Isolation of soil thermophilic bacteria and their ability to utilize propionic acid

Koler, Aleksandra (author), Starčič Erjavec, Marjanca (mentor), Barta, Jiri (co-mentor)

Over the past few decades, due to the large industrial development, enormous quantities of industrial pollutants have been released into the environment, which is a critical problem not only for their accumulation in environment but also for public health. Volatile organic compounds (VOCs) are one of the most important pollutants emitted from chemical, petrochemical and allied industries. VOCs emissions have heavy impact on human and animal health, vegetation and climate. Due to increasing levels of environmental pollution, there has been a concerted effort to explore the use of biological processes to remove organic pollutants from environment. This alternative is attractive because of its low energy consumption, relatively moderate operating costs and minimal by-products generation. Frequently, microorganisms in biofilters are used to break down pollutants present in air streams from chemical industry and other sources. Organisms that live at extreme temperatures, pH, pressure, salinity and in high concentrations of recalcitrant substrates represent one of the last frontiers for biotechnological and industrial discovery. Extremophiles are a rich source of enzymes that are useful in biotechnological processes due to the fact that these enzymes are better suited for harsh industrial processes. Studies suggest that some thermophilic strains occurring in natural high-temperature habitats could be efficiently used for degradation of VOCs. In this work, we isolated thermophilic microorganisms from soil samples and tested them with OxiTop® System for biodegradation of propionic acid. Tested isolates, Aeribacillus Th4 and Geobacillus Th7, have successfully utilized propionic acid at concentration of 500 mg/L. Further, we used Biolog EcoPlate™ system for the analysis of ability of isolates to utilize different carbon sources. The results showed that there are significant differences in the use of different carbon sources for growth among selected isolates.

• Language: English
• Keywords: extremophile microorganisms, thermophilic bacteria, biotechnological processes, biodegradation, volatile organic compounds, propionic acid, microbiological analysis, Biolog EcoPlate™, measuring systems, OxiTop®
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [A. Koler]
• Year: 2017
• PID: 20.500.12556/RUL-96396
• UDC: 579.26:582.23:602.4
• COBISS.SI-ID: 4821880
• Publication date in RUL: 30.09.2017

Secondary language

• Language: Slovenian
• Title: Izolacija termofilnih bakterij iz tal ter njihova sposobnost izrabe propionske kisline

Abstract

Industrija je eden glavnih krivcev za onesnaževanje okolja. Strupene snovi in delci, ki so preko industrijskih odpadkov spuščeni v ozračje, tla in vodo, pa ne predstavljajo nevarnosti le za okolje, temveč tudi za zdravje ljudi. Hlapne organske spojine (HOS) so skupina pomembnih onesnaževalcev, ki jih najdemo v vročih parah, sproščenih iz kemičnih, petrokemičnih in podobnih industrijskih obratov. Emisije hlapnih organskih snovi imajo škodljiv vpliv na zdravje ljudi in živali ter rastlinstvo in podnebje. V skrbi za okolje se v zadnjih letih za odstranjevanje biološko razgradljivih odpadkov vse bolj razvijajo in uporabljajo biološki procesi, pri katerih sodelujejo mikroorganizmi. Prednosti teh alternativnih procesov so v zmanjšani porabi energije, nižjih investicijskih stroških, prilagodljivosti procesa ter zmanjšanem negativnem vplivu na okolje. Organizmi, ki živijo v ekstremnih okoljih (ekstremne vrednosti pH, temperature, tlaka, slanosti ...), predstavljajo pomembno razvijajočo se vejo v biotehnoloških procesih. Ekstremofili so biotehnološko pomembni, saj predstavljajo bogat vir encimov, ki imajo optimum delovanja pri ekstremnih pogojih. Predhodne študije so pokazale, da so nekateri termofilni sevi sposobni degradacije HOS. Iz vzorcev tal smo izolirali termofilne mikroorganizme ter jih testirali za sposobnost izrabe propionske kisline s sistemom OxiTop®. Testirana izolata Aeribacillus Th4 in Geobacillus Th7 sta bila sposobna biodegradacije propionske kisline, ki je bila v gojišče dodana v koncentaciji 500 mg/L. Nadalje smo z uporabo mikroplošč Biolog EcoPlate™ analizirali metabolno aktivnost izolatov. Rezultati so pokazali, da se sposobnost izrabe različnih virov ogljika med različnimi izolati razlikuje.

• Keywords: ekstremofilni mikroorganizmi, termofilne bakterije, biotehnološki procesi, biodegradacija, hlapne organske spojine, propionska kislina, mikrobiološke analize, Biolog EcoPlate™, merilni sistemi, OxiTop®