Psychrophilic Yeast Research Articles

The Glaciozyma antarctica genome reveals an array of systems that provide sustained responses towards temperature variations in a persistently cold habitat.

Extremely low temperatures present various challenges to life that include ice formation and effects on metabolic capacity. Psyhcrophilic microorganisms typically have an array of mechanisms to enable survival in cold temperatures. In this study, we sequenced and analysed the genome of a psychrophilic yeast isolated in the Antarctic region, Glaciozyma antarctica. The genome annotation identified 7857 protein coding sequences. From the genome sequence analysis we were able to identify genes that encoded for proteins known to be associated with cold survival, in addition to annotating genes that are unique to G. antarctica. For genes that are known to be involved in cold adaptation such as anti-freeze proteins (AFPs), our gene expression analysis revealed that they were differentially transcribed over time and in response to different temperatures. This indicated the presence of an array of adaptation systems that can respond to a changing but persistent cold environment. We were also able to validate the activity of all the AFPs annotated where the recombinant AFPs demonstrated anti-freeze capacity. This work is an important foundation for further collective exploration into psychrophilic microbiology where among other potential, the genes unique to this species may represent a pool of novel mechanisms for cold survival.

Mrakia arctica sp. nov., a new psychrophilic yeast isolated from an ice island in the Canadian High Arctic

Two strains of a psychrophilic basidiomycetous yeast species belonging to the genus Mrakia were isolated from a melt-pool mat community, on an ice island located in Disraeli Fjord, Ellesmere Island in the Canadian Arctic. Analysis of the large subunit rDNA D1/D2 domain and internal transcribed spacer region sequences indicated that these strains represent a novel species, and the name Mrakia arctica sp. nov. is proposed. This new species could grow at sub-zero temperatures and in vitamin-free media. Moreover, lipase and cellulase enzymes of M. arctica were strongly active even at −3 °C. These results suggest an important role for M. arctica in the biogeochemical cycle of glacial ecosystems.

Draft Genome Sequence of an Obligate Psychrophilic Yeast, Candida psychrophila NRRL Y-17665T.

ABSTRACTCandida psychrophila is an obligate psychrophilic yeast classified into the family Debaryomycetaceae (Saccharomycotina). Here, we report the draft genome sequence of the type strain, NRRL Y-17665. The genome sequence is 11.2 Mb long and codes for 5,827 predicted proteins.

Genetic diversity of yeasts from East Ongul Island, East Antarctica and their extracellular enzymes secretion

Microbes growing at low temperatures encounter numerous growth constraints. However, fungi that inhabit polar regions can grow and decompose organic compounds at low temperatures. Research on the biodiversity and secretion ability of yeasts from East Ongul Island, and evaluation of their extracellular enzymatic activity at temperatures ranging from −3 to 20 °C, was performed and described in this study. In total, 95 yeast strains were isolated from the surface soil on East Ongul Island, East Antarctica. Based on the internal transcribed spacer (ITS) region and 26S rDNA D1/D2 domain sequence similarity, these strains were classified into 10 genera and 16 species. All strains were categorized as basidiomycetous yeasts. One representative strain was selected from each species, and its ability to grow at temperatures between −3 and 37 °C was evaluated. Strain abilities to secrete extracellular enzymes (lipase, cellulase, and protease) at temperatures ranging from −3 to 20 °C were also investigated. Based on the optimal and maximal growth temperatures, the yeasts were classified as psychrophilic or psychrotolerant. All the strains investigated in this study were able to grow at −3 °C and in vitamin-free media. Psychrophilic yeasts, such as Glaciozyma antarctica, Gl. martinii, Mrakia gelida, and Phenoliferia glacialis, did not secrete pronounced amounts of extracellular enzymes at −3 °C; in contrast, the psychrotolerant yeasts Goffeauzyma gilvescens, Holtermanniella wattica, Tausonia pullulans, and Udeniomyces puniceus secreted copious amounts of enzymes, even at subzero temperatures. These results indicated that psychrotolerant yeasts, rather than psychrophilic yeasts, play important roles in the nutrient cycle in the East Ongul Island ecosystem at near-subzero temperatures.

Large-Scale Production of Glaciozyma antarctica Antifreeze Protein 1 (Afp1) by Fed-Batch Fermentation of Pichia pastoris

Antifreeze proteins (AFPs) are unique proteins that have an affinity toward ice. Due to their potential applications in the food and medical industries, many attempts have been made to produce AFPs in large quantities. In this study, recombinant Afp1 from Glaciozyma antarctica, a psychrophilic yeast, was overexpressed in a methylotrophic yeast, Pichia pastoris, followed by 5-L fermenter expression. The highest yield of Afp obtained from the fermentation was 39.5 mg/L when the cells were cultivated at $$16\,{^{\circ }}\hbox {C}$$ and at pH 5.0. Afp1 was produced as a glycoprotein ( $$\sim $$ 55 kDa) based on gel staining using a glycoprotein kit. Antifreeze activities of the recombinant Afp1 were exhibited through thermal hysteresis (TH) and recrystallization inhibition (RI) where the highest TH value recorded was at $${\sim }0.5\,{^{\circ }}\hbox {C}$$ at 10 mg/mL. This value is higher when compared to the recombinant Afp1 produced in Escherichia coli ( $$0.08\,{^{\circ }}\hbox {C}$$ ) as well as the native antifreeze protein from G. antarctica ( $$0.1\,{^{\circ }}\hbox {C}$$ ). Both TH and RI activities increased when higher protein concentrations were used. Effects of temperature on stability showed that Afp1 had lost its activity after being incubated at a temperature higher than $$20\,{^{\circ }}\hbox {C}$$ . The cryoprotective effects of Afp1 on cellulases showed that the treated cellulase retained up to $$\sim $$ 20% of its activity following several cycles of freeze–thawing. This indicates that Afp1 might act as a cryoprotective agent and has the potential for use in biotechnology applications.

