Environmental control of metabolic fluxes in thermotolerant methylotrophicBacillusstrains

✍ Scribed by Anthony G. Brooke; Elizabeth M. Watling; Margaret M. Attwood; David W. Tempest

• Book ID: 104764125
• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 722 KB
• Volume: 151
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00413141

✦ Synopsis

Recently we have isolated a number of thermotolerant, spore-forming methylotrophic bacilli in pure culture. With a methanol-limited chemostat culture of strain Tsl, incremental increases in the incubation temperature from 45~ to 62.5~ revealed an optimum with respect to growth yield of 52.5 ~ C, and a maximum of 62.5 ~ C. Similar investigations revealed a pH optimum of 7.5 and a broad growth rate optimum with respect to growth yield. The organism displayed a low maintenance energy requirement and high growth yield (attained simultaneously with high growth rates) during growth on methanol. Under all conditions of methanol limitation, substrate was oxidized solely tO biomass and CO2 and carbon recoveries greater than 90% were manifest. Our data suggested that this resulted from an ability of the organism to precisely adjust its catabolic and anabolic pathways to suit prevailing growth conditions. These results are discussed in relation to previously reported data on thermophiles in both batch and chemostat culture.