Fo. Bryant et Hg. Cutler, ISOLATION OF ACTINOMYCES-VISCOSUS STRAIN GA - CHARACTERISTICS OF ITS CELLULAR BIOLOGICAL RETARDANT(S), Letters in applied microbiology, 25(2), 1997, pp. 117-122
Actinomyces viscosus strain GA produces an exocellular biological reta
rdant(s) that prevents certain vegetable plants from becoming overgrow
n. The biological retardant(s) was assayed using the etiolated wheat c
oleoptile assay, and fractionation of culture supernatant fluid result
ed in a partial purification of the retardant(s). The biological retar
dant(s) was most active around pH 7 in the bioassay and when applied t
o sterile soil mixture. The biological retardant(s) was tentatively id
entified as a derivative of a rare hexose carbohydrate (but not an ami
no sugar) but an exact structure was not determined. In a sterilized s
ynthetic soil system, the biological retardant(s) has an effect on tom
ato cultivars similar to that observed by the synthetic plant growth r
egulators Alar (succinic acid 2,2-dimethylhydrazide) and Bonzi (paclob
utrazol).