This same species was later isolated from Illinois horseradish plants with "brittleroot" disease Figure 5 , characterized by phloem necrosis, stunting, and the root fragility from which its name derives.
The third known phytopathogenic spiroplasma, S. The spiroplasma isolated from these plants was distinctly different from S.
Although the first spiroplasmas discovered were plant pathogens, non-phytopathogenic species were quickly identified occupying niches as epiphytes, or causing various diseases in animals, including humans. By far, however, the greatest number reside in insects. The fact that mosquitoes, ticks, honeybees, Drosophila , beetles, leafhoppers, flies and many other insect species harbor spiroplasmas led Hackett and Clark to suggest that these organisms may be one of the most prevalent organisms on earth.
Because the microbes often cause negative effects on the insect they are potentially useful for biocontrol. Spiroplasmas and phytoplasmas cause over diseases in several hundred plant species Calavan and Oldfield The "yellows" diseases fall primarily into two symptom categories. In the first, caused by spiroplasmas and some phytoplasmas, symptoms result primarily from phloem dysfunction and possibly also from competition between the pathogen and the host plant for the phloem-borne photosynthates.
They include wilting, stunting shortened internodes , foliar chlorosis, die-back, occasional leaf yellowing or reddening, phloem necrosis and collapse of the sieve tubes and companion cells, callose deposition in the phloem elements, plant decline and death.
A second type, caused by another group of phytoplasmas, involves plant growth regulator imbalances that result in often-distinctive deformations and overgrowths.
The latter include early development and proliferation of axillary shoots witches' brooming , bunchy top growth, and swollen veins Figure 6. Flowers may be partially or completely sterile, and may exhibit phyllody petals assuming a leaf-like form , asymmetry, virescence petal greening or "breaking" irregular distribution of petal pigment Figure 7.
In one case, the production of poinsettias with variegated bract pigmentation, the latter symptom actually is considered a positive quality. Symptom type and severity will vary with the pathogen, environmental conditions and age of the plant at the time of infection.
Economic devastation may result from reduced product quality or partial to complete yield loss. Critical to effective management of plant diseases are accurate diagnosis, pathogen detection and pathogen identification.
Symptomatology can be an effective means of preliminary diagnosis for some mollicute diseases, particularly for those characterized by significant growth irregularities such as stunting, organ deformation and petal color changes. More definitive means of identifying the causal agent, however, are necessary to confirm the etiology of the disease. Any of the three recognized phytopathogenic spiroplasma species S.
In the s and s convincing associations of phytoplasmas with many diseases were established by electron microscopic studies in which the pathogens were demonstrated in high numbers in sieve elements of symptomatic, but not healthy, plants.
Light microscopy of sectioned plant tissues was employed in combination with the application of Dienes' stain, which colors the mollicute-colonized sieve tubes Figure 10 , and fluorescence microscopy was adapted for tissues stained with the nucleic acid stain, DAPI. More recently, as antisera to a number of phytopathogenic mollicutes became available, ELISA and immunoblotting techniques were successfully adapted. Currently, molecular tagging methods DNA probes and primers of varying sensitivity and specificity are used in most studies, and in the case of phytoplasmas, are often supplemented with RFLP pattern analysis to discern phylogenetic placement and to establish relationships of the disease agent with known mollicutes.
Mollicute-plant host interactions and the underlying physiology that results in the development of symptoms are not well understood. Although mollicutes evolved from walled bacterial ancestors, genes for virulence mechanisms found in such bacteria may or may not be present in the reduced genomes of mollicutes.
Different factors may operate in different mollicute-plant systems, as evidenced by the two symptom categories mentioned above. Since the site of colonization in the plant host is the phloem sieve tubes, it is logical to suspect that phloem disruption could be a factor in symptom production and plant unthriftiness.
However, since the plant pathogenic mollicutes often cause disease in their leafhopper vectors and, in fact, may have originated as insect pathogens that invaded a new niche when introduced into plant phloem by feeding insects , it is possible that disease determinants operating in the insect may also be instrumental in producing plant distress.
Plant pathogenic mollicutes are transmitted by leafhoppers, planthoppers or psyllids Class Insecta: Order Hemiptera: Suborder Homoptera. These small insects feed by inserting straw-like stylets into mesophyll, xylem, or phloem tissues of a suitable plant host. Gentle penetration of the phloem sieve element permits these insects to ingest phloem sap for up to several hours, during which they may acquire spiroplasmas or phytoplasmas from infected plants.
