Identification and transcriptional analysis of poly(cis-1,4-isoprene) degradation gene in Rhodococcus sp. strain RDE2
Identification and transcriptional analysis of poly(cis-1,4-isoprene) degradation gene in Rhodococcus sp. strain RDE2
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DOI：
10.1016/j.jbiosc.2022.01.013
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发表时间：
2022-04-08
影响因子：
2.8
通讯作者：
Kasai, Daisuke
中科院分区：
文献类型：
--
作者：
Gibu, Namiko;Linh, Dao Viet;Kasai, Daisuke
合成和天然聚（顺式-1,4-异戊二烯）橡胶的微生物降解有望成为聚（顺式-1,4-异戊二烯）产品废物（如废轮胎）的替代处理技术。从越南一家橡胶加工厂的废料中分离出革兰氏阳性橡胶降解细菌RDE2红球菌。该菌株以天然橡胶为唯一的碳和能量来源，并产生含有聚顺-1,4-异戊二烯醛基的低聚类异戊二烯代谢物。为了确定聚（顺式- 1,4-异戊二烯）降解的基因，测定了该菌株的全基因组序列。全基因组序列包括5715406 bp的染色体和6个质粒（GenBank登录号AP025186.1 ~ AP025192.1），平均GC含量为67.9%。基因组包含5358个蛋白质编码序列，rRNA和tRNA基因分别有12个和68个拷贝。基于基因组序列分析，确定了lcp基因（RDE2_08,770），该基因负责poly（cis-1,4-异戊二烯）降解的初始步骤。从大肠杆菌中获得的基因产物将聚（顺式-1,4-异戊二烯）解聚为低分子量的低聚类异戊二烯。该基因的转录在菌株RDE2利用聚顺式-1,4-异戊二烯时被激活。lcpR基因（RDE2_08,760）位于lcp的上游，编码一种推测的转录调节因子。lcpR基因产物识别lcp的启动子区域。当lcpR基因被删除时，观察到lcp的组成性转录。因此，我们推断LcpR负调控lcp的转录。这些结果表明lcp和lcpR基因参与了菌株RDE2对聚顺式- 1,4-异戊二烯的利用。(c) 2022，日本生物技术学会。版权所有。
Available online 23 February 2022 The microbial degradation of synthetic and natural poly(cis-1,4-isoprene) rubber is expected to become an alternative treatment technique for waste from poly(cis-1,4-isoprene) products, such as scrap tires. A gram-positive rubber degrading bacterium, Rhodococcus sp. strain RDE2, was isolated from the waste of a rubber-processing factory in Vietnam. This strain grew on natural rubber as a sole source of carbon and energy and produced oligo-isoprenoid metabolites containing aldehyde groups from poly(cis-1,4-isoprene). To identify the genes responsible for poly(cis- 1,4-isoprene) degradation, the complete genome sequence of this strain was determined. The complete genome sequence consists of a 5,715,406 bp chromosome and 6 plasmids (GenBank accession numbers AP025186.1 to AP025192.1) with an average GC content of 67.9%. The genome contains 5358 protein-coding sequences and 12 and 68 copies of rRNA and tRNA genes, respectively. Based on genome sequence analysis, the lcp gene (RDE2_08,770), responsible for the initial step of poly(cis-1,4-isoprene) degradation, was identified. The gene product obtained from Escherichia coli depolymerizes poly(cis-1,4-isoprene) to low-molecular-weight oligo-isoprenoids. The transcription of this gene is activated during the utilization of poly(cis-1,4-isoprene) in strain RDE2. The lcpR gene (RDE2_08,760), which encodes a putative transcriptional regulator, is located upstream of lcp. The lcpR gene product recognizes the promoter region of lcp. When the lcpR gene is deleted, the constitutive transcription of lcp is observed. Thus, it is inferred that the LcpR negatively regulates lcp transcription. These results strongly suggest that the lcp and lcpR genes are involved in poly(cis- 1,4-isoprene) utilization in strain RDE2. (c) 2022, The Society for Biotechnology, Japan. All rights reserved.