Diversity of proteolytic microbes isolated from Antarctic freshwater lakes and characteristics of their cold-active proteases

Despite being an extreme environment, the water temperature of freshwater lakes in Antarctica reaches 10 °C in summer, accelerating biological activity. In these environments, proteolytic microbial decomposers may play a large role in protein hydrolysis. We isolated 71 microbial strains showing proteolytic activity at 4 °C from three Antarctic freshwater lakes. They were classified as bacteria (63 isolates) and eukaryotes (8 isolates). The bacterial isolates were classified into the genera Flavobacterium (28 isolates), Pseudomonas (14 isolates), Arthrobacter (10 isolates), Psychrobacter (7 isolates), Cryobacterium (2 isolates), Hymenobacter (1 isolate), and Polaromonas (1 isolate). Five isolates of Flavobacterium and one of Hymenobacter seemed to belong to novel species. All eukaryotic isolates belonged to Glaciozyma antarctica, a psychrophilic yeast species originally isolated from the Weddell Sea near the Joinville Island, Antarctica. A half of representative strains were psychrophilic and did not grow at temperatures above 25 °C. The protease secreted by Pseudomonas prosekii strain ANS4-1 showed the highest activity among all proteases from representative isolates. The results of inhibitor tests indicated that nearly all the isolates secreted metalloproteases. Proteases from four representative isolates retained more than 30% maximal activity at 0 °C. These results expand our knowledge about microbial protein degradation in Antarctic freshwater lakes.

NEW INDOLIZIDINE ALKALOIDS FROM PSYCHROPHILIC YEAST Glyciozyma antarctica PI12

Two alkaloid compounds: namely 3-(1-aminoethyl)tetrahydro-1H-pyrrolo[1,2-d][1,2,4]oxadiazine-1,4(3H)-dione (1) and tetrahydro-1H-pyrrolo[2,1-c][1,4]oxazine-1,3(4H)-dione (2) was isolated from Glyciozyma antarctica (PI12), a psychrophilic yeast. The isolated compounds were isolated by Radial Chromatography and Thin Layer Chromatography techniques. The chemical structures were elucidated by Ultraviolet-visible, Infrared, Nuclear Magnetic Resonance and Mass Spectroscopy.

Structure Prediction of a Novel Exo-β-1,3-Glucanase: Insights into the Cold Adaptation of Psychrophilic Yeast Glaciozyma antarctica PI12.

We report a detailed structural analysis of the psychrophilic exo-β-1,3-glucanase (GaExg55) from Glaciozyma antarctica PI12. This study elucidates the structural basis of exo-1,3-β-1,3-glucanase from this psychrophilic yeast. The structural prediction of GaExg55 remains a challenge because of its low sequence identity (37%). A 3D model was constructed for GaExg55. Threading approach was employed to determine a suitable template and generate optimal target-template alignment for establishing the model using MODELLER9v15. The primary sequence analysis of GaExg55 with other mesophilic exo-1,3-β-glucanases indicated that an increased flexibility conferred to the enzyme by a set of amino acids substitutions in the surface and loop regions of GaExg55, thereby facilitating its structure to cold adaptation. A comparison of GaExg55 with other mesophilic exo-β-1,3-glucanases proposed that the catalytic activity and structural flexibility at cold environment were attained through a reduced amount of hydrogen bonds and salt bridges, as well as an increased exposure of the hydrophobic side chains to the solvent. A molecular dynamics simulation was also performed using GROMACS software to evaluate the stability of the GaExg55 structure at varying low temperatures. The simulation result confirmed the above findings for cold adaptation of the psychrophilic GaExg55. Furthermore, the structural analysis of GaExg55 with large catalytic cleft and wide active site pocket confirmed the high activity of GaExg55 to hydrolyze polysaccharide substrates.

