Microbial Biota Research Articles

Novel Bioactive Compound Production by Microbial Biota: Potential Antimicrobials

Man is always trying to make his life easier and accomplished. He has faced mass destruction in historydue to epidemics like small pox, malaria and plague. In order to combat diseases, exploration of man ledhim to search for causative agents and their control. A time reached when it was found that microbes arethemselves a source of potent metabolites which have proved to be effective as drugs and medicinesshowing great antibiotic activity. It is necessary to find out new sources for potential new antimicrobialcompounds. Several hundred important compounds have been isolated which have antibiotic activitiesand diverse chemical nature. But these compounds should have minimum toxicity to be useful clinically.Because of the increasing resistance of pathogens, there was a never ending desire and need to searchfor more. Bioactive Compounds have been extracted from microbes which are produced as secondarymetabolites. Day by day, new compounds are being discovered giving a hope of golden future of drugindustry. The current article emphasizes the importance and need to search for new bioactive compoundsto overcome infections caused by multiple drug resistant (MDR) and biofilm forming pathogensirrespective of the previously present knowledge.

A prospective on multiple biological activities of lactoferrin contributing to piglet welfare.

Piglets, especially weaning piglets, show a lower level of immunity and higher morbidity and mortality, owing to their rapid growth, physiological immaturity, and gradual reduction of maternal antibodies, which seriously affects their growth and thus, value. It is important that piglets adapt to nutrient digestion and absorption and develop sound intestinal function and colonization with gut microbiota as soon as possible during their early life stage. Lactoferrin is a natural glycoprotein polypeptide that is part of the transferrin family. It is widely found in mucosal secretions such as saliva and tears, and most highly in milk and colostrum. As a multifunctional bioactive protein and a recommended food additive, lactoferrin is a potential alternative therapy to antibiotics and health promoting additive for piglet nutrition and development. It is expected that lactoferrin, as a natural food additive, could play an important role in maintaining pig health and development. This review examines the following known beneficial effects of lactoferrin: improves the digestion and capacity for absorption in the intestinal tract; promotes the absorption of iron and reduces the incidence of iron deficiency anemia; regulates intestinal function and helps to balance the microbial biota; and enhances the resistance to disease of the piglets via modulating and enhancing the immune system.

A case study on the correlation between radon and multiple geophysicochemical properties of soils in G island, Korea, and effects on the bacterial metabolic behaviors

This study was conducted to assess the natural radiation intensity of radon observed from ‘G’ islands and its effects against Bacillus pumilus, predominantly found throughout the field survey. The physicochemical properties and microbial characteristics were simultaneously investigated and compared. From these studies, it was confirmed that the areal distribution of radon concentration varied from 920 Bq/m3 to 3367 Bq/m3 depending on the soil depth, lithology, or geophysicochemical properties (including pH, moisture content, and grain size) inherently subject to each location. Particularly, the slightly acidic (pH < 6) and low-fertility soil with a higher level of radon concentration exceeding 3000 Bq/m3 had a considerably low level of bacterial density. In contrast, the fertile soil of a relatively middle level of radon radioactivity revealed a much larger bacterial community density, dominated by Bacillus spp., Pseudomonas sp., Paenarthrobacter sp., and Microbacterium sp. Furthermore, the monitored metabolic activity and growth of Bacillus pumilus against the various radon exposure conditions clearly indicated that radon could be considered as the potential ecological risk to natural environmental habitats of microbial soil biota.

Studying the Influence of Acoustic Cavitation and Avalanche-Streamer Discharge on the Quality of Raw Milk in Order to Achieve the Pasteurization Effect

