いち酸化 さんか炭素 たんそ細菌 さいきんじゃありませんでした
ichisanka tansosa ikinja arimasendeshita

Noun
Desu Copula

The polite, past negative form of 一酸化炭素細菌

1. Was not carbon monoxide bacteria.; Was not a carbon monoxide bacterium.

Past/Perfective
Negative
Polite
Terminal Form