Physiology of aquatic microorganisms from the perspective of bioprocess development

Yanming Wang

Research output: ThesisDissertationCollection of Articles

Abstract

Industrial biotechnology is gradually transforming the landscape of chemical production. The driving force that promotes the application of industrial biotechnology includes the increasing concerns of climate change and sustainability of chemical production. Microorganisms and enzymes, as the key catalysts of industrial biotechnology, have been increasingly examined for their suitability in bioprocesses. Currently, most industrial microbial strains have terrestrial origin. Aquatic microorganisms, though believed to be tremendously diverse, have not been extensively used by the existing bioprocesses. One reason is that the physiology of most aquatic microorganisms has not been investigated from the perspective of bioprocess development.
Aiming to bring more aquatic microorganisms to industrial application, by improving the physiological understanding of them, case studies were conducted, characterising eight diverse aquatic microorganisms at different readiness levels of bioprocess development. Neutral lipid production from a green alga, Chlorella protothecoides, was analysed in various levels of nitrogen limiting conditions. The result found that nitrogen limitation, which triggers lipid accumulation, can be achieved in continuous cultivations with constant nitrogen feed. C. protothecoides conducts photosynthesis to maximise the utilisation of available light in mixotrophic conditions. This makes it suitable for stable continuous mixotrophic cultivations for lipid production.
Another photosynthetic aquatic microorganism, Euglena gracilis was studied in more detail interms of cell composition in response to cultivation conditions. The confirmed cellular composition of E. gracilis makes it ideal material for whole cell utilisation as food or feed. Six marine fungi were characterised for hydrolytic activities. Their abilities of hydrolysing several polymers usually found in macroalgae were confirmed. This suggest the existence of enzymes with unique substrate specificity in some of these marine fungi. Marine fungi produce novel compounds of various bioactivities beyond hydrolytic enzymes. The production of an antibacterial macrocyclic polyester, calcaride-A, from Calcarisporium sp. was characterised. A preliminary cultivation process was developed that can produce enough calcaride-A material for further bioactivity research.
The case studies demonstrated that physiological characterisation from the perspective of bioprocess development is crucial for bioprocess development. Though this is not unique to aquatic microorganisms, expanding the physiological characterisation of aquatic microorganisms will hopefully attract more investment to the utilisation of aquatic microorganism.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Aalto University
Supervisors/Advisors
  • Frey, Alexander D., Supervisor, External person
  • Wiebe, Marilyn, Advisor
  • Rischer, Heiko, Advisor
Award date17 May 2019
Publisher
Print ISBNs978-952-60-8522-7
Electronic ISBNs978-952-60-8523-4
Publication statusPublished - 2019
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

physiology
microorganisms
marine fungi
biotechnology
Euglena gracilis
industrial applications
nitrogen
enzymes
case studies
Chlorella
polyesters
lipids
substrate specificity
catalysts
Chlorophyta
macroalgae
polymers
triacylglycerols
climate change
photosynthesis

Keywords

  • aquatic microorganisms
  • microalgae
  • marine fungi
  • chlorella protothecoides
  • euglena gracilis
  • bioactive compounds
  • hydrolytic enzymes
  • bioprocess

Cite this

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title = "Physiology of aquatic microorganisms from the perspective of bioprocess development",
abstract = "Industrial biotechnology is gradually transforming the landscape of chemical production. The driving force that promotes the application of industrial biotechnology includes the increasing concerns of climate change and sustainability of chemical production. Microorganisms and enzymes, as the key catalysts of industrial biotechnology, have been increasingly examined for their suitability in bioprocesses. Currently, most industrial microbial strains have terrestrial origin. Aquatic microorganisms, though believed to be tremendously diverse, have not been extensively used by the existing bioprocesses. One reason is that the physiology of most aquatic microorganisms has not been investigated from the perspective of bioprocess development. Aiming to bring more aquatic microorganisms to industrial application, by improving the physiological understanding of them, case studies were conducted, characterising eight diverse aquatic microorganisms at different readiness levels of bioprocess development. Neutral lipid production from a green alga, Chlorella protothecoides, was analysed in various levels of nitrogen limiting conditions. The result found that nitrogen limitation, which triggers lipid accumulation, can be achieved in continuous cultivations with constant nitrogen feed. C. protothecoides conducts photosynthesis to maximise the utilisation of available light in mixotrophic conditions. This makes it suitable for stable continuous mixotrophic cultivations for lipid production. Another photosynthetic aquatic microorganism, Euglena gracilis was studied in more detail interms of cell composition in response to cultivation conditions. The confirmed cellular composition of E. gracilis makes it ideal material for whole cell utilisation as food or feed. Six marine fungi were characterised for hydrolytic activities. Their abilities of hydrolysing several polymers usually found in macroalgae were confirmed. This suggest the existence of enzymes with unique substrate specificity in some of these marine fungi. Marine fungi produce novel compounds of various bioactivities beyond hydrolytic enzymes. The production of an antibacterial macrocyclic polyester, calcaride-A, from Calcarisporium sp. was characterised. A preliminary cultivation process was developed that can produce enough calcaride-A material for further bioactivity research. The case studies demonstrated that physiological characterisation from the perspective of bioprocess development is crucial for bioprocess development. Though this is not unique to aquatic microorganisms, expanding the physiological characterisation of aquatic microorganisms will hopefully attract more investment to the utilisation of aquatic microorganism.",
keywords = "aquatic microorganisms, microalgae, marine fungi, chlorella protothecoides, euglena gracilis, bioactive compounds, hydrolytic enzymes, bioprocess",
author = "Yanming Wang",
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Physiology of aquatic microorganisms from the perspective of bioprocess development. / Wang, Yanming.