The article presents the results of the studies obtained in the investigation of the quality of milk processed with the use of physical methods of exposure - acoustic cavitation and avalanche-streamer discharge, in order to achieve a pasteurizing effect. It is shown that in the treatment of high-frequency ultrasonic oscillations (over 45 kHz) generated by an electric ultrasonic device of the submersible type of impulse action ”Activator-150”, the number of bacteria of the E. coli group decreased by almost 40%, which allows concluding that the chosen method of influence is effective for the destruction of sanitary and pathogenic (indicative) microflora in raw milk and achieve a certain pasteurization effect. Using low-frequency ultrasonic exposure (20-22 kHz) generated by the cavitation ultrasonic flow type reactor RKU, the raw milk indicators QMAFAnM (Quantity of Mesophilic Aerobic and Facultative Anaerobic Microorganisms) and number of Coliform bacteria did not change after processing, as well as physical and chemical indicators, apart from the indicators of particle fineness. It can be stated that low-frequency ultrasonic cavitation treatment is not effective in terms of achieving a pasteurizing effect. In order to achieve a pasteurization effect by applying avalanche-streamer treatment we assessed its effect on QMAFAnM - the microbiological background of milk. The use of avalanche-streamer discharge does not have the expectation effect on the total number of microorganisms in milk. It is advisable to use high-frequency acoustic cavitation for microbial biota inactivation and avalanche-streamer discharge to reduce spore bacteria contamination.

Carbon Isotope Composition and Concentration of Fe-Group Elements in the Sedimentary Organic Matter from Rocks of Different Ages

The Fe/Co ratio (ppm) in the kerogen from different-aged clastic sediments (Early Proterozoic–Mesozoic) varies from 17 to 4100, and δ13C value varies from –14.8 to –32.6‰. The relationship between Fe/Co and δ13C is determined by the composition of microbial biota in paleobasins and superimposed metamorphic processes. The kerogen from the Vendian deposits of the East European Platform, containing a large amount of saprophytes and actinomycetes is characterized by the maximum Co concentration. The kerogen from deposits metamorphosed under amphibolite-facies conditions are characterized by the minimal δ13C and the maximum Fe/Co ratio values.

Collembola laterally move biochar particles.

Biochar is being discussed as a soil amendment to improve soil fertility and mitigate climate change. While biochar interactions with soil microbial biota have been frequently studied, interactions with soil mesofauna are understudied. We here present an experiment in which we tested if the collembolan Folsomia candida I) can transport biochar particles, II) if yes, how far the particles are distributed within 10 days, and III) if it shows a preference among biochars made from different feedstocks, i.e. pine wood, pine bark and spelt husks. In general, biochar particles based on pine bark and pine wood were consistently distributed significantly more than those made of spelt husks, but all types were transported more than 4cm within 10 days. Additionally, we provide evidence that biochar particles can become readily attached to the cuticle of collembolans and hence be transported, potentially even over large distances. Our study shows that the soil mesofauna can indeed act as a vector for the transport of biochar particles and show clear preferences depending on the respective feedstock, which would need to be studied in more detail in the future.

Energy and carbon budgeting of tillage for environmentally clean and resilient soil health of rice-maize cropping system

Human interventions in the environment leading to higher green house gas emissions which are degrading the soil and environment quality. Traditional/conventional tillage systems following since inception and residue burning are accelerating the degradation of soil and environment leading to food insecurity. The present study was executed to evaluate energy budgeting, carbon foot prints, gaseous emission and soil health under conservation tillage with residue retention for identifying cleaner production technology in rice-maize system. The novelty of the study is that it examines the integrated effect of tillage, residue retention through mulching on GHG emission along with soil health, energy consumption and carbon footprints together as conservation effective measure for sustainable and clean agricultural production. Zero tillage reduced the energy consumption by 56% and carbon footprints by 39% and besides that N2O emission was 20% lower than conventional tillage. Apart from clean environment, soil health was also improved by adoption of zero tillage in terms of NPK status, labile pool of carbon and enzymatic activities; the population of all the microbiota was increased, which was around 21.3, 51.2 and 27.6% higher in bacteria, fungi and actinomycetes. Crop residue retention as residue mulching (rice straw) significantly improved the crop productivity, microbial biota and enzymatic activities of soil, but it increased the energy consumption and carbon footprints by around 10%. N2O emission was also enhanced by residue mulching, and higher the quantity of residue used as mulch, more was emission. Although in initial years some yield penalty (10–15%) was recorded but in long run zero tillage can be a step towards sustainability as it can be a valuable approach for resilient soil health and cleaner production of maize in rice–maize system.

