Cell-wall Type Research Articles

Deeply branching Bacillota species exhibit atypical Gram-negative staining.

In this study, we examined the evolution of bacterial cell envelopes, specifically focusing on Gram-positive and Gram-negative cell wall types in the Bacillota phylum. Our results indicate that certain bacteria can stain Gram-negative despite having a monoderm cell wall structure, thus challenging the conventional interpretation of Gram-staining results. Our observations also question the assumption that Gram-negative staining is always indicative of a diderm structure. These findings have broader implications for understanding how and when cell walls thicken during the evolution of bacterial cell envelopes.

Seed morphology of Cuscuta L. (Convolvulaceae) in Turkey and its systematic importance

Seed morphologies of 14 Cuscuta taxa from Turkey were examined by light (LM) and scanning electron microscopy (SEM). Seed shapes, sizes, epidermal cell shapes, anticlinal/periclinal cell walls and surface patterns of macro and micro morphological features were determined. Seed epidermis cell shapes were generally either irregular or polygonal. The surface pattern was mostly reticulate. This research revealed that Cuscuta species in Turkey have different seed morphologies. The results obtained will aid in the taxonomic evaluation of morphologically closely related species.

Under What Conditions do the Inflorescence Bract Phytoliths of Oat [Avena sativa (L.)] Become Autofluorescent?

ABSTRACT Our previous research from archaeological contexts suggested that phytoliths become autofluorescent when exposed to fire and heat. The present study is an attempt to investigate the conditions under which autofluorescence occurs in the inflorescence bracts of oats (Avena sativa (L.)) when they are heated. Three factors were investigated: temperature; time; and the presence or absence of oxygen. Unheated phytoliths showed no autofluorescence, and oxygen was not required for autofluorescence. We found that some phytoliths become autofluorescent at temperatures as low as 200°C, but at these lower temperatures this is often masked or hidden by organic material and incompletely oxidised material. All phytolith morphotypes, both cell wall and lumen types, fluoresce at temperatures up to 500°C. Melting in our system was observed to begin before 500°C, and at temperatures higher than this most phytoliths were melted, but Rondel seemed to be particularly resistant to heat. They still fluoresce at 900°C after a total heating period of 330 min. The relevance of this work to archaeological contexts is discussed.

A novel method of flash‐hydrolysis assisted pigment extraction (carotenoids) from microalgae biomass

AbstractThe human body can easily convert β‐carotene into retinol (a precursor of vitamin A), a significant ingredient in dietary supplements. The need for commercial natural pigment production, including β‐carotene, has led to intensive research in this area. Processing after biosynthesis is a vital stage that involves the use of nontoxic solvents, efficient mechanical disruption of cells, and the isolation of the required compounds. With the growing popularity of green extraction methods and the increasing market demand for carotenoids due to their health benefits, the use of clean, nontoxic, flash‐hydrolyzed biomass for carotenoid production presents a significant advantage. Furthermore, the remaining biomass can serve as a protein source for animal feed, thereby aligning with the principles of the biorefinery concept. In this study, our aim was to optimize the disruption of cells in two microalgal species using flash hydrolysis (FH). We applied two distinct levels of pressure and four separate temperature conditions over a brief residence time. Following this, we employed an ethanol extraction method to assess the efficiency of carotenoid pigment extraction. Flash hydrolysis is a chemical‐free subcritical water‐based continuous‐flow process, injected with wet biomass slurry at a high temperature (150–250 °C) for a very short time (8–12 s) to obtain bioproducts. In this study, we discovered that the pigment β‐carotene constituted 0.04 to 0.3% of the dry biomass in the case of Chlorella vulgaris. Bands of lutein and zeaxanthin were also observed in the thin layer chromatography (TLC) analysis of the treated slurry. This was achieved under conditions of an effective temperature of 200 °C and a pressure of 1700 psi. The Arthrospira platensis (1Tex), β‐carotene yield was 0.014 to 0.021% of dry biomass. Some lutein and zeaxanthin bands were also found in the treated slurry with an effective temperature of 150 °C and 1000 psi pressure. This study reports pigment extraction by FH for the first time. It is a viable process to scale up high‐value natural products like carotenoids from microalgae at the industrial level without adverse environmental impacts. Due to low residence time, the temperature does not have a negative effect on pigments; cell rupture was accomplished effectively using water as a solvent. A considerable amount of pigment could be recovered from microalgae at specific combinations of temperature and pressure depending on the type of cell wall that microalgae possess.

