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SynopsisGrafting of vinyl monomers onto cellulose-thiocarbamate was carried out using ceric ammonium sulfate (CAS) as a n initiator. The graft yield was found to depend on the amount of thiocarbamate groups, initiator, and monomer concentrations as well as temperature. The graft yield increased with increasing (CAS) concentration. The reactivity of vinyl monomers studied followed the order ethyl acrylate > acrylonitrile. A comparison between the graft yields obtained with the modified cullulose indicated that cellulose thiocarbamates having less than 1.1% nitrogen showed lower graft yields than the unmodified cellulose. Above this, cellulose thiocarbamate was much more amenable to grafting than the unmodified cellulose. The grafted cellulose thiocarbamates exhibited high antifungal activity and had no effect on gram-negative, gram-positive bacteria and yeast. The maximum wne of inhibition was obtained after grafting with 2 h which resulted in 43 and 50% add-on polymer in the cases of acrylonitrile and ethyl acrylate, respectively. Grafted cellulose thiocarbamates with acrylonitrile had higher potency for antifungal activity than that grafted with ethyl acrylate.

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Morphological and physiological studies on an isolated strain of Streptomyces from an Egyptian soil, producing high yields of litmocidin, were carried out. The local strain was compared with litmocidin producing species. The morphologica: and physiological characteristics revealed that the isolated strain is more related to Streptomyces litmocidini. The local strain was considered to be a new species of Streptomyces producing than to Nocadia. The utilization of the different carbon sources by the microorganism for the production of the antibiotic was investigated.