Isolation and Characterization of Factors in Sweet Potato Root Which Agglutinate Germinated Spores of Ceratocystis fimbriata, Black Rot Fungus

A factor which agglutinates the germinated spores of Ceratocystis fimbriata was isolated from the sweet potato root. The factor is a glycoprotein with a molecular weight of 1.6 × 10⁶ daltons and required divalent cations such as Ca²⁺, Mn²⁺, Ni²⁺, and Mg²⁺ for activity. The activity of the factor was pH-dependent. The factor also agglutinated rabbit erythrocytes and is classified as a phytohemagglutinin or lectin. The factor agglutinated germinated spores of seven strains of C. fimbriata to almost the same degree. The factor showed differential agglutinating activity toward the strains in the presence of unidentified low molecular weight factor(s) in the sweet potato root. These results support our earlier suggestion that the spore-agglutinating factors in host plants function as the determinants of specificity in some host-parasite interactions.     

Studies on a Factor in Sweet Potato Root Which Agglutinates Spores of Ceratocystis fimbriata, Black Rot Fungus

A factor which agglutinated the spores of Ceratocystis fimbriata in the presence of Ca²⁺ was purified from sweet potato (Ipomea batatas Lam cv. Norin[1]) root. Element composition of the purified factor was as follows; analysis found: C (29.8%), H (3.97%), O (65.34%), N (0.81%): calculated for C₄₃H₆₉O₇₀N₁: C (30.02%), H (4.01%), O (65.15%), N (0.81%). The factor was mainly composed of galacturonic acid (53% of dry weight) and contained arabinose, fucose, and unidentified component as minor components. The factor also agglutinated A-, B-, AB-, and O types of human erythrocytes to almost the same degree in the presence of Ca²⁺. The differential spore-agglutinating activity of the factor depended on the pH of the assay medium; it agglutinated similarly the germinated spores of sweet potato and coffee strains at pH 7.5 and 5.5, whereas it displayed a distinct differential agglutinating activity at pH 6.5. The factor was assayed for spore-agglutinating activity at pH 6.5, using the germinated and ungerminated spores of seven strains of C. fimbriata; sweet potato, coffee, prune, cacao, oak, taro, and almond strains. The factor agglutinated ungerminated spores of all seven strains similarly, although small differences were observed among strains. On the other hand, a clear differential agglutination was observed among the germinated spores of various strains; sweet potato and almond strains were highly insensitive in comparison with other strains. The growth of the agglutinated spores of C. fimbriata was inhibited. These results are discussed in relation to host-parasite specificity.     

The Isolation and Properties of a Factor in Taro Tuber that Agglutinates Spores of Ceratocystis fimbriata, Black Rot Fungus

A factor which agglutinates spores of Ceratocystis fimbriatain the presence of Ca²⁺ was isolated from taro tuber (Corocasiaesculenta Schott, cv. Shiro). The elemental composition of theisolated factor was as found by analysis: C (33.27%), H (4.27%),O (61.90%), N (0.56%); as calculated for C₆₉H₁₀₆O₉₇N₁: C (33.13%),H (4.27%), O (62.04%), N (0.56%). This factor is composed mainlyof galacturonic acid (85% of its dry weight) and contains arabinose,fucose and an unidentified component as its minor components. The differential spore-agglutinating activity of this factordepends on the pH of the assay medium, differential agglutinatingactivity being present at pH 6.5 toward germinated spores ofvarious strains of C. fimbriata. The differential agglutinationof the spores of these strains changed with the growth stage:Ungerminated spores and hyphae of the strains tested were agglutinatedto the same extent, whereas the germinated spores of these strainswere agglutinated differently. When ungerminated and germinated spores of the strains weretreated with pronase, Macerozyme or phospholipase D, their reactivityto the factor changed. Sonication also caused changes in thereactivity of the spores to the factor; germinated spores ofthe sweet potato strain became highly sensitive to it. Insensitivityto the factor was restored in sonicated spores incubated witha substance released from the spores during sonication. Theseresults are discussed in relation to host-parasite specificity. (Received May 19, 1982; Accepted November 9, 1982)     

