Liew Kok Jun, Teo Seng Chong, Shamsir Mohd Shahir, Sani Rajesh Kumar, Chong Chun Shiong, Chan Kok-Gan, Goh Kian Mau
1Faculty of Science, Universiti Teknologi Malaysia, 81300 Skudai, Johor Malaysia.
2Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, USA.
3 Biotech. 2018 Aug;8(8):376. doi: 10.1007/s13205-018-1391-z. Epub 2018 Aug 13.
bacterium RA is a halo-thermophile isolated from a saline hot spring. Previously, the genome of this bacterium was sequenced using a HiSeq 2500 platform culminating in 91 contigs. In this report, we report on the resequencing of its complete genome using a PacBio RSII platform. The genome has a GC content of 68.3%, is 4,653,222 bp in size, and encodes 3711 genes. We are interested in understanding the carbohydrate metabolic pathway, in particular the lignocellulosic biomass degradation pathway. Strain RA harbors 57 glycosyl hydrolase (GH) genes that are affiliated with 30 families. The bacterium consists of cellulose-acting (GH 3, 5, 9, and 44) and hemicellulose-acting enzymes (GH 3, 10, and 43). A crude cell-free extract of the bacterium exhibited endoglucanase, xylanase, β-glucosidase, and β-xylosidase activities. The complete genome information coupled with biochemical assays confirms that strain RA is able to degrade cellulose and xylan. Therefore, strain RA is another excellent member of family as a repository of novel and thermostable cellulolytic and hemicellulolytic enzymes.
细菌RA是一种从盐温泉中分离出的嗜盐嗜热菌。此前，该细菌的基因组使用HiSeq 2500平台进行测序，最终得到91个重叠群。在本报告中，我们报道了使用PacBio RSII平台对其完整基因组进行的重测序。该基因组的GC含量为68.3%，大小为4,653,222 bp，编码3711个基因。我们感兴趣的是了解碳水化合物代谢途径，特别是木质纤维素生物质降解途径。菌株RA含有57个糖基水解酶（GH）基因，这些基因隶属于30个家族。该细菌由作用于纤维素的酶（GH 3、5、9和44）和作用于半纤维素的酶（GH 3、10和43）组成。该细菌的粗无细胞提取物表现出内切葡聚糖酶、木聚糖酶、β-葡萄糖苷酶和β-木糖苷酶活性。完整的基因组信息以及生化分析证实菌株RA能够降解纤维素和木聚糖。因此，菌株RA作为新型和热稳定的纤维素分解酶和半纤维素分解酶的储存库，是该家族的另一个优秀成员。
