Rod-shaped Forms Research Articles

Molecular docking analysis of mosquito ribosomal protein in selenium nanoparticle bio-synthesis: Implications for pest and pathogen mitigation

BackgroundInsects, rich in diverse proteins, are crucial in nanoparticle biofabrication. This study explores mosquito proteins' potential to reduce selenium ions and produce Selenium nanoparticles (SeNPs). MethodsMosquito larval protein composition was determined via liquid chromatography-mass spectrometry (LC-MS). Molecular docking validated cytoskeletal proteins' efficacy, notably 40S ribosomal protein S7 (binding energy: -6.23) and β-tubulin (binding energy: -5.94), in facilitating selenium ion conversion to SeNPs. SeNPs, mediated by these proteins, were characterized using Ultra Violet-visible spectroscopy, revealing a peak at 295 nm. FT-IR analysis identified biomolecules responsible for capping SeNPs and converting selenious acid to SeNPs. Significant findingsLC-MS detected β-tubulin (1 peptide, 76 amino acids, 8.2 kDa) and 40S ribosomal protein S7 (2 peptides, 192 amino acids, 22.1 kDa). The FT-IR analysis showed peaks at 3420.89 (OH stretch), 2928.35 (aromatic CH stretch), 2344.02 (CC alkynes stretches), etc. X-Ray Diffraction confirmed SeNPs' crystalline structure. Scanning electron microscopy and transmission electron microscopy revealed smooth-surfaced SeNPs in spherical and rod-shaped forms. SDS PAGE analysis post-SeNPs synthesis confirmed 40S ribosomal protein S7 and β-tubulin presence. SeNPs exhibited antibacterial, anti-biofilm, antioxidant, photocatalytic, and insecticidal activities. Median lethal concentrations were 17.674 μg/mL for Culex quinquefasciatus, 31.117 μg/mL for Aedes aegypti, and 81.95 μg/mLfor R. dominica at 48 h. SeNPs suppressed S. aureus biofilm by 33.06 ± 8.26 % and E. coli by 13.8 ± 3.63 %. Vero cells showed no harm at 250 µg/mL SeNPs. At 100 μg/mL, SeNPs exhibited 52.94 % free radical scavenging, compared to 74 % for ascorbic acid. Protein-mediated nanoparticle preparation is favoured for biomedical applications due to ease of synthesis, eco-friendliness, conjugation capability, simple preparation, and utilization of pests.

Analysis of the causes of the occurrence and measures of prevention of pododermatitis in rabbits

Analysis of the causes of the occurrence and measures of prevention of pododermatitis in rabbits

ТИПОМОРФНЫЕ ПРИЗНАКИ САМОРОДНОГО ЗОЛОТА РОССЫПИ РЧ. ЛЕВЫЙ УЛАХАН ХАПТАСЫННААХ И ЕГО ВЕРОЯТНЫЕ КОРЕННЫЕ ИСТОЧНИКИ (АНАБАРСКИЙ ЩИТ)

The paper deals with studied typomorphic features of placer gold of the Left Ulakhan Haptasynnakh River, drainage rocks of the central Billakhskaya tectonofluid zone of the Anabar Shield, aimed at identifying its indicator signs and probable indigenous sources. The predominance of poorly rounded, mainly angular-cloddy individuals with rough pitted-lumpy surface, often with coatings of variable aluminosilicate composition, with small accretions of quartz and potassium feldspar, as well as a fraction >0.5 mm to 40% allowed the studied gold to be attributed to the autochthonous type. The study of nearby sulphidized rocks of the Haptasynnaakh zone showed that an ore mineralization is represented by a variety of mineral forms. The main ore mineral is pyrite. A wide range of telluride minerals was identified with predominance of silver and bismuth tellurides. For the first time, medium-high-grade gold of lamellar and rod-shaped forms was distinguished from crushed samples of mineralized rocks. Comparative analysis of the mineral inclusions composition in poorly rounded placer gold with a wide variation in gold fineness of the Left Ulakhan Haptasynnaakh and mineral parageneses of ores of the Haptasynnaakh ore zone allows researchers to assert that the zone ore manifestations are indigenous sources of the studied gold. The discovery of gold with an ore appearance of fraction >0.5 mm in the placer suggests the presence of mineralization of its coarser fractions in relatively deep horizons. This fact determines positive prospects for further study of the territory.

