Tetrachloroethene transformation to trichloroethene and cis-1,2-dichloroethene by sulfate-reducing enrichment cultures

Tetrachloroethene, also known as perchloroethylene, was reductively dechlorinated to trichloroethene and cis-1,2-dichloroethene by laboratory sulfate-reducing enrichment cultures. The causative organism or group was not identified. However, tetrachloroethene was dechlorinated to trichloroethene in 50 mM bromoethane-sulfonate-inhibited enrichments and to trichloroethene and cis-1,2-dichloroethene in 3 mM fluoroacetate-inhibited enrichments. Overall transformation varied from 92% tetrachloroethene removal in 13 days to 22% removal in 65 days, depending on conditions of the inoculum, inhibitor used, and auxilliary substrate used. Neither lactate, acetate, methanol, isobutyric acid, valeric acid, isovaleric acid, hexanoic acid, succinic acid, nor hydrogen appeared directly to support tetrachloroethene dechlorination, although lactate-fed inocula demonstrated longer-term dechlorinating capability.     

Synthesis and biological activity of 2-desamino and 4-deoxy analogs of 5,10-dideazatetrahydrofolic acid (DDATHF)

Either the 2-amino or the 4-oxo group of the potent GAR formyl-transferase inhibitor 5,10-dideazatetrahydrofolic acid (DDATHF) was replaced with a hydrogen atom and their biological activity evaluated.     

The influence of calcium deficiency on the translocation of photosynthetically fixed 14C in soybeans

Summary Soybean (Glycine max (L.) Merr.) plants were grown at two levels of Ca (0.05 and 2.5 mM Ca) with and without an inorganic source of N in a growth chamber and in the greenhouse. The fourth leaf from the top of the plant was labeled with ¹⁴C, and the distribution of ¹⁴C was measured 24 hours after labeling. The translocation of ¹⁴C out of the labeled leaf was decreased at the low Ca level in both experiments. This decrease occurred before there were any visual Ca deficiency symptoms and before the low Ca level had any effect on dry weight accumulation. The effect of the low Ca level on translocation was the same for plants exposed to an inorganic N source and those that were nodulated. The reduced rate of translocation from the labeled leaf had no measurable effect on the nodule activity as measured by the acetylene reduction method. The data demonstrate the importance of an adequate supply of Ca to the soybean plant for maximum translocation of carbohydrates from the leaves.This paper (76-3-110) is published with the approval of the Director of the Kentucky Agric. Exp. Stn.This paper (76-3-110) is published with the approval of the Director of the Kentucky Agric. Exp. Stn.