Raw pH fall-out as a sign of a mycorrhizal modifier of Sorghum sudanensis

The management of symbiotic Microbial Biota (MB) in the soil as agents that promote the yield and health of crops, is aimed at inducing modifications of the phenotype of plants, both over and under the ground. It is here shown, in Sorghumsudanensis plants, that: i) a simple response to MB inoculation is the result of the fall out of the raw pH; ii) the simple NIR scans of leaves can be considered to rapidly classify the outcomes; iii) the raw pH can be considered a key-variable of leaf modifications. An experiment was carried out on Sorghumsudanensis. The plants were seeded in pots and grown for 66 d, and then a control non-inoculated group (C) was compared with thirteen Arbuscular Mycorrhizae (AM) Glomus inoculated groups and with two commercial MB products. A total of 374 raw pH measurements conducted on the leaves showed that the 5.18 pH units in the C group were scaled by -1.9% (P&lt;0.0336) in the MB group and by -3.4% in the AM group (P&lt;0.0001), with a relevant diversity between groups. Direct discrimination of these three groups, by means of smart NIR-SCIO, showed a % reclassification of the C, MB and AM groups of 74%, 59% and 96% in the fresh leaves and of 65%, 51% and 94% in the dried ground leaves, respectively. The composition of the dried leaves, based on a set of 14 variables predicted via NIRS models, plus the total foliar dry weight and percentage, showed a typical increase in protein, ash and hemicellulose, and a typical decrease in the cellulose, dry matter, crude fiber and crop maturity index. These variables were related to the foliar pH, as a key-variable, by means of a PLS standard model (R2 0.81) in which a low pH steadily favored the dry mass weight and, to a lesser extent, the hemicellulose and the digestible NDF contents; on the other hand, a high pH increased the dry matter percentage and the cellulose content of the leaves. As expected, the leaves of the inoculated plants showed a more juvenile ontogenic status. The epigean botanical modifications can be considered harmonic expressions of a luxuriant symbiosis, as testified by the homologous NIR categorization. The outlook for a symbiotic agriculture, with mycorrhizal plants, should consider the raw pH as a multifaceted variable.

NIRS Footprint of Bio-Fertilizers from Hay Litter-Bags

The biofertilization of cropsusing microbial biota in the soil (MBS) is a modern practice that is used to sustain fertility. MBS agents can promote the yield and health of crops, by luxuriating in the shoot as well as in the root systems. Farmers devoted to systematic MBS fertilization are creating a “Symbiotic” (S) form of agriculture, which offers a greater advantage of resilience than Conventional (C) or organic farming. Since MBS is involved in organic matter degradation, hay-litter-bag probes can be used to reflect a global functionality of the active soil, in the short-medium term. It is here shown that the NIRS hay-litter-bag technique, intended not as mass decay but as a quality evolution of the hay probes, can be modelled as a valid footprint of S vs. C soils. A patented MBS was used in eight experiments in which litter-bags from an S treated thesis were compared with equivalent litter-bags from a non-inoculated C thesis. The chemical signature of the S vs. C in the litter-bag composition was a percentage decrease of sugars and fibres. A smart NIRS device was used to discriminate the origin of the S vs. C litter-bags and a sensitivity of 71% (P&lt;0.0001) was obtained. External validations on 37 S farms showed that three NIRS models discriminated the true positive S spectra, with a sensitivity of 90% as single and 98% as compound probabilities The NIRS radiation of the hay-litter-bags confirmed the results of the S vs. C agriculture soil footprint. Moreover, the SCIO-NIR devices also made it possible to connect the S farms in a smart network.

