Hatakeyama Takashi, Takagi Kazuhiro, Yamazaki Kenichi, Sakakibara Futa, Ito Koji, Takasu Eiichi, Naokawa Takuji, Fujii Kunihiko
Organochemicals Division, National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan.
World J Microbiol Biotechnol. 2015 May;31(5):785-93. doi: 10.1007/s11274-015-1832-3. Epub 2015 Mar 10.
Melamine belongs to the s-triazine family, and industrially used as raw product in many ways all over the world. Melamine has been reported for human harmful effects and detected from some crops, soil and water. To remove melamine from the polluted environment, the efficient melamine-mineralizing microorganisms have been needed. We newly isolated three melamine-degrading bacteria from the same upland soil sample using soil-charcoal perfusion method. These bacteria were classified as Arthrobacter sp. MCO, Arthrobacter sp. CSP and Microbacterium sp. ZEL by 16S rRNA genes sequencing analysis. Both Arthrobacter species completely degraded melamine within 2 days, and consumed melamine as a sole nitrogen source. Both strains also grew in cyanuric acid as sole nitrogen source, and released small quantities of ammonium ions. These strains are the first identified bacteria that can mineralize both melamine and cyanuric acid as sole initial nitrogen source in Arthrobacter sp. Although ammeline and ammelide intermediates were detected, these strains possess none of the known genes encoding melamine degrading enzymes. Since the Arthrobacter strains also degraded melamine in a high pH liquid medium, they present as potential bioremediation agents in melamine-polluted environments.
三聚氰胺属于三嗪家族，在全球范围内被广泛用作多种工业产品的原料。已有报道称三聚氰胺对人体有害，并在一些农作物、土壤和水中被检测到。为了从受污染的环境中去除三聚氰胺，需要高效的三聚氰胺矿化微生物。我们使用土壤 - 木炭灌注法从同一旱地土壤样本中首次分离出三株三聚氰胺降解菌。通过16S rRNA基因测序分析，这些细菌被归类为节杆菌属MCO、节杆菌属CSP和微杆菌属ZEL。两株节杆菌在2天内完全降解了三聚氰胺，并将三聚氰胺作为唯一氮源消耗。这两株菌株也能以氰尿酸作为唯一氮源生长，并释放少量铵离子。这些菌株是首次鉴定出的能够在节杆菌属中将三聚氰胺和氰尿酸作为唯一初始氮源进行矿化的细菌。尽管检测到了三聚氰酸一酰胺和三聚氰酸二酰胺中间体，但这些菌株不具备任何已知的编码三聚氰胺降解酶的基因。由于节杆菌菌株在高pH值液体培养基中也能降解三聚氰胺，它们在三聚氰胺污染环境中具有作为潜在生物修复剂的特性。
