POLYOLS IN SCHIZOPHYLLUM COMMUNE

Sugars and sugar alcohols present in extracts of the wood-rotting mushroom Schizophyllum commune were identified by paper chromatography during fruiting, basidiospore germination, and growth of vegetative mycelium. Homokaryotic fruitbodies and dikaryotic fruits derived from several compatible matings of S. commune contained mannitol and arabitol. Basidiospores shed from dikaryotic fruits also contained mannitol and arabitol while the latter disappeared during spore germination. Vegetative mycelium (strain 699) contained glucose, fructose, mannitol and glycerol while these compounds as well as arabitol occurred in mycelium of strain 845. Polyols are not, therefore, associated exclusively with the sporulation process in S. commune.     

Chromatographie des composants ternaires du mycelium dePenicillium brevicompactum

Résumé L’analyse chromatographique du mycélium et du milieu de culture deP. brevi-compactum a permis d’identifier plusieurs substances ternaires nouvelles, produites par la moisissure: le fructose, le mannitol, l’arabitol ou l’adonitol, et le glycérol. Les résultats obtenus font l’objet d’une discussion.

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Summary Chromatographic analysis ofP. brevi-compactum mycelium and culture medium has revealed different new ternary substances produced by that mould: fructose, mannitol, arabitol or adonitol and glycerol.

     

三种香蘑属野生食用菌菌株的培养条件优化

【背景】供试菌株分别是分离自山西省宁武县管涔山的肉色香蘑Lepista irina、斑褶香蘑L. panaeolus和山西省蒲县五鹿山的紫丁香蘑L. nuda 3种野生食用菌的子实体。【目的】获得3种野生食用菌的最佳培养条件。【方法】以菌丝生长速度为指标研究不同碳源、氮源、碳氮比、pH和培养温度等各因素对菌丝生长的影响,根据Box-Benhnken中心组合试验设计原理,采用3因素3水平的响应面法确定使菌丝体达到最快生长速度的最佳培养碳源、氮源和pH。【结果】肉色香蘑在葡萄糖20.9 g/L、土豆196.47 g/L、pH 6.0、培养温度21 °C的条件下,菌丝日均生长速度达到最大,为1.13 mm/d;斑褶香蘑在甘露醇17.4 g/L、酵母膏8.1 g/L、B族维生素0.1 g/L、K2HPO4 2.5 g/L、MgSO4 2.5 g/L、pH 7.9、培养温度25 °C的条件下,菌丝日均生长速度达到最大,为0.73 mm/d;紫丁香蘑在土豆200 g/L、可溶性淀粉20.5 g/L、KNO3 2.1 g/L、K2HPO4 2.5 g/L、MgSO4 2.5 g/L、B族维生素0.1 g/L、pH 7.0、培养温度25 °C的条件下,菌丝日均生长速度达到最大,为2.38 mm/d。【结论】获得了3种香蘑属菌株的最佳培养条件,为后续优质野生食用菌的引种驯化积累了相关数据和资源。     

Isotopic studies of carbohydrate metabolism during basidiospore germination inSchizophyllum commune

Summary Uptake and respiration of radioactive glucose, mannitol and arabitol were studied during basidiospore germination of the woodrotting mushroomSchizophyllum commune. Glucose uptake was rapid and immediate, depressed at 4° C and unaffected by the protein synthesis antagonist cycloheximide. In contrast, uptake of either mannitol or arabitol exhibited a lag phase while the induction of this process was sensitive to cycloheximide. Prior incubation of basidiospores in unlabelled mannitol induced uptake processes for either labelled mannitol or arabitol. Respiratory rates for either arabitol or mannitol increased markedly upon germination in glucose-asparagine minimal culture medium.This research was supported by Public Health Service Grant AI-04603-09 to Donald J. Niederpruem.     

