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.

Description

BACKGROUND OF THE INVENTION Technical Field

[0001] The invention relates to viruses which control and prevent growth of harmful microorganisms and to processes which employ such viruses. It also relates to protection of helpful microorganisms from virus attack. In particular, the viruses of the present invention lack genes for virulence factors, toxins, antibiotic resistance, and other undesirable genes, and include host-range (h-mutant) viruses which are specific for wild-type virus-resistant strains of targeted microorganisms. More specifically, viruses of the present invention are lytic, thus they control and prevent further growth of harmful microorganisms that infect animals or plants by destroying these microorganisms. Such viruses may also be employed to develop and select strains of beneficial microorganisms which are resistant to wild-type and h-mutant viruses.

[0002] Viruses are known to alter populations of microorganisms, such as bacteria, fungi, algae, and protozoa. It ...