Significance
Lignans, including sesamin, are produced by a wide variety of plants, but the microbial degradation of lignan has not been identified biochemically. Here, we show that
Sinomonas
sp. no. 22 can catabolize sesamin as a sole-carbon source. We identified the sesamin-converting enzyme, SesA, from strain
Sinomonas
sp. no. 22. SesA catalyzed methylene group transfer from sesamin to tetrahydrofolate (THF). The resulting 5,10-CH
2
-THF might find use as a C1-donor for bioprocesses. SesA gene homologs were found in the genomes of both Gram-positive and Gram-negative bacteria, suggesting that sesamin (lignan) utilization is a widespread, but still unrecognized, function in environments where lignans are produced and degraded.
重要性
木脂素,包括芝麻素,由许多植物产生,但木脂素的微生物降解尚未在生化上得到确定。在这里,我们展示了Sinomonas sp. no. 22可以将芝麻素作为唯一的碳源进行分解。我们从Sinomonas sp. no. 22菌株中鉴定了芝麻素转化酶SesA。 SesA催化芝麻素向四氢叶酸(THF)的亚甲基基团转移。由此产生的5,10-CH2-THF可能作为C1供体用于生物过程。在革兰氏阳性和阴性菌的基因组中发现了SesA基因同源物,这表明芝麻素(木脂素)利用是在产生和降解木脂素的环境中普遍存在但尚未被认识的功能。