Methylophilus methylotrophus

    Technical Data

    Type of microorganism Bacterium
    Microorganism name Methylophilus methylotrophus
    Temperature range
    pH range pH 6.5-7 (Vasey & Powell, 1984)
    Carbon and nitrogen source
    Growth  rate (µ) Maximum specific growth rate of 0.52/hour (Vasey & Powell, 1984)
    Companies (product)
    Wild-type or GMO Wild-type
    Feedstock case studies (suitable substrates) Methanol (Vasey & Powell, 1984)
    % SCP (w/w percentage of protein in dried biomass) 81.3% (Øverland et al., 2010)
    cell  biomass dry weight (CDW) = biomass yield? (g/L or g/g?) (weight of biomass/total weight or volume) 
    Protein content in final product 72% (w/w) for Pruteen
    Protein titer (g/L or g/g?) grams of protein / total weight or volume 35-42% (w/w) for the industrial Pruteen process (own calculation based on Vasey & Powell, (1984), with assumption that %SCP in this process is 81.3%, this is the average value of the Pruteen proces according to Øverland et al., (2010))
    Productivity (g/Lh) 6 for Pruteen on industrial scale on methanol as substrate (Vasey & Powell, 1984)
    Protein yield on C-source (% w/w) Biomass yield on C source is 50% for the industrial Pruteen process (Vasey & Powell, 1984). I then calculated the protein yield to be 40.65% (w/w) (with assumption that %SCP in this process is 81.3%, this is the average value of the Pruteen proces according to Øverland et al., (2010))
    Scale Was done on industrial scale (1500 m3 for Pruteen) (Westlake, 1986)
    Downstream purification processing complexity   Flocculation step by combination of heat shock and pH change (also to reduce nucleic acid content). This is seperated by floatation. Then a second seperation step is done by centrifugation (Westlake, 1986)
    Nucleic acid content 15.9% (Øverland et al., 2010)
    Techno-functional and/or nutritional properties (e.g. meat-like texture, amino acid profile, digestibility) High protein content (all amino acids present). All amino acids present in similar amounts as standard fish feed. (Øverland et al., 2010)
    Target application (Food, feed, other) Pruteen was used in feed.
    Advantages Rich in proteins, all amino acids present.
    Challenges (Key limitations, risk factors) Price of substrate (methanol) is high, leading to shutdown of previous products (Pruteen). No regulatory status for use in food anywhere in the world, for feed only in Europe.
    Regulatory status in Europe Allowed for use in feed Europe. Not allowed in food
    Regulatory status in other parts of the world No evidence found that it is allowed as biomass fermentation product in Canada, US or Singapore
    Extra/remark
    Publications/references