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Category: Bacterial Pathogenesis
Ecology of Bacillaceae, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555819323/9781555816759_Chap03-1.gif /docserver/preview/fulltext/10.1128/9781555819323/9781555816759_Chap03-2.gifAbstract:
The most distinguishing feature of most members of the family Bacillaceae (phylum Firmicutes) is their ability to form endospores that provide high resistance to heat, radiation, chemicals, and drought, allowing these bacteria to survive adverse conditions for a prolonged period of time. Bacillaceae are widely distributed in natural environments, and their habitats are as varied as the niches humans have thought to sample. Over the years of microbiological research, members of this family have been found in soil, sediment, and air, as well as in unconventional environments such as clean rooms in the Kennedy Space Center, a vaccine-producing company, and even human blood ( 1 – 3 ). Moreover, members of the Bacillaceae have been detected in freshwater and marine ecosystems, in activated sludge, in human and animal systems, and in various foods (including fermented foods), but recently also in extreme environments such as hot solid and liquid systems (compost and hot springs, respectively), salt lakes, and salterns ( 4 – 6 ). Thus, thermophilic genera of the family Bacillaceae dominate the high-temperature stages of composting and have also been found in hot springs and hydrothermal vents, while representatives of halophilic genera have mostly been isolated from aquatic habitats such as salt lakes and salterns, but less often from saline soils ( 7 , 8 ). The isolates that have been obtained, in particular, from the varied extreme habitats, produce a wide range of commercially valuable extracellular enzymes, including those that are thermostable ( 9 , 10 ).
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Occurrence of Bacillaceae, their ecosystem function, biotic interactions, and applications. The illustration shows different environments from which Bacillaceae have been isolated highlights their main ecosystem functions and biotic interactions, and illustrates selected existing and possible applications.
Occurrence of Bacillaceae, their ecosystem function, biotic interactions, and applications. The illustration shows different environments from which Bacillaceae have been isolated highlights their main ecosystem functions and biotic interactions, and illustrates selected existing and possible applications.
Growth of B. subtilis in soil and morphology on LB agar media. (A) Growth of riverbank isolate B. subtilis PS-209 ( 41 ) was grown in an autoclaved soil microcosm at 28°C, and CFU counts were performed at indicated times on Luria-Bertani (LB) medium. The experiment was performed in three replicates. Error bars represent 95% confidence intervals of means calculated from log10 transformed CFU counts (L. Pal, S. Vatovec, P. Stefanic, T. Danevčič, and I. Mandic-Mulec, unpublished data). (B) Colony morphotypes. Colony morphology was visually examined and photographed after incubation at 37°C for 48 h on LB agar medium. Riverbank microscale and desert macroscale B. subtilis strains are marked with green and yellow, respectively (Courtesy of P. Stefanic).
Growth of B. subtilis in soil and morphology on LB agar media. (A) Growth of riverbank isolate B. subtilis PS-209 ( 41 ) was grown in an autoclaved soil microcosm at 28°C, and CFU counts were performed at indicated times on Luria-Bertani (LB) medium. The experiment was performed in three replicates. Error bars represent 95% confidence intervals of means calculated from log10 transformed CFU counts (L. Pal, S. Vatovec, P. Stefanic, T. Danevčič, and I. Mandic-Mulec, unpublished data). (B) Colony morphotypes. Colony morphology was visually examined and photographed after incubation at 37°C for 48 h on LB agar medium. Riverbank microscale and desert macroscale B. subtilis strains are marked with green and yellow, respectively (Courtesy of P. Stefanic).
Phylogenetic and ecotype simulation analyses of the B. subtilis-B. mojavensis subclade and minimum evolution tree of com sequences. (A) The phylogeny of B. subtilis isolates from riverbank microscale and desert soils is based on a maximum parsimony analysis of the recombination-free concatenation of dnaJ, gyrA, and rpoB, rooted by strain C-125 of B. halodurans ( 19 ). (B) Minimum evolution tree of com sequences (comQ, comX, and partial comP sequences, 1,402 bp) depicts four sequence clusters that correspond to previously identified pherotypes or communication groups within B. subtilis-B. mojavensis clade. Strains are marked with a shape representing their putative ecotype (PE) and by color representing pherotype (yellow, pherotype ROH1/RO-B-2; green, pherotype RS-D-2 /NAF4; orange, pherotype RO-E-2; and blue, pherotype 168). Unmarked strains were used as additional reference strains for tree construction ( 19 ).
Phylogenetic and ecotype simulation analyses of the B. subtilis-B. mojavensis subclade and minimum evolution tree of com sequences. (A) The phylogeny of B. subtilis isolates from riverbank microscale and desert soils is based on a maximum parsimony analysis of the recombination-free concatenation of dnaJ, gyrA, and rpoB, rooted by strain C-125 of B. halodurans ( 19 ). (B) Minimum evolution tree of com sequences (comQ, comX, and partial comP sequences, 1,402 bp) depicts four sequence clusters that correspond to previously identified pherotypes or communication groups within B. subtilis-B. mojavensis clade. Strains are marked with a shape representing their putative ecotype (PE) and by color representing pherotype (yellow, pherotype ROH1/RO-B-2; green, pherotype RS-D-2 /NAF4; orange, pherotype RO-E-2; and blue, pherotype 168). Unmarked strains were used as additional reference strains for tree construction ( 19 ).