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PubMedDate not supplied

Species richness of tropical wood-inhabiting macrofungi provides support for species-energy theory.

A study was undertaken at the El Verde Field Station in Puerto Rico to determine the effect of energy available from newly dead trees on the species richness of macrofungal communities that inhabit them. It is hypothesized that there is a positive relationship between available energy and species richness. Energy was measured using the volume of the dead trees and the wood density of living trees of the same species. One hundred ninety-four logs of known tree species were surveyed 1 y for fruiting bodies of macrofungi at monthly intervals. For individual logs, log volume had a significant positive effect on macrofungal species richness. Younger logs had significantly higher species richness than older logs, and those with less apparent decay had more species than those with more decay. When logs were grouped by tree species, total wood volume and density of live wood had a significant positive effect and average log diameter had a negative effect on total species richness and abundance of the wood-inhabiting macrofungi. Macrofungal richness and abundance constantly increased with initial wood density; there was no evidence for a unimodal relationship. These results support the proposed relationship between species richness and energy.

Ecosystem↗
PubMed2002

Diversity of cuticular wax among Salix species and Populus species hybrids.

The leaf cuticular waxes of three Salix species and two Populus species hybrids, selected for their ability to produce high amounts of biomass, were characterized. Samples were extracted in CH(2)Cl(2) three times over the growing season. Low kV SEM was utilized to observe differences in the ultrastructure of leaf surfaces from each clone. Homologous series of wax components were classified into organic groups, and the variation in wax components due to clone, sample time, and their interaction was identified. All Salix species and Populus species hybrids showed differences in total wax load at each sampling period, whereas the pattern of wax deposition over time differed only between the Salix species. A strong positive relationship was identified between the entire homologous series of alcohols and total wax load in all clones. Similarly strong relationships were observed between fatty acids and total wax load as well as fatty acids and alcohols in two Salix species and one Populus species hybrid. One Salix species, S. dasyclados, also displayed a strong positive relationship between alcohols and alkanes. These data indicate that species grown under the same environmental conditions produce measurably different cuticular waxes and that regulation of wax production appears to be different in each species. The important roles cuticular waxes play in drought tolerance, pest, and pathogen resistance, as well as the ease of wax extraction and analysis, strongly suggest that the characteristics of the cuticular wax may prove to be useful selectable traits in a breeding program.

Hybridization, Genetic↗
PubMed2006

Species-specific RT-PCR amplification of human enteroviruses: a tool for rapid species identification of uncharacterized enteroviruses.

The 65 serotypes of human enteroviruses are classified into four species, Human enterovirus (HEV) A to D, based largely on phylogenetic relationships in multiple genome regions. The 3'-non-translated region of enteroviruses is highly conserved within a species but highly divergent between species. From this information, species-specific RT-PCR primers were developed that can be used to rapidly screen collections of enterovirus isolates to identify species of interest. The four primer pairs were 100 % specific when tested against enterovirus prototype strains and panels of isolates of known serotype (a total of 193 isolates). For evaluation in a typical application, the species-specific primers were used to screen 186 previously uncharacterized non-polio enterovirus isolates. The HEV-B primers amplified 68.3 % of isolates, while the HEV-A and HEV-C primers accounted for 9.7 and 11.3 % of isolates, respectively; no isolates were amplified with the HEV-D primers. Twelve isolates (6.5 %) were amplified by more than one primer set and eight isolates (4.3 %) were not amplified by any of the four primer pairs. Serotypes were identified by partial sequencing of the VP1 capsid gene, and in every case sequencing confirmed that the species-specific PCR result was correct; the isolates that were amplified by more than one species-specific primer pair were mixtures of two (11 isolates) or three (one isolate) species of viruses. The eight isolates that were not amplified by the species-specific primers comprised four new serotypes (EV76, EV89, EV90 and EV91) that appear to be unique members of HEV-A based on VP1, 3D and 3'-non-translated region sequences.

3' Untranslated Regions↗
PubMed1979

Photosynthesis in Grass Species Differing in Carbon Dioxide Fixation Pathways: II. A Search for Species with Intermediate Gas Exchange and Anatomical Characteristics.

