Occurrence of Bacillus thuringiensis in fresh waters of Japan.
Bacillus thuringiensis was recovered at a relatively high frequency from both running and still fresh waters in natural environments of Kyushu, Japan. Of 107 water samples examined, 53 (49.5%) contained this organism. The frequency of B. thuringiensis colonies was 4.4% among 4414 colonies of the Bacillus cereus/B. thuringiensis group. The density of this bacterium in fresh waters averaged 0.45 cfu/ml. Serologically, B. thuringiensis isolates were assigned to 26 H serotypes. Of these, H14/36 (H serovar israelensis/malaysiensis) was the predominant, followed by the serotypes H3abc (kurstaki), H27 (mexicanensis), H3ad (sumiyoshiensis), and H35 (seoulensis). Of 195 isolates, 52 (26.7%) exhibited larvicidal activity against aquatic Diptera; 21 killed Culex pipiens molestus (Culicidae) only, and 31 were active on both the culicine mosquito and the moth-fly, Clogmia albipunctata (Psychodidae). The Diptera-toxic isolates produced spherical or irregularly pointed parasporal inclusions.
Ichimatsu
T
T
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa, Kurume, Fukuoka 839-0861, Japan.
Mizuki
E
E
Nishimura
K
K
Akao
T
T
Saitoh
H
H
Higuchi
K
K
Ohba
M
M
D000818:Animals; D001413:Bacillus thuringiensis / Q000145:classification / Q000302:isolation & purification* / Q000472:pathogenicity; D009033:Culicidae / Q000382:microbiology; D005618:Fresh Water / Q000382:microbiology*; D007564:Japan; D007814:Larva / Q000382:microbiology; D011576:Psychodidae / Q000382:microbiology; D012703:Serotyping; D014871:Water Microbiology