Cell surface properties as factors involved in Proteus vulgaris adhesion to stainless steel under starvation conditions

The purpose of these investigations was to evaluate the influence of limited nutrient availability in the culture medium on Proteus vulgaris biofilm formation on surfaces of stainless steel. The relationship between the P. vulgaris adhesion to the abiotic surfaces, the cellular ATP levels, cell surface hydrophobicity and changes in the profiles of extracellular proteins and lipopolysaccharides was examined. In all experimental variants the starvation conditions induced the bacterial cells to adhere to the surfaces of stainless steel. Higher ATP content and lower cell surface hydrophobicity of P. vulgaris cells was observed upon nutrient-limited conditions. Under starvation conditions a reduction in the levels of extracellular low molecular weight proteins was noticed. High molecular weight proteins formed the conditioning layer on stainless steel plates, making the bacteria adhesion process more favorable. The production of low molecular weight carbohydrates promoted more advanced stages of P. vulgaris biofilm formation process on the surfaces of stainless steel upon starvation.     

Influence of surface modification on vitality and differentiation of Caco-2 cells

Abstract It is widely accepted that the functional and morphological differentiation of cells is initiated and determined by the interaction of molecules of the extracellular matrix and adhesion molecules of the cell membrane. To assess the influence of the underlying matrix on the characteristics of cells, enterocyte-like Caco-2 cells were cultivated on substrates commonly used for cell culture as well as on glass coated with hydrophobic layers. Providing the same starting conditions for growth, the parameters investigated on preconfluent Caco-2 cells were the number of adhering cells, the proliferative activity and the degree of differentiation indicated by the expression of three brush border enzymes. Whereas tissue culture treated polystyrene elicited highest rates of adhesion, proliferation, and differentiation, even glass altered the pattern of brush border enzyme expression. The hydrophobic surfaces strongly decreased the adhesion and the proliferation but the surviving cells exhibited a pronounced higher degree of differentiation. Interestingly, each sub-type of hydrophobic matrix triggered a different pattern of brush border enzyme expression. Thus, the development of a certain phenotype of a cell can not only be triggered by certain components of the extracellular matrix but also by artificially prepared surface coatings of the underlying matrix. In the future it seems to be feasible that cells can be programmed by tailoring the surface of the underlying substrate.     

Starvation-specific formation of a peripheral exopolysaccharide by a marine Pseudomonas sp., strain S9

The marine bacterium Pseudomonas sp. strain S9 produces exopolysaccharides (EPS) during both growth and total energy source and nutrient starvation. Transmission electron microscopy of immunogold-labeled cells demonstrated that the EPS is closely associated with the cell surface during growth (integral EPS), while both the integral form and a loosely associated extracellular (peripheral) form were observed during starvation. Formation and release of the latter rendered the starvation medium viscous. In addition, after 3 h of starvation in static conditions, less than 5% of the cells were motile, compared with 100% at the onset of starvation and approximately 80% subsequent to release of the peripheral EPS at 27 h of starvation. Inhibition of protein synthesis with chloramphenicol added before 3 h of starvation caused no increase in viscosity. However, addition of chloramphenicol at 3 h did not prevent the subsequent increase in viscosity displayed by S9 cells. The amount of integral EPS increased for both nontreated and chloramphenicol-treated S9 cells during the first hour of starvation, with a subsequent equal decrease. The chloramphenicol-treated cells, as well as cells of a transposon-generated mutant strain deficient in peripheral EPS formation, remained adhesive to a hydrophobic inanimate surface during the initial 5 h of starvation, whereas nontreated wild-type cells had progressively decreased adhesion capacity. During the initial 5 h of starvation, most of the nontreated cells but only a small fraction of the chloramphenicol-treated and mutant cells detached from the hydrophobic substratum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Starvation-specific formation of a peripheral exopolysaccharide by a marine Pseudomonas sp., strain S9.

