Habitat, applications and genomics of the aerobic, thermophilic genus Geobacillus

Abstract

Thermophilic bacteria belonging to Bacillus genetic group 5 have been reclassified as being members of Geobacillus gen. nov., with G. stearothermophilus as the type strain. Geobacillus species, literally meaning earth or soil Bacillus, are widely distributed and readily isolated from natural and man-made thermophilic biotopes. Work within our group has however shown that an abundance of genetically distinct Geobacillus isolates can be obtained from temperate Irish soils. As with many thermophiles there is considerable interest in potential industrial application of these bacteria and their gene products. This review describes two novel applications for Geobacillus isolates, firstly in the metabolism of the herbicide glyphosate and secondly in the metabolism of quorum-sensing signal molecules from Gram-negative bacteria. Finally the current state of the art is described for Bacillus genomics, with details given of three independent genome-sequencing projects of Geobacillus isolates.

Isolation and Characterization ofN-Acylhomoserine Lactonase from the Thermophilic Bacterium,Geobacillus caldoxylosilyticusYS-8

“…suggests that the ability for quorum quenching is much more widely spread throughout Geobacillus. 20) G. caldosylosilyticus YS-8 was grown quickly with a growth rate of 1.4 h À1 , this having been generally shown in Geobacillus sp. 21,22) The AHLdegrading activity was also initiated in the early exponential phase and increased by the mid-exponential phase (Fig.…”

Application of a recN sequence similarity analysis to the identification of species within the bacterial genus Geobacillus

“…Clearly, a careful analysis of these species is required to clarify their relationships. It is interesting that all three of the Geobacillus strains currently the focus of genomic sequencing efforts -G. stearothermophilus strain 10 (equal to the BGSC 9A21 in Group 3), G. kaustophilus HTA426 and G. thermoleovorans T80 (McMullan et al, 2004) -may be closely related. If the data analysed in Fig.…”

“…As Gram-positive thermophiles, these organisms have considerable potential for applications in biotechnology and bioremediation (Obojska et al, 2002;Peng et al, 2003). Their roles in natural and artificial thermal biotypes as well as in temperate soil environments are also of interest (Marchant et al, 2002;McMullan et al, 2004). The original genus description included eight species (Nazina et al, 2001).…”

Partial purification and biochemical characterization of an extremely thermo- and pH-stable esterase with great substrate affinity

“…7 In spite of growing interest in thermophiles and their biocatalysts, only a few esterases have been characterized from thermophilic archaea and bacteria. 8 Additionally, the common limitation of industrial application of lipases and esterases is their limited thermostability at high temperatures and pH stability in operating industrial conditions.…”