Production of Gliotoxin in Unsterilized Soil
IT has long been recognized that microbial antagonisms exist in the soil, and the possibility that this might be due to production of antibiotics has been suggested although never actually proved.
Antibiotic production by fungi on organic manures and in soil.
Penicillium patulum, Aspergillus clavatus and A. terreus produced antibiotic substances when grown on organic materials which are used or could be used as manures. The addition of glucose increased the antibiotic titre in every case. Antibiotics were also formed in autoclaved soils enriched with easily available carbon sources and inoculated with one of the following fungi: P. patulum, A. clavatus, A. terreus and two unidentified species of Penicillium. P. patulum formed an antibiotic also on partially sterilized supplemented soil. The degree of antibiotic activity was decreased when soil cultures of P. patulum were contaminated with other organisms from soil or from the air, but even gross contamination with natural soil at 25° did not destroy activity entirely until 11 days had elapsed. Loss of activity was smaller at lower temperatures.
AN INTRODUCTION T O THE SOILS OF THE SOUTH-EASTERN PORTION OF THE AUSTRALIAN ARID ZONE
Summary 
 
Seven soil regions, each of which is dominated by soils belonging to one or two great soil groups, are defined and mapped. The outstanding feature is the presence of a variety of soils with widely differing characteristics. The soils are deeper, have more profile differentiation and are finer-extured than those in most-arid regions and are frequently overlain by currently-forming deposits of wind-transported materials. Because the vegetative cover is better developed and there are only small areas of rocky hills and bare rock pediments, water erosion and deposition are not as prominent as in other arid areas.