Monitoring Seasonal Changes in Winery-Resident Microbiota

During the transformation of grapes to wine, wine fermentations are exposed to a large area of specialized equipment surfaces within wineries, which may serve as important reservoirs for two-way transfer of microbes between fermentations. However, the role of winery environments in shaping the microbiota of wine fermentations and vectoring wine spoilage organisms is poorly understood at the systems level. Microbial communities inhabiting all major equipment and surfaces in a pilot-scale winery were surveyed over the course of a single harvest to track the appearance of equipment microbiota before, during, and after grape harvest. Results demonstrate that under normal cleaning conditions winery surfaces harbor seasonally fluctuating populations of bacteria and fungi. Surface microbial communities were dependent on the production context at each site, shaped by technological practices, processing stage, and season. During harvest, grape- and fermentation-associated organisms populated most winery surfaces, acting as potential reservoirs for microbial transfer between fermentations. These surfaces harbored large populations of Saccharomyces cerevisiae and other yeasts prior to harvest, potentially serving as an important vector of these yeasts in wine fermentations. However, the majority of the surface communities before and after harvest comprised organisms with no known link to wine fermentations and a near-absence of spoilage-related organisms, suggesting that winery surfaces do not overtly vector wine spoilage microbes under normal operating conditions.     

Evolution of fungal pathogens in domestic environments?

Specific indoor environments select for certain stress-tolerant fungi and can drive their evolution towards acquiring medically important traits. Here we review the current knowledge in this area of research, focussing on the so-called black yeasts. Many of these melanised stress-tolerant organisms originate in unusual ecological niches in nature, and they have a number of preadaptations that make them particularly suited for growth on human-made surfaces and substrates. Several pathogenic species have been isolated recently from various domestic habitats. We argue that in addition to enriching for - potentially - pathogenic species, the selection pressure and stress acting on microorganisms in indoor environments are driving their evolution towards acquiring the missing virulence factors and further enhancing their stress tolerance and pathogenic potential. Some of the polyextremotolerant fungi are particularly problematic: they can grow at elevated temperatures, and so they have a higher potential to colonise warm-blooded organisms. As several species of black fungi are already implicated in health problems of various kinds, their selection and possible evolution in human environments are of concern.     

The floristic composition of moulds growing on walls of food and drink processing factories

Samples were taken from heavily moulded walls at a range of food and drink processing plants. Quantitative estimates of the number of moulds, yeasts and bacteria were made and the moulds were identified. The floristic diversity of the germination areas and kilns of several maltings establishments was also investigated. The most commonly isolated organisms were Penicillium spp. although each environment appears to have its own characteristic flora with more than 50% of the total colony forming units isolated at each site being accounted for by three or fewer species. The results are discussed in relation to the microflora of mouldy walls in other environments.Several of the fungi associated with the maltings establishments were not found at any other sites. The origin of these fungi is discussed in relation to the flora associated with grain and processing of malt.     

Removal of Viable Airborne Fungi from Indoor Environments by Benzalkonium Chloride-Based Aerosol Disinfectants

Fungi are ubiquitous in indoor environments, and some taxa can cause clinical symptoms in humans. Thus, from the viewpoint of public health, methods to reduce indoor airborne fungi are needed. The goal of this study was to examine the efficacies of benzalkonium chloride (BAC)–based aerosol disinfectants to remove airborne viable fungi from indoor environments. The laboratory- and field-based experiments were conducted to compare airborne culturable fungal concentrations before and after the disinfectant aerosol applications. The laboratory-based experiments showed the greater efficacies by the BAC-based disinfectant aerosol than by pure-water control aerosol (p <.05, t-test). In the field study using the BAC-based disinfectant aerosols, on average a 58% reduction of total airborne culturable fungal concentrations were observed. Additionally, the significant reduction was found for a group of airborne yeasts or yeast-like organisms (p <.05, Wilcoxon signed rank test). The BAC-based aerosol disinfectants are effective when used to reduce the numbers of airborne culturable fungi, in particular yeasts or yeast-like organisms, from indoor environments.     

