Department of Molecular Biotechnology and Bioinformatics, Faculty of Science, Prince of Songkla University, Hat Yai 90112, Thailand.
Carbohydr Polym. 2013 Jan 30;92(1):421-8. doi: 10.1016/j.carbpol.2012.09.017. Epub 2012 Sep 16.
A total of 59 bacterial strains were isolated from ripe fruits and vegetables and tested for their ability to produce cellulose. Only one identified as Rhodococcus sp. MI 2 based on its taxonomic characteristics and 16S rDNA sequence analysis. The glucose was the only product of digestion by cellulase confirmed by TLC and reversed phase HPLC. Rhodococcus sp. MI 2 produced significantly more cellulose with the SH medium containing glucose than with the coconut juice medium. Rhodococcus sp. MI 2 initially produced 3.91 ± 0.091, 2.20 ± 0.090 and 0.19 ± 0.051 g/L/6 days cellulose under static, agitated and stirred conditions, respectively, whereas A. xylinum 998 produced 1.17 ± 0.065, 1.34 ± 0.115 and 0.12 ± 0.046 g/L/6 days cellulose under the same conditions, respectively. The optimum culture conditions for cellulose production in SH medium were room temperature (25 °C), a 5% (v/v) inoculum, peptone 0.7%, yeast extract 0.9%, and sucrose 1.5%, at a pH of 3.5. The cellulose yield was increased by adding 0.5% CaCO(3) to the SH medium with sucrose but added agar had no effect. The cellulose yield under optimum and static conditions was increased about twice, from 3.7 to 7.4 g/L/14 days.
从成熟的水果和蔬菜中分离出 59 株细菌菌株，并测试其产生纤维素的能力。只有一株根据其分类特征和 16S rDNA 序列分析鉴定为 Rhodococcus sp. MI 2。通过 TLC 和反相 HPLC 确认纤维素酶的唯一产物是葡萄糖。与椰子汁培养基相比，Rhodococcus sp. MI 2 在含有葡萄糖的 SH 培养基中产生的纤维素明显更多。Rhodococcus sp. MI 2 在静态、搅拌和搅拌条件下分别最初产生 3.91±0.091、2.20±0.090 和 0.19±0.051 g/L/6 天纤维素，而 A. xylinum 998 分别在相同条件下产生 1.17±0.065、1.34±0.115 和 0.12±0.046 g/L/6 天纤维素。在 SH 培养基中生产纤维素的最佳培养条件为室温（25°C）、5%（v/v）接种量、蛋白胨 0.7%、酵母提取物 0.9%和蔗糖 1.5%，pH 值为 3.5。在含有蔗糖的 SH 培养基中添加 0.5%CaCO(3)可提高纤维素产量，但添加琼脂则没有影响。在最佳和静态条件下，纤维素产量增加了约两倍，从 3.7 增加到 7.4 g/L/14 天。