State of Cyanobacteria <i>Arthrospira platensis</i> and of Associated Microflora during Long-Term Storage in the State of Anhydrobiosis

Abstract—The biochemical composition of Arthrospira (Spirulina) platensis (Nordstedt) Gomont after long-term storage in the state of anhydrobiosis (4 years, 17 years) was determined by the standard methods. It was shown that protein content (55.3–61.2%) and total carbohydrates content (13.0–15.6%) in cyanobacterial cells were in agreement with the data known from the literature and with our results obtained at the onset of storage. The biomass had low content of free nucleotides (1.8–2.6%), lipids (1.3–11.0%), and especially pigments (0.5–1.3, 0.03–0.12, 1.4–2.0, 0.03–0.05% for chlorophyll a, carotenoids, C-phycocyanin, and allophycocyanin, respectively). The content of nucleic acids content was 3.1–24.0 and 0.11–0.16% for RNA and DNA, respectively. Microscopic examination of A. platensis (17 years of storage) showed high numbers of irreversibly damaged and dead cells (34.2 and 65.8%, respectively). To determine the quantitative and morphological parameters of associated microflora, a complex physicochemical treatment (methanol, ultrasound, and centrifugation) of the reactivated cyanobacterial suspension proved the most efficient. Three main groups were distinguished in the morphological structure of the microbiome (rod-shaped, rounded, and convoluted forms). The community was dominated by rod-shaped forms: large and small rods accounted for 60.5 and 14.4%, respectively. Mycelial forms (thin filaments), cocci, and convoluted forms were less common. On average, the volume of a bacterial cell was 0.27 ± 0.04 µm3. The contribution of bacteria to the biomass of A. platensis varied from 3.3 to 11.3% (8.3 ± 4.4% on average) of the dry weight of A. platensis. It has been suggested that the biochemical parameters and viability of cyanobacteria were affected by the accompanying microflora.

Investigation of biological activity of recultivated iron ore processing wastes of Abagur agglomeration and processing plant, Novokuznetsk

The problem of biotransformation of man-caused disturbed lands is of great importance for the restoration of soil fertility. The leading role in this process is played by soil microorganisms. Toxic industrial waste can make negative adjustments to the species composition of soil microflora (can cause mutation of many microorganisms, as well as the death of some of them). Under certain conditions, in the presence of harmful substances, new microorganisms can arise that decompose precisely those substances that cause soil pollution. Consequently, a new microflora appears, capable of carrying out its trophic functions on an inductive basis on industrially contaminated substrates. As a man-caused control, a mineral substrate of the tailing dump of Abagurskaya agglomeration and processing plant JSC, unfavorable for the vital activity of soil microflora, where, due to the absence of plant residues and other carbon-containing components, an extremely low level of intensity of enzymatic hydrolytic processes was used. The introduction of organic matter containing sewage sludge (WWS) into the substrate as a recultivator creates favorable conditions for the formation of a stable vegetation cover. The presence of an organic component in the mineral substrate of the iron-containing tailings waste creates favorable conditions for the vital activity of microflora. Carbon-containing compounds of technozems create a certain pool of microorganisms. The products of their vital activity create the basis for the formation of an organic-mineral substrate, favorable conditions for the growth of higher plants and the creation of a stable phytocenosis. For the induced manifestation of enzymatic activity under these extreme conditions, a considerable time is required for the bacterial forms introduced from the outside to be able to fix their presence. The maximum activity, comparable both after 1 month and after 3 months with the natural control, was noted on the experimental site with the placement of WWS as a soil conditioner. The presence of WWS and intensive accumulation of leaf litter and other plant residues contribute to the favorable development of cellulose-degrading bacteria, among which rod-shaped forms of the genus Clostridium predominate. The quantitative indicators of the enzymatic activity of technozems are close to the natural level and significantly exceed those of technogenic control.

Enhancing extracellular production of recombinant proteins in Escherichia coli by co-expressing with a haloarchaeal protein containing a putative LolA-like domain.

