Rj. Ellis et al., Comparison of microbial and meiofaunal community analyses for determining impact of heavy metal contamination, J MICROB M, 45(3), 2001, pp. 171-185
The impact of long-term heavy metal contamination on soil communities was a
ssessed by a number of methods. These included plate counts of culturable b
acteria, community level physiological profiling (CLPP) by analysis of the
utilization of multiple carbon sources in BIOLOG plates, community fatty ac
id methyl ester (C-FAME) profiling and dehydrogenase enzyme activity measur
ements. These approaches were complemented with microscopic assessments of
the diversity of the nematode community. Samples from two sites with differ
ent histories of heavy-metal input were assessed. Major differences in micr
obial and meiofaunal parameters were observed both between and within the s
ites. There was a large degree of congruence between each of the microbiolo
gical approaches. In particular, one sample appeared to be distinguished by
a reduction in culturable bacteria (especially pseudomonads), limited resp
onse to carbon sources in CLPP, and major differences in extracted fatty ac
id profiles, The use of multivariate analysis to examine the relationship b
etween microbial and physicochemical measurements revealed that CLPP and pl
ate counts were useful for determining the gross effect of metals on soil m
icrobial communities, whereas proportions of metal-resistant bacteria and d
ehydrogenase activity differentiated between the two sites. Copper and zinc
concentrations and pH ah showed significant correlation with the microbial
parameters. Nematode community structure was affected to a greater extent
by soil pH than by metal content, but the within-site rankings were the sam
e as those achieved for microbiological analyses. The use of these methods
for field evaluation of the impact of industrial pollution may be possible
provided care is taken when interpreting the data. (C) 2001 Elsevier Scienc
e B.V. All rights reserved.