Virus Particles from Conidia of Penicillium Species

Virus particles and their component double-stranded ribonucleic acid (dsRNA) have been isolated from conidia and mycelia of certain Penicillium species. The conidia and mycelia of P. stoloniferum NRRL 5267 contained 75 and 85 mug of dsRNA/g (dry weight), respectively. Of the total dsRNA released from NRRL 5267 conidia, 10% was nonencapsulated. Conidia of P. brevi-compactum NRRL 5260 and P. chrysogenum Q-176 contained 2 and 120 mug of dsRNA/g (dry weight), respectively, whereas mycelium from the two species contained 3 and 95 mug of dsRNA/g (dry weight), respectively. No viruses were isolated from conidia or mycelia of P. stoloniferum NRRL 859. A method is described for disruption of both conidia and mycelia. The technique facilitates the isolation and characterization of fungal viruses and their component dsRNA and also potentiates surveying of fungal isolates for the presence of virus.     

Toxicity to Chicks of Aspergillus and Penicillium Species Isolated from Moldy Pecans

Isolates of Aspergillus chevalieri, A. flavus, A. ochraceus, A. repens, and Penicillium funiculosum and complexes of P. citrinum-P. implicatum isolated from moldy pecan meats were toxic to chicks.     

岩白菜属植物规模化繁殖及遗传稳定性

根据市场需求和野生资源现存状况, 筛选厚叶岩白菜(Bergenia crassifolia)、秦岭岩白菜(B. scopulosa)和岩白菜(B. purpurascens)进行规模化繁殖, 并利用ISSR分子标记对组培苗进行遗传稳定性分析。以顶芽为外植体, 筛选出MS+0.5 mg·L^-1 6-BA+0.01 mg·L^-1 NAA+2.0 mg·L^-1 V_C为最佳增殖培养基, 3种岩白菜属植物增殖系数分别为3.10、2.50和2.10; 在1/2MS+1.0 mg·L^-1 IBA+2.0 mg·L^-1 V_C培养基上, 3种岩白菜属植物生根率分别为85%、80%和75%; 在腐殖土:黄沙:珍珠岩=2:1:1 (v/v/v)的混合基质中, 移栽成活率分别为90%、85%和80%。规模化繁殖厚叶岩白菜20万株, 秦岭岩白菜2万株, 岩白菜1万株, 目前还在持续生产中。ISSR分子标记结果表明, 岩白菜后代遗传变异较大, 秦岭岩白菜后代遗传变异较小, 3个种在继代至第20代时出现了遗传变异; 岩白菜和秦岭岩白菜的平均遗传变异率随继代次数的增加而增加, 厚叶岩白菜的平均遗传变异率随继代次数的增加呈现不规律变化。     

Toxigenic Aspergillus and Penicillium Isolates from Weevil-Damaged Chestnuts

Aspergillus and Penicillium were among the most common genera of fungi isolated on malt-salt agar from weevil-damaged Chinese chestnut kernels (16.8 and 40.7% occurrence, respectively). Chloroform extracts of 21 of 50 Aspergillus isolates and 18 of 50 representative Penicillium isolates, grown for 4 weeks at 21.1 C on artificial medium, were toxic to day-old cockerels. Tweleve of the toxic Aspergillus isolates were identified as A. wentii, eight as A. flavus, and one as A. flavus var. columnaris. Nine of the toxic Penicillium isolates were identified as P. terrestre, three as P. steckii, two each as P. citrinum and P. funiculosum, and one each as P. herquei (Series) and P. roqueforti (Series). Acute diarrhea was associated with the toxicity of A. wentii and muscular tremors with the toxicity of P. terrestre, one isolate of P. steckii, and one of P. funiculosum.     

