掷孢菌科的研究——Ⅲ.不同掷孢酵母属产掷孢子的能力及担子菌酵母形成特大厚垣孢子的规律

本文以分离自中国的大量掷孢酵母为材料,研究了不同属的掷孢酵母生掷孢子的能力,以及此能力的持久性,发现属间差异很大。此外还报道了142株不同酵母的产厚垣孢子的情况,发现与担子菌有关的4属酵母在接近致死温度时,都会出现特大厚垣孢子如红掷孢酵母(Sporobolomyces),布勒掷孢酵母(Bullera),红酵母(Rhodotorula)与隐球酵母(cryptococcus),而属于子囊菌的酵母属(Saccharomyces)则无此现象,从而对某些接近担子菌的酵母又增加了新的认识。     

掷孢菌科的研究III．不同掷孢酵母属产掷孢子的能力及担子菌酵母形成特大厚垣孢子的规律

本文以分离自中国的大量掷孢酵母为材料,研究了不同属的掷孢酵母生掷孢子的能力,以及此能力的持久性,发现属间差异很大。此外还报道了142株不同酵母的产厚垣孢子的情况,发现与担子菌有关的4属酵母在接近致死温度时,都会出现特大厚垣孢子如红掷静酵母Sporobolomyces),布勒掷孢酵母(Bullera),红酵母(Rhodotorula)与隐球酵母(Cryp-tococcus),而属于子囊菌的酵母属(Saccharomyces)则无此现象,从而对某些接近担子菌的酵母又增加了新的认识。     

三个发表于国内的丝孢酵母种名分类地位的订正*

最新的酵母菌分类系统,丝孢酵母属Trichosporon Behrend仅限于产生节孢子的担子菌酵母的无性型。因此,以前根据该属旧的定义在国内发表的三个新种板仓丝孢酵母T. bancangense、北京丝孢酵母T. beijingense和中国丝孢酵母T. sinense的分类地位,需要进行调整。根据26S rDNA D1/D2区的序列分析和最新标准方法重新测定的生理生化反应,发现上述三个种名分别是子囊菌酵母Saccharomycopsis fibuligera, Pichia burtonii和Issatchenkia orientalis的异名。     

我国各类基物上的酵母菌分布及其尿素酶活性

本文讨论了2300株由我国各地分离到的酵母菌和类酵母菌与各类基物的关系。共述及23属,占Lodder(1970)系统的半数以上。在十几类基物中酵母菌的分布各有不同,叶子上有大量掷孢酵母,果实上比其它基物更能获得克勒克酵母属(Kloeckera),在咸腌食品中相对地有较多耐高渗透压的酵母如球拟酵母属(Torulopsis)与德巴利酵母属(Debaryomyces)。对部分属的定种工作也已进行,说明某些属的种在我国均有发现而且为数不少。此外还研究了600余株代表各类酵母的尿素酶活性,结果说明担子菌酵母或系统上接近担子菌的酵母都有尿素酶活性,而子囊菌酵母则无。根据作者的观察子囊菌酵母中裂殖酵母属(Schizosaccharomyces)则常常例外地有尿素酶反应,且常有辅酶Q_(10),从而可见裂殖酵母属有其特有的生物学特性,在系统上很可能与其它子囊菌酵母不同。对属于不完全菌的无孢子酵母也进行了尿素酶活性测定,结果表明它们部分与子囊菌有关,部分与担子菌有关。     

试论酵母遗传学研究的现状

现知广义的酵母菌有39属370多种,在真菌分类系统中分属于子囊菌纲、担子菌纲和半知菌纲。狭义的酵母菌,主要是指面包酵母、啤酒酵母和清酒酵母。本文指的是后者。酵母生活史如图1所示,二倍体酵母生活史如图2所示。     

三个发表于国内的丝孢酵母种名分类地位的订正

最新的酵母菌分类系统,丝孢酵母属Trichosporon Behrend仅限于产生节孢子的担子菌酵母的无性型。因此,以前根据该属目的定义在国内发表的三个新种板仓丝孢酵母T.bancangense,北京丝孢酵母T.beijingense和中国丝孢酵母T.sinense的分类地位,需要进行调整。根据26SrDNA/D 1/D2区的序列分析和最新标准方法重新测定的生理生化反应,发现上述三个种名分别是子囊菌酵母Saccharomycopsis fibuligera,Pichia burtonii和Issatchenkia orientalis的异名。     

201株不同类型酵母的初步分类及胞外脱氧核糖核酸酶和蛋白酶的比较研究

本文初步研究了分离自中国南方数省各种基物上的201株酵母,共发现4个新记录,另有个别疑难菌株拟作进一步研究。对9属174株担子菌酵母与子囊菌酵母进行胞外酶等的比较研究,发现其胞外脱氧核糖核酸酶(DNase)及蛋白酶的产生情况在不同亲缘的酵母间有一定的规律性。并对蛋白酶测试方法进行了改良,从而缩短试验周期并减少了污染机会。     