Soybean and maize differentially metabolize deuterated ferulic and sinapic acids before polymerizing them into the root cell wall

Hydroxycinnamates induce lignification in young plants, leading to the overproduction of lignin as a defense mechanism. Phenylpropanoids-containing oligosaccharides are thought to be a signal of pathogen attack on the cell wall polysaccharides. However, it is unclear if hydroxycinnamates induce lignification by acting solely as stress elicitors or feeding the phenylpropanoid pathway as lignin precursors. To examine this hypothesis, we added 1 mM deuterated ferulic acid (FA) or sinapic acid (SA) to the nutrient solution in which we cultivated soybean or maize plantlets. After 24 h, we assessed the biometric parameters and the contents of ester-linked FA and SA, total lignin, monolignol ratio, and heavy monolignols. FA treatment increased the content of ester-linked FA, syringyl, and guaiacyl monomers measured by nitrobenzene oxidation, lignin content, and reduced root growth in both soybean and maize plants. p-Coumaric acid content ester-linked to the cell wall increased in soybean but decreased in maize after treatment with FA. Treatment with SA also induced lignification in soybean but not in maize. SA increased S-lignin and sinapoyl esters content in the cell wall polymers in both soybean and maize. Residues of deuterated hydroxycinnamates were detected in the lignin of both plants in both treatments. The assay demonstrated that exogenously applied SA and FA were metabolized through the phenylpropanoid pathway. Furthermore, they were, at least partially, exported to the apoplast, where they were ester-linked to cell wall polymers. This suggests hydroxycinnamic acids are metabolized differently by plants with different types of cell walls.

Effects of Lotus Flower Extract on Cotton Fabric and Its Antimicrobial Activity against Wound Causing Pathogens

Abstract Background: Hemp that belongs to the cannabis plant has been used for medicinal purposes for centuries due to the purposes that contained natural plant products. Of all these types, lotus flower extract obtained from the Nelumbo nucifera has been considered to possess some antibacterial activity. This study seeks to evaluate the effectiveness of bacteriostatic activity of lotus flower extract incorporated into fabrics used in coating the dressing. Methods: Leaves of lotus were used and subjected to extraction using methanol and diethyl ether solvents. These extracts were then practiced in a Petri dish plate against the specific pathogens of wound infections obtained from Microbial Type Culture Collection (MTCC). According to the type of cell wall, the pathogens were divided into Gram-positive cocci: Staphylococcus aureus and Streptococcus pyogenes, and Gram-negative: Escherichia coli and Pseudomonas aeruginosa. The antimicrobial effectiveness was tested by means of the disc diffusion method. The phytochemical component was also screened as a way of determining the secondary metabolites present in the extracts. Results: Alkaloids, anthraquinone, flavone, saponin, glycoside, tannin, phenol and cardiac glycoside were present in the Phytochemical analysis of extracts of O.moschata. The antibacterial tests on bacterial species’ growth revealed that all the extracts were moderately effective against S. aureus, showing the zone of inhibition between 5 – 10 mm, whereas against P. aeruginosa and E. coli the extracts were highly effective with a zone of inhibition between 7 – 15 mm. Conclusion: In the case of this research, it is clearly depicted that lotus flower extracts have strong antibacterial properties especially against the Gram-negative bacteria namely P. aeruginosa and E. coli. These findings are in concordance with the ethno medial usage of lotus plant in treating infected wounds and opens up applications in using the extracts to develop antibacterial fabric scarf solutions. More related works should be conducted to investigate the clinical utility and effectiveness of the above extracts in wound healing and their safety.

Imaging and component analysis of pumpkin stem tissue with simultaneous SF-CARS and TPEF microscopy.

A multimodal nonlinear optical imaging platform based on a single femtosecond oscillator is built for simultaneous TPEF and SF-CARS imaging. TPEF microscopy and SF-CARS microscopy is utilized for mapping the distribution of the lignin component and the polysaccharide component, respectively. Visualization of vessel structure is realized. And the relative distribution of lignin and polysaccharide of vessel structure is mapped. Two pumpkin stem tissue areas with different degrees of lignification are observed with simultaneous TPEF and SF-CARS imaging, and two types of cell walls are identified. The different distribution patterns of lignin and polysaccharide in these two types of cell walls, induced by different degrees of lignification, are analyzed in detail.