Mass Production of Conidia of Penicillium frequentans,a Biocontrol Agent Against Brown Rot of Stone Fruits

Conidial production of Penicillium frequentans , a biocontrol agent of the fungal pathogen Monilinia laxa , was tested in liquid and solid-state fermentation. Conidial production of P. frequentans in solid-state fermentation was higher than in liquid-state fermentation. Solidstate fermentation was made in specially designed plastic bags (VALMIC ® ) containing peat:vermiculite (1:1 w/w). Addition of nutrients to the peat:vermiculite increased conidial production of P. frequentans , especially when lentil meal was added. The number of conidia obtained in this solid-state fermentation was maintained in the range of 10 8 -10 9 conidia g -1 from 5 to 120 days after inoculation. Germinability of these conidia was > 90% until 90 days of incubation and declined at 120 days. Optimal initial moisture content in the substrate was 30-40% (v/w). At lower moisture contents, significant reductions in conidial production and germinability were observed, particularly at 10% (v/w). Conidial production was similar when the substrate was inoculated with 10 5 , 10 6 or 10 7 conidia g -1 dry substrate. Fresh conidia produced by solid-state fermentation reduced the incidence of brown rot on plums by 75%.     

Starch Hydrolysis by Conidia of Aspergillus wentii

Soluble starch was hydrolyzed to glucose by conidia of Aspergillus wentii NRRL 2001. Peak yields of glucose were achieved in 3 days. A glucoamylase-like enzyme was assumed to be responsible since maltose was not detected during the conversion. Spore age, storage conditions, and temperature affected the level of glucose accumulated. Iodoacetate inhibited catabolism of the glucose formed and this inhibition increased product yield. Spores of other fungi also hydrolyzed starch but none accumulated glucose naturally as did A. wentii spores.     

Storage of Conidia of Penicillium chrysogenum in Liquid Nitrogen

Conidiated slope cultures of derivative of Penicillium chrysogenum Wis 54-1255 were stored at -196 or +4 C for a period of 3.5 years. After this time, the viability fell to 68% in the former case and to 4% in the latter. At the end of the experiment, 65 single conidial isolates from each series were tested for penicillin yield. Among those from conidia stored at -196 C, the spread of penicillin yields did not differ markedly from that of 65 single conidial isolates made as controls prior to storage. However, 18% of those from conidia stored at +4 C formed a subpopulation with substantially lower penicillin titers than those of control isolates. Storage at -196 C may reduce or prevent a possible source of penicillin yield decay, namely, the selection of spontaneous mutants of low titer present in small numbers in the original culture and selected, as viability decreased, by virtue of their increased longevity relative to that of the parental culture.     

Ribosomes in Dormant and Germinating Conidia of Aspergillus oryzae

Ribosomes were isolated from dormant and germinating conidia of Asp. oryzae No. 13. The ribosomes which consisted of 80 S were easily dissociated into 40 S and 60 S in low Mg^{+ +} buffer. Polyribosomes were not found in dormant conidia, but were found in germinating conidia. Ribosomes in Aspergillus fungi consisted of almost equal amount of RNA and protein, and the base compositions of RNA were alike, as compared as ribosomal RNA between dormant and germinating conidia.     

Production of d-Mannitol by Conidia of Aspergillus candidus

Conidia of Aspergillus candidus converted glucose and other sugars to mannitol. Low pH (ca. 3.0) apparently favored the percentage yield but decreased the fermentation rate.     

Polyfructan and Oligofructans Synthesized from Sucrose by Conidia of Aspergillus sydowi IAM 2544

When conidia of Aspergillus sydowi IAM 2544 was incubated with sucrose, polyfructan and oligofructans were synthesized concomitantly in the incubation mixture. The polyfructan isolated from the incubation mixture was shown to have a molecular weight of the order of 20 × 10⁶ which was comparable to those of microbial levans. But it was comprised of chains of 2→1′ linked β-D-fructofuranoside residues as in inulin of higher plants. This polyfructan was considred to be a very unique polysaccharide which differed from any other fructans ever known. Oligofructans were characterized as fructans of 1-kestose series having the general formula of ((1^F-(fructosyl)_n-sucrose)).     

Simple Method for Mass Production and Collection of Conidia from Hemispora stellata

A simple method is described for the mass production and collection of conidia from Hemispora stellata.     

