葡萄灰葡萄孢生长及产孢条件研究

灰葡萄孢(Botrytis cinerea)可引起葡萄灰霉病,严重影响葡萄产量和品质。探索不同培养基、温度、光照、碳源、氮源等对葡萄灰葡萄孢菌丝生长和分生孢子产生的影响,以及菌丝与分生孢子的致死温度和时间,旨在探索灰葡萄孢生长及产孢的最佳条件。结果显示,灰葡萄孢菌丝生长的最适培养基为PDA培养基,最适温度25℃;产孢最适培养基为MSM培养基,最适温度23℃;在培养基pH3~11范围内灰葡萄孢均能生长并产生分生孢子,菌丝生长和产生分生孢子的最适pH均为6;灰葡萄孢以葡萄糖和乳糖为碳源时生长速率和产孢量达到最佳,而蛋白胨则为灰葡萄孢生长和产孢的最佳氮源;菌丝的致死条件是50℃处理25 min或55℃处理10 min;分生孢子的致死条件是45℃处理30 min或50℃处理10 min。研究为葡萄灰霉病的有效防治及分子生物学研究提供理论依据。     

茶树菇菌丝多糖发酵工艺优化

茶树菇（Agrocybe aegerita）富含抗癌多糖,一般以其子实体为材料进行提取获得多糖,而子实体生长周期较长,利用液态发酵得到的茶树菇菌丝多糖可以有效缩短生产周期。为提高菌丝生物量和菌丝多糖含量,该试验以茶树菇菌丝为材料,通过单因素试验及响应面试验对培养基的碳源、氮源、促生长因子,培养时间及摇床转速进行优化。结果表明,茶树菇菌丝多糖发酵的最佳培养条件为麦芽糖34 g/L、酵母提取粉21 g/L、MnSO4 2.0 g/L、KH2PO4 2.5 g/L、MgSO4 1.5 g/L,pH6.0,摇床转速为130 r/min,培养时间为6 d。在此优化条件下,液态发酵生产的茶树菇菌丝生物量为7.65 g/L,菌丝多糖含量达3.73%。该结果可为液态发酵生产茶树菇多糖提供参考。     

Bistage control of pH for improving exopolysaccharide production from mycelia of Ganoderma lucidum in an air-lift fermentor

It was found that pH control definitely affects mycelial cell growth and exopolysaccharide (EPS) production of the mycelial cultivation of Ganoderma lucidum. Compared to the case of uncontrolled pH cultivation, a culture system whose pH was kept constant at 3 and 6 exhibited improved mycelial cell growth and EPS production, respectively. The bistage pH control technique, that is, shifting the pH from 3 to 6 at the initial phase of the exponential growth, is introduced to improve cell growth and EPS production. This technique can greatly increase EPS production to 20.1 g/l from 4.1 g/l in the case of uncontrolled pH cultivation, without adverse effects on cell growth as in the case of constant maintenance of a high pH. It was also proved that bistage pH control retained the desirable morphologies of the mycelia during cultivation and resulted in low viscosity and yield stress of the culture broth. It will be useful for the application of the culture process to mycelial growth in a large-scale fermentor.     

油菜黑胫病菌Leptosphaeria biglobosa生物学特性研究

为了解我国油菜黑胫病病原菌（Leptosphaeria biglobosa）的生物学特性,在实验室里研究了温度、pH值、光照、碳源及氮源等条件对该病菌营养生长及分生孢子产生的影响。结果表明：病原菌在5℃～35℃均可进行营养生长并产孢,最适生长和产孢温度为25℃;在pH4～10的范围内该菌均能生长并产孢,在pH7的条件下生长最快,产孢最多。光暗交替有利于菌丝生长和产孢,而持续光照不利于菌丝生长,尤其不利于产孢。最适的碳源、氮源分别是可溶性淀粉、牛肉膏。分生孢子的致死温度为52℃。     

Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae

The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi‐open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. © 2013 The Author. Yeast Published by John Wiley & Sons Ltd.     

