Ultrasound and acoustophoresis for collection and processing of oleaginous microorganisms

Abstract

Microorganisms such as micro algae are collected and separated from a host medium such as water. Cellular walls and membranes of the microorganisms are then ruptured to release their lipids using a lipid extraction unit. Thereafter, the lipids from the host medium are collected and separated using a lipid collection and separation unit. Related apparatus, systems, techniques and articles are also described.

What is claimed is: 
     
         1 . A method for collecting lipids from microorganisms, comprising:
 separating microorganisms from an initial mixture of a host fluid and microorganisms;   rupturing the microorganisms to release lipids; and   collecting the lipids.   
     
     
         2 . The method of  claim 1 , wherein the microorganisms are separated from the initial mixture using a first acoustic standing wave. 
     
     
         3 . The method of  claim 1 , wherein the microorganisms are ruptured using a second acoustic standing wave. 
     
     
         4 . The method of  claim 1 , wherein the lipids are collected using a third acoustic standing wave. 
     
     
         5 . The method of  claim 1 , wherein the microorganisms are ruptured by cavitation. 
     
     
         6 . The method of  claim 1 , wherein the lipids are collected by agglomerating such that their buoyancy causes the lipids to float to the top of a flow chamber to result in a lipid layer, the lipid layer being collected. 
     
     
         7 . The method of  claim 1 , wherein the microorganisms are microalgae, yeast, fungi, bacteria, or spores. 
     
     
         8 . The method of  claim 1 , wherein the microorganisms are separated from the host fluid by being driven into a collector pocket. 
     
     
         9 . The method of  claim 1 , wherein the microorganisms are separated from the host fluid by frequency sweeping of a first acoustic standing wave to translate the microorganisms toward a wall of a flow chamber. 
     
     
         10 . An apparatus comprising:
 a first flow chamber comprising at least one first ultrasonic transducer and a first reflector surface opposite the at least one first ultrasonic transducer; and   a second flow chamber operatively connected to the first flow chamber, the second flow chamber comprising at least one second ultrasonic transducer and a second reflector surface opposite the at least one second ultrasonic transducer.   
     
     
         11 . The apparatus of  claim 10 , further comprising a third flow chamber operatively connected to the second flow chamber, the third flow chamber comprising at least one third ultrasonic transducer and a third reflector surface opposite the at least one third ultrasonic transducer. 
     
     
         12 . The apparatus of  claim 11 , wherein the third flow chamber further comprises a recirculation unit comprising a tank, an inlet, an outlet, at least one recirculation arm, and a transducer in either the tank or the at least one recirculation arm. 
     
     
         13 . The apparatus of  claim 12 , wherein the transducer is in the tank and is a plate transducer. 
     
     
         14 . The apparatus of  claim 12 , wherein the transducer is in the tank and is an array transducer. 
     
     
         15 . The apparatus of  claim 12 , wherein the transducer is in the at least one recirculation arm and is a flat transducer. 
     
     
         16 . The apparatus of  claim 12 , wherein the transducer is in the at least one recirculation arm and is a ring transducer.