Plant cell wall composition modulates the gut microbiota and metabolites in in-vitro fermentation

This research investigated the effect of different types of plant cell wall fibres, including cereal (i.e., barley, sorghum, and rice), legume (i.e., pea, faba bean, and mung bean), and tuber (potato, sweet potato, and yam) cell wall fibres on in vitro faecal fermentation profiles and gut microbiota composition. The cell wall composition, specifically the content of lignin and pectin, was found to have a significant influence on the gut microbiota and fermentation outcomes. Compared with type I cell walls (legume and tuber) which have high pectin content, the type II cell walls (cereal) which are high in lignin but low in pectin had a lower fermentation rates and less short-chain fatty acid production. The redundancy analysis showed samples with similar fibre composition and fermentation profiles clustered together, and the principal coordinate analysis revealed separation among different types of cell walls and closer proximity among the same cell wall types. These findings emphasize the importance of cell wall composition in shaping the microbial community during fermentation and contribute to a better understanding of the relationship between plant cell walls and gut health. This research has practical implications for the development of functional foods and dietary interventions.

Pharmacognostic Evaluation of Platycerium bifurcatum (Cav.) C. Chr. (Polypodiaceae)

Ethnopharmacological relevance: Platycerium bifurcatum (CAV.) C. Chr., Commonly known as staghorn fern is an epiphytic plant with diverse medicinal uses, such as anti-ulcer remedy, treating oedema, coughs and hypertension. This research was aim at evaluating the pharmacognostic profile of P. Bifurcatum. Methods: The fresh and air-dried plant materials were evaluated for microscopic characters, ash values, extractive values, moisture content and phytoconstituents. Results: Pharmacognostic evaluation revealed two shape of leaves, one round and the other forked-like shape, dark and light green colour, slightly coarse texture at the abaxial surface and hairy due to the trichome at the adaxial surface, reticulate leaf venation and margin entire, presence non- grandular stellate trichomes at the lower epidermal layer, spongy mesopghyll, collenchyma cells, vascular bundles straight type of epidermal cell wall, anisocytes stomata. Moisture content of 6.283%, total ash value of 8.25% within the standard range, acid insoluble ash of 1%, water soluble of 6.0% and phytochemical screening analysis shows the presence of phenolic, saponins, glycosides and triterpenoid constituents. Conclusion: this study reports the first time the pharmacognostic properties of P. bifurcatum.

A Method for Electroporation of Cre Recombinase Protein into Intact Nicotiana tabacum Cells.

The Cre/lox recombination system has become a powerful technology for gene function analysis in a broad spectrum of cell types and organisms. In our previous report, Cre protein had been successfully delivered into intact Arabidopsis thaliana cells using electroporation. To expand the feasibility of the method of protein electroporation to other plant cells, here we attempt the protein electroporation into tobacco-derived BY-2 cells, one of the most frequently used plant cell lines for industrial production. In this study, we successfully deliver Cre protein into BY-2 cells with intact cell walls by electroporation with low toxicity. Targeted loxP sequences in the BY-2 genome are recombined significantly. These results provide useful information for genome engineering in diverse plant cells possessing various types of cell walls.

Structural characterisation of methanogen pseudomurein cell wall peptide ligases homologous to bacterial MurE/F murein peptide ligases.

Archaea have diverse cell wall types, yet none are identical to bacterial peptidoglycan (murein). Methanogens Methanobacteria and Methanopyrus possess cell walls of pseudomurein, a structural analogue of murein. Pseudomurein differs from murein in containing the unique archaeal sugar N-acetyltalosaminuronic acid instead of N-acetylmuramic acid, β-1,3 glycosidic bonds in place of β-1,4 bonds and only l-amino acids in the peptide cross-links. We have determined crystal structures of methanogen pseudomurein peptide ligases (termed pMurE) from Methanothermus fervidus (Mfer762) and Methanothermobacter thermautotrophicus (Mth734) that are structurally most closely related to bacterial MurE peptide ligases. The homology of the archaeal pMurE and bacterial MurE enzymes is clear both in the overall structure and at the level of each of the three domains. In addition, we identified two UDP-binding sites in Mfer762 pMurE, one at the exterior surface of the interface of the N-terminal and middle domains, and a second site at an inner surface continuous with the highly conserved interface of the three domains. Residues involved in ATP binding in MurE are conserved in pMurE, suggesting that a similar ATP-binding pocket is present at the interface of the middle and the C-terminal domains of pMurE. The presence of pMurE ligases in members of the Methanobacteriales and Methanopyrales, that are structurally related to bacterial MurE ligases, supports the idea that the biosynthetic origins of archaeal pseudomurein and bacterial peptidoglycan cell walls are evolutionarily related.

