Methanopyrus kandleri is a species of archaea that lives in the hydrothermal vents of the Pacific Ocean. This species' optimal temperatures are between 100-122 ºC. This species also does not require oxygen, as it survives off of hydrogen gas and releases methane gas. What environmental classifications would this archaeal species fit into?

• A. Mesophile & Obligate Aerobe.
• B. Non-halotolerant & Psychrophile.
• C. Neutrophile & Facultative Aerobe.
• D. Hyperthermophile & Obligate Anaerobe.

Answer: (D)

Verified step by step guidance

1. Identify the temperature range in which Methanopyrus kandleri thrives. The problem states that it lives optimally between 100-122 ºC.
2. Understand the term 'Hyperthermophile'. Hyperthermophiles are organisms that thrive at extremely high temperatures, typically above 80 ºC. Given the temperature range, Methanopyrus kandleri fits this classification.
3. Consider the oxygen requirements of Methanopyrus kandleri. The problem mentions that it does not require oxygen and survives off hydrogen gas, releasing methane.
4. Define 'Obligate Anaerobe'. Obligate anaerobes are organisms that cannot survive in the presence of oxygen. Since Methanopyrus kandleri does not require oxygen, it fits this classification.
5. Combine the classifications based on temperature and oxygen requirements. Methanopyrus kandleri is both a Hyperthermophile due to its high-temperature preference and an Obligate Anaerobe due to its lack of oxygen requirement.