Several factors may influence an insect species' ability to function as a mollicute vector, including propensity to feed from the host plant, ability to perform sustained phloem ingestion, and suitability as a spiroplasma or phytoplasma multiplication host. Spiroplasmas and phytoplasmas have a propagative relationship with their vectors Fletcher et al..
After being taken up by the feeding insect during phloem ingestion they move into the body cavity via the midgut region of the intestine.
They are thought to move into insect cells via a receptor-mediated internalization event, as shown for S. Once inside gut epithelial cells the mollicutes multiply and then move across the plasmalemma and basal lamina into the hemocoel. Using hemolymph as a multiplication and transport medium, the pathogens migrate to the salivary glands, from which they are ejected with saliva into phloem during subsequent phloem probing. The entire transmission process can take weeks, depending upon the titer of the source and duration of the acquisition feed.
Plant pathogenic mollicutes are not known to be transmitted to the progeny transovarial transmission. The primary field vector of S. Corn stunt is can be devastating to corn-growing regions in central Mexico and, because of the migratory range of D. Other vectors include D. In the United States, the primary field vector is the beet leafhopper, Circulifer tenellus , whereas in Europe Circulifer congeners and Scaphitopius spp.
Unlike the S. Phytoplasmas are transmitted in the same manner as spiroplasmas, but their vectors are not limited to the leafhoppers.
Some phytoplasmas, including the causal agents of coconut lethal yellowing and pear decline, are transmitted by cixiid planthoppers and psyllids, respectively.
Leafhoppers transmit phytoplasmas efficiently; for example, D. Other leafhoppers, Macrosteles quadrilineatus and Scaphoides titanus , are efficient vectors of the aster yellows and flavescence doree phytoplasmas, respectively. There is increasing evidence that phytoplasma infection may be beneficial to vector insects. Insects carrying the maize bushy stunt or aster yellows phytoplasma had higher survival rates than did mollicute-free control insects, especially at lower temperatures, supporting the hypothesis that phytoplasmas may have evolved in insects and moved secondarily to plant hosts.
Interestingly, aphids apparently do not serve as spiroplasma or phytoplasma vectors. It is possible that aphids lack the ability to internalize phytoplasmas at the gut or salivary glands, or that phytoplasmas are incapable of multiplying in aphid hemocoel due to immune responses in the insect or to an inability of the mollicute to metabolize carbohydrates in the aphid hemolymph. However, neither of these hypotheses has been tested empirically.
Management strategies for spiroplasma and phytoplasma induced plant diseases can be divided into those directed at the pathogen and those directed at the vectors.
Pathogen-based methods include resistant plant cultivars, but these are known for only a few host species. One example is the Maylayan dwarf palm, which is planted frequently in popular tourist areas where coconut lethal yellowing is prevalent.
Genotypes of ash with tolerance to the ash yellows phytoplasma also have been identified. Chemical bactericides that inhibit cell wall formation, such as penicillin, are of no use for control of the wall-less mollicutes, but tetracyclines and others that influence the physiology of the prokaryote may limit pathogen titers in the plant McCoy Tetracycline relatives have been used to preserve specimen trees and shrubs in landscape settings, but are not viable options for food plants because of expense and concern for pesticide residues in food products.
Mollicutes have been eliminated from certain valuable plant materials by heat or CO 2 therapies, or by meristem tip culture. Management options directed at the insect vectors are difficult because effective control can be accomplished only if applications precede insect migration into the fields.
If chemicals are applied after vector species are detected in the crop, inoculative insects are likely to introduce the pathogen into host plants before a grower is aware of the insects' presence.
Effective programs for aster yellows in muck-grown carrots and lettuce in the upper Midwest are based on nation-wide monitoring of the migration of M. A subset of the plant diseases characterized by "yellows" type symptoms foliar chlorosis, stunting, unthriftiness and death and also suffering phloem necrosis, visible as a darkened ring in freshly cut stem sections, are incited by walled bacteria.
These diseases have long presented challenges in diagnosis and management. Inability to consistently cultivate a pathogenic microbe from affected plants often led to mistaken attribution of causality, first to plant viruses and later, after plant pathogenic mollicutes were described, to phytoplasmas.
Although most of these agents still resist cultivation in artificial medium our understanding of their nature and diversity has grown considerably, thanks to recent molecular characterization methods.