The marine bacterium Pseudomonas sp. strain S9 produces exopolysaccharides (EPS) during both growth and total energy source and nutrient starvation. Transmission electron microscopy of immunogold-labeled cells demonstrated that the EPS is closely associated with the cell surface during growth (integral EPS), while both the integral form and a loosely associated extracellular (peripheral) form were observed during starvation. Formation and release of the latter rendered the starvation medium viscous. In addition, after 3 h of starvation in static conditions, less than 5% of the cells were motile, compared with 100% at the onset of starvation and approximately 80% subsequent to release of the peripheral EPS at 27 h of starvation. Inhibition of protein synthesis with chloramphenicol added before 3 h of starvation caused no increase in viscosity. However, addition of chloramphenicol at 3 h did not prevent the subsequent increase in viscosity displayed by S9 cells. The amount of integral EPS increased for both nontreated and chloramphenicol-treated S9 cells during the first hour of starvation, with a subsequent equal decrease. The chloramphenicol-treated cells, as well as cells of a transposon-generated mutant strain deficient in peripheral EPS formation, remained adhesive to a hydrophobic inanimate surface during the initial 5 h of starvation, whereas nontreated wild-type cells had progressively decreased adhesion capacity. During the initial 5 h of starvation, most of the nontreated cells but only a small fraction of the chloramphenicol-treated and mutant cells detached from the hydrophobic substratum.(ABSTRACT TRUNCATED AT 250 WORDS)     

The surface hydrophobicity and avirulent character of an encapsulated strain of Klebsiella pneumoniae.

In order to elucidate how virulence is controlled in encapsulated bacteria, some surface properties of an encapsulated but avirulent strain of Klebsiella pneumoniae, strain 277, were examined. Although strain 277 was heavily fimbriated, the fimbriae did not demonstrate an avirulent character and were not responsible for the surface hydrophobicity of this strain. The surface hydrophobicity was well correlated with the capacity of the bacteria to associate with polymorphonuclear cells. More bacteria with hydrophobic surfaces associated with the PMN than nonhydrophobic bacteria. The hydrophobic surface character of this strain was not affected by either trypsin treatment or extraction with salt solution. We assume that the capsule of strain 277 has more hydrophobic polysaccharides than that of the virulent strain. Some chemical modifications might therefore exist in the capsular polysaccharides of the avirulent strain.     

出芽短梗霉Aureobasidium sp. SRF的菌株特性分析及胞外多糖结构鉴定

菌株SRF是1株从意大利树莓(Rubus corchorifolius)果实表面分离、可产胞外多糖的新菌株。在鉴定其分类归属的基础上,对其产生的胞外多糖进行了结构分析和发酵条件优化,为寻找微生物多糖提供新的菌株,为开发利用资源微生物提供借鉴。通过形态学和ITS序列对比分析进行菌株鉴定;通过薄层层析和红外光谱分析,确定胞外多糖结构;通过单因素检测试验,确定影响产糖量的主要因素;响应面Plackett-Burman和Box-Behnken设计筛选发酵产胞外多糖的最优条件。结果表明,出发菌株SRF隶属于出芽短梗霉属,命名为Aureobasidium sp. SRF;SRF所产胞外多糖为普鲁兰多糖;单因素检测表明,对多糖产量影响最大的因素为碳源浓度、氮源浓度、无机离子浓度,其次是碳源、氮源、无机离子、pH值;根据响应面结果确定最优发酵条件为麦芽糖8%(质量分数)、酵母提取物3%(质量分数)、钙离子0.3 g/L、pH 6,产糖量达5.93 g/L。SRF是1株来源于树莓浆果表面,可产胞外普鲁兰多糖的出芽短梗霉新菌株,是1株产微生物多糖的候选菌株。     

Effects of pantolactone and butyrolaectone on the pleiotropic phenotypes of lon mutants and on thermal induction of the SOS phenomena in a tif mutant of Escherichia coli K12

Hydrophobic and charge-charge interactions of Salmonella typhimirium and Serratia marcescens were determined and related to their content of fimbriae and lipopolysaccharide (LPS). The cell surface structures were characterized with hydrophobic interaction chromatography (HIC), electrostatic interaction chromatography (ESIC) and particle electrophoresis measurements. The degree of interaction at the air-water interface was tested using a monolayered lipid film applied to an aqueous surface. The cell surface hydrophobicity of S. typhimurium in the presence of fimbriae was less in smooth than in rought bacteria. Examination of a series of rough mutants of S. typhimurium indicates that reduction of the O-side chain and core oligosaccharides was correlated with increased cell hydrophobicity. The enrichment factors at the air-water interface were significantly higher for fimbriated than for non-fimbriated S. typhimurium cells. Fimbriated S. marcescens cells were less hydrophobic and adhered to a lesser degree at the air-water surface than non-fimbriated counterparts. Electrophoretic measurements and adsorption to ion exchangers gives different information about the surface charge of bacteria. The latter technique gives the interaction between localized charged surfaces.Abbreviations HIC hydrophobic interaction chromatography - ESIC electrostatic interaction chromatography - LPS lipopolysaccharide - PBS phosphate buffered saline solution     