Microbial colonization of human ileal conduits

Morphological and microbiological techniques were used to locate and identify the microorganisms that colonized the human ileal conduits in 17 different patients from 5 days after surgery up to as many as 16 years of service as a urine conduit. The ecological sequence of this colonization assumes some practical importance because the ascending growth of pathogenic organisms in this essentially open, unvalved urinary tract diversion system leads to the development of life-threatening pyelonephritis. Extensive examination of the microvillus surfaces of the ilea of five accident victims by both transmission and scanning electron microscopy showed that these tissue surfaces were not colonized by bacteria, even in the absence of prophylactic antibiotic therapy, and that these surfaces were not occupied by adherent microorganisms after several years of service as a urine conduit, even when the skin surface stoma and the conduit contents were heavily colonized by bacteria and yeasts. During the initial period (10 days) of postoperative antibiotic therapy, the mucus and urine within the conduit were largely colonized by yeasts. A mixed population of yeasts and gram-positive cocci subsequently developed in the conduit itself, and gram-positive cocci were seen to be avidly adherent to epidermal cells at the stoma. As antibiotic protection was gradually withdrawn, gram-negative organisms became a part of the mixed microbial flora of the conduit contents, and some of the potentially pathogenic organisms of this group (e.g., Escherichia spp., Proteus spp., Pseudomonas spp., etc.) were isolated from patients with pyelonephritis that appeared to come from the ileal conduit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microbial colonization of human ileal conduits.

Morphological and microbiological techniques were used to locate and identify the microorganisms that colonized the human ileal conduits in 17 different patients from 5 days after surgery up to as many as 16 years of service as a urine conduit. The ecological sequence of this colonization assumes some practical importance because the ascending growth of pathogenic organisms in this essentially open, unvalved urinary tract diversion system leads to the development of life-threatening pyelonephritis. Extensive examination of the microvillus surfaces of the ilea of five accident victims by both transmission and scanning electron microscopy showed that these tissue surfaces were not colonized by bacteria, even in the absence of prophylactic antibiotic therapy, and that these surfaces were not occupied by adherent microorganisms after several years of service as a urine conduit, even when the skin surface stoma and the conduit contents were heavily colonized by bacteria and yeasts. During the initial period (10 days) of postoperative antibiotic therapy, the mucus and urine within the conduit were largely colonized by yeasts. A mixed population of yeasts and gram-positive cocci subsequently developed in the conduit itself, and gram-positive cocci were seen to be avidly adherent to epidermal cells at the stoma. As antibiotic protection was gradually withdrawn, gram-negative organisms became a part of the mixed microbial flora of the conduit contents, and some of the potentially pathogenic organisms of this group (e.g., Escherichia spp., Proteus spp., Pseudomonas spp., etc.) were isolated from patients with pyelonephritis that appeared to come from the ileal conduit.(ABSTRACT TRUNCATED AT 250 WORDS)     

Biological preservation of plant derived animal feed with antifungal microorganisms: safety and formulation aspects

During storage of moist animal feed, growth of detrimental fungi causing spoilage, or being mycotoxigenic or pathogenic, is a severe problem. Addition of biopreservative yeasts or lactic acid bacteria can significantly reduce this problem. However, their use requires several careful considerations. One is the safety to the animal, humans and the environment, tightly connected to legal aspects and the need for pre-market authorisation when supplementing feed with microorganisms. Although both yeasts and lactic acid bacteria are considered comparatively safe organisms due to low production of toxic metabolites, it is of great importance to understand the mechanisms behind the biopreservative abilities. Another important issue concerns practical aspects, such as the economic production of large amounts of the organisms and the development of a suitable formulation giving the organisms a long shelf life. These aspects are discussed and a recommendation of this review is that both safety and formulation aspects of a specific microbe should be considered at an early stage in the selection of new organisms with biopreservation potential.     

Succession and activity of microorganisms in stored bagasse

Summary Fresh sugarcane bagasse was fermented under defined conditions and investigated regarding a microbial succession during fermentation, in view of the enzyme activities of microorganisms against the main bagasse components: sucrose, pectin, hemicellulose, cellulose, and lignin.Altogether, 400 pure cultures of microorganisms were obtained from 8 g bagasse during 6.5 days of storage. This flora consists of bacteria (74%), actinomycetes (6%), yeasts (13%), and fungi (7%). The yeasts dominate in early fermentation, followed by bacteria, and then by actinomycetes and fungi.This succession coincides with the enzymic activities of the isolated organisms during fermentation. At first, residual sugar is consumed predominantly by the yeasts. Then the bacteria degrade the pectin, the hemicellulose, and in parts, the cellulose. Later, the actinomycetes and the fungi imperfecti attack the hemicellulose, the cellulose, and, partly, the lignin within the bagasse fiber.These results are corroborated by investigations using bagasse from bulk storage.     