Review: Tertiary cell wall of plant fibers as a source of inspiration in material design

The review summarizes the plant lifehacks on material design on the example of the impressive cellulose-enriched cell wall deposited by fibers of many plants. This specific cell wall type is called tertiary since it is deposited after the secondary cell wall and is very distinct in the machinery of formation and function. The basic principles of tertiary cell wall performance include: 1) original composition (two major players – cellulose microfibrils and the version of rhamnogalacturonan I that forms specific supramolecular structures); 2) original cell wall design with axial orientation of all cellulose microfibrils, pronounced lateral interactions between them and the presence of the entrapped rhamnogalacturonan I; 3) dynamic changes in cell wall supramolecular organization due to rhamnogalacturonan I modifications in muro in the course of fiber maturation; 4) the built-in sensors that trace the cell wall state; 5) incorporation of tertiary cell wall into the system with higher level of organization.

- Anatomi Daun Varietas Belimbing (Averrhoa carambola L.) Lokal di Taman Buah Mekarsari Bogor

Sweet star fruit (Averrhoa carambola L., belimbing manis) is one of Indonesia’s most popular fruit plants. Anatomically, the characters of the local sweet star fruit of Mekar Sari Fruit Garden are not widely known, so this study aims to observe the anatomical structure of the leaves. The materials used were star fruit leaves of varieties Demak Jingga, Demak Kapur, Demak Kunir, Welahan, and Wulan. The leaves of star fruit varieties were made microscopic preparations in paradermal incisions using the whole mount method and transverse incisions using the paraffin method. The observation result of the paradermal incision of sweet star fruit leaves showed that the type of epidermal cell wall is straight and shallow grooved. The leaf stomata of five sweet star fruit varieties were paracytic. The calculation of the index value, size and density of stomata varied between varieties. The highest stomata density and index were found in the Welahan variety. The results of the transverse incision of sweet starfruit leaves showed that the five local sweet star fruit varieties have mesophyll tissue of the dorsiventral type. Wulan variety has leaves and mesophyll tissue which tends to be thicker than other varieties.

Blastococcus tunisiensis sp. nov., isolated from limestone collected in Tunisia.

A new actinobacterium strain, designated BMG 823T, was isolated from a limestone sample collected in Tunisia. Its taxonomic position was scrutinized using a polyphasic approach. Colonies of strain BMG 823T were pink orange-coloured, regular and had a moist surface. Cells are Gram-stain-positive, catalase-negative and oxidase-negative. The strain grew at pH 5.5-9, 10-40 °C and in presence of up to 4 % NaCl (w/v). Chemotaxonomically, strain BMG 823T was characterized by cell-wall type III containing meso-diaminopimelic acid as diamino acid, glucose, ribose and rhamnose as whole-cell sugars, MK-9(H4) as predominant menaquinone, and phosphatidylcholine, diphosphadidylglycerol, phosphatidethanolamine, phosphatidylcholine, phosphatidylinositol, unidentified glycolipid, unidentified aminophospholipids and unidentified glycophospholipid as major polar lipids. The fatty acid profile consisted of iso-C16 : 0 and iso-C17 : 1 ω9. Phylogenetic trees based on 16S rRNA gene and genome sequences placed strain BMG 823T within the genus Blastococcus and separated it from all type strains of validly published species. Comparison of 16S rRNA gene sequence similarity, digital DNA-DNA hybridization and average nucleotide identity indicated that strain BMG 823T was most closely related to Blastococcus litoris DSM 106127T and Blastococcus colisei BMG 822T with pairwise values well below the species differentiation thresholds. The distinct phenotypic and genotypic features of strain BMG 823T (=DSM 46838T=CECT 8881T) within the genus Blastococcus warrant its recognition as the type strain for the new species for which we propose the name Blastococcus tunisiensis sp. nov.

