Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan.
Biosci Biotechnol Biochem. 2020 Jun;84(6):1089-1097. doi: 10.1080/09168451.2020.1733927. Epub 2020 Feb 29.
Natural rubber and synthetic poly(-1,4-isoprene) are used industrially in the world. Microbial utilization for the isoprene rubbers has been reported in gram-positive and gram-negative bacteria. Poly(-1,4-isoprene)-cleavage enzymes that are secreted by rubber-utilizing bacteria cleave the poly(-1,4-isoprene) chain to generate low-molecular-weight oligo(-1,4-isoprene) derivatives containing aldehyde and ketone groups. The resulting products are converted to the compounds including carboxyl groups, which could then be further catabolized through β-oxidation pathway. One of poly(-1,4-isoprene)-cleavage enzymes is latex-clearing protein (Lcp) that was found in gram-positive rubber degraders including , and species. The other one is rubber oxygenase A and B (RoxA/RoxB) which have been identified from gram-negative rubber degraders such as and . Recently, the transcriptional regulation mechanisms for Lcp-coding genes in gram-positive bacteria have been characterized. Here, the current knowledge of genes and enzymes for the isoprene rubber catabolism were summarized.
天然橡胶和合成聚（1,4-异戊二烯）在世界范围内被工业用于生产。已报道了在革兰氏阳性菌和革兰氏阴性菌中微生物利用异戊二烯橡胶的情况。利用橡胶的细菌分泌的聚（1,4-异戊二烯）-裂解酶将聚（1,4-异戊二烯）链切割，生成含有醛和酮基团的低分子量寡聚（1,4-异戊二烯）衍生物。所得产物转化为含有羧基的化合物，然后可以通过β-氧化途径进一步代谢。聚（1,4-异戊二烯）-裂解酶之一是乳胶清除蛋白（Lcp），它存在于包括 和 在内的革兰氏阳性橡胶降解菌中。另一种是橡胶加氧酶 A 和 B（RoxA/RoxB），它已从革兰氏阴性橡胶降解菌如 和 中鉴定出来。最近，已经对革兰氏阳性菌中 Lcp 编码基因的转录调控机制进行了研究。在此，总结了异戊二烯橡胶代谢的基因和酶的最新知识。