Thirty-three grass species were examined in two experiments in an attempt to locate plants with photosynthetic responses to O(2), CO(2) compensation concentrations, and leaf anatomy intermediate to those of C(3) and C(4) species. Species examined included seven from the Laxa group in the Panicum genus, one of which, P. milioides Nees ex Trin., has been reported earlier to have intermediate characteristics. The species with O(2)-sensitive photosynthesis typical of C(3) plants showed more than 37% increase in apparent photosynthesis at 2% O(2) compared to 21% O(2) at 25 C and 335 microliters per liter CO(2), whereas in Panicum milioides, P. schenckii Hack., and P. decipiens Nees ex Trin., members of the Laxa group of Panicum, increases ranged from 25 to 30%. The remainder of the species did not respond to O(2). Species with O(2) responses characteristic of C(3) plants exhibited CO(2) compensation concentrations of 44 microliters per liter or higher at 21% O(2) and 25 to 27.5 C and species characterized as O(2)-insensitive had values of microliters per liter or less. The CO(2) compensation concentration (capital GHE, Cyrillic) values of P. milioides, P. schenckii, and P. decipiens ranged from 10.3 to 23.3 microliters per liter. Other species of the Laxa group of Panicum exhibited O(2) response and capital GHE, Cyrillic values of either C(3) (P. laxum Sw., P. hylaeicum Mez., and P. rivulare Trin.) or C(4) (P. prionitis Griseb.) plants. Leaves of species with O(2) response and CO(2) compensation values typical of C(3) plants had poorly developed or nearly empty bundle sheath cells, and much larger distances and mesophyll cell numbers between veins than did the O(2)-insensitive ones. Vein spacings in P. milioides, P. schenckii, and P. decipiens ranged from 0.18 to 0.28 millimeter and mesophyll cell number between veins from 5.2 to 7.8. While these vein spacings are closer than those of most C(3) grasses, two O(2)-sensitive species of Dactylis had vein spacings similar to these Panicums and veins in Glyceria striata, another O(2)-sensitive plant, were separated by only four mesophyll cells and 0.12 millimeter. Bundle sheath cells of the three intermediate Panicums contained greater quantities of organelles than are typical for C(3) grasses.

Journal Article↗
PubMed1983

Photosynthesis of Grass Species Differing in Carbon Dioxide Fixation Pathways : VIII. Ultrastructural Characteristics of Panicum Species in the Laxa Group.

Ultrastructural studies of leaves of seven Panicum species in or closely related to the Laxa group and classified as C(3), C(4) or C(3)-C(4) intermediate were undertaken to examine features associated with C(3) and C(4) photosynthesis. The C(3) species Panicum rivulare Trin. had few organelles in bundle sheath cell profiles (2 chloroplasts, 1.1 mitochondria, and 0.3 peroxisomes per cell section) compared to an average of 10.6 chloroplasts, 17.7 mitochondria, and 3.2 peroxisomes per bundle sheath cell profile for three C(3)-C(4) species, Panicum milioides Nees ex Trin., Panicum decipiens Nees ex Trin. and Panicum schenckii Hack. However, two other C(3) species, Panicum laxum Sw. and Panicum hylaeicum Mez, contained about 0.7, 0.5, and 0.3 as many chloroplasts, mitochondria, and peroxisomes, respectively, as in bundle sheath cell profiles of the C(3)-C(4) species. Chloroplasts and mitochondria in bundle sheath cells were larger than those in mesophyll cells for the C(4) species Panicum prionitis Griseb. and the C(3)-C(4) species, but in C(3) species the organelles were similar in size or were smaller in the bundle sheath cells. The C(3)-C(4) species and P. laxum and P. hylaeicum exhibited an unusually close association of organelles in bundle sheath cells with mitochondria frequently surrounded in profile by chloroplasts. The high concentrations in bundle sheath cells of somewhat larger organelles than in mesophyll cells correlates with the reduced photorespiration of the C(3)-C(4) species.

Journal Article↗
PubMed2002

Morphological and genetic variation in seven species of the endangered Chirostoma "humboldtianum species group" (Atheriniformes: Atherinopsidae).