菠萝蜜黑腐病病原菌的形态学与分子鉴定

为明确菠萝蜜黑腐病的病原菌和分类地位,本研究从海南保亭地区采样,经过田间调查、菌株分离纯化和致病性鉴定,以形态学特征为基础,结合病原菌的ITS序列和EF1-α序列,联合两基因建立系统发育树,最终鉴定该病害的病原.结果 显示:病原菌LTHD006菌丝生长速度快,初期白色絮状,较薄,后期菌丝开始变黑,菌落也开始致密,且与Lasiodiplodia theobromae (ID:CBS175.26)聚为一个分支,支持率为100％,最终将菠萝蜜黑腐病的病原菌鉴定为可可毛色二孢(Lasiodiplodia theobromae).该病害在国内为首次简略报道,研究结果为菠萝蜜黑腐病发病规律和防治的进一步研究提供理论基础.     

Occurrence of Peroxidases in Sweet Potato Infected by the Black Rot Fungus

Changes in the peroxidase activity and the patterns in sweet potato tissue infected by Ceratocystis fimbriata were investigated, by the method of starch-gel electrophoresis, DEAE-cellulose column chromatography and immunochemical analysis, compared with that in cut and healthy tissue. Time-course analysis of the increment of the total peroxidase activity also showed noticeable differences between diseased and cut tissues. The peroxidases in diseased and cut tissues were composed of four major and several minor components. Though electrophoretic analysis did not show so striking differences in the patterns of peroxidases between diseased and cut tissues, there were distinct differences in the ratio of activities of major peroxidase components between both tissues. Immunochemical works indicated that peroxidase A which showed the most prominent increase in diseased tissue was found to be formed in cut tissue though the amounts were appreciably small. The activity of peroxidase C in diseased tissue was not so high as seen in cut tissue.     

Interaction of Pratylenchus penetrans and Rhizoctonia fragariae in Strawberry Black Root Rot

A split-root technique was used to examine the interaction between Pratylenchus penetrans and the cortical root-rotting pathogen Rhizoctonia fragariae in strawberry black root rot. Plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. Isolation of R. fragariae from field-grown roots differed with root type and time of sampling. Fungal infection of structural roots was low until fruiting, whereas perennial root colonization was high. Isolation of R. fragariae from feeder roots was variable, but was greater from feeder roots on perennial than from structural roots. Isolation of the fungus was greater from structural roots with nematode lesions than from non-symptomatic roots. Rhizoctonia fragariae was a common resident on the sloughed cortex of healthy perennial roots. From this source, the fungus may infect additional roots. The direct effects of lesion nematode feeding and movement are cortical cell damage and death. Indirect effects include discoloration of the endodermis and early polyderm formation. Perhaps weakened or dying cells caused directly or indirectly by P. penetrans are more susceptible to R. fragariae, leading to increased disease.     

Role of Pseudomonas fluorescens and INA against Black Rot of Cabbage

Cabbage (Brassica oleracea var. capitata) is an important vegetable crop among crucifers. It is affected by a bacterial disease known as black rot. Black rot is caused by Xanthomonas campestris pv. campestris a disease of worldwide importance. The present study highlights the effect of biotic inducer—Pseudomonas fluorescens—and an abiotic inducer—2,6‐dichloro‐isonicotinic acid—in combating black rot, followed by their effect on the seed treatment and disease incidence, role of antioxidant enzymes followed by validation of the defence‐related genes by quantitative real‐time PCR. The resistant (Pusa mukta) and the highly susceptible (NBH boss) cabbage cultivars were analysed for defence‐related enzymes such as peroxidase and superoxide dismutase. An increase in total peroxidase and superoxide dismutase activity was observed upon inoculation with X. campestris pv. campestris. The activity was greater in resistant cultivar when compared to susceptible ones. Both enzyme activity assays and qPCR analyses for the expression of the defence genes in susceptible and resistant cultivars demonstrated that the peroxidase gene was up‐regulated in resistant cultivar compared to susceptible cultivar. The present study proved that P. fluorescens‐induced resistance against X. campestris pv. campestris in cabbage seedlings is more efficient as compared to the use of INA—abiotic inducer.     