Escherichia coli represents one of the most widely used hosts for recombinant protein production, but its limited capacity for producing extracellular proteins is often cited as a drawback. NJ7G_0991 is an extracellular protein of the haloarchaeon Natrinema sp. J7-2 and comprises a signal peptide, a putative LolA-like domain, and a C-terminal domain of unknown function. Here, we found that the full-length (0991) and the C-terminal domain-deletion variant (0991ΔC) of NJ7G_0991, but not its signal peptide-deletion variant (0991ΔS), were efficiently released into the culture supernatant of E. coli without extensive cell lysis as determined by β-galactosidase activity assay. After lysozyme treatment, E. coli cells producing 0991 or 0991ΔC, but not 0991ΔS, were converted from rod-shaped forms to spheres, suggesting that the secretion of 0991 or 0991ΔC into the periplasm leads to an increase of outer membrane permeability of E. coli. A pelB signal peptide was fused to the N-terminus of the LolA-like domain, and the resulting variant PelB-0991ΔC could be released into the culture supernatant of E. coli more efficiently than 0991ΔC. By using PelB-0991ΔC as a co-expression partner, the extracellular production level of a recombinant thermostable subtilase WF146 could be enhanced by up to 14-fold, and the extracellular concentration of an active site variant of WF146 (WF146-SA) reached up to 129 mg/l. To the best of our knowledge, this is the first report on archaeal protein-based co-expression system for extracellular production of recombinant proteins in E. coli. KEY POINTS: • The haloarchaeal protein NJ7G_0991 can be efficiently released into the culture supernatant of E. coli. • The recombinant NJ7G_0991 increases the outer membrane permeability of E. coli. • The LolA-like domain of NJ7G_0991 can be used as a co-expression partner to improve extracellular production of recombinant proteins in E. coli.

14-3-3 Protein Bmh1 triggers short-range compaction of mitotic chromosomes by recruiting sirtuin deacetylase Hst2

During mitosis, chromosomes are compacted in length by more than 100-fold into rod-shaped forms. In yeast, this process depends on the presence of a centromere, which promotes condensation in cis by recruiting mitotic kinases such as Aurora B kinase. This licensing mechanism enables the cell to discriminate chromosomal from noncentromeric DNA and to prohibit the propagation of the latter. Aurora B kinase elicits a cascade of events starting with phosphorylation of histone H3 serine 10 (H3S10ph), which signals the recruitment of lysine deacetylase Hst2 and the removal of lysine 16 acetylation in histone 4. The unmasked histone 4 tails interact with the acidic patch of neighboring nucleosomes to drive short-range compaction of chromatin, but the mechanistic details surrounding the Hst2 activity remain unclear. Using in vitro and in vivo assays, we demonstrate that the interaction of Hst2 with H3S10ph is mediated by the yeast 14-3-3 protein Bmh1. As a homodimer, Bmh1 binds simultaneously to H3S10ph and the phosphorylated C-terminus of Hst2. Our pull-down experiments with extracts of synchronized cells show that the Hst2–Bmh1 interaction is cell cycle dependent, peaking in the M phase. Furthermore, we show that phosphorylation of C-terminal residues of Hst2, introduced by genetic code expansion, stimulates its deacetylase activity. Hence, the data presented here identify Bmh1 as a key player in the mechanism of licensing of chromosome compaction in mitosis.

Large domains of heterochromatin direct the formation of short mitotic chromosome loops.

During mitosis chromosomes reorganise into highly compact, rod-shaped forms, thought to consist of consecutive chromatin loops around a central protein scaffold. Condensin complexes are involved in chromatin compaction, but the contribution of other chromatin proteins, DNA sequence and histone modifications is less understood. A large region of fission yeast DNA inserted into a mouse chromosome was previously observed to adopt a mitotic organisation distinct from that of surrounding mouse DNA. Here, we show that a similar distinct structure is common to a large subset of insertion events in both mouse and human cells and is coincident with the presence of high levels of heterochromatic H3 lysine nine trimethylation (H3K9me3). Hi-C and microscopy indicate that the heterochromatinised fission yeast DNA is organised into smaller chromatin loops than flanking euchromatic mouse chromatin. We conclude that heterochromatin alters chromatin loop size, thus contributing to the distinct appearance of heterochromatin on mitotic chromosomes.

Effectiveness of Actinomycetes Isolates from Bogor Botanical Gardens Land as Antifungal against Candida albicans Growth in Vitro

Background: Actinomycetes are Gram-positive and anaerobic bacteria noted for its rod-shaped forms. Actinomycetes aso has an antibiotic and antifungal activity. This study aims to identify the effectiveness of Actinomycetes isolate as the antifungal toward C. albicans growth by in vitro. Methods: Collected samples were planted on Starch Casein Agar (SCA) through pour plate method with three dilution series of 10-4, 10-5,10-6. The media used to see the obstacles zone of C. albicans was Sabouraud Dextrose Agar (SDA) with well method diffusion. Results: Actinomycetes isolates found in the samples were 15 isolates. From the three-dilution series, the study gets the size average of clear zone 3,78 mm, 4,03 mm and 3,52 mm. One way Anova (α 0,05) result also confirmed the difference of obstacles zone levels between C. albicans concentration. Conclusions: The compound comes from Actinomycetes that has potential as antifungal with one of its mechanism’s bonds ergosterol and resists fungi protein synthesis.
 
