Membrane-bound and extracellular β-lactamase production with developmental regulation in Streptomyces griseus NRRL B-2682

Abstract

A new type ofβ-lactamase has been isolated and characterized in Streptomyces griseus NRRL B-2682. The enzyme has membrane-bound and extracellular forms. Biochemical characterization of some of the properties of the enzyme showed that it belongs to the class A group of penicillinases. Comparison of the membrane-bound and extracellular forms of theβ-lactamases suggests that they seem to be differently processed forms of the same enzyme. The N-terminal amino acid sequence of the extracellular form of the β-lactamase showed a high degree of similarity to a D-aminopeptidase of another Streptomyces griseus strain. Secretion of the β-lactamase was affected by the differentiation state of the strain since in spontaneous non-sporulating mutants only the membrane-bound form was present. In accordance with this when sporulation of the wild-type strain was inhibited it failed to secrete extracellular β-lactamase. Addition of globomycin to the non-sporulating cells liberated the enzyme from the membrane, indicating that the protein is processed normally by signal peptidase II and a glyceride-thioether group, together with a fatty acid amide-linkage, is responsible for the attachment of the enzyme to the cellular membrane. Under sporulation-repressed conditions addition of peptidoglycan fragments and analogues or inhibition of cell wall biosynthesis by penicillin-G induced β-lactamase secretion and also restored sporulation both in solid and submerged cultures. These results confirm that β-lactamase secretion is tightly coupled to the sporulation process in S. griseus.

High throughput cultivation-based screening on porous aluminum oxide chips allows targeted isolation of antibiotic resistant human gut bacteria

“…However, it should be noted that antibiotics may be broken down by adjacent bacteria on the PAO chip, and hence not all bacteria that grow are by definition resistant. For example, cefotaxime may be degraded through the secretion of a β-lactamase [54, 55]. We could hypothetise that the PAO chip acts as a buffer between the agar medium and the chip surface, thereby reducing the effective concentration of the antibiotic.…”

Lipoprotein processing is required for virulence of Mycobacterium tuberculosis†

“…The peptide antibiotic globomycin specifically inhibits lipoprotein processing by binding to LspA in a non‐competitive manner (Dev et al ., 1985). Biochemical and physiological investigations indicate that globomycin inhibits lipoprotein processing in such diverse organisms as Synechococcus sp., Haemophilus ducreyi , Spiroplasma melliferum , Mycoplasma pneumoniae , Streptococcus zooepidemicus , Staphylococcus aureus and Streptomyces griseus (Maeda and Omata, 1997; Deak et al ., 1998; Gal et al ., 2001).…”

Induction of β-Lactamase Influences the Course of Development in Myxococcus xanthus

“…The work of Kimura et al (28) demonstrating that addition of D-alanyl-D-alanine to slowly sporulating subcultured cells accelerates sporulation is also consistent with this model. A similar model has been suggested to regulate processing and secretion of a ␤-lactamase in Streptomyces griseus (6). We have no evidence that the activity of ␤-lactamase itself is important in the reshaping of the peptidoglycan that happens during sporulation and germination, and current understanding of ␤-lactamases suggests that it is unlikely that the chromosomal ␤-lactamase of M. xanthus acts directly on peptidoglycan or its components (14).…”