The Chirostoma "humboldtianum" group includes seven silverside species considered as a monophyletic assemblage because of their high genetic and morphological similarities. The group includes five moderately large species, "peces blancos" (117-300 mm standard length--SL) and two smaller species, "charales" (70-142 mm SL). These species are of great economical, cultural and ichthyological interest for local populations, and their management practices are controversial. We investigated the morphometric, meristic and allozyme variations of the seven species (13 populations) and related the variations with life history, habitat and management procedures. Nineteen morphometric variables, eight meristic variables (by multivariate analysis) and 23 allozyme loci of the seven species and populations of Chirostoma were compared. Principal component analysis (PC) of morphometric and meristic data indicate that both sets of data provided information to differentiate among the seven species. The variables that accounted for most of this differentiation were head length (HL), predorsal 1 length (PIL) and length of pelvic fin base (PfbL). PC and Discriminant Analysis (DA) with morphometric data also suggested the differentiation of populations within C. grandocule (83% correctly classified organisms), whereas PC and DA with meristic data differentiated populations of C. humboldtianum (80% correctly classified organisms). The most important morphometric variables for the differentiation were anal fin height (AfH), length of anal fin base (AfbL) and predorsal 2 length (P2L) and the meristic variables D2fR. PdS and AfR. The genetic variability data indicate changes in values of some of the species in relation to previously reported data. The present populations of C. grandocule show a reduction in He (0.002 vs. 0.009). Other species showed an increase; for instance, C. consocium consocium, C. humboldtianum, C. lucius, C. promelas and C. sphyraena averaged He = 0.069 vs 0.027. theta indicated significant genetic differentiation among the analysed species (0.247, S.D. 0.159) and theta s supported the morphological data that suggest intra-specific differentiation (0.360, S. D. 0.154).

Animals↗
PubMed2025

Extensive Introgression Failed to Erode Species Boundaries Among Multiple Sympatric Closely Related Species of Roscoea.

How species boundaries are maintained among sympatric closely related species experiencing gene flow is a puzzling question in evolutionary biology. Although introgression is commonly documented, the dynamics and gene function of introgression have rarely been explored to probe why frequent introgression does not necessarily destroy species boundaries in sympatry. In this study, we employ whole-genome resequencing data to examine introgression among five closely related species of Roscoea that coexist in a 'sky island' with seventeen distinct morphological traits. Our findings reveal that introgression has led to the phylogenomic discordance between nuclear and chloroplast genomes among these morphologically distinct species. Additionally, introgression is predominantly asymmetrical in both intensity and gene function, particularly concerning recombination. Notably, the majority of gene functions associated with introgressed loci are unrelated to reproductive processes. Our results suggest that closely related species with incomplete allele assortment can coexist despite theoretical predictions, highlighting the semipermeable nature of species boundaries as reproductive isolation develops. This provides a critical conceptual framework for understanding the interplay between introgression and species persistence. Our finding offers insights into how related sympatric species boundaries can be maintained in the face of frequent asymmetrical gene introgression.

Sympatry↗
PubMed2002

Evidence for species differences in the pattern of androgen receptor distribution in relation to species differences in an androgen-dependent behavior.

Chickens (Gallus gallus domesticus) and Japanese quail (Coturnix japonica), two closely related gallinaceous bird species, exhibit a form of vocalization-crowing-which differs between the species in two components: its temporal acoustic pattern and its accompanying postural motor pattern. Previous work utilizing the quail-chick chimera technique demonstrated that the species-specific characteristics of the two crow components are determined by distinct brain structures: the midbrain confers the acoustic pattern, and the caudal hindbrain confers the postural pattern. Crowing is induced by androgens, acting directly on androgen receptors. As a strategy for identifying candidate neurons in the midbrain and caudal hindbrain that could be involved in crow production, we performed immunocytochemistry for androgen receptors in these brain regions in both species. We also investigated midbrain-to-hindbrain vocal-motor projections. In the midbrain, both species showed prominent androgen receptor immunoreactivity in the nucleus intercollicularis, as had been reported in previous studies. In the caudal hindbrain, we discovered characteristic species differences in the pattern of androgen receptor distribution. Chickens, but not quail, showed strong immunoreactivity in the tracheosyringeal division of the hypoglossal nucleus, whereas quail, but not chickens, possessed strong immunoreactivity in a region of the ventrolateral medulla. Some of these differences in hindbrain androgen receptor distribution may be related to the species differences in the postural component of crowing behavior. The results of the present study imply that the spatial distribution of receptor proteins can vary even between closely related species. Such variation in receptor distribution could underlie the evolution of species differences in behavior.

Animals↗
PubMed2007

Convergence patterns and multiple species interactions in a designed plant mixture of five species.

