Editorial 1st international Pichia anomala mini-symposium (original) (raw)
Related papers
Past, present and future research directions with Pichia anomala
Antonie van Leeuwenhoek, 2011
The first International Pichia anomala Symposium provided a survey of past, recent and ongoing research on this yeast. The research community working with this yeast has focussed on several areas. Based on molecular data, a revision of the taxonomy is required: the name P. anomala is no longer applicable, as the genus Pichia is polyphyletic. The current debate centres on whether the yeast should be designated as Wickerhamomyces anomalus or if the previous name, Hansenula anomala, should be re-instated. The anti-microbial activities of this yeast received considerable attention during the symposium. H. anomala has been extensively studied as a biopreservation agent in many different postharvest systems. Several mechanisms account for its anti-microbial activities, including the production of killer proteins and toxic volatile metabolites. Antiidiotypic antibodies generating an ''internal image'' of a killer protein have been found to possess therapeutic activity against a broad range of microorganisms. A great diversity of H. anomala strains was reported at the symposium. Strains have been isolated from several food and feed systems and even from the intestine and reproductive organs of a malaria vector (Anopheles stephensi). Feed and food supplemented with certain H. anomala strains show an improved quality due, for example, to the addition of advantageous proteins and phytase activity. However, a number of apparent opportunistic pathogenic strains have also been isolated. Strain differentiation, especially the recognition of potentially pathogenic isolates, is an important challenge for the future commercialisation of this yeast. Future industrial and agricultural application of this yeast also raises questions of the economics of large-scale production, its survival during storage (formulation) and of safety regulations, all of which require further investigation.
Pichia anomala: cell physiology and biotechnology relative to other yeasts
Antonie van Leeuwenhoek, 2010
Pichia anomala is a most interesting yeast species, from a number of environmental, industrial and medical aspects. This yeast has been isolated from very diverse natural habitats (eg. in foods, insects, wastewaters etc) and it also exhibits wide metabolic and physiological diversity. Some of the activities of P. anomala, particularly its antimicrobial action, make it a very attractive organism for biological control applications in the agri-food sectors of industry. Being a "robust" organism, it additionally has potential to be exploited in bioremediation of environmental pollutants. This paper provides an overview of cell physiological characteristics (growth, metabolism, stress responses) and biotechnological potential (eg. as a novel biocontrol agent) of P. anomala and compares such properties with other yeast species, notably Saccharomyces cerevisiae, which remains the most exploited industrial microorganism. We await further basic knowledge of P. anomala cell physiology and genetics prior to its fuller commercial exploitation, but the exciting biotechnological potential of this yeast is highlighted in this paper.
Biotechnology, physiology and genetics of the yeast Pichia anomala
FEMS Yeast Research, 2006
The ascomycetous yeast Pichia anomala is frequently associated with food and feed products, either as a production organism or as a spoilage yeast. It belongs to the nonSaccharomyces wine yeasts and contributes to the wine aroma by the production of volatile compounds. The ability to grow in preserved food and feed environments is due to its capacity to grow under low pH, high osmotic pressure and low oxygen tension. A new application of P. anomala is its use as a biocontrol agent, which is based on the potential to inhibit a variety of moulds in different environments. Although classified as a biosafety class-1 organism, cases of P. anomala infections have been reported in immunocompromised patients. On the other hand, P. anomala killer toxins have a potential as antimicrobial agents. The yeast can use a broad range of nitrogen and phosphor sources, which makes it a potential agent to decrease environmental pollution by organic residues from agriculture. However, present knowledge of the physiological basis of its performance is limited. Recently, the first studies have been published dealing with the global regulation of the metabolism of P. anomala under different conditions of oxygenation.
2018
is published Monthly (one volume per year) by Academic Journals. Journal of Yeast and Fungal Research (JYFR), provides rapid publication (monthly) of articles in all areas of the subject such as Yeast physiology, fermentation and biotechnology, Bioremediation, Ethanol fermentation, economic importance of yeast etc. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published shortly after acceptance. All articles published in JYFR are peerreviewed.