Pirates of the haemoglobin

Not all treasure is silver and gold; for pathogenic bacteria, iron is the most precious and the most pillaged of metallic elements. Iron is essential for the survival and growth of all life; however free iron is scarce for bacteria inside human hosts. As a mechanism of defence, humans have evolved ways to store iron so as to render it inaccessible for invading pathogens, such as keeping the metal bound to iron-carrying proteins. For bacteria to survive within humans, they must therefore evolve counters to this defence to compete with these proteins for iron binding, or directly steal iron from them. The most populous form of iron in humans is haem: a functionally significant coordination complex that is central to oxygen transport and predominantly bound by haemoglobin. Haemoglobin is therefore the largest source of iron in humans and, as a result, bacterial pathogens in critical need of iron have evolved complex and creative ways to acquire haem from haemoglobin. Bacteria of all cell wall types have the ability to bind haemoglobin at their cell surface, to accept the haem from it and transport this to the cytoplasm for downstream uses. This review describes the systems employed by various pathogenic bacteria to utilise haemoglobin as an iron source within human hosts and discusses their contribution to virulence.

Archaeal pseudomurein and bacterial murein cell wall biosynthesis share a common evolutionary ancestry.

Bacteria near-universally contain a cell wall sacculus of murein (peptidoglycan), the synthesis of which has been intensively studied for over 50 years. In striking contrast, archaeal species possess a variety of other cell wall types, none of them closely resembling murein. Interestingly though, one type of archaeal cell wall termed pseudomurein found in the methanogen orders Methanobacteriales and Methanopyrales is a structural analogue of murein in that it contains a glycan backbone that is cross-linked by a L-amino acid peptide. Here, we present taxonomic distribution, gene cluster and phylogenetic analyses that confirm orthologues of 13 bacterial murein biosynthesis enzymes in pseudomurein-containing methanogens, most of which are distantly related to their bacterial counterparts. We also present the first structure of an archaeal pseudomurein peptide ligase from Methanothermus fervidus DSM1088 (Mfer336) to a resolution of 2.5Å and show that it possesses a similar overall tertiary three domain structure to bacterial MurC and MurD type murein peptide ligases. Taken together the data strongly indicate that murein and pseudomurein biosynthetic pathways share a common evolutionary history.

Gene Expression Patterns for Proteins With Lectin Domains in Flax Stem Tissues Are Related to Deposition of Distinct Cell Wall Types.

The genomes of higher plants encode a variety of proteins with lectin domains that are able to specifically recognize certain carbohydrates. Plants are enriched in a variety of potentially complementary glycans, many of which are located in the cell wall. We performed a genome-wide search for flax proteins with lectin domains and compared the expression of the encoding genes in different stem tissues that have distinct cell wall types with different sets of major polysaccharides. Over 400 genes encoding proteins with lectin domains that belong to different families were revealed in the flax genome; three quarters of these genes were expressed in stem tissues. Hierarchical clustering of the data for all expressed lectins grouped the analyzed samples according to their characteristic cell wall type. Most lectins differentially expressed in tissues with primary, secondary, and tertiary cell walls were predicted to localize at the plasma membrane or cell wall. These lectins were from different families and had various architectural types. Three out of four flax genes for proteins with jacalin-like domains were highly upregulated in bast fibers at the stage of tertiary cell wall deposition. The dynamic changes in transcript level of many genes for lectins from various families were detected in stem tissue over the course of gravitropic response induced by plant gravistimulation. The data obtained in this study indicate a large number of lectin-mediated events in plants and provide insight into the proteins that take part in tissue specialization and reaction to abiotic stress.

Shedding Light on the Dynamic Role of the "Target of Rapamycin" Kinase in the Fast-Growing C4 Species Setaria viridis, a Suitable Model for Biomass Crops.