柏树火焰层孔菌菌丝体发酵工艺条件优化

柏树火焰层孔菌是中国以及亚洲菌物的新记录属中的新记录种,是一种稀有的药用菌。为寻求高产的生长条件和经济的培养基,进行转速、温度、pH 值、培养液装瓶体积、接种量、碳源、氮源、C/N 对菌丝体生长影响的单因素试验和多因素试验设计,利用液体培养基探索这些条件对菌丝体产量的影响。结果表明：菌丝 生长最适碳源为淀粉,最适氮源为麸皮,P、K、Mg 对菌丝的生长具有促进作用,最适C/N 为20:1～25:1;菌丝生长的最适转速为150r/min,温度为25～30℃,最佳pH 值为5～7,最适培养液装瓶体积为100mL,最适接种量为8mL/100mL。液体培养基的最佳营养条件为：葡萄糖 25g/L、麸皮 125g/L、 K2HPO4 0.25g/L、pH 6.5。通过生长曲线实验得到Logsitic 方程为：y = 0.22/(1+ 1.019e － 0.013x)。     

Killer strains of Saccharomyces: application for apple wine production

The aim of this study was to evaluate possible application of killer strains Saccharomyces paradoxus CBS 3702 (K1), S. cerevisiae CBS 6505 (K2) and S. capensis CBS 7903 (K3) for apple wine production. Apple musts were obtained from Jonagold apples. The optimal pH value of killer toxins activity, the temperature of their formation and the spectrum of activity against selected wine spoilage fungal strains were analysed. The influence of yeast strains on the chemical composition, volatile profile and sensory properties of apple wines was determined using high‐performance liquid chromatography and gas chromatography methods. The pH values of 4.2 (K1, K3) and 4.6 (K2), and a temperature of 28 °C, were optimal for the action of toxins. The analysed killer strains inhibited growth of seven of the 11 tested wine spoilage fungal strains. The samples obtained using the S. cerevisiae killer strain were characterized by the highest fermentation rate, highest ethanol concentration and a balanced level of volatiles, but their taste was described as bitter. S. capensis gained the highest scores in the sensory evaluation. It could be used for semi‐sweet or semi‐dry cider production, because of the lower amounts of ethanol formation but higher synthesis of glycerol, volatile esters and higher alcohols. Copyright © 2016 The Institute of Brewing & Distilling     

烤烟苗期茎部腐烂病病原菌九州镰孢菌的生物学特性

作者于2012年在烤烟（Nicotiana tabacum L.）苗期发现茎部腐烂病。经病原菌的形态特征观察、rDNA-ITS和EF-1α序列分析,该致病菌被鉴定为九州镰孢菌（Fusarium kyushuense）。该病原菌在利马豆培养基上生长温度范围为5~ 41℃,最适30℃;分生孢子产生温度范围为10 ~ 35℃,最适35℃;分生孢子萌发温度范围为5~42℃,最适30~35℃;分生孢子萌发相对湿度范围为70~100%,最适100%;可生长pH值为2~11,最适5~7;光照对菌丝生长和分生孢子萌发没有影响,光暗交替培养菌丝生长变慢,但分生孢子产量增加;在供试的95种碳源中,该病原菌能利用葡萄糖、麦芽糖、反丁烯二酸等89种碳源,不能利用N-乙酰基D-半乳糖胺、N-乙酰基-?-D-葡萄糖胺、葡萄醛酰胺、癸二酸、L-丝氨酸和腺苷-5’-磷酸盐6种碳源。      

Effect of gamma radiation on ochratoxin production by the fungus Aspergillus ochraceus

Mycelial discs of the fungus Aspergillus ochraceus NRRL 3174 were exposed to gamma irradiation and then incubated on synthetic medium (SM). Growth rate, mycelial dry weight and ochratoxin production were measured. A delay in mycelial growth of 24 and 48h over the control occurred following irradiation of mycelial discs with 150 and 200 krad, respectively. No growth occurred from discs exposed to 300 krad. An increase in ochratoxin production occurred on the SM from cultures developing from discs of mycelium which had been irradiated with 50, 100, 150 and 200 krad. The amount of toxin produced was 3500, 4100, 3200 and 3000 ng per plate, respectively, as compared with 2800 ng per plate produced by the control. Exposure of mycelial discs to a temperature of 40°C for 15 and 30 min prior to treatment with 200 krad resulted in complete inhibition in mycelial growth. No growth inhibition or notable change in ochratoxin production was recorded when the mycelial discs were exposed to 25, 50 or 100 krad after the heat treatments. Pure ochratoxin was found to be stable even at 7.5 mrad, and no reduction in its fluorescence intensity under u. v. light was recorded following that dose.     