Yeasts from Different Habitats and Their Potential as Biocontrol Agents
Fermentation, 2018
Ever since plant diseases began causing losses in viticulture, the control of phytopathogenic fungi has become of vital interest for winemakers. The occurrence of novel pests, fungicide resistance, and changed consumer expectations have led to an enormous demand for novel plant protection strategies. As part of integrated protection measures, antagonistic microorganisms have been investigated to a large extent. Such microorganisms can be applied not only in conventional, but also in organic farming as biological control agents (BCA). Particularly, yeasts were found to be interesting candidates for the development of BCA. Many of these eukaryotic microorganisms are found as part of the phylloplane microflora. In this study, we assessed a set of 38 yeast isolates from different habitats, including the guts of termites, for inhibitory effects against some phytopathogenic fungi that have received less attention in earlier studies. The majority of yeasts were found to interfere with fungi infecting grapevine (Eutypa lata, Botrytis cinerea, and Roesleria subterranea), stone fruits (Monilinia fructicola), or rice (Magnaporte oryzae), as well in vitro and in model experiment on fruits. Although most yeast strains secreted glycoside hydrolases and proteases, attempts to demonstrate direct antagonistic activities of lytic enzymes failed. However, in culture filtrates of the termite yeast Papiliotrema odontotermitis OO5, a low molecular thermostable antagonistic factor was detected. Iron depletion as a BCA mechanism was confirmed for strains of Metschnikowia pulcherrima but not for other yeasts.
Isolation and characterization of phylloplane yeasts
2020
In this study, yeasts were isolated from different fruit phylloplane during different seasons (summer, winter, and rainy) to study their population density and then brought to the Department of Mycology and Plant Pathology Laboratory, BHU for further experiment. A total of thirteen different yeast isolates were isolated from different phylloplane and then studied for their different characterization like morphological characters viz; colony colour, colony appearance, nature of growth, cell shape, type of growth, cell dimension etc. and regarding physiological characters viz., C and N utilization, sensitivity to cycloheximide as well as growth progression at different temperature. The finding to the present investigation revealed that colony colour of yeast isolates vary from cremish (Y1 to Y7, Y10 and Saccharomyces cerevisiae) to whitish (Y8, Y11, Y12) and single isolate Y9 gives yellowish colour. Smooth, crusty to granular colony appeared on yeast suitable media (YDPA) and having different growth nature viz; isolates (Y2, Y9 and Y14) shows faster growth as compare to isolate (Y1, Y11, Y12 and Y13) which shows slow colony growth. The cell shape and size ranges from spherical, oval to cylindrical and (1.9 x 1.06 µm to 4.51 x 3.14 µm) respectively. The growth of all isolate was found maximum @ 27°C while Cycloheximide @50 µg/ml found more sensitive and gives cent per cent inhibition over control against all the isolates. Among C & N source, Maltose was found more essential for the growth of all the isolate of yeast.
The treasure trove of yeast genera and species described by Johannes van der walt (1925–2011)
IMA Fungus, 2012
Yeast taxonomy and systematics have in recent years been dealt with intensively primarily by a small group of individual researchers with particular expertise. Amongst these was Johannes P. van der Walt, who had a major role in shaping our current understanding of yeast biodiversity and taxonomy. Van der Walt based his taxonomic studies not only on available cultures, but also by going into the field to isolate yeasts from various substrates. This pioneering work led to the discovery of many new genera and species, which were deposited in the Centraalbureau voor Schimmelcultures (CBS) collections for future studies in taxonomy, genomics, and industrial uses. These treasures collected during more than 60 years provide an outstanding legacy to the yeast community and will continue to exist in his absence. This contribution provides a comprehensive overview of the current nomenclatural and taxonomic status of the yeast genera and species introduced by van der Walt during his career.