食用菌菌丝体中糖醇类成分含量测定的研究

采用高效阴离子色谱-脉冲安培法(HAPEC-PAD)对食用菌菌丝体中糖醇类成分赤藓糖醇、阿糖醇和甘露醇进行分析,并对赤藓糖醇测定的方法进行考察,结果表明该方法对赤藓糖醇的分析具有灵敏度高、分离度好、检测效率高等特点。不同食用菌菌丝体均含有糖醇类成分,但含量和种类差异大,同时发现百令胶囊的测定结果与药典有较大差异,主要含有赤藓糖醇,而非甘露醇。此研究为糖醇类成分的质量标准的建立奠定了基础。     

Endogenous arabitol and mannitol improve shelf life of encapsulated <Emphasis Type="Italic">Metarhizium brunneum</Emphasis>

Successful commercialization of microbial biocontrol agents, such as Metarhizium spp., is often constrained by poor drying survival and shelf life. Here, we hypothesized that culture age would influence endogenous arabitol, erythritol, mannitol and trehalose contents in M. brunneum mycelium and that elevated levels of these compounds would improve drying survival and shelf life of encapsulated mycelium coupled with enhanced fungal virulence against T. molitor larvae. We found that culture age significantly influenced endogenous arabitol and mannitol contents in mycelium with highest concentrations of 0.6?±?0.2 and 2.1?±?0.2 µg/mg after 72 h, respectively. Drying survival of encapsulated mycelium was independent of culture age and polyol content with 41.1?±?4.4 to 55.0?±?6.2%. Best shelf life was determined for biomass harvested after 72 h at all investigated storage temperatures with maximum values of 59.5?±?3.3% at 5 °C followed by 54.5?±?1.6% at 18 °C and 19.4?±?1.3% at 25 °C after 6 months. Finally, high fungal virulence against T. molitor larvae of 83.3?±?7.6 to 98.0?±?1.8% was maintained during storage of encapsulated mycelium for 12 months with larval mortalities being independent of culture age and polyol content. In conclusion, our findings indicate beneficial effects of endogenous polyols in improving shelf life of encapsulated mycelium and this may spur the successful development of microbial biocontrol agents in the future.     

Distribution of the Products of Photosynthesis between Powdery Mildew and Barley

The photosynthetic assimilation of ¹⁴CO₂ has been studied in healthy and mildew-infected barley. The parasite was separated from the host by removing the mycelium with a camel's hair brush. The ethanol soluble metabolites of the parasite, infected host and healthy host were extracted, separated by paper chromatography and individually identified. From this work it appears that there is a rapid movement of label from host to parasite mainly in the form of sucrose which is then quickly metabolized into many compounds. The majority is converted into mannitol, and lesser amounts are converted into trehalose, arabitol, aspartic acid, and glutamic acid. In conidia the major carbon reserve is arabitol instead of mannitol, with lesser amounts of trehalose and mannitol.

Photosynthetic uptake of ¹⁴CO₂ by the complex decreases steadily after inoculation as compared with healthy leaves. However, the ethanol soluble metabolites of the infected host tissue differ only slightly from those of healthy host tissue. The major differences are a slight decrease in the amount of sucrose and increases in malic acid and serine.

     

Temporal accumulation of mannitol and arabitol in Geotrichum candidum

The temporal depletion and accumulation of polyols were investigated in the fungus Geotrichum candidum. The major intracellular polyols were tentatively identified by paper chromatography as mannitol and arabitol. Inositol was also present in small quantities, and trehalose was also detected in appreciable concentrations.Germination and vegetative growth depended on the type and concentration of the sole exogenous carbon source. Mannitol occurred in arthrospores at 9.4% of the dry weight after several days growth in 2% (w/v) glucose solid medium, and became depleted during germination and vegetative growth in liquid medium containing 2% (w/v) glucose, 2% (w/v) sodium acetate or 25% (w/v) glucose as sole carbon source. This hexitol latter accumulated during arthrosporulation. The depletion and accumulation of ethanol-soluble carbohydrate believed to be primarily trehalose was temporally similar to that of mannitol. Arabitol accumulated intracellularly during germination and vegetative growth in sodium acetate medium and 25% glucose medium. This pentitol was not detected intracellularly at any culture age during growth in 2% glucose medium.Prolonged incubation of the culture in 25% glucose medium after stationary phase was reached resulted in the gradual disappearance of arabitol from the arthrospores simultaneously with an increase in intracellular mannitol. In comparison, ethanol-soluble carbohydrate did not change with prolonged incubation in this medium.     

