Vpliv interakcij med bakterijama Bacillus subtilis in Streptomyces rimosus na produkcijo sekundarnih metabolitov

Podnar, Eli (author), Mandić Mulec, Ines (mentor), Danevčič, Tjaša (co-mentor)

V magistrski nalogi smo preučevali interakcije med bakterijama Bacillus subtilis in Streptomyces rimosus, da bi ugotovili ali se njuni metabolni profili spreminjajo ob kokultivaciji. Bakteriji smo sočasno gojili na trdnem gojišču in po inkubaciji izvedli ekstrakcijo metabolitov ter ekstrakte analizirali s tankoplastno kromatografijo. Ugotovili smo, da bakterija S. rimosus R7 pri kokultivaciji z bakterijo B. subtilis PS-216 na trdnih gojiščih SM in ISP5 sintetizira spojino, ki jo zaznamo kot vijolično liso v profilu TLC pri valovni dolžini 365 nm. Prav tako smo vijolično liso zaznali pri kokultivaciji bakterij S. rimosus M4018 in B. subtilis PS-216 na trdnem gojišču SM, medtem ko se pri kokultivaciji bakterije B. subtilis PS-216 z bakterijo S. rimosus W vijolična lisa ni pojavila. Različne mutante (?degQ, ?srfA, ?katA, ?spo0A) bakterije B. subtilis PS-216 so še vedno sprožile sintezo vijolične spojine pri S. rimosus R7. Spremenjen metabolni profil v kokulturi smo zaznali tudi pri bakteriji B. subtilis PS-216, ki sproži sintezo vijolične lise pri bakteriji S. rimosus R7. Sprožilec, ki ga sintetizira bakterija B. subtilis ni poznan. Sprožilec je topen v gojišču, obstojen pri višjih temperaturah (24 h pri 80 °C), izgubi aktivnost med avtoklaviranjem in verjetno ni proteinske narave. Sinteza molekule sprožilca ni odvisna od prisotnosti bakterije S. rimosus, saj vijolična lisa nastane po dodatku izrabljenega gojišča bakterije B. subtilis PS-216.

• Language: Slovenian
• Keywords: Bacillus subtilis, Streptomyces rimosus, mikrobne interakcije, sekundarni metaboliti, tankoplastna kromatografija
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [E. Podnar]
• Year: 2019
• PID: 20.500.12556/RUL-109401
• UDC: 579.22/.26:579.852.1+579.873.7:604.4
• COBISS.SI-ID: 5088632
• Publication date in RUL: 01.09.2019

Secondary language

• Language: English
• Title: The impact of interactions between Bacillus subtilis and Streptomyces rimosus on the secondary metabolites production

Abstract

This master thesis addresses the change in metabolic profiles during co-cultivation of two bacterial species, Bacillus subtilis and Streptomyces rimosus. Bacteria were cocultivated on the solid medium and metabolites were extracted after incubation using methanol. Methanol extracts were then analysed by thin-layer chromatography. We observed that during co-cultivation with B. subtilis PS-216 on solid SM and ISP5 media the S. rimosus R7 synthesizes a compound that we perceived as a violet spot in the TLC profile at a wavelength of 365 nm. The violet spot appeared also when we co-cultivated B. subtilis PS-216 with S. rimosus M4018 but not with the strain S. rimosus W on solid SM medium. We have also tested various mutants (?degQ, ?srfA, ?katA, ?spo0A) of B. subtilis PS-216 and found that they still induce production of the violet spot during co-cultivation with S. rimosus R7. Moreover, B. subtilis PS-216 metabolic profile changed in co-cultivation with S. rimosus R7 as compared to monoculture. Next, we investigated the trigger produced by B. subtilis PS-216 that induces the synthesis of the violet spot in TLC profile of S. rimosus R7. We found that the unknown trigger is soluble in medium, fairly temperature resistant (24h on 80 °C) and is not a peptide. Synthesis of the trigger produced by B. subtilis PS-216 is independent of the presence of S. rimosus R7 as the violet spot appears after the addition of the spent medium of B. subtilis PS-216.

• Keywords: Bacillus subtilis, Streptomyces rimosus, microbial interactions, secondary metabolites, thin layer chromatography