 days, the yield of reducing sugars was 24 %. As a result, the eco-friendly reuse of red seaweed waste by this isolate appears to be feasible for the production of reducing sugars and could be a valuable resource. To the best of our knowledge, this is the first study to directly demonstrate the ability of Bacillus sp. SYR4 to degrade both agar and carrageenan.