Phloem-resident walled bacteria are generally very small bacilli that generally possess Gram-negative prokaryotic cell morphology. The outer membranes of some are wavy or rippled in appearance, a feature that gave rise to the early name "Rickettsia-like organism" or RLO. As scientists worldwide gain access to physical and molecular tools such as electron microscopy, 16S rDNA sequence analysis and PCR, the number of diseases attributed to phloem-colonizing walled bacteria grows.
In his recent review, Davis lists twenty four diseases in monocots and dicots, herbaceous plants and trees, vegetables, fruits and grains, and ornamental plants. Only a few of the phloem-resident bacterial plant pathogens have been placed taxonomically, and these fall into the phylum Proteobacteria. Candidatu s Liberobacter asiaticum and Candidatus L. The uncultivated agent of papaya bunchy top falls into the K-1 subgroup of the same family. Unlike the other phloem-colonizing bacteria, Sm is readily cultured on common bacteriological media and cucurbit-infecting strains have been shown to differ significantly from strains isolated from other ecological niches.
Strains of Sm inhabit the rhizosphere root zone of plants, producing beneficial effects as plant growth promoting rhizobacteria PGPR. Because of their anti-fungal properties certain Sm strains are also being evaluated as potential biocontrol agents in agricultural applications. Yet, certain strains invade plant tissues and cause economically devastating diseases in agronomically important crops. Since most of the phloem-resident walled phytobacteria are uncultivable in artificial media, most of our knowledge of the phylogenetic placement of this group of pathogens comes from molecular analysis of cloned regions such as the 16S rDNA.
Pathogens of other significant diseases, such as clover club leaf, have not yet been taxonomically characterized. However, other tools have been used to characterize these bacteria. Chromosome Mutations — II This tutorial is a continuation of the first lesson on chromosomal mutation.
Movement of Molecules Across Cell Membranes Molecules move within the cell or from one cell to another through different strategies. Origins of Life on Earth Earth was created around 4.
Growth and Plant Hormones Plants, like animals, produce hormones to regulate plant activities, including growth. Related Articles No related articles found See all Related Topics.
The most definitive specimens for recovery of F. In addition, blood cultures should be performed, especially when the septicemic form of tularemia is suspected.
Recently, however, clinical isolates of this organism that lacked the cysteine growth requirement have been described elsewhere [ 31 ]. Traditionally, agar media supplemented with cysteine and glucose have been used to recover F. However, it has recently been found that enriched chocolate agar and nonselective BCYE adequately support the growth of F.
Most isolates appear after 2—4 days of incubation [ 29 ]. Even when adequate specimens are processed under optimal culture conditions, recovery of F. When it is recovered in the laboratory, however, extreme care should be exercised in handling F. It is a common cause of laboratory-acquired infection, notwithstanding its very infrequent isolation.
Biosafety level 2 precautions should be employed [ 36 ]. In addition to biopsy-specimen cultures, blood cultures, especially for patients with the septicemic form of tularemia, may be appropriate even though they are rarely positive and the optimal detection system has not been delineated. As noted previously, current blood culture practices frequently involve use of a continuous-monitoring device. The media employed with these systems are typically enriched and probably support growth of F.
Indeed, recovery of F. Incubation of blood culture bottles beyond the usual 5 to 7-day cycle recommended with these systems may be required; alternatively, a terminal gram stain and subculture could be done when the index of suspicion is high.
Attempts to culture this organism are rarely necessary; however, if culture is to be performed, it should be restricted to the acute, primary stage of infection. The specimens of choice are skin lesion biopsy specimens, blood, and CSF from patients with clinical evidence of meningeal involvement [ 43 ].
Optimal sample sizes and transport conditions have not been defined. In light of the absence of such information, transport of specimens directly to the laboratory, followed by immediate inoculation and incubation of media, are recommended. Several different media have been proposed for culturing B. All are derived from Kelly's medium, originally described in as a means for propagating Borrelia hermsii , the cause of tick-borne relapsing fever in North America [ 44 ].
Supplementation of BSK-II medium with various antimicrobial agents has been recommended as a means of enhancing recovery of B. Cultures should be examined visually every 2—3 days for macroscopic evidence of growth e. If growth is observed, a drop of turbid medium should be removed and examined for the presence of organisms morphologically compatible with B. Either phase-contrast or dark-field microscopy is the preferred method of visualizing B.
