Survival of microorganisms after drying and storage

Abstract

Bacteria, yeasts and fungi suspended in a dextran solution were added to ampoules containing strips of filter paper which were dried without vacuum conditions. The ampoules were sealed and stored in the dark at room temperature. Viability counts were made of the original suspension immediately after drying and after storage periods of 3-48 months. Although bacterial cultures of many general did not show much resistance against dry conditions, bacteria of 13 other general had survived well or moderately after 4 years of storage. Most of the dried yeast cultures had survived after this period. Of the 16 fungal genera tested, species of 6 genera exhibited growth after 4 years. Results of this study were compared with those of two other preservation methods by which the same microorganisms were used.

Desiccation tolerance of prokaryotes.

“…The survival rates of Arthrobacter, Pseudomonas, Mycobacterium, Escherichia, Micrococcus, and Saccharomyces cells were rather similar when the cells were counted immediately after fast or slow drying (20 min and 24 h, respectively). After prolonged storage, viabilities were higher for slow-dried, as opposed to fast-dried, cells (11,12). These observations were true for E. coli only when more than about 8 mg of water per 108 cells was present on paper filters.…”

“…To dry cells in air, cultures may be applied to some inert support which can be held, until dry, under a vapor phase of controlled humidity or a stream of air. Immobilization of cells on dry sand or dry paper has been used to preserve the viability of beta-hemolytic streptococci and other bacteria for more than 4 years (12,213).…”

Responses of Rhizobia to Desiccation in Relation to Osmotic Stress, Oxygen, and Temperature

“…Dysfunction of intracellular enzymes has been proposed to be responsible for cell death at 83% RH. Antheunissen et al (2) showed that when dried slowly, rhizobia can survive desiccation for up to 4 years. These long-term storage studies are rare, but they show that in the family Rhizobiaceae, sinorhizobia can survive desiccation for years.…”

Implementación y evaluación de dos métodos deconservación y generación de la base de datos del banco de cepas y genes del Instituto de Biotecnología de la Universidad Nacional de Colombia (IBUN)

“…Como se observó en este estudio, en lo referente a la preservación realizada en papel filtro, Antheunisse en 1981 encontró que esta técnica fue adecuada para 13 géneros de bacterias incluyendo E.coli, Pseudomonas y otras Enterobacterias, con una buena o moderada supervivencia (11).…”