Potentially pathogenic yeast isolated from the throat and cloaca of an Arctic colonial seabird: the little auk (Alle alle)

Yeasts are a distinctive group of microfungi, but compared to other microorganisms, their ecological function and biodiversity are poorly known. This is especially so where polar ecosystems are concerned. With climate changes and increasing pollution levels in the Arctic, it can be anticipated that there will be an increase in the prevalence and diversity of fungi colonizing live organisms. With these changes, it is crucial to investigate and monitor species diversity and prevalence of fungi in this fragile environment. In this study, yeasts were examined from throat and cloaca of a small colonial seabird, the little auk (Alle alle), a keystone species in the Arctic ecosystem. Samples were collected from 94 adults and 17 nestlings in breeding colony in Magdalenefjorden (NW Spitsbergen) in 2009. In total, twelve species of yeast from eight genera were found in 12 % of the samples, with the Dipodascus genus being the most prevalent. All yeast species were found in the adults, but only one species, Cryptococcus macerans, was found in a single nestling. In individuals where fungus was isolated, it was only isolated from either the throat or the cloaca, except for two cases, where fungus was found in both throat and cloaca. The presence of yeast was not related to sex but age of the birds, with adults being more prone to colonization by yeasts than the nestlings. The relatively low prevalence and diversity of yeast in little auks suggest that these birds are random carriers of fungi, with minor health impacts.     

Plant–Microbe Interactions: Wetting of Ivy (Hedera helix L.) Leaf Surfaces in Relation to Colonization by Epiphytic Microorganisms

Abstract Leaf wettability, cuticular wax composition, and microbial colonization of upper and lower leaf surfaces of ivy (Hedera helix L.) was investigated for young and old leaves sampled in June and September. Contact angles of aqueous buffered solutions measured on young leaf surfaces ranged between 76° and 86° and were not dependent on the pH value of the applied droplets. Contact angles measured on old leaf surfaces were up to 32°, significantly lower than on young leaf surfaces. Furthermore, contact angles were significantly lower using aqueous solutions of pH 9.0 compared to pH 3.0, indicating the influence of ionizable functional groups on leaf surface wetting properties. Observed changes in leaf wetting properties did not correlate with different levels of alkanoic acids in cuticular waxes. However, microscopic examination of the leaf surfaces indicated the influence of epiphytic microorganisms on wetting properties of old leaves, since their surfaces were always colonized by epiphytic microorganisms (filamentous fungi, yeasts, and bacteria), whereas surfaces of young leaves were basically clean. In order to analyze the effect of epiphytic microorganisms on leaf surface wetting, surfaces of young and clean ivy leaves were artificially colonized with Pseudomonas fluorescens. This resulted in a significant increase and a pH dependence of leaf surface wetting in the same way as it was observed on old ivy leaf surfaces. From these results it can be deduced that the native wetting properties of leaf surfaces can be significantly masked by the presence of epiphytic microorganisms. The ecological implications of altered wetting properties for microorganisms using the leaf/atmosphere interface as habitat are discussed. Received: 20 March 1999; Accepted: 5 July 1999; Online Publication: 18 July 2000     

Extracellular enzymes produced by microorganisms isolated from maritime Antarctica

Antarctic environments can sustain a great diversity of well-adapted microorganisms known as psychrophiles or psychrotrophs. The potential of these microorganisms as a resource of enzymes able to maintain their activity and stability at low temperature for technological applications has stimulated interest in exploration and isolation of microbes from this extreme environment. Enzymes produced by these organisms have a considerable potential for technological applications because they are known to have higher enzymatic activities at lower temperatures than their mesophilic and thermophilic counterparts. A total of 518 Antarctic microorganisms, were isolated during Antarctic expeditions organized by the Instituto Antártico Uruguayo. Samples of particules suspended in air, ice, sea and freshwater, soil, sediment, bird and marine animal faeces, dead animals, algae, plants, rocks and microbial mats were collected from different sites in maritime Antarctica. We report enzymatic activities present in 161 microorganisms (120 bacteria, 31 yeasts and 10 filamentous fungi) isolated from these locations. Enzymatic performance was evaluated at 4 and 20°C. Most of yeasts and bacteria grew better at 20°C than at 4°C, however the opposite was observed with the fungi. Amylase, lipase and protease activities were frequently found in bacterial strains. Yeasts and fungal isolates typically exhibited lipase, celullase and gelatinase activities. Bacterial isolates with highest enzymatic activities were identified by 16S rDNA sequence analysis as Pseudomonas spp., Psychrobacter sp., Arthrobacter spp., Bacillus sp. and Carnobacterium sp. Yeasts and fungal strains, with multiple enzymatic activities, belonged to Cryptococcus victoriae, Trichosporon pullulans and Geomyces pannorum.     