1 株产桔青霉素扩展青霉的鉴定及其产毒条件优化

在腐烂柑橘表面筛选出1株产桔青霉素（citrinin,CIT）的菌株H1,经鉴定为扩展青霉,并进一步研究培养基、温度、pH值、溶氧量、培养时间等对菌株H1生长及产CIT能力的影响。结果表明：在pH?3的YSM培养基上25?℃摇床培养2?周,菌株产生的CIT产量最高,为12.8?μg/g,pH?11的碱性条件下产毒受到抑制。     

Botryticidal Activity of Nanosized Silver‐Chitosan Composite and Its Application for the Control of Gray Mold in Strawberry

Botrytis cinerea Pers, the gray mold fungus, is among the most dangerous plant pathogens that cause great losses in agricultural crops. The botryticidal activities of nanosized silver (nano Ag), fungal chitosan (CTS) irradiated fungal chitosan (IrCTS), and nano Ag‐IrCTS composite were investigated. All of the examined materials exhibited powerful antifungal activity against B. cinerea. The most effective compound was nano Ag‐IrCTS composite with a minimal inhibitory concentration of 125 μg/mL. The microscopic examination, of treated B. cinerea with the composite, revealed that an obvious alteration in mycelial shape was appeared accompanied and moderate lysis in fungal hyphae. With the prolongation of treatment, most of the fungal mycelia were lysed into small and elastic fragments. The consequence of strawberries coating, with antifungal composite based solution, was the disappearance of gray mold infection signs in 90% of the contaminated fruits after 7 d of storage, treated fruits had a fresh‐like appearance at the end of storage. Coating with nano Ag‐IrCTS solution could be highly recommended regarding its efficiency in prohibiting B. cinerea growth, preventing gray mold decay and enhancing the overall quality of coated strawberry fruits.     

Use of whey permeate for cultivating Ganoderma lucidum mycelia

A novel approach to utilizing whey permeate, the cultivation of mycelia of the edible mushroom Ganoderma lucidum, is introduced. The major objective of this research was to use whey permeate as an alternative growth medium for the cultivation of mycelia of edible mushroom G. lucidum and to find an optimum condition for solid-state cultivation. Response surface analysis was applied to determine the combination of substrate concentration (25 to 45 g of lactose/L), pH (3.5 to 5.5), and temperature (25 to 35°C) resulting in a maximal mycelial growth. The radial extension rates, estimated by measuring the diameters of growing colonies on the Petri dishes, were used as the growth of the mycelia at different conditions. In the model, pH and temperature significantly affected mycelial growth, but lactose concentration did not. The condition predicted to maximize the radial extension rate of 17.6 ± 0.4 mm/d was determined to be pH 4.4 and temperature 29.4°C. Therefore, the results suggest that whey permeate could be utilized as a growth substrate for the cultivation of mycelia from the edible mushroom G. lucidum, enhancing the use of this by-product by the cheese manufacturing industry.     

Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--part 1. Inhibition of growth and aflatoxin production of Aspergillus parasiticus by Korean soybean paste (Doen-jang) and identification of the active component

The inhibitory effect of methanol extract of Korean soybean paste on the mold growth and aflatoxin production of a toxigenic strain of Aspergillus parasiticus ATCC 15517 was studied using different concentrations of the extract in yeast-extract sucrose broth. While inhibition in mold growth due to increasing the concentration of the extract was observed, the more remarkable effect was the inhibition of aflatoxin production. Reduction of mycelial weight as a result of addition of the extract was observed to range between 1.5 to 12.9% while reduction of aflatoxin production quantified by high-performance liquid chromatography ranged from 14.3 to 41.7%. Five percent of the extract significantly reduced aflatoxin production at the end of the incubation period (P < 0.05), although the effect on mycelial growth was less pronounced. This study indicates that soybean paste could also be an effective inhibitor of aflatoxin production even though mycelial growth may be permitted. The main active component identified by gas chromatography-mass spectroscopy was linoleic acid.     

