title: High antioxidant and DNA protection activities of N-acetylglucosamine (GlcNAc) and chitobiose produced by exolytic chitinase from Bacillus cereus EW5.
abstract: Chitin-degrading bacterial strains were screened and tested for their ability to degrade shrimp-shell waste (SSW). Among the potential strains, B. cereus EW5 exhibited the highest chitin-degrading ability compared with other strains and produced 24 mg of reducing sugar per gram of dry SSW after 4 days of incubation. A TLC analysis of SSW biodegradation revealed that the chitosaccharides produced in the culture supernatant were mainly N-acetylglucosamine (GlcNAc) and chitobiose due to the isolate's exolytic chitinase activity. The culture supernatant exhibited a high degree of antioxidant activity, as indicated by 83% DPPH, 99.6% ABTS, 51% hydroxyl radical scavenging activity and 0.34 reducing power. The formation of GlcNAc and chitobiose during biodegradation of SSW is considered to be the major contributor to the antioxidant activity. The EW5 culture supernatant also displayed inhibition of DNA damage, enhancing the reutilization value of SSW. This report presents the first description of fermented production of GlcNAc and DNA protective activity of culture supernatant from SSW by B. cereus.
authors: Department of Biotechnology, Pukyong National University, 45 Yongso-Ro, Nam-Gu, Busan, 608-737 Korea.
authors: Mohammed Shariful
authors: MS
authors: Azam
authors: Department of Biotechnology, Pukyong National University, 45 Yongso-Ro, Nam-Gu, Busan, 608-737 Korea.
authors: Eun Jung
authors: EJ
authors: Kim
authors: Department of Oceanography, Environmental and Marine Sciences and Technology, Pukyong National University, 45 Yongso-Ro, Nam-Gu, Busan, 608-737 Korea.
authors: Han-Soeb
authors: HS
authors: Yang
authors: Department of Biotechnology, Pukyong National University, 45 Yongso-Ro, Nam-Gu, Busan, 608-737 Korea.
authors: Joong Kyun
authors: JK
authors: Kim
keywords: Antioxidant; Bacillus cereus; DNA protection; Exochitinase; GlcNAc