The Target of Rapamycin (TOR) kinase pathway integrates energy and nutrient availability into metabolism promoting growth in eukaryotes. The overall higher efficiency on nutrient use translated into faster growth rates in C4 grass plants led to the investigation of differential transcriptional and metabolic responses to short-term chemical TOR complex (TORC) suppression in the model Setaria viridis. In addition to previously described responses to TORC inhibition (i.e., general growth arrest, translational repression, and primary metabolism reprogramming) in Arabidopsis thaliana (C3), the magnitude of changes was smaller in S. viridis, particularly regarding nutrient use efficiency and C allocation and partitioning that promote biosynthetic growth. Besides photosynthetic differences, S. viridis and A. thaliana present several specificities that classify them into distinct lineages, which also contribute to the observed alterations mediated by TOR. Indeed, cell wall metabolism seems to be distinctly regulated according to each cell wall type, as synthesis of non-pectic polysaccharides were affected in S. viridis, whilst assembly and structure in A. thaliana. Our results indicate that the metabolic network needed to achieve faster growth seems to be less stringently controlled by TORC in S. viridis.

Application of single-cell real-time imaging flow cytometry in rapid detection of pathogenic fungi in clinical liquid specimens

Rapid and direct observation of fungal spores or hyphae in clinical liquid specimens poses a challenge for the diagnosis of invasive fungal infection. To allow rapid detection of fungal pathogens, we designed a new method of fungal cell detection involving double fluorescence staining with calcium fluorescent white (CFW) and SYTOX green combined with single-cell real-time imaging flow cytometry (IFC). IFC allowed quick detection and analysis of detailed morphology of the spores and pseudohyphae of Candida albicans, and small hyphae and typical truncated large mycelia of Aspergillus fumigatus. Further, cell sorting based on fluorescence, the width-to-height ratio and bright-field parameters preferentially identified spores or hyphae with a typical cell wall. The specificity and overall coincidence rate of IFC for fungi detection in common clinical samples were 100% and 98.18%, respectively. Moreover, the detection rate by IFC (102/105, 97.14%) was significantly higher (P = 0.002) than that by wet mount method (89/105, 84.5%). Therefore, IFC is a reliable diagnostic method with a high potential for application for rapid diagnosis of fungal infection in the clinic.

Long-Chain Fatty Acids Degradation by Desulfomonile Species and Proposal of "Candidatus Desulfomonile Palmitatoxidans".

Microbial communities with the ability to convert long-chain fatty acids (LCFA) coupled to sulfate reduction can be important in the removal of these compounds from wastewater. In this work, an enrichment culture, able to oxidize the long-chain fatty acid palmitate (C16:0) coupled to sulfate reduction, was obtained from anaerobic granular sludge. Microscopic analysis of this culture, designated HP culture, revealed that it was mainly composed of one morphotype with a typical collar-like cell wall invagination, a distinct morphological feature of the Desulfomonile genus. 16S rRNA gene amplicon and metagenome-assembled genome (MAG) indeed confirmed that the abundant phylotype in HP culture belong to Desulfomonile genus [ca. 92% 16S rRNA gene sequences closely related to Desulfomonile spp.; and ca. 82% whole genome shotgun (WGS)]. Based on similar cell morphology and average nucleotide identity (ANI) (77%) between the Desulfomonile sp. in HP culture and the type strain Desulfomonile tiedjei strain DCB-1T, we propose a novel species designated as “Candidatus Desulfomonile palmitatoxidans.” This bacterium shares 94.3 and 93.6% 16S rRNA gene identity with Desulfomonile limimaris strain DCB-MT and D. tiedjei strain DCB-1T, respectively. Based on sequence abundance of Desulfomonile-morphotype in HP culture, its predominance in the microscopic observations, and presence of several genes coding for enzymes involved in LCFA degradation, the proposed species “Ca. Desulfomonile palmitatoxidans” most probably plays an important role in palmitate degradation in HP culture. Analysis of the growth of HP culture and D. tiedjei strain DCB-1T with short- (butyrate), medium- (caprylate) and long-chain fatty acids (palmitate, stearate, and oleate) showed that both cultures degraded all fatty acids coupled to sulfate reduction, except oleate that was only utilized by HP culture. In the absence of sulfate, neither HP culture, nor D. tiedjei strain DCB-1T degraded palmitate when incubated with Methanobacterium formicicum as a possible methanogenic syntrophic partner. Unlike D. tiedjei strain DCB-1T, “Ca. Desulfomonile palmitatoxidans” lacks reductive dehalogenase genes in its genome, and HP culture was not able to grow by organohalide respiration. An emended description of the genus Desulfomonile is proposed. Our study reveals an unrecognized LCFA degradation feature of the Desulfomonile genus.