It is known that convergence and divergence can occur in complex plant communities, but the relative importance of biotic and abiotic factors driving these processes is less clear. We addressed this issue in an experiment using a range of mixed stands of five species that are common in Swiss fens (Carex elata, C. flava, Lycopus europaeus, Lysimachia vulgaris and Mentha aquatica) and two levels of water and nutrients. One hundred and seventy-six experimental mixtures were maintained in large pots (75 l) for two consecutive growing seasons in an experimental garden. The stands varied systematically in the initial relative abundance of each of the five species and in overall initial stand abundance. The changes in biomass over 2 years were modelled as linear functions of treatments and the initial biomass of each species. The dynamics of the system were mainly driven by differences in the identity of species and by a negative feedback mechanism but also by different abiotic conditions. In all mixtures, C. elata became more dominant over time, which caused an overall convergence of community composition. In addition, the rate of change of each species' biomass was negatively related to its own initial abundance. Thus, a negative feedback further contributed to the convergence of communities. Species responded differently to water level and nutrient supply, causing community dynamics to differ among treatments. However, the different abiotic conditions only slightly modified the overall convergence pattern. Competitive interactions between more than two species were weaker than the negative feedback but still significantly influenced the species' final relative abundance. The negative feedback suggests that there is niche partitioning between the species, which permits their coexistence.

Biomass↗
PubMed2001

Studies into abstract properties of individuals. VI. The degree of emergence in individuals, populations, species and a three species lineage.

Emergent properties derived from the integration among descriptive variables were explored in three related grass species, Achnatherum lemmonii, Achnatherum hendersonii and Achnatherum wallowaensis. Different levels of organization were compared: individuals, populations, species, species-pairs and all three species combined. Emergence was seen at all levels with populations having the lowest degree followed by individuals, species and combinations of species. Because there were no variables unique to any level analyzed, emergence is more than the appearance of new structures. As the degree of emergence increases there is also an increase in variation in integration, the result of new growth rates. Time may explain the different degrees of emergence at the different levels. The trend populations-species-combination of species is easily related to time; the first are younger than the last. An individual develops over a greater period of time than a population. The greater time of existence of a species may account for a greater degree of emergence than an individual. In an individual the local time expressed during ontogeny establishes boundary conditions for an individual. As that local time becomes incorporated into global, or phylogenetic, time, the boundary conditions for taxa and lineages is established.

Phylogeny↗
PubMed2004

The phylogeny of a species-level tendency: species heritability and possible deep origins of Bergmann's rule in tetrapods.

One of the most widely recognized generalizations in biology is Bergmann's rule, the observation that, within species of birds and mammals, body size tends to be inversely related to ambient temperature. Recent studies indicate that turtles and salamanders also tend to follow Bergmann's rule, which hints that this species-level tendency originated early in tetrapod history. Furthermore, exceptions to Bergmann's rule are concentrated within squamate reptiles (lizards and snakes), suggesting that the tendency to express a Bergmann's rule cline may be heritable at the species level. We evaluated species-level heritability and early origination of Bergmann's rule by mapping size-latitude relationships for 352 species onto a tetrapod phylogeny. When the largest available dataset is used, Bergmann's rule shows significant phylogenetic signal, indicating species-level heritability. This represents one of the few demonstrations of heritability for an emergent species-level property and the first for an ecogeographic rule. When species are discretely coded as showing either Bergmann's rule or its converse, parsimony reconstructions suggest that: (1) the tendency to follow Bergmann's rule is ancestral for tetrapods, and (2) most extant species that express the rule have retained this tendency from that ancient ancestor. The first inference also generally holds when the discrete data or size-latitude correlation coefficients are analyzed using maximum likelihood, although the results are only statistically significant for some versions of the discrete analyses. The best estimates of ancestral states suggest that the traditional adaptive explanation for Bergmann's rule-conservation of metabolic heat-was not involved in the origin of the trait since that origin predates the evolution of endothermy. A more general thermoregulatory hypothesis could apply to endotherms and some ectotherms, but fails to explain why salamanders have retained Bergmann's rule. Thus, if thermoregulation underlies the origin of a Bergmann's rule tendency, this trait may have been continuously maintained while its cause changed. Alternatively, thermoregulation may not underlie Bergmann's rule in any tetrapod group. The results also suggest that many extinct groups not included in our analyses followed Bergmann's rule.

Animals↗
PubMed2003

Analysis, characterization, and loci of the tuf genes in lactobacillus and bifidobacterium species and their direct application for species identification.

