Survival of Lyophilized Bacillus popilliae in Soil1

Abstract

Survival of lyophilized vegetative Bacillus popilliae in dry soil and in soil kept in atmospheres with different relative humidities (RH) was determined. Cells survived for at least 1 year when the RH was 22% or lower, but an RH of 33% or higher reduced viability. At 33% RH, no bacteria were recovered after 5 months of storage; at 42% or above, no bacteria were recovered after 1 month of storage. The difficulty of producing large numbers of Bacillus popilliae spores in vitro has stimulated interest in the possibility of using stabilized vegetative cells to control the Japanese beetle. It has been shown that more than 50% of young, actively growing cells of B. popilliae survive lyophilization, and approximately 10% of the original cells will still be viable after 6 months of storage at room temperature (7). Recently, cells lyophilized in our laboratory produced typical milky disease when injected into Japanese beetle larvae (G. St. Julian, personal communication). This study was undertaken to determine survival of lyophilized B. popilliae in dry soil and in in soils stored in atmospheres having different relative humidities (RH). MATERIALS AND METHODS Organism. B. popilliae NRRL B 2-309, originally obtained from the Northern Utilization Research and Development Division, Peoria, Ill., was used in collecting experimental data. Medium. The medium contained 1.5% tryptone

Colonization of soil by Arthrobacter and Pseudomonas under varying conditions of water and nutrient availability as studied by plate counts and transmission electron microscopy

“…The introduction of laboratory-grown bacterial, fungal, and actinomycete cultures into either natural or sterile soil is a common procedure for studying microbial growth and interactions in this habitat (10,11,14,15,17,18,20,21,23,25). The use of sterile soil for this is advantageous in that a simplified artificial ecosystem can be established that lacks at least some of the unknown variables operating in a natural soil (14,21,23,24).…”

Use of Coating to Protect Lyophilized Bacillus popilliae from Moisture1

“…413. (4). Actively growing cultures were maintained by daily transfer of a 5% inoculum of brothcultures.…”

Heat-Induced Increase in the Number of Viable Cells in Lyophilized Preparations of Bacillus popilliae1

“…The strain of B. popilliae used and the medium for growth have been described (7). Cells were grown for 9 to 12 h, removed from the growth medium by centrifugation, and suspended in 5% sodium glutamate plus 0.5% gum tragacanth.…”