Effect of varying amplitude and frequency of stress factors on abundance, activity and diversity, of soil microorganisms

 

Student/in: Tamara Altenburger, BSc
Termin: 24.06.2024, 09:30 Uhr
Ort: Seminarraum Biologie (Foyer)

1. Prüfer/in: Univ.‐Prof. Dr. Paul Illmer 
2. Prüfer/in: Univ.-Prof. Mag. Dr. Susanne Zeilinger-Migsich
Vorsitzende/r: Nadine Präg, MSc PhD

 

Interessierte Kolleginnen und Kollegen sind herzlich willkommen!

 

Abstract

Temperature and pH are central factors for the abundance, activity and diversity of soil microorganisms. In the natural environment, these factors are not constant but subject to variation. Many studies have focused on the response of soil microorganisms to changes in abiotic parameters like temperature and pH on a linear scale, but the frequency of changes has not been considered in existing studies so far. Therefore, the aim of this work is to investigate, how the amplitude and the frequency of changes in two stress factors (temperature, pH) affect the abundance, activity and diversity of soil microorganisms.

For this study, sterile soil from Matsch (South Tyrol) was reinoculated with non-sterile soil. The soil was then exposed to different temperature and pH variations, i.e. variations in amplitude and frequency, meaning the number of changes per unit of time. After the treatment, soil samples were analysed regarding microbial abundance (cfu), activity (dehydrogenase activity) and diversity (DNA extraction and Illumina sequencing).

We found distinct differences in the above mentioned parameters, describing soil microorganisms between high and low amplitude and also varying the frequency of alteration led to highly significant effects. To fully understand how global change affects soil microorganisms, both constant and fluctuating conditions need to be considered.