Novel Interaction between Laccase and Cellobiose Dehydrogenase during Pigment Synthesis in the White Rot Fungus Pycnoporus cinnabarinus

When glucose is the carbon source, the white rot fungus Pycnoporus cinnabarinus produces a characteristic red pigment, cinnabarinic acid, which is formed by laccase-catalyzed oxidation of the precursor 3-hydroxyanthranilic acid. When P. cinnabarinus was grown on media containing cellobiose or cellulose as the carbon source, the amount of cinnabarinic acid that accumulated was reduced or, in the case of cellulose, no cinnabarinic acid accumulated. Cellobiose-dependent quinone reducing enzymes, the cellobiose dehydrogenases (CDHs), inhibited the redox interaction between laccase and 3-hydroxyanthranilic acid. Two distinct proteins were purified from cellulose-grown cultures of P. cinnabarinus; these proteins were designated CDH I and CDH II. CDH I and CDH II were both monomeric proteins and had apparent molecular weights of about 81,000 and 101,000, respectively, as determined by both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pI values were approximately 5.9 for CDH I and 3.8 for CDH II. Both CDHs used several known CDH substrates as electron acceptors and specifically adsorbed to cellulose. Only CDH II could reduce cytochrome c. The optimum pH values for CDH I and CDH II were 5.5 and 4.5, respectively. In in vitro experiments, both enzymes inhibited laccase-mediated formation of cinnabarinic acid. Oxidation intermediates of 3-hydroxyanthranilic acid served as endogenous electron acceptors for the two CDHs from P. cinnabarinus. These results demonstrated that in the presence of a suitable cellulose-derived electron donor, CDHs can regenerate fungal metabolites oxidized by laccase, and they also supported the hypothesis that CDHs act as links between cellulolytic and ligninolytic pathways.     

Biodegradation of Cyanide by a White Rot Fungus, Trametes versicolor

The cyanide degradation abilities of three white rot fungi, Trametes versicolor ATCC 200801, Phanerochaete chrysosporium ME 496 and Pleurotus sajor-caju, were examined. T. versicolor was the most effective with 0.35 g dry cell/100 ml degrading 2 mm KCN (130 mg/l) over 42 h, at 30°C, pH 10.5 with stirring at 150 rpm.     

Regulation of Nicotinamide Adenine Dinucleotide Phosphate-specific Glutamate Dehydrogenase in Germinated Spores of Geotrichum candidum

Germinating spores of Geotrichum candidum produce only a nicotinamide adenine dinucleotide phosphate-linked glutamate dehydrogenase. Synthesis of glutamate dehydrogenase was repressed by the presence of ammonia, whereas urea, glutamate, or glutamine were ineffective. The enzyme was not subject to catabolite repression and was localized in the cell sap fraction. The glutamate dehydrogenase has been purified 93-fold and showed maximal activity at pH 8.2 in the forward and reverse directions. When measuring the initial reaction rate at pH 7.2, a variety of tricarboxylic acid cycle intermediates displayed additive and unidirectional activation of the reductive amination reaction and inhibition of the oxidative deamination reaction. The modulating effects were pH-dependent and diminished at alkaline pH values. Substrate inhibition exerted by α-ketoglutarate was strongest at neutral pH.     

