Inhibition of growth of obligately chemolithotrophic thiobacilli by amino acids

Nonproteinogenic D-Amino Acids at Millimolar Concentrations Are a Toxin for Anaerobic Microorganisms Relevant to Early Earth and Other Anoxic Planets

“…A number of studies found inhibition to be either shortlived (Davis and Maas, 1949;Rowley, 1953b;Coleman, 1959) or completely preventable through the addition of other, seemingly antagonistic, amino acids (Davis and Maas, 1949;Rowley, 1953aRowley, , 1953bLu et al, 1971). The transient nature of inhibition in the former studies was not observed in these experiments, where the presence of the D-isomer resulted in total inhibition of MIR (Fig.…”

“…Common terrestrial D-amino acids have been shown to partially or fully inhibit growth of a number of aerobic bacteria, including Lactobacillus arabinosus (Fox et al, 1944), Bacillus subtilis (Trippen et al, 1976), strains of Erwinia (Grula, 1960) and Thiobacillus (Lu et al, 1971), Corynebacterium collunge (Trippen et al, 1976), and Escherichia coli (Davis and Maas, 1949;Rowley, 1953aRowley, , 1953b. Conversely, Zhang and Sun (2014) recently demonstrated that common aerobic soil bacteria are capable of consuming D-enantiomers of alanine, aspartic acid, glutamic acid, and leucine at 4 mM concentration, proposing an enzymatic reverse mechanism that not only detoxifies the D-amino acids but renders them a bioavailable source of carbon and nitrogen.…”

Active Transport of Amino Acids by Membrane Vesicles of Thiobacillus neapolitanus

“…These organisms are permeable to a wide variety of organic compounds which are extensively assimilated and metabolized when supplied in the growth medium (Rittenberg, I 969; Kelly, 1971) and can, under certain conditions, actually increase growth yield (Kuenen & Veldkamp, 1973). These findings have disproved the hypothesis (Winogradsky, I 890) that organic compounds are generally and uniquely toxic to chemolithotrophs, and recent work (Kelly, 1969;Lu, Matin & Rittenberg, 1971) has shown that the toxicity of specific organic compounds towards these organisms resembles that in certain heterotrophs (Gladstone, I 939 ;Umbarger, 1969).…”

“…Thiobacillus neapolitanus (kindly supplied by S. C. Rittenberg, University of California, Los Angeles, U.S.A.) was grown at 28 "C in a cheinostat of 1.5 1 working volume, which was equipped with devices for automatic pH control. The medium (Matin & Rittenberg, 1971) used contained per 100 ml: NH,CI, 0 -1 g; MgSO,, 0.05 g; K,HPOI, 0.5 g; KH,PO,, 0.5 g; solution of trace elements (Vishniac & Santer,r957), 0-1 ml; and Na,S,O,, 1.0 g. Growth was limited by thiosulphate; see Kuenen & Veldkainp (r973) for details. Cultures were frequently checked for heterotrophic contaminants by streaking on nutrient agar plates.…”

The obligate autotroph — the demise of a concept

“…Different species, and, indeed, different strains of the same species, are in general sensitive to different amino acids. Recently we surveyed the L-amino acid sensitivities of three strains of thiobacilli (Table 9; Lu, Matin and Rittenberg, 1971). Our strain of 7".…”