The Effect of Solid Surfaces upon Bacterial Activity

Abstract

The bacterial population of water samples from the sea, lakes or other sources usually increases during storage. While several different factors may be operative (Prescott and Winslow, 1931), it is noteworthy that the magnitude of the increase is often related to the size of the receptacle in which the water is stored. For example, Whipple (1901) found that the bacterial population of water, which initially contained an average of 77 bacteria per ml., increased to 300 per ml. in a gallon, 900 per ml. in a quart, 7,020 per ml. in a pint and 41,400 per ml. in 2-ounce bottles after 24 hours' incubation under comparable conditions. He attributed this to the greater availability of oxygen in the small receptacles which were not filled to capacity. However, ZoBell and Stadler (1940) have shown that the multiplication and respiration of aerobic bacteria is independent of the oxygen tension within the examined ranges of 0.30 to 36 mgm./liter. Using oxygen consumption as well as bacterial multiplication in glass-stoppered bottles filled to capacity with sea water as criteria, ZoBell and Anderson (1936) noted that bacteria are generally more active in small than in large receptacles of similar shape. Since the small receptacles present relatively more solid surface per unit volume of stored water than large receptacles, they concluded that solid surfaces are beneficial to bacteria in dilute nutrient solutions. A similar conclusion was reached by Lloyd (1937). The following report is concerned with the ways in which solid or adsorbing surfaces may influence bacterial activity. GLASS SURFACES ADSORB NUTRIENTS Inasmuch as the effect of volume or solid surfaces upon bacterial activity can be demonstrated only in very dilute nutrient solutions and since the effect is more pronounced with colloidal than with dissolved nutrients, ZoBell (1937) suggested that nutrients may be concentrated on solid surfaces. This explanation is supported by more recent observations here and elsewhere. The work of ZoBell and Grant (1943) shows that bacterial activity is directly proportional to the concentration of nutrients when the latter is less than 10 mgm./l. Since sea water ordinarily contains less than 5 mgm./l. of organic matter (Krogh, 1931), only a small part of which is readily attacked by bacteria (Waksman and Carey, 1935a), it follows that any factor which tends to concentrate the organic matter would promote bacterial activity. Although the small quantity and complexity of the organic content of sea water make it difficult to estimate the amount which is adsorbed by glass or other solid surfaces under different conditions, there are several ways in which Contribution from the Scripps Institution of Oceanography, New Series No. 204.

Bacterial exopolymer and PHB production in fluctuating ground-water habitats

“…1) may be seen as a change in the rate of production in response to a surfaceassociated stimulus, that is used by the cell to achieve irreversible sorption. This behaviour of enhanced polymer synthesis upon sorption is consistent with the early observations by ZoBell [49], confirmed by e.g. [38,50], of two phases of sorption, the second of which was associated with production of extracellular adhesive material.…”

Sorption of Streptococcus suis on various soil particles from an Alfisol and effects on pathogen metabolic activity

“…Sorption of nutrients on soil particles is helpful for attached bacteria. Solid particles larger than bacteria were reported to be more beneficial than smaller ones (Zobell, 1943). Therefore, the improved growth of S. suis in the exponential stage may be attributed to the accumulation of nutrients on the surfaces of silts and sands.…”

Advantages to microbes of growth in permeable aggregates in marine systems1

“…Heterotrophic bacteria degrade and decompose organic matter, so attachment to zooplankton feces, lysed phytoplankton, or other particulate organic matter clearly provides increased substrate availability to attached microorganisms capable of digesting those substrates. ZoBell(1943) and Kjellcbcrg et al ( 1983) speculated that nonnutritive surfaces concentrate dilute substrates. An increased availability of substrate would result in enhanced microbial growth at surfaces when compared to growth of dispersed cells, assuming growth is proportional to substrate concentration.…”