Physiological Characterisation of Nitrogen Fixing Bacteria in Pure and Mixed Cultures
(2025) KMBM01 20251Applied Microbiology
Biotechnology
Biotechnology (MSc)
- Abstract
- The scope of this Master Thesis project is divided in two parts. In the first part, the objective is to characterise various strains of Azotobacter vinelandii under diazotrophic conditions with regards to growth rate and production of metabolites, such as ammonium or PHB. This will allow for an assessment on which nitrogen fixing strain displays the most promising results for use in the second part of the thesis. The second part covers the evaluation of a synthetic co-culture of Azotobacter vinelandii with Pseudomonas putida in nitrogen-free medium. Positive controls of both strains and media conditions were performed to build more favourable comprehension of metabolic activities for these two strains. A series of methods, assays and... (More)
- The scope of this Master Thesis project is divided in two parts. In the first part, the objective is to characterise various strains of Azotobacter vinelandii under diazotrophic conditions with regards to growth rate and production of metabolites, such as ammonium or PHB. This will allow for an assessment on which nitrogen fixing strain displays the most promising results for use in the second part of the thesis. The second part covers the evaluation of a synthetic co-culture of Azotobacter vinelandii with Pseudomonas putida in nitrogen-free medium. Positive controls of both strains and media conditions were performed to build more favourable comprehension of metabolic activities for these two strains. A series of methods, assays and techniques were used and modified for a better and well-built story that explains this abundance of results in the most comprehensive and standardized way. This thesis presented affirmative results on the use of A. vinelandii and P. putida as cooperating microorganisms in a co-culture, with data trends supporting the established hypotheses on synergistic effects of this consortium. This project also introduced Flow Cytometry methods for detection of cell populations, as well as demonstrated the potential of A. vinelandii, as a strain with a plethora of benefits in creating sustainable and highly efficient microbial applications. (Less)
- Popular Abstract
- Tiny partnership for a greener future
One of the main curiosities that drives microbiologists is discovering how we can implement bacteria into our everyday necessities, a term that us scientist like to call bioproducts. During the course of time, it has been a very common practice to use pairs of bacteria to make useful everyday products. Everything from yoghurt and cheese to antibiotics and natural fertilizers are often created by these team mates. This project explored the idea of combining two interesting bacteria species, Azotobacter vinelandii and Pseudomonas putida in one environment. These talented microorganisms work great individually, A. vinelandii is able to pull nitrogen from air to make natural fertilizer, while P. putida... (More) - Tiny partnership for a greener future
One of the main curiosities that drives microbiologists is discovering how we can implement bacteria into our everyday necessities, a term that us scientist like to call bioproducts. During the course of time, it has been a very common practice to use pairs of bacteria to make useful everyday products. Everything from yoghurt and cheese to antibiotics and natural fertilizers are often created by these team mates. This project explored the idea of combining two interesting bacteria species, Azotobacter vinelandii and Pseudomonas putida in one environment. These talented microorganisms work great individually, A. vinelandii is able to pull nitrogen from air to make natural fertilizer, while P. putida can turn waste into building blocks for eco-friendly plastics like nylon. Without a doubt they work well separately, but what would the outcome be if we put them together?
The answer can be found in this research, where we found out that these bacteria have a great affinity and they work together to produce a combined effect, greater than the sum of their separate effects. Promising results showed that the two species exchange resources they naturally produce and support each other. This kind of cooperation called a co-culture, can help design a sustainable way to make bioproducts without relying on harmful chemicals or non-renewable resources.
This exact partnership between A. vinelandii and P. putida is an innovative idea that few researchers have explored. Therefore, this study offers a starting point for future projects in green biotechnology. The potential of A. vinelandii and P. putida is immersive, and I believe they can help solve some challenging problems in unsustainable industrial production, agriculture and plastic pollution. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9188650
- author
- Meta, Xhilda LU
- supervisor
- organization
- course
- KMBM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Azotobacter, Nitrogen fixation, PHB, Co-culture, Pseudomonas, Flow cytometry, Applied microbiology
- language
- English
- id
- 9188650
- date added to LUP
- 2025-05-20 09:19:23
- date last changed
- 2025-06-17 14:43:08
@misc{9188650,
abstract = {{The scope of this Master Thesis project is divided in two parts. In the first part, the objective is to characterise various strains of Azotobacter vinelandii under diazotrophic conditions with regards to growth rate and production of metabolites, such as ammonium or PHB. This will allow for an assessment on which nitrogen fixing strain displays the most promising results for use in the second part of the thesis. The second part covers the evaluation of a synthetic co-culture of Azotobacter vinelandii with Pseudomonas putida in nitrogen-free medium. Positive controls of both strains and media conditions were performed to build more favourable comprehension of metabolic activities for these two strains. A series of methods, assays and techniques were used and modified for a better and well-built story that explains this abundance of results in the most comprehensive and standardized way. This thesis presented affirmative results on the use of A. vinelandii and P. putida as cooperating microorganisms in a co-culture, with data trends supporting the established hypotheses on synergistic effects of this consortium. This project also introduced Flow Cytometry methods for detection of cell populations, as well as demonstrated the potential of A. vinelandii, as a strain with a plethora of benefits in creating sustainable and highly efficient microbial applications.}},
author = {{Meta, Xhilda}},
language = {{eng}},
note = {{Student Paper}},
title = {{Physiological Characterisation of Nitrogen Fixing Bacteria in Pure and Mixed Cultures}},
year = {{2025}},
}