Surface Sampling of Spores in Dry-Deposition Aerosols

The ability to reliably and reproducibly sample surfaces contaminated with a biological agent is a critical step in measuring the extent of contamination and determining if decontamination steps have been successful. The recovery operations following the 2001 attacks with Bacillus anthracis spores were complicated by the fact that no standard sample collection format or decontamination procedures were established. Recovery efficiencies traditionally have been calculated based upon biological agents which were applied to test surfaces in a liquid format and then allowed to dry prior to sampling tests, which may not be best suited for a real-world event with aerosolized biological agents. In order to ascertain if differences existed between air-dried liquid deposition and biological spores which were allowed to settle on a surface in a dried format, a study was undertaken to determine if differences existed in surface sampling recovery efficiencies for four representative surfaces. Studies were then undertaken to compare sampling efficiencies between liquid spore deposition and aerosolized spores which were allowed to gradually settle under gravity on four different test coupon types. Tests with both types of deposition compared efficiencies of four unique swabbing materials applied to four surfaces with various surface properties. Our studies demonstrate that recovery of liquid-deposited spores differs significantly from recovery of dry aerosol-deposited spores in most instances. Whether the recovery of liquid-deposited spores is overexaggerated or underrepresented with respect to that of aerosol-deposited spores depends upon the surface material being tested.     

Role of Extracellular Polymeric Substances in the Surface Chemical Reactivity of Hymenobacter aerophilus,a Psychrotolerant Bacterium

Bacterial surface layers, such as extracellular polymeric substances (EPS), are known to play an important role in metal sorption and biomineralization; however, there have been very few studies investigating how environmentally induced changes in EPS production affect the cell''s surface chemistry and reactivity. Acid-base titrations, cadmium adsorption assays, and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the surface reactivities of Hymenobacter aerophilus cells with intact EPS (WC) or stripped of EPS (SC) and purified EPS alone. Linear programming modeling of titration data showed SC to possess functional groups corresponding to phosphoryl (pK_a ∼6.5), phosphoryl/amine (pK_a ∼7.9), and amine/hydroxyl (pK_a ∼9.9). EPS and WC both possess carboxyl groups (pK_a ∼5.1 to 5.8) in addition to phosphoryl and amine groups. FT-IR confirmed the presence of polysaccharides and protein in purified EPS that can account for the additional carboxyl groups. An increased ligand density was observed for WC relative to that for SC, leading to an increase in the amount of Cd adsorbed (0.53 to 1.73 mmol/liter per g [dry weight] and 0.53 to 0.59 mmol/liter per g [dry weight], respectively). Overall, the presence of EPS corresponds to an increase in the number and type of functional groups on the surface of H. aerophilus that is reflected by increased metal adsorption relative to that for EPS-free cells.Acid-base titrations are frequently used to characterize microbial cell surface reactivity, in particular, the ability of the cell to adsorb and desorb protons (19, 21, 47). This ability is conferred by the presence of proton-reactive surface functional groups that are also responsible for the surface adsorption of other cations, including dissolved metals. Thus, a microbe''s ability to immobilize metals and influence metal transport is largely dependent on the nature of the reactive sites found at the cell-water interface, namely, their concentrations and chemical affinities (in terms of equilibrium surface stability constants) for cations such as protons and metals.Both Gram-negative and Gram-positive bacteria have been characterized extensively using acid-base titration to determine their reactivity with respect to geochemical processes (18, 22, 33). To date, most work has focused on mesophilic and strictly heterotrophic model organisms; however, some work has also been done with cyanobacteria (29, 44) and thermophiles (19, 47). While proton sorption assays provide information on surface site densities and acidity constants, a more direct assessment of a microbe''s ability to interact with aqueous metals is the metal adsorption assay, where a cell''s ability to adsorb metal ions from solution is measured over a range of pH values. Metal adsorption assays have been used to characterize microbes from a wide variety of environments to determine their potential for bioremediation of heavy metal contamination (21, 26), their influence on geochemical cycling (5, 16), and their ability to serve as nucleation sites for mineral authigenesis (3, 43). Although more than 80% of the Earth''s biosphere is cold (37), to our knowledge there have been no published studies of acid-base surface chemistry for psychrotolerant bacteria, although recent studies examining metal adsorption have been published (53, 54).Extracellular polymeric substances (EPS) are produced by both prokaryotes and eukaryotes in a wide variety of environments (15). Although the relative quantities of EPS components are highly variable, polysaccharides are usually dominant, with proteins and, to a lesser extent, nucleic acids and lipids also present (15). The production of EPS can be important in mediation of environmental interactions, such as adhesion to surfaces and aggregation (35, 49); mineral weathering (28, 51); microbial tolerance of toxic metals through sequestration of metal ions outside the cell (1, 11); and biomineralization (27). Indeed, the stability of metal-surface complexes is great enough to affect metal mobility in many aqueous systems (14), which can, in turn, affect the distribution of metals in the environment (32).The physical and chemical characteristics of EPS have usually been studied using cells with intact EPS or on purified EPS (7, 8, 17, 34, 41, 51). Interestingly, few studies have compared cells with and without surface layers such as EPS (44, 47), despite the fact that EPS and other external layers alter the cell surface presented to the environment, potentially changing both the type and the quantity of functional groups available for environmental interactions. Accordingly, the purpose of this study was to determine the changes in cell surface reactivity resulting from the production of EPS by Hymenobacter aerophilus, a psychrotolerant bacterium. Acid-base titrations and cadmium adsorption assays were used to compare the numbers and types of functional groups on the surfaces of bacterial cells presenting intact EPS and those from which EPS had been removed mechanically.     

