TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred System: In the wastewater treatment unit (T1), the device for separating is selected from: a clarifier vessel, a dissolved air flotation vessel, or a membrane bioreactor, which is connected to the growth vessel with a device for recycling the bacterial suspension in the aqueous bulk liquid between the growth vessel and the clarifier vessel, dissolved air flotation vessel, or membrane bioreactor. The wastewater treatment unit (T1) further comprises device for dewatering and is disposed between the device for removing the bacterial mass and the drier.    TECHNOLOGY FOCUS - FOOD - Preferred Process: In method (M1): MCRT is less than or equal to 6 days, and MWRT-MCRT is less than or equal to 1 day; the separating is carried out by gravity separating, dissolved air flotation, or by a membrane bioreactor; the aqueous waste stream added to the growth vessel comprises dissolved and/or suspended metabolizable food or beverage byproducts from a food processing plant producing human or animal food; and the drying is carried out for about less than or equal to 1 day, at 65-95 (preferably 80) degrees C. The aqueous waste stream comprises dissolved and/or suspended metabolizable food or beverage byproducts from a food processing plant producing human or animal food. The bacterial culture comprises bacteria selected from: genetically modified bacteria, Micrococci, Bacilli, Flavobacteria, methanogens, Pseudomona, Nitrosomona, Nitrobacteri, nitrifying bacteria, and/or aerobic heterotrophs. The process (M1) further involves dewatering the removed bacterial mass prior to the drying. The nutrients selected from macronutrients, micronutrients, vitamins, and/or amino acids are added to the bacterial growth vessel. The macronutrients are biologically assimilable sources of C, H, O, N, and P. The vitamins are selected from vitamin A, vitamin B1, vitamin B2, vitamin B3, vitamin B5, vitamin B6, vitamin B7, vitamin B9, vitamin B12, vitamin C, vitamin D, vitamin E, and vitamin K. The aqueous bulk liquid has a BOD of 200-200000 mg/l. The dried bacterial mass has a ratio of protein/ash of about 6.0/1 to 8.0/1. The process is a continuous process or a batch process. The MCRT is about 1-6 days. In the process (M2): the first signal is associated with a concentration of the first portion of the bacterial mass within the first portion of the aqueous bulk liquid; the first portion of the aqueous bulk liquid is within a waste stream entering the waste water treatment system; and the first signal is associated with a flow rate of the waste stream entering the waste water treatment vessel; the second signal is associated with at least one of a concentration of the second portion of the bacterial mass within the second portion of the aqueous bulk liquid and a flow rate of the second portion of the aqueous bulk liquid; the predetermined range is 2-8 days; and the adjusting includes: calculating a pump control signal based on the calculated MCRT of the bacterial mass within the waste water treatment system and a target MCRT within the predetermined range; and transmitting the pump control signal to a variable-speed pump disposed within a flow path of the second portion of the aqueous bulk liquid exiting the waste water treatment system. The method (M2) further involves: adjusting the flow rate of the second portion of the aqueous bulk liquid such that a mean waste residence time of the bacterial mass is within a predetermined range. The method (M3) further involves: generating an invoice reflecting the adjusted contract price. At least one of: the calculating the processing cost and the calculating the recovery value is performed continuously when the BOD level of the aqueous waste stream is being reduced. Calculating the processing cost includes: receiving a first signal associated with a flow rate of the aqueous waste stream into a waste water treatment system; receiving a second signal associated with the input BOD level of the aqueous waste stream; calculating several processing costs as a function of time, each processing cost from the processing costs is calculated based on the first signal and the second signal; and calculating an arithmetic mean of the processing costs for predetermined period. Calculating the recovery cost includes: receiving a signal associated with a flow rate of the bacterial mass removed from the aqueous waste stream; receiving a signal associated with a protein