PubMed Health⌕ Search

Biomedical subjects

A R COLMER

Publications and source records attributed to A R COLMER.

18 recordsLinked to original sources

COLIFORMS ASSOCIATED WITH SUGARCANE PLANTS AND JUICES.

A study of the coliforms found on sugarcane plants throughout the growing season indicated that members of the genus Aerobacter comprise a part of the epiphytic microflora. When quantitative determinations were made of the coliforms by means of the most probable number technique, no completed tests were obtained on young sugarcane plants during the test period of February through May; however, Paracolobactrum aerogenoides was isolated frequently. Nine different IMViC types of coliforms were identified among the 198 isolates chosen for study. The predominating coliform found at the top, middle, and bottom portions of the sugarcane plants was A. cloacae, but the type predominating in leaf-sheath water was A. aerogenes. Only once was Escherichia coli found associated with the plants at the high dilutions necessary for determining most probable numbers. The numbers of different coliforms occurring in sugarcane juice were generally divided equally among A. aerogenes, A. cloacae, and E. coli. More variety among the IMViC types seemed to occur on the cane plants than in the leaf-sheath water or the cane juice in the mill.

Enterobacter↗

The effect of 2,3,6-trichlorophenylacetic and 2,2-dichloropropionic acids on nitrite oxidation.

The effects of two herbicides, 2,3,6-trichlorophenylacetic acid, sodium salt, and 2,2-dichloropropionic acid, sodium salt, on nitrite-oxidizing bacteria were studied by the soil perfusion technique. The time of application of 2,3,6-trichlorophenylacetic acid affected its toxicity to the nitrifier. When it was present in the environment as the nitrifier started growth, it was more toxic than if the organisms were allowed to nitrify actively before they were subjected to the herbicide. The herbicide 2,2-dichloropropionic acid at rates up to 700 ppm had little effect on nitrite oxidation. The toxicity of 2,3,6-trichlorophenylacetic acid for Nitrobacter was reduced by 2,2-dichloropropionic acid irrespective of whether the cells came into contact with the agents before or during active oxidation. The mode of action for this phenomenon has not been determined.

Bacteria↗

Relation of the iron oxidizer, Thiobacillus ferrooxidans, to thiosulfate.

Colmer, Arthur R. (Louisiana State University, Baton Rouge). Relation of the iron oxidizer, Thiobacillus ferrooxidans, to thiosulfate. J. Bacteriol. 83:761-765. 1962.-A restudy has been made of Thiobacillus ferrooxidans secured from the acid drainage of some northern West Virginia coal mines. Cultures isolated from ferrous iron agar and then subcultured for 85 consecutive transfers in thiosulfate broth during a period of 14 months were able to use ferrous iron as their energy source when returned to ferrous iron broth. Thiosulfate utilization was quantitatively followed by iodine titration and pH change; ferrous iron oxidation was quantitatively determined by use of 1,10-phenanthroline.Characteristic colonial forms were produced by T. ferrooxidans growing on thiosulfate agar irrespective of whether the inoculum was from iron broth or thiosulfate broth.

Acidithiobacillus↗