Exopolysaccharide Distribution of and Bioemulsifier Production by Acinetobacter calcoaceticus BD4 and BD413

The heavily encapsulated Acinetobacter calcoaceticus BD4 and the “miniencapsulated” single-step mutant A. calcoaceticus BD413 produced extracellular polysaccharides in addition to the capsular material. The molar ratio of rhamnose to glucose (3:1) in the extracellular BD413 polysaccharide fraction was similar to the composition of the capsular material. In both strains, the increase in capsular polysaccharide was parallel to cell growth and remained constant in stationary phase. The extracellular polysaccharides were detected starting from mid-logarithmic phase and continued to accumulate in the growth medium for 5 to 8 h after the onset of stationary phase. Strain BD413 produced one-fourth the total rhamnose exopolysaccharide per cell that strain BD4 did. Depending on the growth medium, 32 to 63% of the rhamnose polysaccharide produced by strain BD413 was extracellular, whereas in strain BD4 only 7 to 14% was extracellular. In all cases, strain BD413 produced more extracellular rhamnose polysaccharide than strain BD4 did. In glucose medium, strain BD413 also produced approximately 10 times more extracellular emulsifying activity than strain BD4 did. The isolated capsular polysaccharide obtained after shearing of BD4 cells showed no emulsifying activity. Thus, strain BD413 either produces a modified extracellular polysaccharide or excretes an additional substance(s) that is responsible for the emulsifying activity. Emulsions induced by the ammonium sulfate-precipitated BD413 extracellular emulsifier require the presence of magnesium ion and a mixture of an aliphatic and an aromatic hydrocarbon.     

The effect of mutations affecting synthesis of lipopolysaccharides and calcofluor-binding polysaccharides on biofilm formation by <Emphasis Type="Italic">Azospirillum brasilense</Emphasis>

The thickness and antigenic properties of biofilms produced by Azospirillum brasilense Sp245 and its mutants deficient in the synthesis of lipopolysaccharides (Lps) and calcofluor-binding polysaccharides (CBPS) at the interface between water and hydrophilic or hydrophobic solid surfaces were compared. The mutants deficient in acidic LpsI synthesis produce thicker biofilms on hydrophilic surfaces. Biofilms produced on hydrophobic surfaces by bacteria that are unable to synthesize CBPS are less pronounced. Defects in CBPS production in Azospirillum mutants with impaired flagellar motility can cause adverse effects on the cell ability to attach to hydrophobic and hydrophilic surfaces. The loss of the neutral LpsII antigen by the mutants capable of producing CBPS does not affect their behavior on hydrophobic surfaces, which is probably due to the compensatory increase in the total polysaccharide production. The fundamental change in the Lps structure correlates with the activation of biofilm formation by the relevant mutants on hydrophilic and hydrophobic surfaces.     

Sulfated polysaccharides from marine sponges: conspicuous distribution among different cell types and involvement on formation of in vitro cell aggregates

Marine sponges (Porifera) display an ancestral type of cell-cell adhesion, based on carbohydrate-carbohydrate interaction. The aim of the present work was to investigate further details of this adhesion by using, as a model, the in vitro aggregation of dissociated sponge cells. Our results showed the participation of sulfated polysaccharides in this cell-cell interaction, as based on the following observations: (1) a variety of sponge cells contained similar sulfated polysaccharides as surface-associated molecules and as intracellular inclusions; (2) ³⁵S-sulfate metabolic labeling of dissociated sponge cells revealed that the majority (two thirds) of the total sulfated polysaccharide occurred as a cell-surface-associated molecule; (3) the aggregation process of dissociated sponge cells demanded the active de novo synthesis of sulfated polysaccharides, which ceased as cell aggregation reached a plateau; (4) the typical well-organized aggregates of sponge cells, known as primmorphs, contained three cell types showing sulfated polysaccharides on their cell surface; (5) collagen fibrils were also produced by the primmorphs in order to fill the extracellular spaces of their inner portion and the external layer surrounding their entire surface. Our data have thus clarified the relevance of sulfated polysaccharides in this system of in vitro sponge cell aggregation. The molecular basis of this system has practical relevance, since the culture of sponge cells is necessary for the production of molecules with biotechnological applications.     