 

Microorganisms of various ecological-trophic groups in the saline ground waters of Primorsky Region (distribution, number, participation in accumulation of microelements)

A small number of ecological-trophic groups of bacteria are noted in saline groundwater’s (30-50 g/L). The obtained data show, that thionic and halophilic forms of saprophytic bacteria dominated, developing in presence of 10% NaCl. Among saprophytic microorganisms, rod-shaped forms of the genus Microbacterium sp. significantly dominated. A significant accumulation of Cu, Co and light REEs by brine microbial communities is shown.

Biosynthesis of Gold and Silver Nanoparticles Using Extracts of Callus Cultures of Pumpkin (Cucurbita maxima)

The potential of callus cultures and field-grown organs of pumpkin (Cucurbita maxima) for the biosynthesis of nanoparticles of the noble metals gold and silver has been investigated. Biosynthesis of AuNPs (gold nanoparticles) and AgNPs (silver nanoparticles) was obtained with flowers of C. maxima but not with pulp and seeds. With callus cultures established in MS-based medium the biogenesis of both AuNPs and AgNPs could be obtained. At 65 °C the biogenesis of AuNPs and AgNPs by callus extracts was enhanced. The AuNPs and AgNPs have been characterized by UV-visible spectroscopy, TEM, DLS and XRD. Well-dispersed nanoparticles, which exhibited a remarkable diversity in size and shape, could be visualized by TEM. Gold nanoparticles were found to be of various shapes, viz., rods, triangles, star-shaped particles, spheres, hexagons, bipyramids, discoid particles, nanotrapezoids, prisms, cuboids. Silver nanoparticles were also of diverse shapes, viz., discoid, spherical, elliptical, triangle-like, belt-like, rod-shaped forms and cuboids. EDX analysis indicated that the AuNPs and AgNPs had a high degree of purity. The surface charges of the generated AuNPs and AgNPs were highly negative as indicated by zeta potential measurements. The AuNPs and AgNPs exhibited remarkable stability in solution for more than four months. FTIR studies indicated that biomolecules in the callus extracts were associated with the biosynthesis and stabilisation of the nanoparticles. The synthesized AgNPs could catalyse degradation of methylene blue and exhibited anti-bacterial activity against E. coli DH5α. There is no earlier report of the biosynthesis of nanoparticles by this plant species. Callus cultures of Cucurbita maxima are effective alternative resources of biomass for synthesis of nanoparticles.

Answer to November 2015 Photo Quiz

Answer: Actinobaculum schaalii. The Gram stain of material from the abscess showed many Gram-positive cocci and Gram-negative coccobacilli. The organism that grew in aerobic culture initially presented as a pleomorphic Gram-positive organism with both coccoid and rod-shaped forms. After extended

Diversity of bacterial forms in ice wedge of the Mamontova Gora glacial complex (Central Yakutiya)

Electron microscopic investigation of four samples of ancient ice wedge from the Pleistocene glacial complex of Mamontova Gora (Yakutiya, Russia) revealed high diversity of bacteriomorphic particles. Their structural features included the presence of electron-transparent zones, presumably inclusions containing storage compounds, and microenvironment (capsules or external sheaths). These features may be a result of adaptive strategies providing for microbial survival under permafrost conditions. Predominance of rod-shaped forms morphologically resembling coryneform actinobacteria was found. X-ray microanalysis revealed organic origin of bacteriomorphic particles. Some particles were characterized by incomplete spectra of the major biogenic elements, resulting probably from low-temperature damage to the cellular structures. Total numbers of aerobic heterotrophic bacteria determined by plating on nutrient media were comparable to the values obtained for permafrost soils and Arctic ice. Predominance of coryneform actinobacteria was observed. Abundance of these evolutionarily early groups of actinobacteria may indicate the ancient origin of the microflora of the relic frozen rocks.

