Lect 8 Flashcards
Microbial products are important in
They grow
Food
Feed
Agriculture
Healthcare
On various medi
Microbes produces
Amino acids
enzymes
vitamins
organic acids alcohol
antibiotics
peptides
growth factors
Bioactive metabolites
Single cell proteins are
Microbes have …and can grow…
These proteins are either..or …
Purified/edible proteins from microbes
High protein content
Low cost media(ag waste)
Food or feed grade
SCP are rich in …which is absent in most plants and animals
First SCP….up to…for…by….
Essential amino acids (lysine/methionine)
Pruteen
70% protein
Pig feed
Oxidation of methanol by methylophilus methylotrophus
Imperial chemical industries
Needs and advantages for microbial SCP
sustainable
Cost effective
Relief to agricultural sector
Wide variety of substrate
Fast growth and high yield
Can be tailored
Climate resistant
Pharma and biofuels
Production steps
Selection
Fermentation
Harvesting
Processing
Selection general criteria
Non toxic
Non pathogenic
Resistant to pH/temp/mineral conc
Cheap and effective substrate
Easy extraction
High yield
Algae selection
Ex
Adv
Disadv
Spirulina and chlorella
Solar energy/fast growth/ easy cultivation/60%protein of good quality expect cysteine which contains sulfur
High chlorphyl causes gut problems
Crllulose undigestable by humans
Low cell density 1-2g/l
Costly recovery (filteration/skimming)
Fungi selection
Ex
Adv
Disadv
Quorn by venenatum
Tastes like meat so good for animal alternative
Easy recovery by filtration
50-55% good aa
Slow growth
Yeast contamination if not sterilised frequently
Bacterial contamination if ph is higher than 5
Mycotoxin production
Bacteria
Methylophilus/bacillus/brevibacterium
Wide substrate range
Fast growth and short generation time
Pathogenic contamination
Endotoxin by gram -ve
Fermentation is done in…which is ..or.under….with controlled……usually…..
Fermentor
Glass or stainlesssteel
Sterile conditions
Temp/pH/humidity
Fed batch
Harvesting is either by..or…
Afterwards…under..
Centrifugation(yeast and bacteria)
Filtration (filamentous fungi)
Drying, sterile conditions
Processing is done to…..like
Protein isolation is done by disrupting…by….
Remove impurities
Carbs,nucleic acids,lipids,salts
Cell wall
Freezing and thawing cycles
Crushing
Grinding
Thermal shock
Problems with SCP
High nucleic acid conc then any other protein source leading to high uric acid concentrations leading to gout and kidney stones
Indigestible cell wall
Yeast> nausea, vomiting, gastrointestinal reactions
Algae> chlorophyll
Filamentous fungi» slow growth means high contamination risk, might produce mycotoxins
Microbial enzymes are used in
…as they….
Their nature
Metabolic and biochemical reactions
Lower the activation energy
Proteins except for ribozymes
Highly specific
Why enzymes from microorganisms not from plants or animals
More active and stable
Large scale production
Easier production/extraction/purification
Limited space and time req
Work in different environments
Independent of seasons
Process for enzymes
Slee tion
Media formulation
Production
Recovery and purification
Selection rules
Post selection
for enzymes
Maximum quantities of the enzyme in the shortest time possible with minimal byproducts
Strain improvements to optimize enzyme production by mutation or genetic engineering
From the organism chosen …can be taken in…
An inoculum
Liquid media
Media formulation
All nutrients for adequate growth
Low cost ingredients and nutritionally safe
Optimal pH
Production
Submerged fermentation is mainly used
Solid state fermentation is also used for fungal enzymes
Fungal enzymes
Amylases
Cellulases
Proteases
Pectinases
Purification and extraction
Enzyme is either..or..
Then…
Extracellular, excreted/ intracellular in the cell
Precipitated using solvents like acetone or alcohol
Last steps fpr enzyme
Either drying by…or…
Commercial enzyme maybe ….or…
Sold in …form or…
Filtering and drying
Low temp
Vacuum drying
Crude/ highly purified
Dry powder
Concentrates
