Aerobic heterotrqphic bacteria isolated from water, mud, and macrophytes of Lake Grasmere, New Zealand

Abstract

Aerobic heterotrophic bacteria were isolated from the water, mud, Elodea canadensis, and concentrated plankton of Lake Grasmere in inland Canterbury (43° 05' S, 171° 45'E) at intervals between April 1969 and July 1971. The characteristics of 1567 isolates are described. The bacteria were assigned to the following groups: pseudomonads, pink-pigmented pseudomonads, Alcaligenes/ Achromobacter, flavobacteria, Cytophaga, Enterobacteriaceae, Aeromonas/Vibrio, Acinetobacter, Chromobacterium, coryneforms, Micrococcaceae, and Bacillus. In the water the predominant bacteria in most of the samples were pseudomonads, Alcaligenes/Achromobacter, flavobacteria, and coryneforms. The bacterial population varied from year to year but at any one time the bacteria isolated from different areas of the lake were similar. Three mud samples were examined: only 20% of the bacteria isolated from a sample from the surface of the mud were Gram-positive, but the other two samples from up to 5 cm deep in the mud included 49% and 74% Gram-positive bacteria. Elodea canadensis supported an epiphytic population, predominantly of pseudomonads and flavobacteria, which was more stable than the population in the water. Enterobacteriaceae and Aeromonas/Vibrio, although common at times in the water, were rarely isolated from E. canadensis. Bacteria were enumerated from samples of concentrated plankton as the numbers of algae and zooplankton fluctuated. Less than 17% of the colony-forming heterotrophic bacteria were in close association with the plankton. No particular group of bacteria became more common as the plankton populations died back.

Enumeration and Characterization of Bacterial Colonists of a Submersed Aquatic Plant, Eurasian Watermilfoil ( Myriophyllum spicatum L.)

“…On the other hand, colonies with different physical properties sometimes had similar cellular and biochemical properties and therefore may belong to the same bacterial group (Table 2). Similar observations were also recorded by Ramsay (18). During bacterial culture purification and subculturing, we observed that the colony characteristics of each bacterial isolate remained stable if growth medium and incubation temperature were not changed.…”

“…have been reported to be the most dominant bacterial groups associated with another freshwater macrophyte, Ranunculus penicillatus (7). Ramsay (18) reported that Pseudomonas spp., Flavobacterium spp., coryneforms, and enterobacters were the predominant genera associated with Elodea canadensis in a freshwater lake.…”

“…The isolates were then placed into broad bacterial groups by a modification (Fig. 1) of the approach described by Ramsay (18).…”

Difference in bacterial floras among different size fractions of suspended particles in a hypertrophic pond.

“…The dominant genera of heterotrophic bacteria isolated from the water of Himon-ya Pond were found to be Pseudomonas (including Pseudomonas-like type), Flavo bacterium, Moraxella, Caulobacter, and Acinetobacter, being similar to those isolated from the waters of various lakes and ponds by several investigators (LIGHTHART, 1975;RAMSAY, 1977;TANAKA et al, 1977;KONDA and TEZUKA, 1979;STALEY et al, 1980;KoNDA, 1982;TEZUKA et al, 1982). However, the dominancy of these genera clearly differed among the bacterial populations in the four fractions separated by size fractionation of suspended particles in the pond water (Fig.…”

“…Their bacterial floras also showed the highest diversity during October and November, when suspended particles such as dead organisms and detritus seemed to increase with decreasing algal biomass. SIMIDU et al (1971SIMIDU et al ( , 1977, RAMSAY (1977), SOCHARD et al (1979), MATSUDA (1974), andTANAKA et al (1980) evidenced clear differences in the bacterial floras developed on different kinds of suspended particles, such as phytoplankton, zooplankton, particulate detritus, and particulate inorganic matter, in natural aquatic environments. FU-KAMI et al (1981), KOGURE et al (1982), and reported that the particle-associated bacterial flora fluctuated during the decomposition process of phytoplankton cells or detritus particles under experimental conditions.…”