Nanometer‐scale characterization of exceptionally preserved bacterial fossils in Paleocene phosphorites from Ouled Abdoun (Morocco)

Micrometer-sized spherical and rod-shaped forms have been reported in many phosphorites and often interpreted as microbes fossilized by apatite, based on their morphologic resemblance with modern bacteria inferred by scanning electron microscopy (SEM) observations. This interpretation supports models involving bacteria in the formation of phosphorites. Here, we studied a phosphatic coprolite of Paleocene age originating from the Ouled Abdoun phosphate basin (Morocco) down to the nanometer-scale using focused ion beam milling, transmission electron microscopy (TEM), and scanning transmission x-ray microscopy (STXM) coupled with x-ray absorption near-edge structure spectroscopy (XANES). The coprolite, exclusively composed of francolite (a carbonate-fluroapatite), is formed by the accumulation of spherical objects, delimited by a thin envelope, and whose apparent diameters are between 0.5 and 3μm. The envelope of the spheres is composed of a continuous crown dense to electrons, which measures 20-40nm in thickness. It is surrounded by two thinner layers that are more porous and transparent to electrons and enriched in organic carbon. The observed spherical objects are very similar with bacteria encrusting in hydroxyapatite as observed in laboratory experiments. We suggest that they are Gram-negative bacteria fossilized by francolite, the precipitation of which started within the periplasm of the cells. We discuss the role of bacteria in the fossilization mechanism and propose that they could have played an active role in the formation of francolite. This study shows that ancient phosphorites can contain fossil biological subcellular structures as fine as a bacterial periplasm. Moreover, we demonstrate that while morphological information provided by SEM analyses is valuable, the use of additional nanoscale analyses is a powerful approach to help inferring the biogenicity of biomorphs found in phosphorites. A more systematic use of this approach could considerably improve our knowledge and understanding of the microfossils present in the geological record.

Synergistic anti-bacterial and proteomic effects of epigallocatechin gallate on clinical isolates of imipenem-resistant Klebsiella pneumoniae

Imipenem-resistant Klebsiella pneumoniae (IRKP) were used to explore the synergistic anti-bacterial and proteomic effects of imipenem alone or in combination with epigallocatechin gallate (EGCg). The minimal inhibitory concentrations (MICs) of EGCG for 12 clinically isolated IRKP strains ranged from 300 to 650 μg/ml. Each of the 12 IRKP strains experienced a 4- to 64-fold reduction in the MIC of imipenem upon co-incubation with 0.25 × MIC level of EGCg. The time-kill method was used on the 12 IRKP clinical isolates to evaluate the bactericidal activities of imipenem alone or with EGCg. Compared to imipenem alone, EGCg with imipenem demonstrated enhanced bactericidal activity. Two-dimensional polyacrylamide gel electrophoresis identified eight down-regulated and four up-regulated proteins in the IRKP strain upon exposure to 1 × MIC of EGCg. Analysis of the outer membrane protein profiles of IRKP cultures treated with EGCg revealed unique changes in outer membrane proteins. In addition, scanning electron microscopic analysis demonstrated the presence of cells with wrinkled surfaces containing perforations and irregular rod-shaped forms after treatment with EGCg or imipenem. These studies demonstrate that EGCg can synergize the bacterial activity of imipenem and differentially stimulate the expression of various proteins in IRKP.

Subaerial freshwater phosphatic stromatolites in Deer Cave, Sarawak — A unique geobiological cave formation

A suite of distinctive freshwater subaerial phosphatic stromatolites is developed close to the northeastern entrance of Deer Cave, Gunung Mulu National Park, Sarawak, Borneo, in conditions of very low light but ample supply of nutrients from guano. These stromatolites are not particulate; they are composed of alternating layers of more porous and more dense amorphous hydroxylapatite. This biomineralization occurs as moulds of coccoid (the majority) and filamentous (less abundant) cyanobacteria. Mineralization occurs at a pH of ~ 7.0 in the extracellular sheaths and in micro-domains of varying carbonate content in the surrounding mucus of the biofilm. The most recent surfaces that are not yet strongly mineralized show still-living filamentous, coccoid and rod-shaped forms. Trace element composition shows enrichment in metal ions, especially Mn and Zn. The stromatolites are present as horizontal shelves arranged in series on a steep rock face that is vertically under a guano-laden shelf. The rock face undergoes active dissolution from acidic guano drainage water (e.g., pH of 2.43) and from aggressive rainwater from an overhead discharge. However, the rock surface under the stromatolite is protected while the rest of the cliff face is backcut, creating a hoodoo-like effect. The stromatolites are ~ 15–20 cm deep, ~ 4–7 cm thick, and of variable width, generally ~ 50 cm. Eventually, guano and biological detritus in the descending water film lodge in the lee of the stromatolite lip, causing local acidification and erosion of stromatolite and rock on the underside of the ledge. A dynamic equilibrium is established between upward accretion of the fresh surface and destruction at the base such that the base of the stromatolite does not reflect the date of its inception and the stromatolite climbs up the wall.