Diversifying crop rotation increased metabolic soil diversity and activity of the microbial community

Agricultural intensification has increased food production by reducing crop diversity and increasing fertilization and crop protection. Unfortunately, intensification has also reduced soil ecosystem services. Diversifying crop rotations could be a feasible alternative to promote positive feedbacks between soil biota and soil properties. Here, we investigated the impact of diversifying crop rotations on functional composition and diversity of the heterotrophic soil bacterial communities. We studied three frequent rotations with a total number of crops ranging from two to four. Before the experiment, all plots were cultivated with soybean. In the first experimental year, the crop sequences were (1) fallow/soybean, (2) barley/soybean, and (3) field pea/maize. In the second year, all plots were subjected to a wheat/soybean double crop. The experiment was replicated in three locations of the Rolling Pampa (Argentina). Soil and plant sampling took place immediately after the soybean harvest, in the second year. The most diverse rotation (field pea/maize, wheat/soybean) showed the highest standing biomass and litter and the most metabolically diverse and active soil microbial community (P ≤ 0.05). In turn, metabolic diversity was positively associated with plant and litter biomass (r2 = 0.7) and with soil pH (r2 = 0.72). Our results revealed that crop rotation affects soil metabolic bacterial diversity and activity (P ≤ 0.05). The most diverse rotation (four different crops) had also the most diverse and active soil microbial biota, concomitantly with a higher plant biomass production and soil pH. Because soil microbial activity and metabolic diversity detected in specific rotations potentially contribute to soil aggregate formation and other soil properties intimately related with nutrient cycling and plant production, the negative effect of agricultural intensification could be attenuated by designing specific and more diverse crop rotations.

An eukaryote-bearing microbiota from the early mesoproterozoic Gaoyuzhuang Formation, Tianjin, China and its significance

On the basis of expanded documentation of complex fossils, early Mesoproterozoic has already been proven asan important Era for eukaryotic evolution. In order to portray the biological community of this critical era, we studied a new silicified microbiota from the ∼1560Ma Gaoyuzhuang Formation in the classic Jixian section, Tianjin, China. In total, eighteen species have been recognized, four species have been identified informally and five species have been identified in open nomenclature. Similar to other Proterozoic microbial mat biota, the new microbiota is dominated by cyanobacteria filaments and coccoids as well. Potential eukaryotic microfossils, such as ornamented coccoids, filaments with flanges and terminal cell, were firstly recovered. Amongst them, filaments with flanges and conidia-like terminal cell probably were the earliest unidirectional growing multi-cellular organisms as well as the earliest phylogeny-resolved multicellular eukaryotes. Combined with increasing records of Proterozoic eukaryotes, these microfossils indicated that eukaryotes have evolved into a new level in Early Mesoproterozoic.

Risk of biodeterioration of cultural heritage objects, stored in the historical and modern repositories in the Regional Museum in Rzeszow (Poland). A case study

Museum artefacts are generally stored for a long period in repositories and are prone to microbiological colonisation. The goal of this research was to assess the risk of biodeterioration of artefacts stored in the Regional Museum in Rzeszow, Poland. The museum building consists of the historic and newly built parts and the aim was to verify the hypothesis about higher airborne concentrations of microorganisms in the historic part. In all repositories, the number of bacterial colonies was higher than those of fungi. The most polluted depots were those where different types of artefacts were stored. There were no differences in the number of fungal colonies in the repositories located in the historic and modern parts of the museum. The differences concerned only bacteria. The most common fungi were Penicillium expansum and Penicillium spp., while among bacteria Micrococcus luteus/lylae and Staphylococcus warneri. The highest microorganism biodiversity was in the historical depots and the lowest in the room with a book collection in the modern part of the museum. Findings showed that the microbial biota is not specific for either building type or the kind of artefact. Regarding bacteria, we detected the effect of ‘historical building air’.

Ecotoxicity and environmental safety related to nano-scale zerovalent iron remediation applications.

This mini-review summarizes the current information that has been published on the various effects of nano-scale zerovalent iron (nZVI) on microbial biota, with an emphasis on reports that highlight the positive aspects of its application or its stimulatory effects on microbiota. By nature, nZVI is a highly reactive substance; thus, the possibility of nZVI being toxic is commonly suspected. Accordingly, the cytotoxicity of nZVI and the toxicity of nZVI-related products have been detected by laboratory tests and documented in the literature. However, there are numerous other published studies on its useful nature, which are usually skipped in reviews that deal only with the phenomenon of toxicity. Therefore, the objective of this article is to review both recent publications reporting the toxic effects of nZVI on microbiota and studies documenting the positive effects of nZVI on various environmental remediation processes. Although cytotoxicity is an issue of general importance and relevance, nZVI can reduce the overall toxicity of a contaminated site, which ultimately results in the creation of better living conditions for the autochthonous microflora. Moreover, nZVI changes the properties of the site in a manner such that it can also be used as a tool in a tailor-made approach to support a specific microbial community for the decontamination of a particular polluted site.