Comparison of Growth and Primary Shunt Product Formation by Claviceps purpurea Cultured on Succinic Acid and Glucose as Carbon Sources

Growth on a medium containing succinic acid as the sole carbon source produced 1 g (dry weight) of mycelium per liter of medium by 50 days of incubation, whereas 25 g of mycelium was produced in 10 days when glucose was also present in the medium. Primary shunt metabolism took place during growth on succinic acid in spite of the extremely slow growth. Mycelia grown on succinic acid contained a higher percentage of residual mycelium and phosphate, but a lower percentage of mannitol, carbohydrate, lipid, and water-soluble nitrogen, than mycelia grown on a mixture of glucose and succinic acid. Thus, although primary shunt metabolism is favored by rapid growth on a rich, balanced sugar medium, it can also take place during extremely restricted growth in a medium containing succinic acid as the sole carbon source.     

水葫芦黑斑病菌Alternaria alternata的生物学特性研究

在不同试验条件下培养水葫芦黑斑病菌Alternaria alternata菌株,探讨其主要的生物学特性,结果表明：该菌株生长的最佳培养基为PSA,最佳C源为葡萄糖,弱碱性和中性N源对该菌菌丝生长具有明显的促进作用,而酸性N源对其具有抑制作用。菌株生长的最佳pH值为pH7,最适温度为27℃。湿度越大,对菌株生长越有利。     

Characterisation of optimum cultural environmental conditions for the production of high numbers of Metarhizium anisopliae blastospores with enhanced ecological fitness

The aim of this study was the production of high numbers of M. anisopliae blastospores with enhanced germination efficiency under conditions of water-stress (ecological fitness). Different nitrogen sources and concentrations were screened for their ability to induce blastospore production while keeping pH and water activity (a_w) at fixed levels (6.8, and 0.98 a_w, respectively). After optimum nitrogen status was determined (cornsteep solid (CS) + yeast extract (YE); or cottonseed flour (CF) + YE), the effect of interaction of nitrogen source, pH (3.5, 5, 6.8, 8, 9 and 10) and solutes for a_w adjustment (KCl, NaCl, PEG 200) on blastospore production, endogenous polyol content (glycerol, erythritol, arabitol and mannitol) and total protein, were determined. For both ionic (NaCl, KCl) and non-ionic solutes (PEG 200), optimum blastospore production (between 4×10⁷ and 2×10⁸ blastospores ml^-1) and growth occurred in the pH range 6.8-8, with the CF + YE nitrogen profile giving higher yields than CS + YE. Optimum conditions for high erythritol and total protein endogenous concentrations (40.37-73.44 and 14.33-18.90 mg g^-1 fresh weight, respectively) occurred between pH 6.8 and 8 by ionic a_w modification (KCl, NaCl) and with the CF + YE nitrogen profile. Germination of blastospores produced under these cultural conditions was between 62 and 89% under conditions of water-stress (0.96 a_w). On the other hand, blastospores with lower amounts of erythritol and total protein content had decreased germination (8-67%). These results could have significant implications for developing a liquid fermentation medium for the production of high numbers of fungal propagules with enhanced efficacy under non-optimum environmental conditions.     

