Effect of 6-benzyladenine on the initiation of adventitious roots on mung bean hypocotyl

Cuttings incubated with 6-benzyladenine showed extensive celldivision and tracheid differentiation in the cortex and rootprimordia did not form. The histological and enzyme data suggestthat the formation of isoperoxidases is associated with theearly differentiation of specialized parenchyma cells involvedin the formation of root primordia. (Received June 13, 1973; )     

Potentiation of methicillin activity against methicillin-resistant Staphylococcus aureus by diterpenes

Totarol is a diterpene compound extracted from the totara tree. Totarol and eight other diterpenes were found to potentiate methicillin, one reducing the minimum inhibitory concentration of methicillin against resistant Staphylococcus aureus 256-fold. Totarol did not inhibit the synthesis of DNA or peptidoglycan in S. aureus, but reduced the respiration rate by 70%. Under potentiation conditions, diterpenes had only a slight effect on the respiration rate, but had a significant effect on expression of PBP 2a. We conclude that the primary staphylococcal target for totarol is the respiratory chain, but that potentiation of methicillin by diterpenes is by interference with PBP 2a expression.     

Bactericidal properties of an organic N-chloramine formed in situ

Agent I (3-chloro-4,4-dimethyl-2-oxazolidinone) formed in situ was compared with pre-formed agent I as a disinfectant against Staphylococcus aureus. In situ formation involved combining the non-chlorinated oxazolidinone precursor with calcium hypochlorite to form 5 and 10 mg/l total chlorine concentrations of agent I. The variables included in the study were temperature, pH and concentration. Overall the bacteria were killed more rapidly at 22 degrees than at 4 degrees C. The in situ formation appeared to occur most rapidly at pH 7.0, slightly slower at pH 9.5, and very slowly at pH 4.5 as evidenced by the presence of residual free chlorine. In the in situ experimental runs the 5 and 10 mg/l concentrations were equally effective in obtaining a six log decline in cfu/ml. This study indicates the potential for using the organic N-chloramine as a general purpose disinfectant while omitting the laboratory synthesis of the final product.