We analyzed the tuf gene, encoding elongation factor Tu, from 33 strains representing 17 Lactobacillus species and 8 Bifidobacterium species. The tuf sequences were aligned and used to infer phylogenesis among species of lactobacilli and bifidobacteria. We demonstrated that the synonymous substitution affecting this gene renders elongation factor Tu a reliable molecular clock for investigating evolutionary distances of lactobacilli and bifidobacteria. In fact, the phylogeny generated by these tuf sequences is consistent with that derived from 16S rRNA analysis. The investigation of a multiple alignment of tuf sequences revealed regions conserved among strains belonging to the same species but distinct from those of other species. PCR primers complementary to these regions allowed species-specific identification of closely related species, such as Lactobacillus casei group members. These tuf gene-based assays developed in this study provide an alternative to present methods for the identification for lactic acid bacterial species. Since a variable number of tuf genes have been described for bacteria, the presence of multiple genes was examined. Southern analysis revealed one tuf gene in the genomes of lactobacilli and bifidobacteria, but the tuf gene was arranged differently in the genomes of these two taxa. Our results revealed that the tuf gene in bifidobacteria is flanked by the same gene constellation as the str operon, as originally reported for Escherichia coli. In contrast, bioinformatic and transcriptional analyses of the DNA region flanking the tuf gene in four Lactobacillus species indicated the same four-gene unit and suggested a novel tuf operon specific for the genus Lactobacillus.

Adult↗
PubMed2000

Germ-cell warfare in ascidians: sperm from one species can interfere with the fertilization of a second species.

Ascidians (invertebrate chordates) are very abundant in many marine subtidal areas. They often live in dense multispecies clumps; thus, interspecific competition for space may be intense. Although most noncolonial species are broadcast spawners, their eggs can be fertilized only by sperm of the same species (1). Multiple fertilization is lethal and all animals have evolved blocks to polyspermy. Ascidian eggs block polyspermy by enzymatic (2) and electrical mechanisms (3). Sperm bind to N-acetylglucosamine groups on the vitelline coat (4, 5, 6, 7). Follice cells surrounding the vitelline coat release N-acetylglucosaminidase during egg activation (8), preventing the binding of all sperm but a few (2). I show here that this interaction is not species-specific; sperm from one species can cause glycosidase release from follicle cells of a second species. Furthermore, once glycosidase release has been induced, the subsequent addition of sperm from the egg-producing species fails to fertilize a substantial proportion of these eggs. This leads to the hypothesis that sperm from one species of ascidian can interfere with fertilization of a second species. While intraspecific sperm competition has been well documented in several taxa (9, 10), this is the first record of sperm competition between species, or interspecific sperm competition.

Acetylglucosaminidase↗
PubMed1991

Species-diagnostic differences in a ribosomal DNA internal transcribed spacer from the sibling species Anopheles freeborni and Anopheles hermsi (Diptera:Culicidae).

Approximately 460 base pairs (bp) of DNA sequence that included the second internal transcribed spacer (ITS2) and some flanking 5.8S and 28S ribosomal RNA coding regions were compared between the two closely related and morphologically indistinguishable mosquito species Anopheles freeborni and A. hermsi and a third related species, A. occidentalis. Sequences were determined from 14 clones of polymerase chain reaction (PCR)-amplified DNA obtained from four colonies of A. freeborni, two colonies of A. hermsi, and one individual A. occidentalis. Four clones showed independent single bp differences from the consensus for the relevant species. Eleven sites differed between the consensus sequences of A. hermsi and A. freeborni; 28 sites differed between A. hermsi and A. occidentalis. With the exception of a single bp mismatch in the 5.8S and two single bp mismatches near the undetermined junction of the ITS2 and 28S regions, all differences were confined to the ITS2 region. A PCR-based species-diagnostic assay for the cryptic species A. hermsi and A. freeborni was developed; it uses four synthetic oligonucleotides, two derived from areas of interspecies sequence difference in the ITS2, and two derived from highly conserved regions in the flanking coding sequences. Small amounts of mosquito DNA amplified in the presence of these four primers produce fragments of diagnostic size for each species: 900 bp for A. freeborni, 350 bp for A. hermsi, and approximately 1.2-1.4 kb for various other Anopheles species tested. We believe that this general approach to the development of species-diagnostic assays can be extended easily to other complexes of closely related, morphologically indistinguishable species.

Animals↗
PubMed2003

[Molecular evolution of satellite DNA CLsat in lizards of the Darevskia species (Sauria: Lacertidae): correlation with species diversity].