白腐菌对染料脱色和降解作用的研究进展

白腐菌应用于废水处理始于二十世纪八十年代。本文对印染废水的处理方法、白腐菌及其对污染物的降解机理作了简要概述 ,着重介绍了白腐菌对染料脱色和降解作用的研究进展。白腐菌对染料的脱色解降作用机理有部分尚待进一步研究 ;同时 ,白腐菌的吸附作用亦不容忽视。     

Surface Display of Recombinant Proteins on Bacillus thuringiensis Spores

The insecticidal protoxin from Bacillus thuringiensis has been shown to be a major component of the spore coat. We have developed a novel surface display system using B. thuringiensis spores in which the N-terminal portion of the protoxin is replaced with a heterologous protein. The expression vector with a sporulation-specific promoter was successfully used to display green fluorescent protein and a single-chain antibody (scFv) gene that encodes anti-4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (anti-phOx) antibody. The spores that carry the anti-phOx antibody can bind to phOx specifically.     

Role of P450 Monooxygenases in the Degradation of the Endocrine-Disrupting Chemical Nonylphenol by the White Rot Fungus Phanerochaete chrysosporium

The white rot fungus Phanerochaete chrysosporium extensively degraded the endocrine disruptor chemical nonylphenol (NP; 100% of 100 ppm) in both nutrient-limited cultures and nutrient-sufficient cultures. The P450 enzyme inhibitor piperonyl butoxide caused significant inhibition (∼75%) of the degradation activity in nutrient-rich malt extract (ME) cultures but no inhibition in defined low-nitrogen (LN) cultures, indicating an essential role of P450 monooxygenase(s) in NP degradation under nutrient-rich conditions. A genome-wide analysis using our custom-designed P450 microarray revealed significant induction of multiple P450 monooxygenase genes by NP: 18 genes were induced (2- to 195-fold) under nutrient-rich conditions, 17 genes were induced (2- to 6-fold) in LN cultures, and 3 were induced under both nutrient-rich and LN conditions. The P450 genes Pff 311b (corresponding to protein identification number [ID] 5852) and Pff 4a (protein ID 5001) showed extraordinarily high levels of induction (195- and 167-fold, respectively) in ME cultures. The P450 oxidoreductase (POR), glutathione S-transferase (gst), and cellulose metabolism genes were also induced in ME cultures. In contrast, certain metabolic genes, such as five of the peroxidase genes, showed partial downregulation by NP. This study provides the first evidence for the involvement of P450 enzymes in NP degradation by a white rot fungus and the first genome-wide identification of specific P450 genes responsive to an environmentally significant toxicant.Endocrine-disrupting chemicals (EDCs) are widely distributed environmental contaminants. Surfactants are among the most commonly found environmental EDCs because of their extensive applications, which range from use as industrial chemicals to inclusion in common consumer products. In the United States, Japan, and Western Europe, surfactants are employed most frequently as detergents and as agents in textile, fiber, cosmetics, and pharmaceutical manufacturing. Nearly as common are uses in mining and flotation and in petroleum, paint, lacquer, plastic manufacturing, food, pulp and paper, agrochemical, and leather and fur industries (21).Alkylphenol ethoxylates are an important class of surfactants. Biodegradation of alkylphenol ethoxylates results in shortening of the ethoxylate chains, ultimately leading to the generation of