Microcolonial Fungi on Rocks: A Life in Constant Drought?

Black microcolonial fungi (MCF) and black yeasts are among the most stress-resistant eukaryotic organisms known on Earth. They mainly inhabit bare rock surfaces in hot and cold deserts of all regions of the Earth, but some of them have a close phylogenetic relation to human pathogenic black fungi which makes them important model organisms also with respect to clinical mycology. The environment of those fungi is especially characterized by extreme changes from humidity to long periods of desiccation and extreme temperature differences. A key to the understanding of MCF ecology is the question about metabolic activity versus dormancy in the natural environments. In this study, the time lag from the desiccated state to rehydration and full metabolic activity and growth was measured and defined in accordance with simulated environmental conditions. The ability to survive after desiccation and the speed of rehydration as well as changes of the whole cell protein pattern are demonstrated. Whereas both mesophilic strains—Exophiala jeanselmei and Knufia perforans (=Coniosporium perforans)—show a clear reaction toward desiccation by production of small proteins, Cryomyces antarcticus—the extremotolerant MCF—does not show any response to desiccation but seems just to down-regulate its metabolism. Data on intracellular sugar suggest that both trehalose and mannitol might play a cell protective role in those fungi.     

Phenotypic characterization of Aspergillus niger and Candida albicans grown under simulated microgravity using a three-dimensional clinostat

The living and working environments of spacecraft become progressively contaminated by a number of microorganisms. A large number of microorganisms, including pathogenic microorganisms, some of which are fungi, have been found in the cabins of space stations. However, it is not known how the characteristics of microorganisms change in the space environment. To predict how a microgravity environment might affect fungi, and thus how their characteristics could change on board spacecraft, strains of the pathogenic fungi Aspergillus niger and Candida albicans were subjected to on-ground tests in a simulated microgravity environment produced by a three-dimensional (3D) clinostat. These fungi were incubated and cultured in a 3D clinostat in a simulated microgravity environment. No positive or negative differences in morphology, asexual reproductive capability, or susceptibility to antifungal agents were observed in cultures grown under simulated microgravity compared to those grown in normal earth gravity (1 G). These results strongly suggest that a microgravity environment, such as that on board spacecraft, allows growth of potentially pathogenic fungi that can contaminate the living environment for astronauts in spacecraft in the same way as they contaminate residential areas on earth. They also suggest that these organisms pose a similar risk of opportunistic infections or allergies in astronauts as they do in people with compromised immunity on the ground and that treatment of fungal infections in space could be the same as on earth.     

深海真菌多样性及其代谢产物生物活性的研究进展

深海环境复杂多样,深海微生物逐渐进化以适应其生存环境。真菌作为深海环境中的重要微生物类群,是开发海洋生物的新兴资源。综述了近年来深海真菌的物种多样性、活性代谢产物的多样性及其生物学功能等的研究进展,并对未来深海真菌的应用进行了展望。     

Marine microorganisms as an untapped source of bioactive compounds

The search for novel biologically active molecules has extended to the screening of organisms associated with less explored environments. In this sense, Oceans, which cover nearly the 67% of the globe, are interesting ecosystems characterized by a high biodiversity that is worth being explored. As such, marine microorganisms are highly interesting as promising sources of new bioactive compounds of potential value to humans. Some of these microorganisms are able to survive in extreme marine environments and, as a result, they produce complex molecules with unique biological interesting properties for a wide variety of industrial and biotechnological applications. Thus, different marine microorganisms (fungi, myxomycetes, bacteria, and microalgae) producing compounds with antioxidant, antibacterial, apoptotic, antitumoral and antiviral activities have been already isolated. This review compiles and discusses the discovery of bioactive molecules from marine microorganisms reported from 2018 onwards. Moreover, it highlights the huge potential of marine microorganisms for obtaining highly valuable bioactive compounds.     

A comparative analysis of microflora during biofilm development on grape seeds exposed to methanol in a biofilter

The attachment of microorganisms onto biotic surfaces to form biofilm structures on the support media of a biofilter has great impact on biodegradation systems. This study examined the composition of the microbial community that developed on grape seeds (GS) used as support media in methanol degradation biofilters. They were analyzed using conventional microbiology techniques and API galleries. Analysis of microbial counts showed that, in GS before methanol exposure, bacteria and filamentous fungi were predominant over yeasts. In contrast, GS exposed to methanol exhibited more bacteria and yeasts than fungi. Most of the Gram-negative bacteria were the Pseudomonas genus, Bacillus staerothermophilus, Bacillus amyloliquefaciens, and Bacillus pumilus. Rhodotorula mucilaginosa was the primary yeast found. The filamentous fungi Aspergillus sp. Cladosporium cladosporioides, Fusarium sp., and Alternaria sp. were also detected. No Gram-positive bacteria growth was found on GS exposed to methanol. Using scanning electron microscopy, biofilm formation on the GS was examined to reveal the presence of both prokaryotic and eukaryotic microorganisms as biomass accumulation was visible on the seeds. Seeds exposed to methanol for 90 days showed a mature biofilm with cuticle and epidermal layer decline, as well as biofilm dissolution into grape seed integuments.     

