Some Micro‐organisms Isolated From the Rotted Surfaces of Waterproofed Sisal Rope

Abstract

After soil burial of sisal rope and baler twine treated with a water repellent, the aerobic microflora was examined. Ten fungi and 71 bacteria capable of growth on an inorganic basal medium with the water repellent as the sole source of organic carbon were isolated. Six of the fungi were penicillia. All the bacteria were rod shaped and all except five were Gram-negative ; they comprised members of the genera Pseudomonas, Alcaligenes, Bacterium and Achromobacter, in decreasing numerical order.In studies of the interactions between the bacteria and the ten fungi on potato dextrose agar, bacteria actively suppressed fungal growth in only 9% of cases, the most readily inhibited fungus of the cultures studied thoroughly being a member of the genus Paecilomyces. Fungi completely overgrew the bacteria in 34% of cases, the most aggressive fungus being a Penicillium. In the remaining 57% of tests neither bacterium nor fungus was seriously affected by the other. The fungi did not suppress one another.The reduction in mean tensile strength of single fibres taken from waterproofed baler twine was not significantly different from that of fibres from untreated twine, after soil burial for 7 days at 30'.