Use of viruses and virus-resistant microorganisms for controlling microorganism populations

Abstract

A lytic virus specific for a target strain of a microorganism and substantially free of undesirable genes may be utilized in processes including control of populations of microorganisms. The virus may include a host-range mutant, or “h-mutant.” A method for generating virus includes growing virus-resistant variants of a target strain of a microorganism in the presence of viruses that are specific for the target strain. Only h-mutant viruses will proliferate. Wild-type virus-resistant and virus-resistant variants of a microorganism are also disclosed, as are methods generating such variants. Methods for controlling target strain microorganisms include introducing virus into a treatment site where control of a population of a target strain microorganism is desired or introducing virus-resistant variants of a microorganism into treatment sites where the presence of the microorganism is desired.

1 . A composition for controlling a population of a beneficial microorganism, comprising a virus-resistant variation of the beneficial microorganism.  
   
   
       2 . The composition of  claim 1 , wherein the virus-resistant variation comprises resistance to a wild-type of a virus specific for the beneficial microorganism.  
   
   
       3 . The composition of  claim 1 , wherein the virus-resistant variation comprises resistance to an h-mutant virus specific for the beneficial microorganism.  
   
   
       4 . The composition of  claim 1 , further comprising: 
 an h-mutant virus specific for an undesirable microorganism.    
   
   
       5 . The composition of  claim 1 , wherein the beneficial microorganism comprises at least one of  Pantoea annanus, Serratia entomophilia, Enterobacter aerogenes, T. ferroxidans , a member of the genus  Acidiphilium , a member of the genus  Rhodococcus , a member of the genus  Sulfobus , and a member of the genus  Thiobacillus.    
   
   
       6 . A method of controlling a population of a beneficial microorganism, comprising introducing a virus-resistant variation of the beneficial microorganism into a treatment site.  
   
   
       7 . The method according to  claim 6 , wherein introducing comprises exposing a toxic chemical or other pollutant to the virus-resistant variation of the beneficial microorganism.  
   
   
       8 . The method according to  claim 6 , wherein introducing comprises introducing at least one of  Pantoea ananus, Serratia entomophilia, Enterobacter aerogenes, T. ferroxidans , a member of the genus  Acidiphilium , a member of the genus  Rhodococcus , a member of the genus  Sulfobus , and a member of the genus  Thiobacillus  into the treatment site.  
   
   
       9 . The method according to  claim 6 , wherein introducing is effected to control growth of fungi.  
   
   
       10 . The method according to  claim 6 , wherein introducing is effected to control the proliferation or spread of an insect population.  
   
   
       11 . The method according to  claim 10 , wherein introducing is effected to control the proliferation or spread of insect populations as exemplified by New Zealand grass grub and locusts.  
   
   
       12 . The method according to  claim 10 , wherein introducing includes applying the virus-resistant variation of the beneficial microorganism to a plant.  
   
   
       13 . The method according to  claim 6 , wherein introducing is effected to oxidize sulfide to sulfuric acid.  
   
   
       14 . The method according to  claim 6 , wherein introducing is effected to release petroleum and petroleum-related substances from bituminous shale.  
   
   
       15 . The method according to  claim 6 , wherein introducing is effected to acidify sulfur.  
   
   
       16 . The method according to  claim 6 , wherein introducing effects at least one of acidifying alkaline soil, decomposing rubber products, bioremediating hazardous chemicals or pollutants, treating sewage or wastewater, treating odors or sources of odors, fermentation processes.  
   
   
       17 . A method of generating a virus-resistant variant of a microorganism, comprising: 
 isolating an h-mutant virus by exposing a wild-type microorganism to a virus specific for the wild-type microorganism;    isolating a virus-resistant variant of the microorganism by exposing the wild-type microorganism to the h-mutant virus;    isolating at least one second h-mutant virus by exposing the virus-resistant variant of the microorganism to the at least one h-mutant virus; and    isolating at least one second virus-resistant variant of the microorganism by exposing at least one of the wild-type microorganism and at least one type of virus-resistant variant of the microorganism to the at least one second h-mutant virus.    
   
   
       18 . The method according to  claim 17 , wherein at least one of isolating the virus-resistant variant and isolating the at least one second virus-resistant variant comprises growing at least one of the wild-type microorganism and the virus-resistant variant in the presence of an h-mutant virus specific for the microorganism.  
   
   
       19 . The method according to  claim 18 , wherein isolating the at least one second virus-resistant variant comprises isolating at least one second virus-resistant variant having resistance to infection by a plurality of h-mutant viruses.  
   
   
       20 . A composition for controlling populations on food products of a microorganism that is pathogenic to a mammal, comprising an h-mutant virus specific for and capable of infecting a virus-resistant variation of a target strain of the microorganism.  
   
   
       21 . The composition of  claim 20 , wherein the microorganism are enteric pathogens, as exemplified by  Salmonella, Campylobacter , or  E. coli.    
   
   
       22 . The composition of  claim 20 , wherein the target strain comprises  E. coli  0157:H7.