BIOS2460 Lab 11 Biochemical Test 2 .rtf - BIOS-2460 Lab 11...

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BIOS-2460 Lab 11 Biochemical Tests Part 2 Part 1: Nitrate Reduction Test Nitrate Reduction Reading: Nitrate Reduction Video: Example Table: Nitrate Reduction Test Results & Interpretations Result Interpretation Symbol Gas (non-fermenter) Denitrification – production of nitrogen gas (NO 3 - NO 2 - N 2 ) + Gas (fermenter, unknown status) Source of gas unknown, requires addition of reagents Red color (after reagents A & B) Nitrate reduction to nitrite (NO 3 - NO 2 - ); Nitrate reductase present + No color change (after reagent A & B) Incomplete test, requires addition of zinc oxide dust No color change (after addition zinc) Nitrate reduction to nongaseous nitrogenous compounds (NO 3 - NO 2 - NO, ½ N 2 O, or ½ N 2 ) + Red color (after addition zinc) No nitrate reduction - Questions: 1. If you have an uninoculated tube, is it a positive or negative control? What information is provided by the uninoculated control?
2. Why is gas production not recognized as a nitrate reduction when the organism is a known fermenter?

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