Alcaligenes denitrifzcans n.sp.

SUMMARY: A new species of the genus Alcaligenes is described which is able to produce gas from nitrate. The ability to reduce nitrate with formation of nitrogen gas is common to several kinds of bacteria, particularly the non-fermentative Gram-negative rods. The named bacteria of this type about which we have personal know-ledge are Pseudomonas aeruginosa, P. stutzeri and Malleornyces pseudornallei. Various strains of Brucella of all species may produce a small amount of gas from nitrate. The phenomenon appears to be most common among the polar flagellated organisms of the Pseudomonas genus. Fig. 1. Alcaligenes denitri,ficans n.sp. showing typical flagellation. Leifson flagella stain (Leifson, 1951). Photomicrograph, x 3600. Among some 100 strains of peritrichously flagellated Gram-negative 'rods in our collection are eight which produce gas from nitrate, Six of these are old stock cultures from various sources; all oxidize glucose and some xylose. The other two strains were received from L. R. Fredrich (Purdue University) and were isolated from soil. These two strains appear to be alike and do not attack any of the carbohydrates tested. They appear to be typical of the Alcaligenes genus. We suggest that they be recognized as a species of Alcaligenes with the name Alcaligenes denitrijcans n.sp. Alcaligenes denitrificans n.sp. 51