Department of Biochemistry, Kurukshetra University, Kurukshetra 136 119, India.
N Biotechnol. 2011 Oct;28(6):581-7. doi: 10.1016/j.nbt.2010.12.004. Epub 2011 Jan 11.
High level production of an extracellular cellulase-poor alkali stable xylanase has been conceded from newly isolated Bacillus pumilus SV-85S under solid state fermentation using wheat bran as a substrate. Optimization of the fermentation conditions enhanced the enzyme production to 73,000 ± 1,000 IU/g dry substrate, which was 13.8-fold higher than unoptimized conditions (5,300 IU/g). The enzyme titre was highest after 48 h of incubation at 30°C with 1:3 ratios of substrate to moistening agent using wheat bran as a carbon source. The enzyme could be produced in significant levels by using either tap water or distilled water alone as a moistening agent. An elevated production of xylanase by B. pumilus SV-85S in the presence of wheat bran, a cheap and easily available agro-residue, in shorter duration would apparently reduce the enzyme cost substantially. The enzyme was completely stable over a broad pH (5-11) range and retained 52% of its activity at a temperature of 70°C for 30 min. The desired characteristics of this enzyme together with economic production would be important for its application in paper and pulp industry.
高产胞外纤维素酶缺乏型耐碱木聚糖酶的毕赤酵母 SV-85S 菌株在固态发酵条件下,以麦麸为底物,可实现该酶的高效表达。发酵条件的优化使酶产量提高到 73,000 ± 1,000 IU/g 干底物,比未优化条件下(5,300 IU/g)提高了 13.8 倍。在 30°C 下,以麦麸为碳源,底物与润湿剂的比例为 1:3,发酵 48 h 时酶活最高。单独使用自来水或蒸馏水作为润湿剂,均可以显著产酶。毕赤酵母 SV-85S 在廉价易得的农业废弃物麦麸存在的情况下,可以在较短的时间内大量产生木聚糖酶,显然会大大降低酶的成本。该酶在较宽的 pH(5-11)范围内完全稳定,在 70°C 下保温 30 min 后仍保留 52%的活性。该酶具有所需的特性和经济生产能力,将在造纸和纸浆工业中有重要的应用价值。