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A cellulase-free xylanase production by Thermomyces lanuginosus SSBP using bagasse pulp was examined under submerged (SmC) and solid-state cultivation (SSC). Higher level of xylanase activity (19,320 +/- 37 U g(-1) dried carbon source) was obtained in SSC cultures than in SmC (1,772 +/- 15 U g(-1) dried carbon source) after 120 h with 10% inoculum. The biobleaching efficacy of crude xylanase was tested on bagasse pulp, and the maximum brightness of 46.1 +/- 0.06% was observed with 50 U of crude xylanase per gram of pulp, which was 3.8 points higher than the brightness of untreated samples. Reducing sugars (26 +/- 0.1 mg g(-1)) and UV-absorbing lignin-derived compounds in the pulp filtrates were observed as maximum in 50 U of crude xylanase-treated samples. T. lanuginosus SSBP has potential applications due to its high productivity of xylanase and its efficiency in pulp bleaching.

Glycerol, a non-biodegradable by-product during biodiesel production is a major concern to the emerging biodiesel industry. Many microbes in natural environments have the ability to utilize glycerol as a sole carbon and energy source. The focus of this study was to screen for microorganisms from soil, capable of glycerol utilization and its conversion to value added products such as ethanol and 1,3-propanediol (1,3-PDO). Twelve bacterial isolates were screened for glycerol utilization ability in shake flask fermentations using M9 media supplemented with analytical grade glycerol (30 g/L) at various pH values (6, 7 and 8) and temperatures (30°C, 35°C and 40°C). Among these, six bacterial isolates (SM1, SM3, SM4, SM5, SM7 and SM8) with high glycerol degradation efficiency (>80%) were selected for further analysis. Highest level of 1,3-PDO production (15 g/L) was observed with isolate SM7 at pH 7 and 30°C, while superior ethanol production (14 g/L) was achieved by isolate SM9 at pH 8 and 35°C, at a glycerol concentration of 30 g/L. The selected strains were further evaluated for their bioconversion efficiency at elevated glycerol concentrations (50-110 g/L). Maximum 1,3-PDO production (46 g/L and 35 g/L) was achieved at a glycerol concentration of 70 g/L by isolates SM4 and SM7 respectively, with high glycerol degradation efficiency (>90). Three isolates (SM4, SM5 and SM7) also showed greater glycerol tolerance (up to 110 g/L). The isolates SM4 and SM7 were identified as Klebsiella pneumoniae and SM5 as Enterobacter aerogenes by 16S rDNA analysis. These novel isolates with greater glycerol tolerance could be used for the biodegradation of glycerol waste generated from the biodiesel industry into value-added commercial products.

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