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Penicillinase (beta-lactamase) formation by blue-green algae.
Archives of Microbiology
|March 1, 1977
Summary
Blue-green algae possess beta-lactamase (penicillinase) enzymes, enabling some strains to resist penicillin. Enzyme activity and location in Coccochloris elabens and Anabaena species depend on growth pH and nitrogen source.
Area of Science:
- Microbiology
- Biochemistry
- Enzymology
Background:
- Blue-green algae, also known as cyanobacteria, are prokaryotic microorganisms.
- Beta-lactamase enzymes are known to confer resistance to beta-lactam antibiotics like penicillin.
- Previous research has not extensively documented beta-lactamase activity in diverse blue-green algae species.
Purpose of the Study:
- To investigate the presence and characteristics of beta-lactamase activity in various blue-green algae strains.
- To determine the influence of growth conditions, specifically pH and nitrogen source, on beta-lactamase production and localization.
- To compare the substrate specificity of beta-lactamases from different cyanobacterial species.
Main Methods:
- Screening of multiple blue-green algae strains for beta-lactamase activity.
- Cultivation of selected strains (Coccochloris elabens and Anabaena) under controlled pH conditions (neutral vs. alkaline) and varying nitrogen sources (NaNO3, N2 fixation, CO2/N2).
- Enzyme assays on intact and disrupted cells to assess beta-lactamase localization and activity against different penicillin and cephalosporin substrates.
Main Results:
- Beta-lactamase activity was detected in several blue-green algae strains, conferring penicillin resistance.
- In Coccochloris elabens and Anabaena, alkaline pH (around 10) led to extracellular or easily accessible enzyme expression, while neutral pH resulted in cell-bound, cryptic enzyme.
- The identified beta-lactamases showed higher activity against penicillins than cephalosporins, with strain-specific differences in substrate profiles.
Conclusions:
- Blue-green algae can produce functional beta-lactamases, contributing to antibiotic resistance mechanisms.
- Environmental pH is a critical factor regulating the expression and accessibility of beta-lactamase in these organisms.
- The characterized penicillinases exhibit distinct substrate preferences, highlighting potential for strain-specific enzymatic properties.