INVESTIGADORES
DELGADO Osvaldo Daniel
congresos y reuniones científicas
Título:
Evidence of andrimid production by a psychrotolerant Serratia proteamaculans strain.
Autor/es:
SANCHEZ LA; DELGADO OD
Lugar:
Mar del Plata
Reunión:
Congreso; VIII Congreso de Microbiologia General; 2012
Institución organizadora:
Sociedad Argentina de Microbiologia General
Resumen:
Key
factors such as frequent and inappropriate use of antibiotic causing increased
bacterial resistance to those commonly used, in addition to an irregular
emergence generated from a detriment of pharmaceutical companies involved in
drugs discovery makes the development of new antibiotics is an increasing
worldwide problem and a constant challenge. The necessity to reduce additives
in the food industry has triggered the search for natural antimicrobial
substances produced by microorganisms from different sources with the aim to
preserve processed foods by inhibiting microorganisms associated with
food-borne illness.
Most
antibiotics emerged from search programs (screening)
in natural sources using microbiological tools which include the isolation of
new microorganisms, modification of well-known producer microorganisms or
metabolic engineering of fermentation processes.
This
work involves structure elucidation and characterization of an antimicrobial
produced by a psychrotolerant Serratia proteamaculans 136 strain. The antibiotic peptide
was produced at low temperatures (4°C) and strong activity was revealed against
both pathogenic and non-pathogenic bacteria at different CIM values. The effect
over ultra-structure of sensitive bacteria was observed by transmission
electron microscopy at different inhibition stages, resulting in the presence
of pores in the bacterial surface and loss of cytoplasmic content by disruption
of the cell membrane. Andrimid structure was confirmed by combining LC MS/MS
and NMR approaches. The
parental ion (479.2 m/z) showed six product ions with 121, 195, 226, 239, 268,
343 m/z and differences in relative abundance of each ion type. To state the
antimicrobial sum formula, mass data in addition to natural isotopes
distribution with their relative intensities were evaluated under SIRIUS
software in [M + H]+ form,
using an efficient deconvolution algorithm in order to obtain the
possible sum formula. This study constitutes the first report of cold-active
andrimid production by a S.
proteamaculans strain.
The possible horizontally transference among Pantoea, Pseudomonas and Serratia genera
is discussed. The work also highlights cold environments as a suitable source
of microorganisms with the ability to produce cold-active biomolecules of
biotechnological interest.