Rapid Method for Isolation of Desiccation-Tolerant Strains and Xeroprotectants

• Published in: Applied and Environmental Microbiology Vol. 76; no. 15; pp. 5254 - 5262
• Main Authors: Narváez-Reinaldo, J.J, Barba, I, González-López, J, Tunnacliffe, A, Manzanera, M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01-08-2010; American Society for Microbiology (ASM)
• Subjects: Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Bacteria - metabolism; Biological and medical sciences; Cells; Chloroform; Colony Count, Microbial; Desiccation; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Drying agents; Fundamental and applied biological sciences. Psychology; Magnetic Resonance Spectroscopy; Methods; Microbial Viability; Microbiology; Microorganisms; Molecular Sequence Data; Molecules; NMR; Nuclear magnetic resonance; Protective Agents - chemistry; Protective Agents - isolation & purification; Protective Agents - metabolism; Proteins; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Soil Microbiology; Stress, Physiological; Tolerance; Isolation; Method; Desiccation
• ISSN: 0099-2240; 1098-5336; 1098-6596
• DOI: 10.1128/AEM.00855-10

A novel biotechnological process has been developed for the isolation of desiccation-tolerant microorganisms and their xeroprotectants, i.e., compatible solutes involved in long-term stability of biomolecules in the dry state. Following exposure of soil samples to chloroform, we isolated a collection of desiccation-tolerant microorganisms. This collection was screened for the production of xeroprotectants by a variation of the bacterial milking (osmotic downshock) procedure and by a novel air-drying/rehydration ("dry milking") incubation method. The resultant solutes were shown to protect both proteins and living cells against desiccation damage, thereby validating them as xeroprotectants. Nuclear magnetic resonance (NMR) analytical studies were performed to identify the xeroprotectants; synthetic mixtures of these compounds were shown to perform similarly to natural isolates in drying experiments with proteins and cells. This new approach has biotechnological and environmental implications for the identification of new xeroprotectants of commercial and therapeutic value.