content of the bacterial mass removed from the aqueous waste stream; and receiving input associated with a market price for animal feed. At least one of the calculating the processing cost and the calculating the recovery value includes calculating a mean cell retention time of the bacterial mass within a waste water treatment system. At least one of the calculating the processing cost and the calculating the recovery value includes calculating a mean waste residence time of the bacterial mass mean. In the method (M4): the adjusting includes: adjusting a target MCRT and MWRT of the bacterial mass within a waste water treatment system; and transmitting a pump control signal to a variable-speed pump disposed within the waste water treatment system. In the process (M1): the process involves prior to the step (A), receiving the aqueous waste stream from a food and/or beverage processing plant comprising dissolved or suspended metabolizable food and/or beverage byproducts with BOD levels of 100 mg/l. The dried bacterial mass is provided to animal feed producers as a replacement for fish meal in animal feeds. The bacterial mass is dried to a solids content of at least 80% and is provided as an animal feed ingredient. The method (M1) further involves: determining the protein content of the dried bacterial mass; diverting bacterial mass having a protein content greater than or equal to 40% to a storage vessel; diverting bacterial mass having a protein content of less than 40% to a waste vessel; and providing the bacterial mass with a protein content greater than or equal to 40% as a protein source for animal feed. Preferred Composition: The dried and deactivated bacterial mass has: crude protein content of at least 60%; vitamin B12 content of greater than 5 mg/kg; true protein content of greater than 55%; a pMC value of at least 90; and the protein/ash ratio of 6.0/1 to 8.0/1. The composition (C1) comprises amino acids as follows (%): alanine (4.65), arginine (2.02), aspartic acid (5.43), glutamic acid (4.12), glycine (3.46), histidine (0.86), isoleucine (2.26), leucine (3.57), lysine (2.57, methionine (1.25, cystine (0.31, phenylalanine (2.07, proline (2.19), serine (1.45), threonine (3.21), tryptophan (0.74), tyrosine (2.18), and valine (3.13), (total 45.47%, and crude protein 53.80%); or alanine (3.82), arginine (3.60), aspartic acid (6.36), glutamic acid (8.04), glycine (2.81), histidine (1.46), isoleucine (3.38), leucine (5.06), lysine (4.34), methionine (1.41), cysteine (0.55), phenylalanine (3.29), proline (2.77), serine (2.82), threonine (3.11), tryptophan (0.98), tyrosine (2.83), and valine (3.52), (total 60.15%). The composition further comprises carbon compounds from sources selected from vegetables, fruits, and sugars. EXAMPLE - A wastewater stream having a biochemical oxygen demand (BOD) level of 5000 mg/l (no anaerobic pretreatment) was introduced at a rate of 3 gallons per minute into a continuously stirred tank reactor (CSTR) containing a mixed community of unidentified bacteria obtained from the aerobic basin of a wastewater treatment serving a brewery. Activated sludge was not returned to the aerobic basin so the hydraulic residence time (HRT) of 2 days equaled the mean bacterial cell retention time (MCRT). The microorganisms were fed excess nitrogen and phosphorus in the form of urea and phosphoric acid, as well as an aqueous mixture of micronutrient metals and consisting of (wt.%): soluble aluminum compounds (less than 1), boric acid (less than 1), citric acid (less than 1), cobalt sulfate (1-5), copper sulfate (1-5), ferric chloride (1-5), manganese sulfate (1-5), nickel chloride (1-5), sodium molybdate (1-5), yeast extract (less than 1), and zinc sulfate (1-5), of the final mixture. This micronutrient mixture was added at 1 mu l/250 ml of wastewater. Process operating conditions therefore provided mean waste residence time (MWRT) value of 2.5 days, and MWRT-MCRT of 0.5 days. Biomass was removed from the CSTR and dewatered in a high-speed continuous centrifuge to a solids content of about 6%. The dewatered biomass was then dried at 68 degrees C for 12 hours to obtain a protein animal feed additive. The single cell protein feed additive had the following contents: crude protein (64.7%); crude fat (5%); mineral material (15%); crude fiber (5.5); and total amino acids (60.15%), and vitamins as follows (mg/kg): niacin (83.3), thiamine B1 (7.7), riboflavin (39), vitamin B12 (12), and vitamin E (29.8 IU/kg).