Phylogeny of sulfate-reducing bacteria(1)

Three starvation regimes (a deficient culture medium, a saline buffer solution and distilled water) were evaluated for their possible effect on cell surface characteristics of Azospirillum lipoferum 1842 related to the initial adsorption of the bacterium to surfaces. The bacteria survived for 7 days in all media although they did not multiply. Upon transfer from a rich growth medium (nutrient agar) to starvation conditions, cell surface hydrophobicity dropped sharply but recovered its initial value within 24 to 48 h, except in phosphate-buffered saline, the length of the recovery period depending on the starvation medium. Starvation affected the sugar affinity of the A. lipoferum cell surface mainly towards p-aminophenyl-alpha-D-mannopyranoside, to a lesser extent to glucose, but not to other monosaccharides tested. Starvation changed the concentration of several cell surface proteins but did not induce the synthesis of new ones. The cell surface hydrophobic protein (43 kDa) of A. lipoferum 1842 was unaffected by any starvation treatment for a period of up to 48 h, but later disappeared. These data showed that starvation is not a major factor in inducing changes in the cell surface which lead to the primary phase of attachment of Azospirillum to surfaces.     

Morphological Study of Streptococcus mutans and Two Extracellular Polysaccharide Mutants

Two extracellular polysaccharide mutants of Streptococcus mutans GS-5 were obtained and examined. The mutants were distinguished by colonial morphology and by growth on and adherence to hard surfaces. A technique was devised which allowed these bacteria to be studied as they appeared when grown on a hard surface in liquid medium which contained sucrose. Negative stains, replicas, and scanning electron micrography clearly revealed differences in cellular aggregation due to the various extracellular polysaccharides produced. Comparison of sections of the adherent parent strain (GS-5) with those of the nonadherent mutant (GS-511) allowed the extracellular polysaccharide(s) responsible for adhesion to be visually localized.     

Identification of an extracellular polysaccharide network essential for cytochrome anchoring and biofilm formation in Geobacter sulfurreducens

Transposon insertions in Geobacter sulfurreducens GSU1501, part of an ATP-dependent exporter within an operon of polysaccharide biosynthesis genes, were previously shown to eliminate insoluble Fe(III) reduction and use of an electrode as an electron acceptor. Replacement of GSU1501 with a kanamycin resistance cassette produced a similarly defective mutant, which could be partially complemented by expression of GSU1500 to GSU1505 in trans. The Δ1501 mutant demonstrated limited cell-cell agglutination, enhanced attachment to negatively charged surfaces, and poor attachment to positively charged poly-d-lysine- or Fe(III)-coated surfaces. Wild-type and mutant cells attached to graphite electrodes, but when electrodes were poised at an oxidizing potential inducing a positive surface charge (+0.24 V versus the standard hydrogen electrode [SHE]), Δ1501 mutant cells detached. Scanning electron microscopy revealed fibrils surrounding wild-type G. sulfurreducens which were absent from the Δ1501 mutant. Similar amounts of type IV pili and pilus-associated cytochromes were detected on both cell types, but shearing released a stable matrix of c-type cytochromes and other proteins bound to polysaccharides. The matrix from the mutant contained 60% less sugar and was nearly devoid of c-type cytochromes such as OmcZ. The addition of wild-type extracellular matrix to Δ1501 cultures restored agglutination and Fe(III) reduction. The polysaccharide binding dye Congo red preferentially bound wild-type cells and extracellular matrix material over mutant cells, and Congo red inhibited agglutination and Fe(III) reduction by wild-type cells. These results demonstrate a crucial role for the xap (extracellular anchoring polysaccharide) locus in metal oxide attachment, cell-cell agglutination, and localization of essential cytochromes beyond the Geobacter outer membrane.     