CHARACTERIZATION OF “SA PANEDDA” TRADITIONAL PASTA FILATA CHEESE OF MONTE ACUTO

Panedda is a traditional Sardinian food product. It is fresh pasta filata cheese made from cow’s milk, either raw or heat treated. The aim of this work was to acquire data on traditional cheesemaking process and microbiological profile of Panedda. In 3 dairies located in Monte Acuto area samples from 2 batches were collected during the whole cheesmaking process. Samples of raw milk, curd, acidified curd, pasta filata, and finished product after 7 and 20 days of ripening were collected and microbiologically analyzed. The results showed good hygienic quality in the finished product at 7 days and a decrease of coliforms, E. coli and coagulase-positive Stafilococci was observed during the further ripening. No pathogenic microorganisms were found in all the samples. Among Lactic Acid Bacteria rod-shaped forms were the most prevalent microflora and Enterococci reached levels of about 6 log cfu/g. The results of this study showed satisfactory hygienic characteristics of Panedda and will be useful to preserve traditional cheesemaking process.

A morphological transition in the pleomorphic bacterium Ramlibacter tataouinensis TTB310

We provide microscopic evidence that motile rod-shaped forms of Ramlibacter tataouinensis TTB310 are formed from dividing cyst-like cells. Careful estimation of the size of the two morphotypes was conducted using optical and transmission electron microscopy (TEM). The cyst-like cell was shown to be a sphere with a diameter D c = 850 nm . The rod-shaped form was a round-ended cylinder with length L r = 2.91 μm and diameter D r = 239 nm . The membrane area of the two morphotypes was the same. However, the formation of rods from cysts involved loss of two-thirds of the cell volume. TEM showed that, prior to division and transition into rods, cysts contained condensed cytoplasmic material. These results suggest that the morphological transition occurs by pure reshaping of cells.

Nodular Fraction of Phosphatic Sand from the Namibia Shelf

Morphology, microstructure, and chemical composition of the nodular fraction of phosphatic sand from the outer Namibia shelf are considered. The nodules are divided into three varieties: concretions, phosphatic casts of shells pelecipod and gastropod, and phosphatized sea lion coprolites. A part of nodules shows massive homogeneous structure, whereas other nodules contain sand-size phosphatic grains derived from the host phosphatic sand. All nodules display the same spectrum of microstructures, including colloform, granular-globular, and crystallomorphic ones. The crystallomorphic nodules are composed of scattered and aggregated crystallites of isometric, rod-shaped, and dumbbell-shaped forms, as well as crystallized shells on grains incorporated into nodules. Phosphatized remains of diatoms, foraminifers, and embryonic gastropods, as well as vermicular and filamentous bacterial forms occur among biogenic components of the nodules. Framboidal pyrite is present in all nodules. In terms of phosphate microstructure, character of organic remains, and chemical composition, the nodules are similar to phosphate grains of the host sand, recent phosphorites from the inner Namibia shelf, and some ancient phosphorites.

Bacteria in the Tatahouine meteorite: nanometric-scale life in rocks

We present a study of the textural signature of terrestrial weathering and related biological activity in the Tatahouine meteorite. Scanning and transmission electron microscopy images obtained on the weathered samples of the Tatahouine meteorite and surrounding soil show two types of bacteria-like forms lying on mineral surfaces: (1) rod-shaped forms (RSF) about 70–80 nm wide and ranging from 100 nm to 600 nm in length; (2) ovoid forms (OVF) with diameters between 70 and 300 nm. They look like single cells surrounded by a cell wall. Only Na, K, C, O and N with traces of P and S are observed in the bulk of these objects. The chemical analyses and electron diffraction patterns confirm that the RSF and OVF cannot be magnetite or other iron oxides, iron hydroxides, silicates or carbonates. The sizes of the RSF and OVF are below those commonly observed for bacteria but are very similar to some bacteria-like forms described in the Martian meteorite ALH84001. All the previous observations strongly suggest that they are bacteria or their remnants. This conclusion is further supported by microbiological experiments in which pleomorphic bacteria with morphology similar to the OVF and RSF objects are obtained from biological culture of the soil surrounding the meteorite pieces. The present results show that bacteriomorphs of diameter less than 100 nm may in fact represent real bacteria or their remnants.