无机氮源对红曲霉调控初探

采用以硫酸铵、硝酸铵、硝酸钾、亚硝酸钠4种不同的无机盐作为氮源,探讨其对红曲霉（Monascus）菌株GZUM-25菌落形态、菌丝形态以及色素种类和产量的影响。结果表明,在以硫酸铵为氮源的培养基上,红曲霉菌落的基质菌丝和气生菌丝生长紧密,且气生菌丝在边缘呈放射状,菌丝粗壮、分支多,色素种类多且色价最高为13.5 U/mL;在以硝酸钾为氮源的培养基上,菌落基质菌丝较为疏松,气生菌丝呈毛绒状,菌丝较为粗壮但不具有分支,色素种类单一,色价较高为1.91 U/mL;在以亚硝酸钠为氮源的培养基上,菌落基质菌丝细长且不具有分支,色价最低0.08 U/mL。由此可知,铵盐可以促进红曲霉菌丝的生长发育和次级代谢产物的生成,而亚硝酸盐则有抑制作用。     

Bistage control of pH for improving exopolysaccharide production from mycelia of Ganoderma lucidum in an air-lift fermentor

It was found that pH control definitely affects mycelial cell growth and exopolysaccharide (EPS) production of the mycelial cultivation of Ganoderma lucidum. Compared to the case of uncontrolled pH cultivation, a culture system whose pH was kept constant at 3 and 6 exhibited improved mycelial cell growth and EPS production, respectively. The bistage pH control technique, that is, shifting the pH from 3 to 6 at the initial phase of the exponential growth, is introduced to improve cell growth and EPS production. This technique can greatly increase EPS production to 20.1 g/l from 4.1 g/l in the case of uncontrolled pH cultivation, without adverse effects on cell growth as in the case of constant maintenance of a high pH. It was also proved that bistage pH control retained the desirable morphologies of the mycelia during cultivation and resulted in low viscosity and yield stress of the culture broth. It will be useful for the application of the culture process to mycelial growth in a large-scale fermentor.     

Novel episomal vectors and a highly efficient transformation procedure for the fission yeast Schizosaccharomyces japonicus

Schizosaccharomyces japonicus is a fission yeast for which new genetic tools have recently been developed. Here, we report novel plasmid vectors with high transformation efficiency and an electroporation method for Sz. japonicus. We isolated 44 replicating segments from 12 166 transformants of Sz. japonicus genomic fragments and found a chromosomal fragment, RS1, as a new replicating sequence that conferred high transformation activity to Sz. japonicus cells. This sequence was cloned into a pUC19 vector with ura4⁺ of Sz. pombe (pSJU11) or the kan gene on the kanMX6 module (pSJK11) as selection markers. These plasmids transformed Sz. japonicus cells in the early‐log phase by electroporation at a frequency of 123 cfu/µg for pSJK11 and 301 cfu/µg for pSJU11, which were higher than previously reported autonomously replicating sequences. Although a portion of plasmids remained in host cells by integration into the chromosome via RS1 segment, the plasmids could be recovered from transformants. The plasmid copy number was estimated to be 1.88 copies per cell by Southern blot analysis using a Sz. pombe ura4⁺ probe. The plasmid containing ade6⁺ suppressed the auxotrophic growth of the ade6‐domE mutant, indicating that the plasmid would be useful for suppressor screening and complementation assays in Sz. japonicus. Furthermore, pSJU11 transformed Sz. pombe cells with the same frequency as the pREP2 plasmid. This study is a report to demonstrate practical use of episomal plasmid vectors for genetic research in Sz. japonicus. RS1 has been submitted to the DDBJ/EMBL/GenBank database (Accession No. AB547343). Copyright © 2010 John Wiley & Sons, Ltd.     

大球盖菇培养基的筛选及培养条件的优化

大球盖菇(Stropharia rugoso-annulata)具有很高的营养价值和药用价值,但是目前对于大球盖菇培养基的筛选以及培养条件的优化研究还不够深入。本研究通过测定不同母种培养基配方下大球盖菇的菌丝生长速度、生长势以及菌落生长指数,筛选出大球盖菇最适宜母种培养基;测定不同液体培养基配方下大球盖菇菌丝球的生物量,筛选出最适宜的液体培养基;并在单因素试验的基础上,以大球盖菇菌丝球生物量为响应值,应用Box-Benhnken中心组合法对大球盖菇液体菌种培养条件进行了优化。结果表明:最适宜大球盖菇母种生长的配方为马铃薯200 g、干稻草150 g、蔗糖20 g、玉米粉10 g、蛋白胨3 g、酵母膏2 g、维生素B1 5 mg、琼脂20 g、水1000 mL;最适宜大球盖菇液体种生长的配方为蔗糖20 g、玉米粉30 g、稻草粉15 g、蛋白胨2 g、酵母膏1 g、维生素B1 5 mg、水1000 mL (pH自然);液体菌种最佳培养条件为转速140 r/min,接种量8%,培养时间12 d,三次平行实验得到的实际的大球盖菇菌丝球生物量平均为0.8108 g/100 mL,与预测值0.8282 g/100 mL相符。     