Giemsa or silver stains are preferred but often are not available in clinical microbiology laboratories. At least once weekly in macroscopically negative cultures, a drop of medium from the bottom of culture tubes should be stained blindly for the presence of organisms morphologically compatible with B.
The likelihood of recovering B. Recovery from blood has been reported for only 3. Obviously, isolation rates are variable and tend to be low even when care is taken to maximize recovery. Irrespective of the specimen processed, recovery of B. The Leptospiraceae family is generally divided into 2 species, Leptospira interrogans and Leptospira biflexa , the latter species encompassing free-living, nonpathogenic forms [ 59 ].
More than serovars of L. Organisms in the L. Leptospira species are harbored by numerous wild and domesticated animals [ 60 ] and are excreted in the urine. The diagnosis of leptospirosis usually is based on the results of serological tests. Recovery of the organism in culture is largely restricted to reference and public health laboratories.
However, occasionally, general clinical microbiology laboratories are justified in attempting to culture Leptospira species from human specimens. Blood should be cultured during the acute stage of the disease, CSF and urine later in the illness. Numerous different semisolid media, dispensed in 5 to mL aliquots in sterile screw-capped tubes, may be used to propagate Leptospira species. These include Ellinghausen-McCullough medium as modified by Johnson and Harrison EMJH ; supplemented with bovine serum albumin and polysorbate 80; and Fletcher's, Stuart's, and Korthof's media [ 59—63 ], the latter 3 being supplemented with rabbit serum.
Blood is cultured by placing 1—4 drops of specimen into each of 3—5 culture tubes. With CSF specimens, 0. Whenever an antibiotic-containing medium is inoculated, a companion tube lacking antibiotic should also be inoculated. By use of aseptic technique, a drop of medium 1—3 cm below the surface is aspirated and examined with a dark-field or phase-contrast microscope for the presence of spirochetes with characteristic morphology and motility. A positive control culture should be inoculated with a known viable stock culture of Leptospira species at the time all clinical specimens are processed.
This process attests to the adequacy of what is invariably a little-used culture routine and serves as a source of organisms from which microscopic comparisons can be made. Alternative leptospiral culture methods have been described elsewhere but remain investigational [ 64 , 65 ].
Given the technical complexity and difficulties in culturing Leptospira , one can understand why such requests should virtually always be referred to public health or reference lab-oratories. Bartonella species are small, curved, highly fastidious gram-negative bacilli. Five species have been delineated: Bartonella bacilliformis, Bartonella vinsonii, Bartonella quintana, Bartonella henselae , and Bartonella elizabethae [ 66 , 67 ].
Uncommonly, B. In addition, B. For patients suspected of having bartonella infections, blood or biopsy specimens of involved tissue offer the best opportunity for culture recovery of the organism [ 66 ].
Most recent experience with isolation of Bartonella species in the laboratory has been with B. Although B. Recently, a chemically defined liquid medium has been described that yielded excellent growth of several clinical isolates of B. The utility of this liquid medium for processing clinical specimens from patients with bartonella infections needs to be further explored.
Tissue specimens should be transported to the laboratory expeditiously and then, after homogenization, inoculated directly onto solid medium.
Blood specimens should be collected in lysis-centrifugation Isolator tubes and transported directly to the laboratory, and concentrates should be subcultured promptly to solid media [ 66 ].
The optimal volume of blood per culture, the preferred number of cultures, and the timing of collection for maximum recovery of Bartonella species have not been defined.
Similarly, the optimal subculture routine is unknown. Recovery of Bartonella species from instrument-based broth blood cultures has been described elsewhere [ 76 , 77 ]; however, the optimal system has not been defined. The culture routines described above are probably also applicable to non- henselae Bartonella species, in particular, B.
Growth of B. The yield from cultures for Bartonella species is unknown. Even when cultures are performed under optimal conditions, isolation rates are very low. As a result, serology [ 66 ] and non-culture-based molecular detection methods such as PCR [ 78 ] are important adjuncts to establishing an etiologic diagnosis of bartonella infections.