201株不同类型酵母的初步分类及胞外脱氧核糖核酸酶和蛋白酶的比较研究*

本文初步研究了分离自中国南方数省各种基物上的20l株酵母,共发现4个新记录,另有个别疑难菌株拟作进一步研究。对9属174株担子菌酵母与子囊菌酵母进行胞外酶等的比较研究,发现其胞外脱氧核糖核酸酶(D№se)及蛋白酶的产生情况在不同亲缘的酵母间有一定的规律性。并对蛋白酶测试方法进行了改良,从而缩短试验周期并减少了污染机会。     

抑菌试验用于测定T-2毒素

本文从镰刀菌中提取T-2毒素,对不同的酵母菌进行抑菌试验,结果证明红酵母属(Rho-dotorula)的三个种,即红酵母(R.glutrnis)、深红酵母(R.ruber)和小红酵母(R.minuta)对T-2毒素最敏感,被定为测毒敏感菌。将抑菌试验与家兔皮肤反应试验、豌豆发芽抑制试验进行对比,结果有部分重合,但不能相互取代。由于抑菌试验具有快速、简便、准确的优点,可做为测定T-2毒素的方法之一。     

掷孢菌科的研究 Ⅱ.中国叶表掷孢酵母的初步分类及掷孢酵母属的种类

作者多年来从我国禾本科等植物叶表分离了大量掷孢酵母,本文重点报道70株掷孢酵母与类酵母的初步分类,共分为三属,即掷孢酵母属(Sporobolomyces),布勒掷孢酵母属(Bul-lera)与腥掷孢菌属(Tilletiopsis);其中掷孢酵母属占75％。至于53株掷孢酵母,共分为三种,即玫红掷孢酵母(Sporobolomyces roseus)、赭色掷孢酵母(Sporobolomyces salmonicolor)、Sporobolomyces shibatanus);经统计,后者最为常见,占此属的84％。这些种在我国尚未见报道,作为新记录。     

A colour reaction for the differentiation of ascomycetous and hemibasidiomycetous yeasts

Seventy yeast strains, representative of twenty-six ascogenous genera, four saprobic hemibasidiomycetous genera and thirteen genera of the Cryptococcales were tested for their reaction with the stabilized aromatic diazonium compound, Diazonium Blue B salt. An aqueous, buffered solution of this compound gave a characteristic red colouration with the colonies of the hemibasidiomycetous species and those Cryptococcales characterized by the hemibasidiomycetous cell-wall type. The characteristic colour reaction was not observed with colonies of either the ascomycetous yeasts or those Cryptococcales characterized by the ascomycetous cell-wall type.The possible taxonomic use of the colour reaction with Diazonium Blue B salt as an affinitive characteristic is discussed.     

Yeast killer toxins,molecular mechanisms of their action and their applications

Killer toxins secreted by some yeast strains are the proteins that kill sensitive cells of the same or related yeast genera. In recent years, many new yeast species have been found to be able to produce killer toxins against the pathogenic yeasts, especially Candida albicans. Some of the killer toxins have been purified and characterized, and the genes encoding the killer toxins have been cloned and characterized. Many new targets including different components of cell wall, plasma membrane, tRNA, DNA and others in the sensitive cells for the killer toxin action have been identified so that the new molecular mechanisms of action have been elucidated. However, it is still unknown how some of the newly discovered killer toxins kill the sensitive cells. Studies on the killer phenomenon in yeasts have provided valuable insights into a number of fundamental aspects of eukaryotic cell biology and interactions of different eukaryotic cells. Elucidation of the molecular mechanisms of their action will be helpful to develop the strategies to fight more and more harmful yeasts.     

Shifts in community composition provide a mechanism for maintenance of activity of soil yeasts in the presence of elevated copper levels

Soil dilution plates were prepared from different soil samples using a solid synthetic selective medium containing (i). glucose as carbon source, (ii). thymine as nitrogen source, (iii). vitamins, (iv). minerals, and (v). chloramphenicol as antibacterial agent. Using the Diazonium Blue B colour reaction, it was found that both ascomycetous and basidiomycetous yeasts were able to grow on this medium. Subsequently, the medium was used to enumerate yeasts in soil microcosms prepared from four different soil samples, which were experimentally treated with the fungicide copper oxychloride, resulting in copper (Cu) concentrations of up to 1000 ppm. The selective medium supplemented with 32 ppm of Cu was used to enumerate Cu-resistant yeasts in the microcosms. The results showed that the addition of Cu at concentrations >or=approximately 1000 ppm did not have a significant effect on total number of yeasts in the soil. Furthermore, it was found that Cu-resistant yeasts were present in all the soil samples, regardless of the amount of Cu that the soil was challenged with. At the end of the incubation period, yeasts in the microcosms with zero and approximately 1000 ppm of additional Cu were enumerated, isolated, and identified with sequence analyses of the D1/D2 600-650 bp region of the large subunit of ribosomal DNA. Hymenomycetous species dominated in the control soil, while higher numbers of the urediniomycetous species were found in the soil that received Cu. These observations suggest that urediniomycetous yeasts may play an important role in re-establishing overall microbial activity in soils, following perturbations, such as the addition of Cu-based fungicides.     