Partial Chemical and Physical Characterization of Two Extracellular Polysaccharides Produced by Marine, Periphytic Pseudomonas sp. Strain NCMB 2021

The marine bacterium Pseudomonas sp. strain NCMB 2021, which can attach to solid, and especially hydrophobic, surfaces, elaborates two different extracellular polysaccharides in batch cultures. One (polysaccharide A) was produced only during exponential growth and contained glucose, galactose, glucuronic acid, and galacturonic acid in a molar ratio of 1.00:0.81:0.42:0.32. It produced viscous solutions, formed gels at high concentrations, and precipitated with several multivalent cations. The other (polysaccharide B) was released at the end of the exponential phase and in the stationary phase. It contained equimolar amounts of N-acetylglucosamine, 2-keto-3-deoxyoctulosonic acid, an unidentified 6-deoxyhexose, and also O-acetyl groups. Despite its high molecular weight (10⁵ to 10⁶ as judged by gel filtration), the polysaccharide produced aqueous solutions with very low viscosities and was also soluble in 90% aqueous phenol, 80% methanol, and 80% ethanol.     

Extracellular polymeric substances responsible for bacterial adhesion onto solid surface

The influence of extracellular polymeric substances (EPS) on bacterial cell adhesion onto solid surfaces was investigated using 27 heterotrophic bacterial strains isolated from a wastewater treatment reactor. Cell adhesion onto glass beads was carried out by the packed-bed method and the results were discussed in terms of the amount of each EPS component produced and cell surface characteristics such as zeta potential and hydrophobicity. Protein and polysaccharides accounted for 75-89% of the EPS composition, indicating that they are the major EPS components. Among the polysaccharides, the amounts of hexose, hexosamine and ketose were relatively high in EPS-rich strains. For EPS-poor strains, the efficiency of cell adhesion onto glass beads increased as the absolute values of zeta potential decreased, suggesting that electrostatic interaction suppresses cell adhesion efficiency. On the other hand, the amounts of hexose and pentose exhibited good correlations with cell adhesiveness for EPS-rich strains, indicating that polymeric interaction due to the EPS covering on the cell surface promoted cell adhesion. It was concluded that, if the EPS amount is relatively small, cell adhesion onto solid surfaces is inhibited by electrostatic interaction, and if it is relatively large, cell adhesion is enhanced by polymeric interaction.     

The triggering effect of surfaces and surfactants on heat output,oxygen consumption and size reduction of a starving marine Vibrio

The marine Vibrio DW1 exhibited a positive response in heat output to a dialysis membrane surface in the presence of substrate (100 mM sodium glutamate) and, more particularly, in the absence of exogenous substrate (starvation conditions). The latter result paralleled the previously reported decrease in cell volume and increase in oxygen consumption by starving bacteria at a similar surface. Modified Morita's salts (MMS) did not extract nutrients from the dialysis membrane, but an artificial seawater containing tris buffer (ASW-tris) did extract surface active and nutrient materials from the membrane. The ASW-tris membrane extract and a commercial surfactant, Tween 85, were found to mimic the effects of the dialysis membrane surface by inducing a decrease in cell volume, and an increasing oxygen consumption and heat output of Vibrio DW1 even in the bulk liquid. The significance of the adsorption of naturally occurring surfactants at surfaces in relation to the behaviour of bacteria at the surfaces is discussed.Abbreviations ASW artificial seawater - MMS modified Morita's salts - NMMS nutrient modified Morita's salts - MMSG MMS plus 100 mM sodium glutamate     

The effect of mutations in the synthesis of lipopolysaccharides and calcofluor-binding polysaccharides on biofilm formation by Azospirillum brasilense

The thickness and antigenic properties of biofilms produced by Azospirillum brasilense Sp245 and its mutants deficient in the synthesis of lipopolysaccharides (Lps) and calcofluor-binding polysaccharides (CBPS) at the interface between water and hydrophilic or hydrophobic solid surfaces were compared. The mutants deficient in acidic LpsI synthesis produce thicker biofilms on hydrophilic surfaces. Biofilms produced on hydrophobic surfaces by bacteria that are unable to synthesize CBPS are less pronounced. Defects in CBPS production in Azospirillum mutants with impaired flagellar motility can cause adverse effects on the cell ability to attach to hydrophobic and hydrophilic surfaces. The loss of the neutral LpsII antigen by the mutants capable of producing CBPS does not affect their behavior on hydrophobic surfaces, which is probably due to the compensatory increase in the total polysaccharide production. The fundamental change in the Lps structure correlates with the activation of biofilm formation by the relevant mutants on hydrophilic and hydrophobic surfaces.     