Because of the resurgence of pertussis as a clinical problem in the United States [ 79 ], there is renewed interest in the recovery of B. Bordetella parapertussis may cause a similar albeit less-severe illness and may not have the same epidemiological implications as B. However, environmental Gemmata spp. In the clinical microbiology laboratory also, Gemmata spp. Indeed, Gemmata organisms are fastidious bacteria requiring highly specific culture medium 12 , 13 , Accordingly, conventional automated microbial detection of blood culture system is not appropriate to detect such bacteria undetected and less sensitive than culturing mock-infected blood on Caulobacter agar Nevertheless, their resistance to most of the routinely used antibiotics 16 and the recently demonstrated association with humans 10 , 11 support the potential of Gemmata organisms to behave as opportunistic pathogens warranting furthur investigations 2.
Accordingly, providing environmental and nutritional conditions similar to those existing in the natural habitat where yet uncultured bacteria are detected, may be an option for tentative isolation and culture 17 , In marine environments, a large fraction of Plantomycetes reside permanently in sponges pointing to highly integrated symbiotic relationships between the host sponge and Planctomycetes The reasons for such a symbiosis may be mechanical or nutritional relationships and chemotaxis as nutrients released by marine sponge surfaces may attract bacteria 19 and provoke their attachment via glycoproteins and uncharacterized holdfast structures.
The holdfast of marine bacteria can form temporal or permanent junctions to stabilize the biofilm 20 , 21 and may help Gemmata organisms to ensure a rapid growth and their reproduction by budding 8 , 22 , Based on these knowledges, we hypothesized that creating in the laboratory an attached-living style using dead marine sponge tissues spongin may act as a growth-promoting condition to improve the culturabily of Gemmata organisms.
We sought to test the growth-enhancement effect of complementing Gemmata species standard culture medium with marine sponge filtrate and sponge small fractions as a solid phase to mimic planctomycetes natural environment in order to develop a new biphasic culture system for Gemmata spp. By observing the organoleptic traits of the three different media after autoclaving, we observed a more yellow color of the media supplemented with marine sponge extracts while the unsupplemented Caulobacter standard liquid medium remained very light straw yellow.
It is probable that the yellow color resulted from the diffusion of chemical compounds from sponge after autoclaving since the sponge, heated in deionized water alone without Caulobacter components showed a slight yellow color. However, the autoclaving process did not significantly alter the macroscopic and microscopic structures of the sponge skeleton compared to control unautoclaved sponge skeletons.
In stationary broth cultures, the macroscopic appearance of the supplemented broth changed considerably during the course of culture. Indeed, growth occured in the form of a pink pellet that developed at the bottom of the tube. The pink pellet appeared at day-3 G. In medium A growth occured with proportional increase of the air bubbles in the medium but the pink pellet did not appear in parallel in medium B. Indeed, for medium A, at day-1 post-inoculation, we observed air bubbles that increased significantly in number at days 3—4 and throughout the experiment up to a peak at day 6—7 for inoculated media while the tubes containing non-inoculated medium A exhibited no air bubbles.
Also, after being vortexed, the enriched media showed a stable foam of at least 2. At day post-inoculation, this foam did not appear after the vortex process for inoculated supplemented media while it always appeared from non-inoculated medium. These observations suggested the possible presence of amphiphilic molecules from the sponge skeleton medium that have been dissolved in the standard medium. Also, the fact that the foam that appeared at the beginning of the experiment did not appear at day post-inoculation suggested that some molecules, which formed this foam, were completely consumed by the bacteria or bacterial growth has induced an inhibition of this foam, due to the releasing of acid toxic products pH 3.
By vortexing the tubes, the supplemented media appeared to be in well-clouded at the 3 rd day of the experiment compared to the non-supplemented media that remained limpid until the small pink layer began to appear at the day 7—8 post-inoculation G.
Under our microscopic visualization, all non-inoculated, negative control tubes remained sterile over the entire experiments, and culture on soild media provided confirmation. The composition of the medium was an important factor affecting both the rosettes formation G. In inoculated tubes, both strains were ovoid with a pleomorphism characteristic of bacteria from supplemented broth and usually occurred in pairs mother cell with small bud located at one pole versus singly from unsupplemented medium at day-1 post-inoculation.
On solid agar, these small buds after their growth can be seen near one of the two poles of the mother cell which appears bigger. In contrast, with the presence of sponge as a solid support, bacteria tend to cling, preferably, to the sponge fragments to ensure their budding. The negative control plates remained sterile over the entire experiments. In the media containing sponge extracts, growth yield was not proportional to the sponge extract concentration from 0.
