Minutes 1878

https://place.asburyseminary.edu/freemethodistminutesyearbooks/1016/thumbnail.jp

Minutes 1877

https://place.asburyseminary.edu/freemethodistminutesyearbooks/1015/thumbnail.jp

Microbial Maintenance: A Critical Review on Its Quantification

Microbial maintenance is an important concept in microbiology. Its quantification, however, is a subject of continuous debate, which seems to be caused by (1) its definition, which includes nongrowth components other than maintenance; (2) the existence of partly overlapping concepts; (3) the evolution of variables as constants; and (4) the neglect of cell death in microbial dynamics. The two historically most important parameters describing maintenance, the specific maintenance rate and the maintenance coefficient, are based on partly different nongrowth components. There is thus no constant relation between these parameters and previous equations on this subject are wrong. In addition, the partial overlap between these parameters does not allow the use of a simple combination of these parameters. This also applies for combinations of a threshold concentration with one of the other estimates of maintenance. Maintenance estimates should ideally explicitly describe each nongrowth component. A conceptual model is introduced that describes their relative importance and reconciles the various concepts and definitions. The sensitivity of maintenance on underlying components was analyzed and indicated that overall maintenance depends nonlinearly on relative death rates, relative growth rates, growth yield, and endogenous metabolism. This quantitative sensitivity analysis explains the felt need to develop growth-dependent adaptations of existing maintenance parameters, and indicates the importance of distinguishing the various nongrowth components. Future experiments should verify the sensitivity of maintenance components under cellular and environmental conditions

Stress responses of subsurface bacteria. Final report, June 1, 1995--February 1, 1998

Five questions were investigated in this research: (1) can subsurface bacteria and phylogenetically related surface strains be cultured on a single carbon/energy substrate; (2) is the behavior of subsurface bacteria the same as phylogenetically related surface strains when both are subjected to progressive, chronic carbon/energy source starvation; (3) which phyllogenetic groups survive better; (4) do other factors affect survival in the degree that phyllogeny does (5) do dormant forms appear during starvation; (6) is ppGpp present in subsurface bacteria and what is its persistence in carbon/energy starvation