Compositions and methods are provided for use in controlling souring and corrosion causing prokaryotes, such as SRP, by treating oil and gas field environments or treatment fluids with a newly identified bacterial strain ATCC Accession No. PTA-124262 as a self-propagating whole cell that produces an anti-SRP bacteriocin in situ. In another aspect, the methods use one or more toxic peptides or proteins isolated therefrom in methods to control unwanted prokaryotic growth in these environments.

A process is disclosed for production of a polyhydroxyalkanoate that includes depolymerization of a post-consumer polyhydroxyalkanoate and utilization of the hydroxyalkanoate monomer thus produced as a carbon source for a microorganism capable of production of a polyhydroxyalkanoate. Methods can be utilized for true cyclic use of polyhydroxyalkanoates including polyhydroxybutyrates. Various aspects are described including simultaneous depolymerization and polymer production, utilization of purified depolymerase enzymes and/or microorganisms that express a depolymerase in conjunction with a microorganism that produces polymer, utilization of microorganisms that produce both a depolymerase and a new polymer, and utilization of genetically modified organisms to produce natural or modified depolymerase enzymes.

Non-naturally occurring vesicles derived from bacteria, e.g., pathogenic bacteria, methods for making the vesicles, and methods for using compositions of these vesicles are disclosed. Methods of using the vesicles include prevention and/or treatment of bacterial infections. Also provided herein are compositions that include vesicles derived front bacteria and tumor vesicles, methods for making the tumor vesicles, and methods for using the compositions of bacterial vesicles and tumor vesicles. Methods of using the compositions of bacterial vesicles and tumor vesicles include treatment of cancer in a subject. Tumor vesicles may be derived from cancer cells present in the subject to be treated or from a cancer cell line expressing at least one neoantigen. The neoantigen may be specific to the subject and may have been identified by sequencing of the cancer cells from the subject. The neoantigen may be a neoantigen known to be commonly expressed in a particular type of cancer.