NOVEL BIOACTIVE PRODUCTS FROM ANTARCTIC BACTERIA
Marine bacteria have considerable importance as sources of biologically active products. Marine microorganisms that live in cold regions have been largely underexplored, and may be endowed with interesting chemical repertoire. The microorganisms that thrive in these cold environments are referred to...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | Italian English |
Published: |
2016
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Subjects: | |
Online Access: | http://www.fedoa.unina.it/10703/ http://www.fedoa.unina.it/10703/1/Thesis-FilomenaSannino.pdf |
Summary: | Marine bacteria have considerable importance as sources of biologically active products. Marine microorganisms that live in cold regions have been largely underexplored, and may be endowed with interesting chemical repertoire. The microorganisms that thrive in these cold environments are referred to as psychrophiles or cold-adapted bacteria and are able to produce a large number of bioactive compounds, such as antimicrobial, anti-fouling and various pharmaceutically-relevant activities. In this contest, the aim of my PhD project was the research of new bioactive compounds of biotechnological interest from Polar marine bacteria. In particular, I focused my attention on three classes of molecules: I. Antimicrobial volatile organic compounds (VOCs); II. Anti-biofilm molecules; III. Cryoprotectant compounds. In order to explore the Pseudoalteromonas haloplanktis TAC125 (P.haloplanktis TAC125) chemical diversity as source of bioactive compounds, a suitable synthetic growth medium was developed, containing D-gluconate and L-glutamate as carbon, nitrogen and energy sources (GG medium). The definition of a synthetic medium is necessary for the scale up of P. haloplanktis TAC125 growth in automatic bioreactors. Moreover, a defined “minimum” medium could enhance the secondary metabolites production, and it surely makes their purification easier. Preliminary studies demonstrated that some Antarctic marine bacteria are able to produce volatile organic compounds (VOCs) that specifically inhibit the growth of Burkholderia cepacia complex (Bcc) strains. Amongst the tested Antarctic marine bacteria, P.haloplanktis TAC125 was further investigated. It is known that the P.haloplanktis TAC125 production of VOCs changes with growth medium composition. With the aim to identify the anti-Bcc VOCs, a suitable capture trap for volatile compounds was developed. A bioactive compound was identified, the methylamine, and its anti-Bcc activity was demonstrated by defining the Minimum Volatile Inhibitory Concentration (MVIC) on a panel of Bcc ... |
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