Fungi in acidic fire: A potential source of industrially important enzymes

The microbial life that exists in harsh habitats of low pH possess several unique characteristics, which assign interesting qualities to these microorganisms and enable them to thrive in such a harsh environment. Among microorganisms inhabiting low pH environments, fungi are the second largest reported organisms. These acidophilic fungi are the main source of acid–stable enzymes that could be utilized in many industries including paper, leather making, food and feed industries, where the efficacy of commonly available enzymes is limited by challenges like stability and functional kinetics. The current review discusses the acidophilic fungi with emphasis on their diversity and pH homeostasis mechanisms adopted against low pH environments. In addition, an overview about the acid–stable enzymes obtained from these acidophilic fungi, their main sources and potential applications have also been discussed.     

Yeast forms dominate fungal diversity in the deep oceans

Fungi are the principal degraders of biomass in most terrestrial ecosystems. In contrast to surface environments, deep-sea environmental gene libraries have suggested that fungi are rare and non-diverse in high-pressure marine environments. Here, we report the diversity of fungi from 11 deep-sea samples from around the world representing depths from 1,500 to 4,000 m (146-388 atm) and two shallower water column samples (250 and 500m). We sequenced 239 clones from 10 fungal-specific 18S rRNA gene libraries constructed from these samples, from which we detected only 18 fungal 18S-types in deep-sea samples. Our phylogenetic analyses show that a total of only 32 fungal 18S-types have so far been recovered from deep-sea habitats, and our results suggest that fungi, in general, are relatively rare in the deep-sea habitats we sampled. The fungal diversity detected suggests that deep-sea environments host an evolutionarily diverse array of fungi dominated by groups of distantly related yeasts, although four putative filamentous fungal 18S-types were detected. The majority of our new sequences branch close to known fungi found in surface environments. This pattern contradicts the proposal that deep-sea and hydrothermal vent habitats represent ancient ecosystems, and demonstrates a history of frequent dispersal between terrestrial and deep-sea habitats.     

一种气射流型中医按压方法与仪器

本文介绍一种根据中医推拿的按压手法研制的气射流按压仪,通过控制气压的大小和气射流脉冲频率来模拟按压手法。在对人体手部穴位的试验中我们发现,无论控制多少气压值,在离喷口一定距离处能感受的力最大,此段距离应该是仪器对穴位进行治疗的最佳距离。我们通过更精确的实验和轴对称亚声速等温自由射流的工程计算解释了这个现象并为确定这个距离提供理论依据。     

Symbiotic interactions of culturable microbes with the nickel hyperaccumulator Berkheya coddii and the herbivorous insect Chrysolina clathrata

Chrysolina clathrata is a specialized phytophagous beetle feeding exclusively on the herbaceous nickel hyperaccumulating plant Berkheya coddii. These organisms appear impervious to the toxic levels of nickel in their environment. In the current study we aimed to identify microorganisms that may have symbiotic relationships with these organisms. Culture techniques were used to isolate bacteria and fungi from plants and the faeces of beetles reared under laboratory conditions. The identity of isolates was determined using morphology and molecular techniques. Several genera of filamentous fungi (Alternaria, Aspergillus, Bipolaris, Cladosporium, Epicoccum, Fusarium, and Penicillium), yeasts (Cryptococcus, Meyerozyma, and Rhodotorula), as well as endophytic bacteria (Bacillus and Lysinibacillus) were isolated from the leaves of the plant. We also selectively isolated yeasts (Candida, Cryptococcus, Debaryomyces, Meyerozyma and Wickerhamomyces) from the beetle’s faeces. Subsequently we determined the minimum inhibitory Ni-concentration (MIC) of all isolates. The endophytic bacteria, filamentous fungi and the yeasts Candida intermedia, Cryptococcus flavescens and Meyerozyma guilliermondii, showed notable Ni resistance, while the beetle’s gut seems to select for Ni resistant yeasts.