Conidia of Aspergillus oryzae as Naturally Immobilized Phosphatases

The following enzymes were detected in conidia of Aspergillus oryzae var. No. 13 that were collected from a soy sauce factory: phosphatases acting nonspecifically on nucleotides; ribosidase(s) acting on adenosine, inosine, guanosine and xanthosine; and deaminases acting on guanine, adenosine, guanosine, cytidine, AMP and GMP. Most phosphatase activity was found to be bound firmly to the conidia. Thus, when a nucleotide solution was passed through a conidia-containing column, the corresponding nucleoside was recovered as a clear and colorless solution. The bound phosphatases were rather stable at pH 4 to 9 and at temperatures below 50°C. The optimum conditions for activity were at about 45°C and at pH about 5 and 8. When UMP·Na₂ solution was passed through a column containing 5 g of the conidia, about 200 mg of substrate was hydrolyzed per 1 hr. Conidia of molds belonging to the genus Aspergillus may be industrially employed as naturally immobilized phosphatases.     

Fine-structural Changes during Germination of Conidia of Penicillium griseofulvum Dierckx

Conidia of Penicillium griseofulvum Dierckx have been examinedby electron-microscopy at a series of stages throughout thecourse of germination. The conidia have two-layered walls butduring germination a third, inner wall layer appears which maybe quite distinct or rather indistinct according to the compositionof the germination medium. The germ-tube wall is continuouswith this third spore-wall layer only. Ungerminated conidiacontain a nucleus and mitochondria. During swelling mitochondriaincrease in size and become lobed, endoplasmic reticulum becomesvisible, and vacuoles are formed. Septa formed in germ-tubesare perforate and have Woronin bodies associated with them.The structural changes during germination can be correlatedwith changes in physiological behaviour of the germinating conidia.     

Comparative Analysis of Aspergillus oryzae with Normal and Abnormal Color Conidia

This study focuses on the characteristic of strains with anomalous color conidium and compares with normal color conidium. Comparative analysis of enzymes activity and extracellular proteins revealed that A. oryzae with anomalous color conidium was not different from the strain with normal color conidium. In addition, A. oryzae with anomalous color conidium could not influence the palatability and quality of the soy sauce. These findings provide an insight into A. oryzae with anomalous color conidium.     

Taka-Amylase A in the Conidia of Aspergillus oryzae RIB40

A study of Taka-amylase A of conidia from Aspergillus oryzae RIB40 was done. During the research, proteins from conidia and germinated conidia were analyzed using SDS–PAGE, 2-D gel electrophoresis, Western blot analysis, MALDI-TOF Mass spectrometry, and native-PAGE combined with activity staining of TAA. The results showed that TAA exists not only in germinated conidia but also in conidia. Some bands representing degraded products of TAA were detected. Conidia, which formed on starch (SCYA), glucose (DCYA), and glycerol (GCYA) plates, contained mature TAA. Only one active band of TAA was detected after native-PAGE activity staining. In addition, TAA activity was detected in cell extracts of conidia using 0.5 M acetate buffer, pH 5.2, as extraction buffer, but was not detected in whole conidia or cell debris. The results indicate that TAA exists in conidia in active form even when starch, glucose, or glycerol is used as carbon source. TAA might belong to a set of basal proteins inside conidia, which helps in imbibition and germination of conidia.     

Adhesion of Nongerminated Botrytis cinerea Conidia to Several Substrata

Conidia of the plant pathogenic fungus Botrytis cinerea adhered to tomato cuticle and to certain other substrata immediately upon hydration. This immediate adhesion occurred with both living and nonliving conidia. Adhesion was not consistently influenced by several lectins, sugars, or salts or by protease treatment, but it was strongly inhibited by ionic or nonionic detergents. With glass and oxidized polyethylene, substrata whose surface hydrophobicities could be conveniently varied, there was a direct relationship between water contact angle and percent adhesion. Immediate adhesion did not involve specific conidial attachment structures, although the surfaces of attached conidia were altered by contact with a substratum. Freshly harvested conidia were very hydrophobic, with more than 97% partitioning into the organic layer when subjected to a phase distribution test. Percent adhesion of germinated conidia was larger than that of nongerminated conidia. Evidence suggests that immediate adhesion of conidia of B. cinerea depends, at least in part, on hydrophobic interactions between the conidia and substratum.