Optimization of Calvatia gigantea mycelia production from distillery wastewater

The focus of wastewater management has evolved from treatment technology into resource recovery, which enables one to minimize contaminants and to generate value‐added products. Calvatia gigantea is used not only as a source of food, but has also been used as a traditional Chinese medicine for thousands of years. In this study, the mycelial production of C. gigantea was studied under submerged fermentation conditions using non‐pretreated distilled wastewater from Chinese liquor production. The fermentation medium composition was optimized using response surface methodology involving a Box–Behnken design. Fermentation conditions were optimized using an orthogonal experimental design. The optimized medium composition was the non‐pretreated distilled wastewater of Chinese liquor supplemented with cornflour at 2.35 g/100 mL, (NH₄)₂SO₄ at 1.11 g/100 mL and CuSO₄ at 0.12 g/100 mL. The optimized fermentation conditions were a rotation speed of 150 rpm, an inoculum size of 10% (v/v), a fermentation temperature of 26 °C and a fermentation time 4.5 days. A maximum mycelial biomass yield of 2.75 g/100 mL was achieved using the optimized medium under the optimized conditions. Results from this study suggest that this is a feasible technology for the mycelial production of C. gigantea using the non‐pretreated distilled wastewater from Chinese liquor production. Copyright © 2015 The Institute of Brewing & Distilling     

灵芝液体发酵产胞内多糖的培养基优化

以菌丝生物量及菌丝胞内多糖为指标,用液体发酵方法培养灵芝菌丝并获得菌丝胞内多糖,通过单因素及正交试验,研究了碳源、氮源、微量元素对灵芝菌丝生长及多糖产量的影响。结果表明:灵芝液体发酵生产菌丝多糖最适合培养基组合为:麦芽糖2.0%、酵母提取粉2.0%、ZnSO40.015%、VB10.10%、KH2PO40.2%、MgSO40.05%、pH 6.0,菌丝多糖产量高达6.64%。     

Effects of Onion (Allium cepa L.) and Garlic (Allium sativum L.) Essential Oils on the Aspergillus versicolor Growth and Sterigmatocystin Production

Abstract: In the present study the effects of individual and combined essential oils (EOs) extracted from onion (Allium
cepa L.) bulb and garlic (Allium sativum L.) clove on the growth of Aspergillus versicolor and sterigmatocystin (STC) production were investigated. The EOs obtained by hydrodistillation were analyzed by GC/MS. Twenty one compounds were identified in onion EO. The major components were: dimethyl‐trisulfide (16.64%), methyl‐propyl‐trisulfide (14.21%), dietil‐1,2,4‐tritiolan (3R,5S‐, 3S,5S‐ and 3R,5R‐ isomers) (13.71%), methyl‐(1‐propenyl)‐disulfide (13.14%), and methyl‐(1‐propenyl)‐trisulfide (13.02%). The major components of garlic EO were diallyl‐trisulfide (33.55%), and diallyl‐disulfide (28.05%). The mycelial growth and the STC production were recorded after 7, 14, and 21 d of the A. versicolor growth in Yeast extract sucrose (YES) broth containing different EOs concentrations. Compared to the garlic EO, the onion EO showed a stronger inhibitory effect on the A. versicolor mycelial growth and STC production. After a 21‐d incubation of fungi 0.05 and 0.11 μg/mL of onion EO and 0.11 μg/mL of garlic EO completely inhibited the A. versicolor mycelial growth and mycotoxins biosynthesis. The combination of EOs of onion (75%) and garlic (25%) had a synergistic effect on growth inhibition of A. versicolor and STC production. Practical Application: A substitution of synthetic preservatives with natural antimicrobial compounds in food safety to control fungal contamination and mycotoxin production.