title: Titrostat: a reliable technique for continuous cultivation of microorganisms utilizing liquid or gaseous water insoluble substrates.
abstract: We describe a method for continuous cultivation of microorganisms utilizing liquid or gaseous water insoluble substrates as a single source of carbon and energy. The water insoluble substrate, which is also the growth-limiting factor, enters the cultivation space as a manually adjustable single-compound material flow. All nonlimiting nutrients (with the exception of oxygen) enter the cultivation space as ingredients of titrant solution which feed rate is reliably coupled to the rate of substrate addition by means of the system titrator. The method provides mild starting conditions appropriate for primary isolation of microorganisms utilizing substrates with growth-inhibiting properties such as BTEX (benzene, toluene, ethylbenzene, and xylene). The sound control over the microbial specific growth rate makes it suitable for precise kinetic studies as well. We provide a detailed description of both the principles of the method and the equipment used. The dependence of the systems operative range on the concentration of titrant solution is illustrated in the case of continuous cultivation of a mixed bacterial culture on toluene.
authors.affiliation: Bulgarian Academy of Sciences, Institute of Microbiology, Acad G Bonchev St, Block 26, 1113 Sofia, Bulgaria.
authors.forename: S
authors.initials: S
authors.lastname: Mutafov
authors.forename: B
authors.initials: B
authors.lastname: Angelova
authors.forename: H-P
authors.initials: HP
authors.lastname: Schmauder
authors.forename: T
authors.initials: T
authors.lastname: Avramova
authors.forename: L
authors.initials: L
authors.lastname: Boyadjieva
mesh_terms: D000150:Acinetobacter / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D016954:Acinetobacter calcoaceticus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D000465:Algorithms; D000641:Ammonia / Q000378:metabolism / Q000494:pharmacology; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D005740:Gases / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008828:Microbiological Techniques / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012997:Solvents / Q000378:metabolism / Q000494:pharmacology; D017186:Titrimetry; D014050:Toluene / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D005740:Gases; D012997:Solvents; D014050:Toluene; D000641:Ammonia