Nutritional and temporal control of arabitol and mannitol accumulation in Geotrichum

Summary Intracellular arabitol and mannitol accumulation is under nutritional and temporal control during arthrospore germination, vegetative growth, and arthrospore formation in Geotrichum. Arabitol is not produced if the glucose concentration in the medium is low. Arabitol is produced in large quantities in the cells if the carbon source is acetate or if the glucose level is above 10%. Low levels of glucose do not repress acetate induction of arabitol formation. Arabitol began to accumulate during spore swelling and vegetative growth in the presence of acetate. Mannitol appeared to serve as a carbon and energy reserve during starvation and arthrospore germination; the concentration of mannitol in vegetative cells remained barely detectable until sporulation commenced.This research was supported by National Science Foundation Grant GB-8327 and Public Health Service Grant Al-04603-09 to D.J.N.     

Control of arabitol formation in Schizophyllum commune development

Summary Dikaryotic cells of S. commune synthesized polyols throughout the life cycle when grown on glucose, cellobiose, or cellulose. Basidiospores contained arabitol and mannitol which were depleted during germination. The mannitol content of the young germlings rose to normal levels within a day; arabitol accumulation remained depressed for 5 to 7 days and then returned to normal levels characteristic of vegetative cells. Individual homokaryons differed in their production of intracellular polyols, which, unlike germlings, remained constant with cultural age. Homokaryon (str. 699) produced low levels of arabitol but high levels of glycerol while another homokaryon (str. 845) was the reverse. Mixtures of these homokaryons as well as the dikaryon (699×845) produced arabitol and glycerol levels intermediate between the parent homokaryons. High concentrations of glucose did not change the nature of the polyols produced. Arabitol formation could be induced prematurely in germlings or elevated in the dikaryon by growth on acetate or ethanol. Both homokaryons responded to growth on acetate with elevated arabitol production; acetate induction of arabitol formation was repressed in all types of cells if glucose were added simultaneously with acetate. Maltose, cellobiose, and trehalose also stimulated arabitol formation in young germlings, suggesting that glucose repression was the cause of decreased arabitol formation in basidiospore germlings. There was no correlation between the formation of arabitol and the derepression of isocitrate lyase or change in specific activities of alkaline and acid phosphatase in germlings grown on various carbon sources.     

Arabitol accumulation in Geotrichum candidum

Culture conditions which lead to the intracellular accumulation of arabitol and mannitol in Geotrichum candidum were investigated. The accumulation of arabitol was dependent on the concentrations of metabolizable hexoses, the non-metabolizable disaccharide sucrose, NaCl and KCl in the growth medium. In media containing 2% (w/v) glucose, fructose or l-sorbose cultures contained only mannitol after 48 h or 72 h growth. In media containing 10% (w/v) to 30% (w/v) glucose, or 25% (w/v) fructose or l-sorbose there was an increase in the total concentration of intracellular polyol due to the accumulation of arabitol. This pentitol was also found to accumulate intracellularly when the organism was grown in medium containing 34% (w/v) sucrose, 0.7 M NaCl or 0.7 M KCl in addition to 2% (w/v) glucose. Under the conditions tested no change in the accumulation of mannitol or ethanol-soluble carbohydrate, believed to be primarily composed of trehalose, was evident.Intracellular polyol was released during incubation of arthrospores obtained from media containing 25% or 10% glucose, in distilled water at 25° C, but no polyol was released under these conditions from arthrospores obtained from growth in 2% glucose medium.     

不同碳氮比对薄盖灵芝液体培养的影响

采取液体深层发酵的方法 ,研究了不同碳氮比对薄盖灵芝 [Ganodermacapense (Lloyd)Teng]液体培养的影响。结果表明 ,在氮量固定的情况下 ,随碳量的增加 ,薄盖灵芝菌丝体干重逐渐增大 ,各处理发酵液的pH值呈“上升→下降→平稳”的变化趋势 ;当碳量固定时 ,各处理的pH值变化基本呈“双峰”型。不同碳氮比对薄盖灵芝液体发酵影响较大 ,通过对菌丝生长量、pH值的测定以及对发酵液及菌球培养性状的观察 ,认为碳氮比在 2 0∶1～ 4 0∶1(C3～C7)对薄盖灵芝的液体发酵均较适宜。其中以 30∶1(C5 )为最适宜 ,在此条件下 ,终止发酵的pH值为 3 4 ,菌球数量虽为 113个 10mL发酵液 ,但菌丝体干重为 6 83 4mg dL。发酵液澄清度高 ,呈真溶液状 ,菌球大小均匀。     

