Microthrix parvicella


Biological Products:



Bioaugmentation products for Wastewater applications in Papermills, Refineries, Chemical, Tanneries, Municipalities, Textiles, Steel, Agriculture, Animal feedlot,  Gun Powder plant, Food and Beverage- Dairy Products, Orange Juice factory, Wineries, Cookie factory, Vegetable processing plant, Meat packing, Barbecue Restaurant, Aquaculture, Ornamental Ponds for algae control, CAFO, Nursing homes, Military, Campgrounds, Universities, Regulatory agencies


Lab Services:



Filamentous Identification Lab Service. One reason to identify filaments is to determine the filaments characteristics and then determine the type present.  If the type is found out, a root cause can usually be associated with a particular filament.  If the cause is known, then a correction can be made to alleviate problems. Chlorination is only a quick fix.  Without process changes, filaments will grow back after chlorination.

Wastewater Biomass Analyses and Cooling Tower Analyses also available


Training Materials:



Training is an integral part of any job. Not everyone is at the same level of training. Many people want beginning concepts and basics. Some need technical information or troubleshooting. Some want equipment, technology or process information.

We have developed a full set of Basic training, Advanced training, Filamentous Identification the Easy Way as well as custom training CD's Manuals. We also provide hands-on training classes and soon will have an Online "E-University".




 Microthrix parvicella  

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M parvicella

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We hope you like the new look of our Filamentous Bacteria Identification Pages

If you would like more information on filaments, you might want to consider purchasing our Filamentous Identification the Easy Way Training materials.

We also have our lab that can perform a Filamentous identification lab analyses of your own MLSS for more information


Microthrix parvicella

This filament is very common in grease and oil environments. Don't get overly technical.  When trying to determine species, stick to the basics, and focus on the causes and controls of the filaments present. The main point of any filamentous identification is not to get a PhD, but to fix your plant!



 Medium length, non-motile filaments (100-400 µm).  Irregularly coiled filaments with no branching and no cell septa.  Cells are square (0.6 x 0.8 µm).    Filaments are found in spaghetti-like tangles within the floc structure causing open, lacy, diffuse floc  or in loose patches free in the bulk solution.  The filament staining is strongly Gram positive or Gram variable when in the floc structure and Neisser negative with Neisser positive granules observed frequently.  Short clear spaces may occur in the filament.  Usually easy to identify due to its staining characteristics. Intracellular  PHB granules may give beaded effect.  No sulfur granules.  No attached growth or sheath present.  It is a common cause of foaming.


Similar Organisms:

Nocardia  is similar in causes although Microthrix parvicella lacks the branching that Nocardia  has. Type 0914 looks similar although a bit larger and less spaghetti-like.




This filament is usually found in environments where there low F/M (0.05-0.2 lbs BOD) and with a long MCRT (10-40 days) but with high grease.  High wastewater grease and fat content are usually the biggest cause.  Found more commonly in the colder climates in the north. Municipalities that have high grease in lift stations can have high problems with this filament as well as Nocardia.  



F/M can be changed by decreased sludge wasting, changing from complete mix to plug flow. Grease control upstream with DAF or bioaugmentation can also help.


Very rarely is M. parvicella due to older sludge. Usually the main culprit is grease and oils. Optimize your collection systems, primaries. Use Bioaugmentation if needed, especially if a food plant or municipality that gets slugs of grease after high rains.


Microthrix parvicella  ranks 7th in number of predominance.


For more information on Filamentous Identification


Type 1701

More photos to come. . .


 If you need more information on our Filamentous Identification the Easy Way Training CD or on Internet training on Filamentous bacteria, causes and controls

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