Selective recovery of Streptosporangium fragile from soil by indirect immunomagnetic capture

• Published in: Microbiology (Society for General Microbiology) Vol. 141; no. 9; pp. 2149 - 2156
• Main Authors: Mullins, Paul H, Gurtler, Hanne, Wellington, Elizabeth M. H
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.09.1995; Society for General Microbiology
• Subjects: Actinomycetales - immunology; Actinomycetales - isolation & purification; Agronomy. Soil science and plant productions; Animals; Antibodies, Bacterial - immunology; Arthrobacter - isolation & purification; Bacteriological Techniques; Biochemistry and biology; Biological and medical sciences; Cation Exchange Resins; Chelating Agents; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; Immunomagnetic Separation; Microbiology; Microspheres; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Rabbits; Resins, Synthetic; Soil Microbiology; Soil science; Spores, Bacterial; Actinomycetales; Soils; Immunomagnetic method; Antibody; Bacteria; Isolation; Actinomycetes; Actinoplanaceae; Spores; Immunological method
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/13500872-141-9-2149

Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK Culture and Metabolite Collection, Novo Nordisk, Bagsvaerd, DK-2880, Denmark ABSTRACT A polyclonal antibody raised to Streptosporangium fragile spores reacted strongly and specifically with the immunizing strain and to a number of related species of Streptosporangium , as determined by dot immunoblotting. An indirect immunomagnetic capture method was developed for the recovery of the target organism from sterile and non-sterile soil, using sheep anti-rabbit M-280 Dynabeads. The effects of different soil blocking agents, antibody labelling concentrations and spore/Dynabead capture times on the recovery of S. fragile spores were investigated. Pre-blocking of antibody binding sites within the soil, with either 2% partially hydrolysed gelatin or 10% skimmed milk, was essential prior to immunomagnetic capture. Increasing the capture time from 15 to 60 min did not affect spore recovery; however, a 10-fold decline in the magnetic bead concentration did result in a significantly lower recovery of spores from soil. S. fragile was selectively enriched (1:190-fold) when present as a mixed population with Arthrobacter oxydans in sterile soil. The indirect immunomagnetic capture method was used to selectively recover S. fragile spores seeded into non-sterile soil, although some background binding of non-target bacteria was noted. The target was successfully recovered from a sterile soil microcosm after 14 d incubation and the capture rate was increased by the inclusion of an initial soil dispersion and biomass concentration procedure, using the ion-exchange resin Chelex 100. Tel: +44 1203 523184. Fax: +44 1203 523701. e-mail: eg@dna.bio.warwick.ac.uk Keywords: immunocapture, Streptosporangium , soil, magnetic beads, selective isolation