Fungal primary and secondary metabolism.pdf

Fungal primary and secondary metabolism.pdf

1. FUNGAL
PHYSIOLOGY
SUBMITTED BY SUBMITTED TO
ANCYVARGHESE DR.ARYAP MOHAN
1
ST
MSC BOTANY ASST.PROFESSOR
ST.TERESA’SCOLLEGE, EKM ST.TERESA’SCOLLEGE, EKM
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2. OVERVIEW
INTRODUCTION. –3
METABOLISM -4
FUNGAL METABOLISM -5
PRIMARY METABOLISM. –6-14
SECONDARY METABOLISM –15-17
REFERENCE. -18
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3. PHYSIOLOGY ?
•Refers to the nutrition,
metabolism, growth,
reproduction & death of
fungal cells.
•Interaction of fungi with their
biotic & abiotic surroundings.
BENEFITS OF FUNGAL
METABOLISM
•Biogeochemical cycling of carbon in nature.
•In agriculture –mutualistic symbiont
•Detoxification of organic pollutants
•Bioremediatingheavy metals
•Economically important industrial commodities
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4. WHAT IS METABOLISM ?
PROCESS BY WHICH BODY CHANGES FOOD
AND DRINK INTO ENERGY .
CATABOLISM
•Break down of moleculesto obtain energy.
Eg.Glycolysis
ANABOLISM
•The synthesis of all compounds needed
for the growth.
Eg.Synthesisof proteins from amino acids.
PRIMARY METABOLISM
•Essential for the growthto occur.
Eg.Proteins, Carbohydrates, Nucleic acids…etc
SECONDARY METABOLISM
•Biproductsor intermediates of Primary
metabolism.
•Not absolutely necessary for survival.
Eg.Penicillin, Mycotoxin…etc
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5. SPECIAL ABOUT FUNGAL METABOLISM ……
•Chemotrophic heterotrophs.
•Simple monosaccharides, amino acids, fatty
acids…etcare easily transported across
plasmalemma.
•Degradation done by extracellular enzymes
released through walls.
•Depolymerasesof fungi–proteases, pectic
enzymes, lipases, amylases & cellulases.
•Primary metabolism includes, Glycolysis,
Gluconeogenesis, Respiration, and
Fermentation .
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6. CARBON CATABOLISM
•Catabolic pathways areoxidative processes.
•Electrons are removedfrom intermediate carbon
compounds.
•These are used to generate energy in the form of ATP.
•Catabolic sequence –
Glucose Pyruvic acid = Glycolysis
•Provides fungal cells energy, precursor molecules and
Reducing power (NADPH) for biosynthetic pathways.
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7. GLYCOLYSIS
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8. GLUCONEOGENESIS
•A process that transforms non-carbohydrate
substrates(such as lactate, amino acids, &
glycerol) into glucose.
•Occur in cytoplasm.
•Provides glucose when dietary intake is insufficient
or absent.
•Also essential in the regulation of acid-base balance,
amino acid metabolism & synthesis of carbohydrate
derived structural compounds.
•Reversal of glycolysis.
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9. WHAT IS NEXT IN AEROBIC CONDITION ?
•Process of utilisationof Oxygen to
breakdown Glucose, amino acids,
fatty acids to produce ATP –
Aerobic Respiration
•Energy yielding pathways in which
inorganic molecules (O2) serve as
terminal electron acceptor = Aerobic
Respiration
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10. AEROBIC RESPIRATION
•Under normal oxidative conditions pyruvic acid derived from glycolysis is
broken down to CO2 & H2O via TCA Cycle.
•Very little ATP is formed directly from glycolysis or TCA Cycle .
•Instead reduced co-enzymes like NADH2 & NADPH2 are
produced.
•ATP is produced when these co-enzymes are reoxidised.
•Under Aerobic condition, co-enzymes are usually reoxidisedby means of
electron transport chain –O2 serves as the terminal electron acceptor.
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11. WHAT IS NEXT IN ANAEROBIC CONDITIONS ?
•Under Anaerobic conditions only glycolysis operates.
•Reduced co-enzymes are oxidisedin 2 ways
•1.Lactic acid fermentation
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12. •2. Alcohol fermentation
•Growth continues until lactic acid or ethanol accumulate
to toxic levels.
•Energy yielding processes where organic
compounds serve as both electron acceptor and
donor is termed as Fermentation
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13. MIXED ACID FERMENTATION
•It is the metabolic process by which a six
carbon sugar (Glucose C6H12O6 ) is
converted into a complex and
variable mixture of acid.
•A type of anaerobic fermentation seen
common in bacteria; it is also seen in
some anaerobic fungi also.
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14. Aerobic
Respiration
Total no.ofATP
produced = 38
molecules
36 molecules –
formed in Citric
acid cycle
2 molecules
formed outside
the mitochondria.
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15. SECONDARY METABOLISM
•Most active when normal growth is restricted.
•No obvious role in the life of the organism.
•Secondary metabolism = ‘Escape valve’ which removes the intermediates of Primary
pathways when growth stops & converts them into compounds with little or no
physiological activity.
•Used for Competition, Antagonism, Self defense mechanisms.
•Includes a wide range of isoprenoides, alkaloids, antibiotics, toxins…etc
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16. PATHWAYS IN WHICH SECONDARY
METABOLITES ARE PRODUCED
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17. •Secondary metabolites are species –or strain specific.
•They are organic compounds resulting from specific biosynthetic pathways with
low molecular weight,and are not essential for fungal growth but their
natural production.
•Fungi are a rich source of secondary metabolites; among which some
are beneficiary and some others are toxic.
•Beneficiarysecondary metabolites –antibiotics ( penicillin), Gibberellin ( a
plant hormone first isolated from a fungi Gibberellafujikuroi
•Toxicsecondary metabolites –Alkaloids released by ergot fungus –Claviceps
purpurea
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18. REFERENCE
•Sharma P.D.1998. The Fungi. Rastogipublications
•Madan Mira and ThindK.S. 1998. Physiology of fungi.A.P.H. Publishing corporation
•Bilgrami,K.S. and Verma,R.N. 1978. Physiology of Fungi. Vikaspublishing house pvtltd.
•Wisecaver,J.H,Slot,J.C, & Rokas,A. 2014. The evolution of fungal metabolic pathways.plos
genetics 10(12),e1004816
•onlinelibrary.wiley.com<doi<ab
Walker,M. and White,A. (2017). Introduction to Fungal physiology
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