Features
of
Different
Microorganisms
and
the
SCP
Produced
From
Them -
Feature |
Algae |
Bacteria |
Yeast |
Filamentous fungi |
Growth Rate |
Low |
Highest |
Quite high |
Lower than bacteria and yeast |
Substrate |
Light, inorganic carbon sources, e.g., CO2 (preferably) |
A wide range of substrates |
Most substrates, except, hydro carbons and CO2 |
Limited substrates (mostly starchy and cellulosic materials) |
| PH range |
Upto II |
5 -7 |
5 -7 |
3 -8 |
Cultivated in |
Open ponds, tanks; in sunlight |
Bioreactors |
Bioreactors |
Bioreactors |
Risk of contamination |
Serious |
High; precautions necessary |
Low |
Low if grown below pH 5 |
Biomass recovery |
Difficult and costly with unicellular algae |
Problematic; improved methods are needed |
Easy; by centrifugation |
Easy for filamentous or pellet forms |
Protein content (crude) |
Up to 60% |
80% or more |
55 - 60% |
50 - 55% |
Amino acid profile |
Generally good; low in S - containing amino acids |
Generally good; a small deficit in S - containing acids |
Generally good; deficit in S - containing amino acids |
Low in S - containing amino acids |
Nucleic acid content |
- |
Very high (20% RNA) |
High (15% RNA) |
High (15% RNA) |
Removal of nucleic acids |
- |
Necessary |
Necessary |
Necessary |
Toxins
|
- |
Geam bacteria may produce endotoxins |
- |
Many species produce mycotoxins |
| Other features |
1. Low yield (1-2 g dry wt/1)
2. High chlorophyll content; unsuitable for humans |
- |
High B vitamin content |
Chitin may contain a significant proportion of N content, which is unavailable |
|