At sponge extract concentrations of 0. Thus, colonies enumerations revealed that the cultures of G. Indeed, from standard Caulobacter broth, the number of G. Likewise, the addition of sponge small fractions in the standard broth supplemented with sponge filtrate biphasic system showed that the number of Gemmata obscuriglobus colonies was 1.
Thus, the following enumerations after the serial vortex resulted to the very high increasing of colonies from the medium supplemented with small fractions of marine sponge biphasic system , as shown in Fig. Growth-enhancement effect of complementing Gemmata obscuriglobus standard culture medium red bar with marine sponge filtrate green bar and sponge small fractions as a solid phase yellow bar.
The number of G. Data presented are for a 7 days period culture. Standard errors are represented by error bars.
Likewise, the same effects of the addition of sponge extracts were observed with Gemmata massiliana. Indeed, bacteria sub-cultured in each broth of the three tested liquid media were plated on Caulobacter solid agar and then counted after a day incubation period.
Thus, the number of G. The addition of sponge small fractions for bacterial attachment in the standard broth supplemented with sponge filtrate biphasic system increased the growth rate and colonies enumerations were 1.
As described for G. From day-7 to day post-inoculation, the depletion of nutrients and potential growth factors thus marks the stationary phase of bacterial growth while the bacterial growth progressed in the unsupplemented medium.
Growth-enhancement effect of complementing Gemmata massiliana standard culture medium red bar with marine sponge filtrate green bar and sponge small fractions as a solid phase yellow bar. On the surface of both media, both colonies were circular, convex and had entire margins with sometime a litle bud daugher cell near to mother cell. Relatively, the growth of both organisms from medium supplemented with marine sponge filtrate was more rapid, with small colonies becoming visible at day 5 G.
Although Gemmata spp. Failure to isolate any Gemmata organism from these specimens may rely on the fact that PCR-based detected organisms were dead and indeed, no characterization of their viability has been attempted. Alternatively, failure to isolate and culture may be due to inappropriate culture conditions of the clinical specimens.
Blood culture remains the gold standard for diagnosing bloodstream infections but conventional cultivation of Gemmata microorganisms from blood culture is requiring specific conditions for blood collection and culture Mimicking culture strategies by environmental microbiologists, we aimed to incorporate marine sponge skeleton fragments and spongin-based sponge skeleton extract in the culture medium routinely used to grow G. Indeed, our observations revealed a significant growth-promoting effect after complementing Caulobacter standard medium with marine sponge skeleton filtrate.
These results imply that some yet unknown thermosoluble growth factors are strongly and possibly bound to the sponge skeletons and have been dissolved by heat autoclaving in supplemented media. The existence of an intimate relationship between planctomycetes and marine sponges 19 can be ascribed partly to these observations via a mounting molecular evidence, stimulating the rapid growth of slow-growing bacteria like planctomycetes.
Spongia sp. Spongin consists mostly of carbon, nitrogen, oxygen and hydrogen and the the presence of sulfuris connected with the disulfide bonds of cysteine has also been reported in spongin structure Sponginous collagens analysis of the sponge Spongia officinalis obliqua revealed that not only proteinogenic amino acids but also halogenated Brominated tyrosines were occured in these sponges More reports have pointed that sponge collagen is a good biomaterial for medical 32 , pharmaceutical 33 , nutraceutical 34 and cosmeceutical 34 , 35 , 36 applications bone tissue regeneration, moisturizer in cosmetic formulations.
Indeed, collagen has the properties related to its gel formation, surface behavior, which includes emulsion, foam formation, stabilization stable foam occurred in our tested media, see above for details , adhesion, protective colloid function and film-forming capacity. In addition, collagen is a good surface-active agent and has an ability to penetrate a lipid-free interface 37 , All these propreties make it a good component which are likely contributed to improve the Gemmata nutrition, which are bacteria well-known to uptake of such macromolecules by their endocytosis-like process 39 , Additionnaly, some of sponge skeletons solubilized molecules by heat in our enriched media are likely Glycosaminoglycans a source of N-acetyl-glucosamine, N-acetyl-galactosamine, uronic acid , a well-known polysaccharide from sponginous skeletons of Spongia officinalis and S.
The N-acetyl-glucosamine from these Glycosaminoglycans represents a good source of both carbone and nitrogen for planctomycetes nutrition 12 , 13 and this can explain partly the molecular evidence stimulating the rapid growth of slow-growing Gemmata spp.
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