The structure and evolution of a satellite DNA family was examined in lizards from the genus Darevskia (family Lacertidae). Comparison of tandem units of repeated DNA (satDNA), CLsat, in all species from the genus Darevskia has shown that their variability is largely based on single-nucleotide substitutions, which constitute about 50 diagnostic positions underlying classification of the family into three subfamilies. Maximum differences between the subfamilies reached 25%. At this level of tandem unit divergence between the subfamilies, no cross-hybridization between them was observed (at 65 degrees C). The individual variability of one subfamily within the species was on average 5% while the variability between species consensuses within a subfamily was 10%. The presence of highly conserved regions in all monomers and some features of their organization show that satellites of all Darevskia species belong to one satDNA family. The organization of unit sequences of satellites CLsat and Agi also detected by us in another lizard genus, Lacerts s. str. was compared. Similarity that was found between these satellites suggests their relatedness and common origin. A possible pathway of evolution of these two satDNA families is proposed. The distribution and content of CLsat repeat subfamilies in all species of the genus was examined by Southern blotting hybridization. Seven species had mainly CLsatI (83 to 96%); three species, approximately equal amounts of CLsatI and CLsatIII (the admixture of CLsatII was 2-3%); and five species, a combination of all three subfamilies in highly varying proportions. Based on these results as well as on zoogeographic views on phylogeny and taxonomy of the Darevskia species, hypotheses on the evolution of molecular-genetic relationships within this genus are advanced.

Animals↗
PubMed1980

The liver specific protein: evidence for species-specific and non-species-specific determinants.

Liver specific protein (LSP) is known to be a macrolipoprotein of complete organ-specificity but without complete species-specificity. This membrane antigen is believed to play an important role in the pathogenesis of human and experimental chronic active hepatitis (CAH). In the present study, we investigated the species-crossreactivity of LSP by crossed immunoelectrophoresis, tandem crossed immunoelectrophoresis and fused rocket immunoelectrophoresis. With a sheep anti human LSP serum, two determinants of human LSP could be detected--one was found to be species-specific, the other crossreacted with rabbit, rat, swine and mouse LSP; no reaction was found with bovine and sheep LSP. A rabbit anti human LSP serum, after short term immunization, reacted only with a species-specific determinant of human LSP, no species-crossreactivity was observed. In contrast, rabbits with experimentally induced CAH, after longterm immunization with human LSP, had developed an autoantibody to rabbit LSP in addition to antibodies to the species-specific determinant of human LSP. Antibodies to the liver membrane antigen (LM-Ag) could not be detected. In conclusion human LSP contains a species-specific and a non-species-specific determinant. CAH in rabbits is induced by the loss of tolerance to the non-species-specific determinant.

Animals↗
PubMedDate not supplied

Electrophoretic pattern of peptidoglycan hydrolases, a new tool for bacterial species identification: application to 10 Lactobacillus species.

Lactobacilli have been used as industrial starters for a long time, but in many cases their phenotypic identification is still neither easy nor reliable. Previously we observed that the cell wall peptidoglycan hydrolases of Lactobacillus helveticus were highly conserved enzymes; the aim of the present work was to determine whether peptidoglycan hydrolase patterns obtained by renaturing SDS-PAGE could be of interest in the identification of lactobacilli species. For that purpose, the peptidoglycan hydrolase patterns of 94 strains of lactobacilli belonging to 10 different species were determined; most of the species studied are used either in dairy, meat, bakery or vegetable fermentations: L. helveticus, L. acidophilus, L. delbrueckii, L. brevis, L. fermentum, L. jensenii, L. plantarum, L. sake, L. curvatus and L. reuteri. Within a species, the strains exhibited highly similar patterns: the apparent molecular weights of the lytic bands were identical, with only slight variations of intensity. Moreover, each species, including phylogenetically close species such as L. sake and L. curvatus, or L. acidophilus and L. helveticus, gave a different pattern. Interestingly, the closer the species were phylogenetically, the more related were their patterns. The sensitivity of the method was checked using various quantities of L. acidophilus cells: a peptidoglycan hydrolase extract of 5 x 10(6) cells was sufficient to obtain an informative pattern, as was a single colony. Finally, the method was also successfully applied to distinguish two Carnobacterium species. In conclusion, the electrophoretic pattern of peptidoglycan hydrolases is proposed as a new tool for lactobacilli identification: it is rapid, sensitive and effective even for phylogenetically close species. Furthermore, this work provides the first evidence of the potential overall taxonomic value of bacterial peptidoglycan hydrolases.

Bacterial Proteins↗