Paper Title
Biobleaching Property of Β-1,4-Xylanase from a Novel Mangrove Associated Actinobacterium Streptomyces Olivaceus (Msu3) Using Pretreated Rice Straw Pulp

The efficacy of biobleaching property of xylanasefrom amangrove associated actinobacteriumStreptomyces olivaceus (MSU3)was studied using rice straw pulp. Previously, the rice straw pulp waspretreated with different concentrations of xylanase(20 to 120IU)and titanium dioxide(0.1 to 0.8g)separately under laboratory condition. In bleaching process, the maximum reduction level of kappa number (15.68k), reducing sugar (112.32mg/g), degree of brightness (40.17ISO), residual lignin level (2.35%), release of phenolic (λ2370.1218OD) and hydrophobic (λ4650.0421OD)groupswere achieved in 100IU xylanasemediated bleaching than titanium dioxide bleaching, respectively atthe optimized conditions of pH 7, temperature 40°C and incubation time of 3h. Finally, the bleaching efficiency of pretreated pulp samples with surface cell disruption wasanalyzed through scanning electron microscope. The significant surface cell porosity modifications were observed in xylanase treated straw pulp rather than titanium dioxide treated pulp. Based on the result, it could be confirmed that the xylanase from the selected actinobacteriumcan able to efficiently bleach the straw pulp than the chemical mediated bleaching. Key words - Bleaching,Rice straw pulp,Streptomycessp, Titanium dioxide, Xylanase