Environmental factors and growth Flashcards
Where can they grow
- inside gut
- in soil
- in fresh water lake
- in root of legume
- Food production
What do they need nutrient for
- energy
- biosynthesis
- growth (reducing power, CO2, hydrogen and e- to organi molecules also support energy & biosynthesis)
95% of any cell consists of only a few macronutrients:
[ dry weight from high to low]
Carbon, oxygen, nitrogen, hydrogen, phosphorous, sulphur
macronutrients needed for component of
lipid, carbohydrate, protein, nucleic acids
Other macronutritents and function
Magnesium - Enzyme co factors, complex ATP, stabilises ribosomes and membranes
Iron - Electron transport, enzyme co-factors
Calcium - endospore heat resistance and many roles
Potassium - enzyme activity
Trace elements needed
Cobalt, zinc, Manganese, Nickel, copper, molybdenum
if anything limiting in macro or micronutrients, microbes would
growth would stop
varied fueling reactions
CO2 > carbon source
Organic compounds > energy , carbon source, electron
Light > energy source
Organic carbon can derive from ______ ; can be used by __________ as _________ (3)
eg glucose, fatty acids, amino acids
heterotrophy bacteria
Used as:
- backbone for all cellular components (along with H & O)
- energy source - for fermentation or respiration
- supplies electrons
= CHO + O2 > CO2 + H2O + e-
= Reduced carbon, more energy (e-)
often preferred C-source
Glucose
which can use over 100 different C- compounds
Burkholderia cepacia
Many common soil bacteria can utilise unusual compounds such as
pesticides, rubber, antibiotics
Others highly, restricted like -Leptospira use only_______ for C source
long chain fatty acids
What is inorganic carbon ?
can be used by ________
fixed by ________ or ___________
Inorganic carbon (CO2) > a source of carbon autotrophy bacteria
- Must be reduced (fixed) for incorporation into cell building blocks
- Fixed in photosynthesis: CO2 + H2O > CH2O + O2
or chemically: CO2 + H2S > CH2O + S
Fixation is an expensive process, NOT a source of energy, needs an alternate source of energy (eg light)
Glucose is a source of
Carbon, hydrogen, oxygen
Cysteine is a source of
Carbon, hydrogen, oxygen, sulphur, nitrogen
Carbon dioxide is a source of
Carbon, oxygen
The sources of nutrients- Nitrogen compose organic/ inorganic molecules ? examples
Required for
-Organic molecules
- ammonia [can be incorparted into amino acid synthesis]
- nitrate (NO3-), which can reduce to ammonia (NH4+) via nitrate reduction
- Nitrogen gas via nitrogen fixation (N2 to NH3) eg Rhizobium in plants - nitrogenase
protein, nucleic acid, some lipids, carbohydrate
~50% of all nitrogen fixation is in ________ by _______
oceans, eg Cyanobacteria
Sources of nutrients: Phosphorus absorbed as __________
Sulphur absorbed as __________
Mostly absorbed as inorganic phosphate
Generally absorbed as sulphate (SO42+) and reduced (Assimilatory sulphate reduction)
Nutritional types of microbes
Define organisms by their carbon, energy and electron sources
Bacteria used reduced, preformed organic compounds as source of carbon
Heterotrophs