Characterization of fungi isolated from the equipment used in the International Space Station or Space Shuttle.

As a part of a series of studies regarding the microbial biota in manned space environments, fungi were isolated from six pieces of equipment recovered from the Japanese Experimental Module "KIBO" of the International Space Station and from a space shuttle. Thirty-seven strains of fungi were isolated, identified and investigated with regard to morphological phenotypes and antifungal susceptibilities. The variety of fungi isolated in this study was similar to that of several previous reports. The dominant species belonged to the genera Penicillium, Aspergillus and Cladosporium, which are potential causative agents of allergy and opportunistic infections. The morphological phenotypes and antifungal susceptibilities of the strains isolated from space environments were not significantly different from those of reference strains on Earth.

A prospective observational study of vulvovagintis in pregnant women in Argentina, with special reference to candidiasis.

To evaluate the frequency of yeast, bacteria or protozoa in pregnant women and to correlate the possible associations of these microorganisms and their relationships with vulvovaginitis (VV) and cervicitis. Vaginal specimens were collected and prepared for smears in microscope slides for the evaluation of yeast, Trichomonas vaginalis and bacteria. Samples were cultured in specific culture medium. Cervical specimens were used to investigate the presence of Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma spp. and Mycoplasma hominis. We enrolled 210 pregnant women, aged 10-42years old. Of them, 38.1% were symptomatic. Symptoms were most prevalent in the second and third trimesters of pregnancy coincident with a major prevalence of microorganisms. In this study, 39.5% of pregnant women had normal microbial biota and symptoms of VV due to non-infectious causes were observed (6.2%). The occurrence of vulvovaginal candidiasis was 25% and Candida albicans with a prevalence of 80.7% was the dominant species (P=0.005) while non-albicans Candida species and other yeast were more common in asymptomatic ones (P=0.0038). The frequency of bacterial vaginosis, T.vaginalis, C.trachomatis and N.gonorrhoeae were 18.1%, 1.4, 1.4% and 0.5% respectively.

Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil

Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually 13C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota.

Phototrophic microflora colonizing substrates of man-made origin in Billefjorden Region, Central Svalbard

Substrates created by human have a significant impact on Arctic terrestrial environment. These substrates are new potential niche for microbial biota, which may have several essential chemical agents supporting microbial growth. Wood, concrete, brick, ceramic and other different building materials, which have been introduced by human in this iso-lated environment, are colonized with terrestrial and aero-terrestrial microorganisms living in the natural niches near the substrates like soil, rocks, etc., but these materials newly-introduced to Svalbard terrestrial ecosystems can also work as vectors for invasion of new species into the environment. We have collected different types of artificial substrates mainly in the region of Petuniabukta bay and studied the species composition of microbial phototrophs living there. A total of 25 taxa of cyanobacteria and algae were documented on different types of substrates like brick walls, concrete, glass, iron, wood and plastic. A commonality in species diversity was observed with similar substrates in temperate climatic regions. Fottea stichococcoides, Sphaerococcomyxa olivacea, Polysphaera composita and Diplosphaera chodatii were first time recorded from Svalbard Archipelago.

