Structural properties and biological activities of the extracellular polysaccharide of Bacillus subtilis LZ13-4

• Published in: International journal of biological macromolecules Vol. 259; no. Pt 1; p. 129176
• Main Authors: Yan, Chunyue, Ji, Shuaiqi, Wu, Rina, Li, Mo, He, Kairu, Shi, Haisu, Wang, Cong, Yang, Hui, Guo, Jia, Wu, Junrui
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2024
• Subjects: Antioxidants - chemistry; Bacillus subtilis - metabolism; Bacillus subtilis LZ13-4; Exopolysaccharides; Fructose; Functional activity; Galactose; Glucose; Polysaccharides - chemistry; Exopolysaccharides; Functional activity; Bacillus subtilis LZ13-4
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.129176

The remarkable functional characteristics of Bacillus subtilis extracellular polysaccharides (BSPS) are of great interest. Therefore, in the present study, BSPS was isolated and characterized to obtain two fractions, BSPS-1 and BSPS-2, respectively, and to investigate their biological activities. BSPS-1 contained fructose, glucose, and galactose (molar ratio: 25.27:43.37:31.36), while BSPS-2 contained fructose with only trace amounts of glucose, galactose, and mannose (molar ratio: 55.08:19.03:19.21:6.68), and their respective average molecular weights were 16.9 kDa and 202.67 kDa. With a 93.55 % clearance of ABTS•+ at a concentration of 2 mg/mL of BSPS-1, the antioxidant activity revealed that BSPS-1 had greater antioxidant activity than BSPS-2 and that both were concentration-dependent. The inhibitory effect on HepG2 cells demonstrated that BSPS-1 and BSPS-2 significantly inhibited the proliferation of HepG2 and increased the expression of apoptotic proteins, causing apoptosis. The inhibition rate on HepG2 cells was dose-dependent and reached 52.7 % and 40.3 % after 48 h of action. BSPS-2 and 800 μg/mL BSPS-1 growth was inhibited in the G1/G0 phase, while 200 and 400 μg/mL BSPS-1 growth was inhibited in the S phase. In conclusion, the study of the BSPS's structure and properties can offer a theoretical foundation for real-world industrial applications. •BSPS-1 and BSPS-2 were first isolated from Bacillus subtilis LZ13-4.•BSPS-1 consists of fructose, glucose and galactose and BSPS-2 consists of fructose, glucose, galactose and mannose.•BSPS-1 showed potential antioxidant activity and better anticancer activity.