Examination of adhesive determinants in three species of Lactobacillus isolated from chicken

The microbial adhesion process includes passive forces; electrostatic interactions; hydrophobic, steric forces; lipoteichoic acids; and specific structures, such as external appendages (lectins) and (or) extracellular polymers. In a previous work, we showed that Lactobacillus animalis, L. fermentum, and L. fermentum ssp. cellobiosus had lectinlike proteic structures on their surfaces and high hydrophobicity values on the cell surface of L. fermentum ssp. cellobiosus. Here, we examined the presence of the bacterial forces or structures that could be involved in the interaction between bacteria and epithelial cells. Lactobacillus animalis and L. fermentum possessed a net negative surface charge, whereas L. fermentum ssp. cellobiosus showed similar affinity to both cationic and anionic exchange resins, aggregated in the presence of ammonium sulfate, and had high affinity (75.4%) to a hydrophobic matrix. Only L. animalis was shown to have ribitol teichoic acids in the cell wall. The amount of polysaccharides from cell walls varied between different strains, with L. fermentum ssp. cellobiosus having the highest concentration. Lectin extracts obtained from lactobacilli did not possess sugar residues, thereby demonstrating the proteic nature of the superficial surface structures of three strains. The lactic acid bacteria studied here showed different surface determinants, which could be involved in the interactions between these lactobacilli and intestinal epithelial cells.     

Statistic evaluation of the influence of species variation,culture conditions,surface wettability and fluid shear on attachment and biofilm development of marine bacteria

A budding coccoid bacterium, (CH1), a Vibrio sp. and a Pseudomonas sp. were investigated for factors governing their attachment to glass surfaces in static batch culture and laminar flow continuous culture systems. An analysis of variance showed that the three species exhibited very different responses. For CH1 attachment was dependent on cell density, incubation time and nutrient concentration. The Vibrio sp. was affected by nutrient concentration while the attachment of the Pseudomonas sp. was independent of cell density, incubation time and nutrient concentration. A comparison of attachment to hydrophilic and hydrophobic surfaces showed that attachment of the Vibrio sp. and CH1 to hydrophilic surfaces was 3 and 10 times greater respectively than to hydrophobic surfaces while Pseudomonas attached in equal numbers to both surfaces. The continuous culture system with defined flow hydrodynamics and growth conditions at steady state revealed a random sampling effect 3 times smaller than the batch culture system did. When the biofilm development of Pseudomonas sp. was followed during 46 h at different fluid shear under laminar and turbulent flow conditions, the former biofilm reached 3.3·10⁸ cells·cm^-2 and the latter 8.2·10⁷ cells·cm^-2.Non-common abbreviation NSS Nine salt solution     

Multiple carbohydrate receptors on lymphocytes revealed by adhesion to immobilized polysaccharides

Phosphomannan polysaccharides and fucoidan, a polymer of fucose 4-sulfate, have been demonstrated to inhibit adhesion of lymphocytes to tissue sections that contain high endothelial venules (Stoolman, L. M., T. S. Tenforde, and S. D. Rosen, 1984, J. Cell Biol., 99:1535-1540). We have investigated the potential cell surface carbohydrate receptors involved by quantitating adhesion of rat cervical lymph node lymphocytes to purified polysaccharides immobilized on otherwise inert polyacrylamide gels. One-sixth of the lymphocytes adhered specifically to surfaces derivatized with PPME (a phosphomannan polysaccharide prepared from Hansenula holstii yeast), whereas up to half of the cells adhered to surfaces derivatized with fucoidan. Several lines of evidence demonstrated that two distinct receptors were involved. Adhesion to PPME-derivatized gels was labile at 37 degrees C (decreasing to background levels within 120 min) whereas adhesion to fucoidan-derivatized gels was stable. Soluble PPME and other phosphomannans blocked adhesion only to PPME-derivatized gels; fucoidan and a structurally related fucan blocked adhesion to fucoidan-derivatized gels. Other highly charged anionic polysaccharides, such as heparin, did not block adhesion to either polysaccharide-derivatized gel. Adhesion to PPME-derivatized gels was dependent on divalent cations, whereas that to fucoidan-derivatized gels was not. The PPME-adherent lymphocytes were shown to be a subpopulation of the fucoidan-adhesive lymphocytes which contained both saccharide receptors. These data reveal that at least two distinct carbohydrate receptors can be found on peripheral lymphocytes.