Aalto University, 2019.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - Physiology of aquatic microorganisms from the perspective of bioprocess development

AU - Wang, Yanming

PY - 2019

Y1 - 2019

N2 - Industrial biotechnology is gradually transforming the landscape of chemical production. The driving force that promotes the application of industrial biotechnology includes the increasing concerns of climate change and sustainability of chemical production. Microorganisms and enzymes, as the key catalysts of industrial biotechnology, have been increasingly examined for their suitability in bioprocesses. Currently, most industrial microbial strains have terrestrial origin. Aquatic microorganisms, though believed to be tremendously diverse, have not been extensively used by the existing bioprocesses. One reason is that the physiology of most aquatic microorganisms has not been investigated from the perspective of bioprocess development. Aiming to bring more aquatic microorganisms to industrial application, by improving the physiological understanding of them, case studies were conducted, characterising eight diverse aquatic microorganisms at different readiness levels of bioprocess development. Neutral lipid production from a green alga, Chlorella protothecoides, was analysed in various levels of nitrogen limiting conditions. The result found that nitrogen limitation, which triggers lipid accumulation, can be achieved in continuous cultivations with constant nitrogen feed. C. protothecoides conducts photosynthesis to maximise the utilisation of available light in mixotrophic conditions. This makes it suitable for stable continuous mixotrophic cultivations for lipid production. Another photosynthetic aquatic microorganism, Euglena gracilis was studied in more detail interms of cell composition in response to cultivation conditions. The confirmed cellular composition of E. gracilis makes it ideal material for whole cell utilisation as food or feed. Six marine fungi were characterised for hydrolytic activities. Their abilities of hydrolysing several polymers usually found in macroalgae were confirmed. This suggest the existence of enzymes with unique substrate specificity in some of these marine fungi. Marine fungi produce novel compounds of various bioactivities beyond hydrolytic enzymes. The production of an antibacterial macrocyclic polyester, calcaride-A, from Calcarisporium sp. was characterised. A preliminary cultivation process was developed that can produce enough calcaride-A material for further bioactivity research. The case studies demonstrated that physiological characterisation from the perspective of bioprocess development is crucial for bioprocess development. Though this is not unique to aquatic microorganisms, expanding the physiological characterisation of aquatic microorganisms will hopefully attract more investment to the utilisation of aquatic microorganism.

AB - Industrial biotechnology is gradually transforming the landscape of chemical production. The driving force that promotes the application of industrial biotechnology includes the increasing concerns of climate change and sustainability of chemical production. Microorganisms and enzymes, as the key catalysts of industrial biotechnology, have been increasingly examined for their suitability in bioprocesses. Currently, most industrial microbial strains have terrestrial origin. Aquatic microorganisms, though believed to be tremendously diverse, have not been extensively used by the existing bioprocesses. One reason is that the physiology of most aquatic microorganisms has not been investigated from the perspective of bioprocess development. Aiming to bring more aquatic microorganisms to industrial application, by improving the physiological understanding of them, case studies were conducted, characterising eight diverse aquatic microorganisms at different readiness levels of bioprocess development. Neutral lipid production from a green alga, Chlorella protothecoides, was analysed in various levels of nitrogen limiting conditions. The result found that nitrogen limitation, which triggers lipid accumulation, can be achieved in continuous cultivations with constant nitrogen feed. C. protothecoides conducts photosynthesis to maximise the utilisation of available light in mixotrophic conditions. This makes it suitable for stable continuous mixotrophic cultivations for lipid production. Another photosynthetic aquatic microorganism, Euglena gracilis was studied in more detail interms of cell composition in response to cultivation conditions. The confirmed cellular composition of E. gracilis makes it ideal material for whole cell utilisation as food or feed. Six marine fungi were characterised for hydrolytic activities. Their abilities of hydrolysing several polymers usually found in macroalgae were confirmed. This suggest the existence of enzymes with unique substrate specificity in some of these marine fungi. Marine fungi produce novel compounds of various bioactivities beyond hydrolytic enzymes. The production of an antibacterial macrocyclic polyester, calcaride-A, from Calcarisporium sp. was characterised. A preliminary cultivation process was developed that can produce enough calcaride-A material for further bioactivity research. The case studies demonstrated that physiological characterisation from the perspective of bioprocess development is crucial for bioprocess development. Though this is not unique to aquatic microorganisms, expanding the physiological characterisation of aquatic microorganisms will hopefully attract more investment to the utilisation of aquatic microorganism.

KW - aquatic microorganisms

KW - microalgae

KW - marine fungi

KW - chlorella protothecoides

KW - euglena gracilis

KW - bioactive compounds

KW - hydrolytic enzymes

KW - bioprocess

M3 - Dissertation

SN - 978-952-60-8522-7

PB - Aalto University

ER -