血红铆钉菇SN菌株生物学特性研究

采用组织分离法从野生血红铆钉菇子实体分离得到1株性状稳定的分离株SN,并对其生物学特性进行了研究.结果表明:最适合菌株生长的碳源为葡萄糖和蔗糖,最适宜的氮源为蛋白胨,菌丝生长的最适温度为22～24℃,最适pH为8,无光照培养时菌丝长势较好.培养料中添加20％腐殖质适合菌丝的生长.     

中华羊茅内生真菌Neotyphodium sp.生物学与生理学特性的研究

本文对中华羊茅Festuca sinensis内生真菌Neotyphodium sp.的生物学与生理学特性进行了报道。研究发现:中华羊茅内生真菌能在10-30℃生长,5℃和35℃几乎不能生长,最适生长温度是25℃;适宜的pH是7-9;不同的碳、氮源利用能力不同,利用能力最好的分别是甘露醇和酵母浸液;在不同培养基上的生长速度与产孢特性存在差异,马铃薯葡萄糖琼脂(PDA)培养基上生长最快,水琼脂(WA)和海水营养琼脂(SNA)培养基上生长最慢,但WA和SNA产孢最多。     

Kinetic studies on citric acid production by Aspergillus niger. II. The two-stage process.

A two-stage process of submerged citric acid fermentation with replacement of growth medium by fermentation medium has been worked out. The optimum composition of mineral nutrients and pH of the fermentation medium of the second stage of the process were determined. An addition of 0.5 g/l of NH4NO3 as nitrogen source and 0.1 g/l of MgSO4-7H2O as magnesium source ensured effective conversion of sucrose to citric acid. An addition to KH2PO4, on the other hand, was definitely unfavourable as it considerably reduced the product yield. The medium for the second stage of fermentation should be acidified to about pH 2.2, while the water used for washing the mycelium from the remains of the growth medium should have a pH of 2.5--3.5. Under these conditions, with an initial sucrose concentration of 100 g/l, after 132 hr fermentation at 26 degrees up to 90 g/l of citric acid was obtained, which corresponds to a productivity of over 16 g/l. day. The highest activity for citric acid formation was found in three- or four-day-old mycelium.     

Effect of the energy source on the NADH/NAD ratio and on pyruvate catabolism in anaerobic chemostat cultures of Enterococcus faecalis NCTC 775

Abstract: Enterococcus faecalis was grown under anaerobic conditions in chemostat cultures on energy sources with different degress of reduction (i.e. mannitol, glucose, pyruvate) at various culture pH values. Intracellular NADH/NAD ratios were measured and were found to be influenced both by the nature of the energy source and by the culture pH value. Highest ratios were found with mannitol as energy source and with high culture pH values. A role for the redox potential of the NADH/NAD couple as a regulatory effector is suggested by a correlation of the redox potential with the in vivo distribution of the carbon flux between pyruvate formate lyase and the pyruvate dehydrogenase complex.     

绿僵菌无纺布菌条的制作(I)液体种子培养条件

研究了金龟子绿僵菌菌株M a83液体培养最佳营养及环境条件,为无纺布培养提供良好的液体种子。以生物量为指标,通过液体摇瓶试验确定了绿僵菌M a83菌株液体种子培养参数,对不同的氮源、碳源及其浓度和初始pH进行单因素分析。结果表明,绿僵菌M a83菌株液体种子培养最佳营养条件为4%黄豆粉,2%白砂糖,0.5%MgSO4.7H2O,0.05g/LKC l,0.1g/L FeSO4.7H2O,1.0g/L KH2PO4,pH6.3~6.5。70L发酵罐培养,干生物量第三天可达35g/L,显著优于筛选前培养基(SDA,28g/L,a=0.05)。