alkylphenols, particularly nonyl- and octylphenols. Nonylphenol (NP) is the commercially predominant alkylphenol, representing nearly 85% of the total alkylphenol market. NP is a hydrophobic compound used primarily in the chemical manufacturing industry and exists as multiple congeners (11). Several congeners are relatively resistant to biodegradation and are therefore frequently detected in wastewater treatment plant effluents and rivers (15, 20, 25, 31, 48). In previous studies, 4-n-NP has been used as a test compound in risk assessment and biodegradation analyses (16, 23, 39). However, industrially generated technical-grade NP, consisting of more than 30 different isomers, is less biodegradable (14). This characteristic is due to the fact that more than 85% of these isomers possess a quaternary carbon atom in the branched alkyl chain, making them chemical contaminants of high environmental significance (28, 38, 40). Investigation of the susceptibility of technical-grade NP to biodegradation and assessment of health risks from this agent in in vitro and in vivo biological model systems are therefore warranted.NP is known to bind to the estrogen receptor, thereby mimicking the effects of endogenous hormones, and has been shown to induce synthesis of vitellogenin and inhibit testicular growth in rainbow trout (18, 37, 41). This observation has led to increased interest in the biodegradation and elimination of this class of xenobiotic surfactants from the environment.Certain microorganisms belonging to the bacterial and yeast groups have the ability to degrade NP (4, 5, 38, 39). Recent studies have shown the abilities of selected fungi, including white rot fungi, to degrade this chemical, albeit to various extents (33). Extracellular oxidases (laccases) have been implicated in the fungal oxidation of NP (2, 19).The model white rot fungus Phanerochaete chrysosporium is known for its ability to oxidize a wide variety of environmental toxicants. This unique characteristic has been attributed largely to its extracellular peroxidase system. Past studies have provided ample evidence, however, that environmental toxicants can be oxidized or biodegraded even in the absence of peroxidases under nutrient-sufficient (nonligninolytic) conditions (26, 44, 46), suggesting a primary role for other oxidative enzyme systems such as P450 monooxygenases.P. chrysosporium has recently been shown to possess an extensive P450 enzyme system, with ∼150 P450 monooxygenase genes in its genome (8, 30). Although there have been isolated reports indicating the involvement of P450 monooxygenation in the oxidation of xenobiotic chemicals in this organism, limited information on the identification of specific P450 genes/enzymes and related phase I and II metabolic genes important in such oxidations is available.It is well known that in other biological systems, inducers of P450 monooxygenases can also be substrates for oxidation by these enzymes (1). These considerations led us to study P450 genes inducible by NP, with the aim of identifying the putative P450 catalyst(s) involved in NP degradation. The results led to the first direct evidence for the involvement of fungal P450 enzymes in the degradation of the EDC NP and functional genomic identification of specific P450 monooxygenases responsive to an environmentally significant contaminant.     