Yeast strains from the Schirmacher Oasis,Antarctica

Summary Soil samples from the Schirmacher Oasis of Antarctica were examined for the presence of yeasts. The number of yeast cells in the samples varied between 600 and 3000 g of wet soil. Eight pure cultures were obtained. All of the eight isolates were nonfermentative and all but one was Diazonium Blue B (DBB)-positive, indicating their basidiomycetous affinity. Based on their morphology, reproductive behavior, growth at different temperatures and salt concentrations, nutritional characteristies and various biochemical tests, all the eight cultures have been identified. Three of them are red yeasts, Rhodotorula rubra, one Bullera alba, one a dimorphic, Candida humicola and one Candida famata. The remaining two cultures have been tentatively identified as Candida ingeniosa and Candida auriculariae.     

Isolation and characterization of ethanol-producing yeasts from fruits and tree barks

Aims:  Isolation and identification of yeasts converting xylose to ethanol.
Methods and Results:  A total of 374 yeasts were isolated from a variety of rotten fruits and barks of trees. Out of these, 27 yeast strains were able to assimilate xylose and produce 0·12–0·38 g of ethanol per gram of xylose. Based on phylogenetic analysis of D1/D2 domain sequence of LSU (Large Subunit) rRNA gene and phenotypic characteristics the ethanol-producing strains were identified as member(s) of the genera Pichia, Candida , Kluyveromyces, Issatchenkia, Zygosacchraomyces , Clavispora, Debaryomyces , Metschnikowia , Rhodotorula and Cryptococcus.
Conclusion:  Yeast strains producing ethanol from xylose have been isolated from a variety of rotten fruits and barks of trees and identified.
Significance and Impact of the Study:  Environmental isolates of yeasts which could convert xylose to ethanol could form the basis for bio-fuel production and proper utilization of xylan rich agricultural and forest wastes.     

Assessment of phylloplane yeasts on selected Mediterranean plants by FISH with group- and species-specific oligonucleotide probes

A previous culture-dependent survey of phylloplane yeasts from selected Mediterranean plants showed that a few species were present in high densities in almost all leaf samples, regardless of the plant type, location or sampling season. However, a few species appeared to be restricted to Cistus albidus leaves, namely Cryptococcus cistialbidi . Here, we describe a culture-independent FISH assay to detect and quantify whole yeast cells in leaf washings. After optimization, the technique was used to check the apparent association between C. albidus leaves and C. cistialbidi and the abundance and ubiquity of other basidiomycetous yeast species such as Erythrobasidium hasegawianum and Sporobolomyces spp. in leaf samples from this and other neighboring plants ( Acer monspessulanum and Quercus faginea ). No yeast cells were detected in Pistacia lentiscus leaf samples. We were also able to demonstrate that three phylloplane yeasts ( C. cistialbidi, E. hasegawianum and Sporobolomyces spp.) appeared to be log-normally distributed among individual C. albidus leaves. The log-normal distribution has important implications for the quantification of phylloplane yeasts based on the washing and plating of bulk leaf samples, which will tend to overestimate the size of the respective populations and become an error source in yeast surveys or related biocontrol studies.     

Role of yeasts in the qualitative structuring of extra virgin olive oil

This review sought to describe the role played by some components of the microbiota of extra virgin olive oil (EVOO), particularly yeasts, in structuring the physicochemical and sensorial quality of freshly produced olive oil. Yeasts can survive during the entire storage period of the product. To date, approximately 25 yeast species isolated from oil produced in more than six countries have been identified, eight of which are classified as new species. Some yeast species improve the health qualities of oil, whereas many others improve the chemical composition and sensory characteristics based on β-glucosidase and esterase enzymes, which are involved in the hydrolysis of the bitter glucoside known as oleuropein. However, some species, which are typically favoured by the high water content in the oily matrix, such as lipase-producing yeasts, can worsen the initial chemical characteristics of EVOO oil during storage. Some physical treatments that are compatible with the EVOO production specification affect the biotic component of the oil by reducing the concentration of yeasts. The possibility of minimizing the invasive action on the biotic component of the oil by appropriately selecting the physical treatment for each oil is discussed.     

Short Communication: Characterization and succession of yeast populations associated with spontaneous fermentations during the production of Brazilian sugar-cane aguardente

A succession of yeasts was observed during fermentation of aguardente with Saccharomyces cerevisiae being the predominant species. Candida sake, Kluyveromyces marxianus var. drosophilarum and apiculate yeasts were also frequent. Transient yeast species were found in variable numbers, probably due to the daily addition of sugar-cane juice. Killer yeasts were isolated and may have a role in the exclusion of some transient and contaminant species.     

毕赤酵母中海藻糖的积累

毕赤酵母是甲基营养型酵母属中较常见的酵母,可用甲醇作为唯一碳源,进行蛋白质的表达.在发酵过程中菌体内含有少量的海藻糖,在40℃高温下,海藻糖的含量与30℃下比较,可提高20%以上.该数据为毕赤酵母表达后再利用提供了一定的依据.