Bacteria AND aminoacid metabolism

In an attempt to reproduce resistance to Listeria monocytogenes induced by primo-infection, a vaccinal strain of low virulence capable of affording a good immunity was looked for. After a double mutation in regard to streptomycin, i.e. dependence then reversion to independence, nine strains were obtained from a Listeria monocytogenes field strain of low virulence. In addition, five of these reverse strains were made resistant to erythromycin. Measure of virulence of the resulting 14 strains was performed on mice by spleen counts three days after subcutaneous inoculation of 10(5) bacteria...

There is a general consensus that biological specificity is a structure-derived property. If a living system is going to maintain its structure and function then the newly synthesized molecules should replace the faulty ones at the correct time and in the correct places so that the previously established cellular topology will be preserved. In addition, pre-existing spatial determinants which will direct the asymmetrical assembly of the newly synthesized molecules should be available. Therefore, regulation of turnover of cellular architecture represents an essential feature of living systems...

Staphylococci--chemoorganotrophic bacteria whose main habitats are human and animal organisms--can accumulate poly-beta-hydroxybutyrate (PHB) in their cells. The polymer is metabolized in endogenous turnovers preceding degradation of aminoacids, proteins and RNA. PHB depolymerase was not found in staphylococci but beta-hydroxybutyrate dehydrogenase was estimated, purified and characterized.

The usual models for cell multiplication only involve macromolecular events and ignore the influence of metabolism. The conjecture presented here shows how metabolism could be involved. Separate pathways might cooperate for the synthesis of a small molecule, acting as positive control of several macromolecular syntheses, including stable RNA synthesis. A detailed analysis of the available data showing an influence of metabolites on macromolecular syntheses suggests that two main pathways might cooperate, one involving serine and folic acid metabolism and the second involving threonine and the branched chain aminoacids...

The inhibitory analysis has shown that E. tenella does not include ready folic acid into metabolic process but synthesizes its metabolite, 7:8-dihydrofolic acid (DHFA), from its precursor, para-aminobenzoic acid (PABA), which enters the host's organism. PABA can be fully substituted in the process of metabolism by sulphadimesin (SD) at the molar ratio PABA: SD=1: 16.7. As a concurrent antagonist of PABA SD is 6 times stronger in the parasite-host system of Coccidia than in bacteria in cultural medium. The increase in PABA content in relation to SD more than 1: 16...

A peculiarity of the amino acid pool has been discovered for the first time in bacteria utilizing such synthetic compounds as gamma butyrolactam, epsilon-caprolactam and zeta-aminoenanthic acid. The main components of the amino acid pool are omega-aminoacids (including synthetic ones) as well as glutamic acid. The total amino acid content increases upon utilization of the compounds being tested three times (Pseudomonas fluorescens), five times (Pseudomonas dacunchae) and seven times (Pseudomonas perolens) as compared to the control variants...