Constitutive and Induced Trehalose Transport Mechanisms in Spores of the Fungus Myrothecium verrucaria

Trehalose is absorbed by two distinct systems-one constitutive, the other induced by turanose and to a lesser extent by nigerose but not by trehalose. The constitutive system is apparently mediated by a surface trehalase; the induced system has the characteristics of a permease. The specificity of the induced system is apparently limited to the alpha glucosyl-glucose or glucosyl-fructose linkage, because absorption of kojibiose, nigerose, maltose, isomaltose, turanose, sucrose, and melezitose, in addition to that of trehalose, was increased. Absorption of beta-linked or of galactose-containing disaccharides was not increased. The constitutive and induced trehalose-absorbing systems differ in their activity, specificity, lability to acid treatment, effects of substrate concentration, and pH optima. Both systems require oxygen, and no marked differential effects of inhibitors were observed. The activity of the induced system is proportional to log turanose concentration (from about 1 to 300 mug/ml), and is an approximate linear function of time of exposure (from about 1 to 50 min). Accumulation of trehalose occurred against a concentration gradient in both systems but particularly in the induced. No leakage was observed. The activity of the induced system declined slowly upon removal of the inducer. Accumulated trehalose is metabolized after activation by azide as are the endogenous trehalose reserves. The accumulated trehalose appears to enter the endogenous trehalose pool found in these spores, although some data suggest it may be more accessible. Respiratory data indicate that absorbed trehalose is available for metabolism while in transit from the external membrane to the internal pool.     

白腐菌菌体对染料的生物吸附脱色及机理研究

目的：研究了白腐菌菌体吸附染料特性、影响因素及吸附机理。方法：采用分光光度法、吸附热特性、傅立叶变换红外光谱（FTIR）分析等系统地对菌体吸附特性及机理进行研究。结果：白腐菌BP对不同类型的染料有不同的吸附效果,240min内染料RBBR脱色率能达82.35%。菌体对RBBR的合适吸附条件为：温度28℃、转速100r/min、菌体粒径小于60目。吸附符合Freun-dlich模式,为多分子层吸附。菌体吸附染料主要通过菌体表面的羟基、羧基、胺基及磷酸基团与染料分子以共价键、离子交换或氢键结合来进行。结论：利用白腐菌菌体能有效的对部分染料进行吸附脱色。     

Types of Rot, Rate of Rotting, and Analysis of Pectic Substances in Apples Rotted by Fungi

The rate at which the fungi grew through apples was determinedin various ways and used to estimate their rate of linear advance.Five fungi were studied;they were Sclerotinia fructigena (firm-browncoloured rot, rapid growth through apples), Botrytis cinerea(soft, light-brown coloured rot, rapid growth through apples),Psyrenochaeta furfuracea (firm to soft rot, variable in colourbut generaly dark, slow growth through apples), Penicilliumexpansion A (soft, white rot, slow growth through apples) andPenicillium expansum B (soft, white rot, medium rate of growththrough apples). S. fructigena which had the highest rate oflinear advance which was about three times that of P. furfuraceawhich had the lowest. Methods for extracting different types of pectic substancesfrom sound and rotted tissues are described, and details aregiven of a rapid and reasonably accurate colorimetric methodof determining the anhydrogalacturonic acid content of theseextracts. The firm-rot fungi reduced the water-insoluble pecticsubstances by 10–20 per cent., but the soft-rot fungicaused much larger changes, up to 70 per cent. being degraded,The firm-rot and soft-rot fungi had different effects on thepectic substances insoluble in dilute acid but soluble in dilutealkali. The soft-rot fungi had little effect on these substances,or reduced their concentration, whereas the firm-rot fungi causedsubstantial increases compared with sound tissue. These resultsare considered in terms of pectic enzyme activity. Analysisof extracts by paper chromatography showed that galacturonicacid, absent from sound tissue, was present in each type ofrotted tissue. Di- and tri-galacturonic acids were present inrots caused by P. expansum, and these rots probably also containedproducts from the break-down of other polysaccharides.