Effect of Native American Bean-corn Biculture Planting on Free-living Bacterial Abundance and Plant Growth

Native American tribes with bountiful harvests. Today it is widely recognized that this associated intercropping system derives much of its success from symbiotic bacteria (e.g. Rhizobium). These bacteria colonize the roots of leguminous plants, allowing them to fix atmospheric nitrogen into ammonia. However, the effect of this intercropping practice on the microbial community, independent of the effect of the symbiotic nitrogen-fixing bacteria, is not well understood. Therefore, a study was designed to model the effects of simultaneously intercropping bean and corn on the abundance of aerobic heterotrophic, free-living nitrogen-fixing, and symbiotic nitrogen-fixing bacteria, as well as plant growth and fecundity markers. In parallel, the benefits mediated by rhizobia were evaluated by inoculating a duplicate set of treatments with N-Dure, a rhizobia-containing inoculum. Native American varieties of pole-bean (Phaseolus vulgaris L.) and corn (Zea mays mays L.) were planted in monoculture and biculture treatments. All cultivations were maintained under greenhouse conditions for 52 days with daily watering and no additional fertilizer or microbial amendments. Although a significant increase in weight per plant was noted for the inoculated biculture when compared to either the inoculated bean or corn monocultures (p ≤ 0.05), the abundance of heterotrophic and free-living nitrogen-fixing bacteria did not show a significant change from the related controls, with or without inoculation. However, symbiotic nitrogen-fixing bacteria, as measured by root nodulation, increased significantly (p ≤ 0.05) for the inoculated biculture and single planting. Thus, these data confirm that corn benefited from this associated intercropping system as shown by an increase in plant biomass that can be attributed to Rhizobium. However, neither the legume-bacteria symbiotic relationship nor the increase in plant biodiversity resulting from this intercropping practice appears to have had significant effects on the abundance of the two common soil-associated bacterial groups evaluated, though further research would be necessary to fully assess the changes to heterotrophic bacterial diversity at the species level. KEYWORDS: Three Sisters; Nitrogen-fixing Bacteria; Inoculation with Rhizobia; Plant Growth Promoting Bacteria; Soil Microbial Biota; Corn and Bean Simultaneous Planting.

Characterization of culturable bacterial endophytes and their capacity to promote plant growth from plants grown using organic or conventional practices.

Plants have a diverse internal microbial biota that has been shown to have an important influence on a range of plant health attributes. Although these endophytes have been found to be widely occurring, few studies have correlated agricultural production practices with endophyte community structure and function. One agricultural system that focuses on preserving and enhancing soil microbial abundance and biodiversity is organic farming, and numerous studies have shown that organically managed system have increased microbial community characteristics. Herein, the diversity and specificity of culturable bacterial endophytes were evaluated in four vegetable crops: corn, tomato, melon, and pepper grown under organic or conventional practices. Endophytic bacteria were isolated from surface-sterilized shoot, root, and seed tissues and sequence identified. A total of 336 bacterial isolates were identified, and grouped into 32 species and five phyla. Among these, 239 isolates were from organically grown plants and 97 from those grown conventionally. Although a diverse range of bacteria were documented, 186 were from the Phylum Firmicutes, representing 55% of all isolates. Using the Shannon diversity index, we observed a gradation of diversity in tissues, with shoots and roots having a similar value, and seeds having the least diversity. Importantly, endophytic microbial species abundance and diversity was significantly higher in the organically grown plants compared to those grown using conventional practices, potentially indicating that organic management practices may increase endophyte presence and diversity. The impact that these endophytes could have on plant growth and yield was evaluated by reintroducing them into tomato plants in a greenhouse environment. Of the bacterial isolates tested, 61% were found to promote tomato plant growth and 50–64% were shown to enhance biomass accumulation, illustrating their potential agroecosystem application.

Sulfur-cycling fossil bacteria from the 1.8-Ga Duck Creek Formation provide promising evidence of evolution's null hypothesis

The recent discovery of a deep-water sulfur-cycling microbial biota in the ∼ 2.3-Ga Western Australian Turee Creek Group opened a new window to life's early history. We now report a second such subseafloor-inhabiting community from the Western Australian ∼ 1.8-Ga Duck Creek Formation. Permineralized in cherts formed during and soon after the 2.4- to 2.2-Ga "Great Oxidation Event," these two biotas may evidence an opportunistic response to the mid-Precambrian increase of environmental oxygen that resulted in increased production of metabolically useable sulfate and nitrate. The marked similarity of microbial morphology, habitat, and organization of these fossil communities to their modern counterparts documents exceptionally slow (hypobradytelic) change that, if paralleled by their molecular biology, would evidence extreme evolutionary stasis.