| Abstrakt: |
Exopolysaccharides or extracellular polymeric substances (EPS) has become an important resource and is being increasingly used in the biotechnology and biopharmaceutical industries. However, its production from glycerol under thermophilic conditions has not been reported. This study is aimed at isolating high-performance, EPS-producing bacteria under thermophilic conditions using glycerol as the substrate. Among the isolated microorganisms, Bacillus sonorensisstrain NTV10 exhibited the highest EPS production. The optimum cultivation conditions in the enrichment medium (HS medium) were 1 g/L glycerol, 45 °C, and pH 7, with the highest EPS production of 15.97 mg/mL. We confirmed that NTV10 prefers thermophilic conditions for the highest EPS production. However, the utilization of glycerol was low because of the presence of yeast extracts and peptone in the HS medium. Therefore, the ability of glycerol conversion into EPS by NTV10 was evaluated using minimal medium (medium E*). We found that 15 g/L glycerol exhibited the highest EPS production (8.8 mg/mL). The monosaccharide composition of EPS from both media was similar, containing glucose, mannose, and rhamnose in a relative ratio of 5.1:2.2:1. The results of the IR spectrum showed the presence of mainly carboxyl and hydroxyl groups in the EPS product, which was in accordance with the monosaccharide composition. These properties can be applied in various industries such as food processing, cosmetics, and pharmaceuticals. The experimental knowledge derived from this study can be used to promote the use of glycerol as a renewable substrate for bioconversion into highly valuable products, such as EPS production. |
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