Lipidomic analysis of psychrophilic yeasts cultivated at different temperatures

Analysis of polar lipids from eight psychrophilic yeasts (Cryptococcus victoriae, Cystofilobasidium capitatum, Holtermaniella wattica, Mrakiella aquatica, M. cryoconiti, Rhodotorula lignophila, Kondoa malvinella and Trichosporon aggtelekiense) grown at 4–28°C by hydrophilic interaction liquid chromatography/high resolution electrospray ionization tandem mass spectrometry determined 17 classes of lipids and identified dozens of molecular species of phospholipids including their regioisomers. Most of the yeasts were able to grow over the whole temperature range, reaching the highest biomass at 4 or 10°C. On temperature drop to 4°C, all eight strains showed a significant decrease of MUFA and a simultaneous increase of PUFA such as α-linolenic acid, the content of which in the biomass reached up to 20%. We also found alterations in the proportions of individual phospholipids (PI, PE and PC), the PC/PE-ratio decreasing with decreasing temperature. With increasing temperature the content of PoO-PC rose while that of LL-PC decreased, the drop in the content of LL-PC being nearly 100-fold while the content of PoO-PC increased more than twice.A change in temperature brought about changes in molecular species of PC (molecular species PO-PC versus OP-PC) as well as PE, i.e. PO-PE and OP-PE. The phase transition temperature of PO-PC differs from OP-PC by 7°C and the difference between PO-PE and OP-PE is some 10°C; we thus assume that the cell compensates for the adverse temperature effect by changing the fatty acids in the sn-1 and sn-2 positions.

Effects of Natural and Artificial Colorants on Hot Smoked Garfish—Belone belone (Linnaeus, 1761)—Stored at 4 ± 1ºC

ABSTRACTIn this study, the effects of natural and artificial colorants on the shelf life of hot smoked garfish were investigated in terms of its chemical, microbiological, and sensory quality. Turmeric and Sunset Yellow FCF were used as the natural and artificial colorants, respectively. The amount of total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA), counts of total mesophilic aerobic bacteria, total psychrophilic aerobic bacteria, total yeast and molds increased during the storage (p < 0.05). The results showed that turmeric and Sunset Yellow FCF had a significant effect on pH value and salt content of hot smoked garfish samples during storage (p < 0.05). According to the sensory analysis results, the shelf life of hot smoked garfish stored at 4 ± 1ºC was determined as 17 days.

Thermotolerance and molecular chaperone function of an SGT1-like protein from the psychrophilic yeast, Glaciozyma antarctica.

The ability of eukaryotes to adapt to an extreme range of temperatures is critically important for survival. Although adaptation to extreme high temperatures is well understood, reflecting the action of molecular chaperones, it is unclear whether these molecules play a role in survival at extremely low temperatures. The recent genome sequencing of the yeast Glaciozyma antarctica, isolated from Antarctic sea ice near Casey Station, provides an opportunity to investigate the role of molecular chaperones in adaptation to cold temperatures. We isolated a G. antarctica homologue of small heat shock protein 20 (HSP20), GaSGT1, and observed that the GaSGT1 mRNA expression in G. antarctica was markedly increased following culture exposure at low temperatures. Additionally, we demonstrated that GaSGT1 overexpression in Escherichia coli protected these bacteria from exposure to both high and low temperatures, which are lethal for growth. The recombinant GaSGT1 retained up to 60% of its native luciferase activity after exposure to luciferase-denaturing temperatures. These results suggest that GaSGT1 promotes cell thermotolerance and employs molecular chaperone-like activity toward temperature assaults.

Endophytic symbiont yeasts associated with the Antarctic angiosperms Deschampsia antarctica and Colobanthus quitensis

Fungal diversity in Antarctic seems to be greater than what is known and remains largely unexplored. In this study, we identified the endophytic symbiont yeasts associated with leaves of the angiosperms Deschampsia antarctica and Colobanthus quitensis living on King George Island, Antarctica using a culture-based approach. One hundred and twelve yeast isolates were obtained from the tissue of the different plants sampled. These yeasts were identified using sequencing of the D1/D2 domains of the LSU region of the rRNA gene as Cryptococcus victoriae, Cystobasidium laryngis, Rhodotorula mucilaginosa, Sporidiobolus ruineniae and Leucosporidium aff. golubevii. The psychrophilic yeast C. victoriae was the most abundant species associated with the two angiosperms. Cystobasidium laryngis occurs only in the leaves of D. antarctica. In contrast, R. mucilaginosa, S. ruineniae and L. aff. golubevii occurred only in C. quitensis. Phylogenetic analysis indicates the Antarctic endophytic yeast strains are closely related to taxa obtained from substrates located in different habitats of the world. However, the endophytic yeast C. victoriae was closely related to psychrophilic taxa isolated from Antarctica, but also from the Arctic, Alpine and Himalayan environments. The abundance of endophytic yeasts associated with Antarctic angiosperms suggests a possible symbiotic relationship with their plant hosts, which may provide shelter and growing conditions suitable for the yeasts’ survival, dispersal and colonization other Antarctic environments. In contrast, the endophytic yeasts might directly or indirectly promote the fitness of their host plants by producing metabolites beneficial to plant survival in the extreme environments of Antarctica.

Cold-Adapted Yeasts from Patagonia Argentina

The Patagonian Andes possess a great variety of glaciers, large temperate ice masses, and glacially formed water bodies. Most of these environments are included in protected areas characterized by low anthropogenic impact and minimal atmospheric pollution. Studies on occurrence of psychrotolerant (cold-adapted) and psychrophilic yeasts in these natural environments have allowed the characterization of native cold-adapted yeast communities, the description of six novel species, as well as description of the capability of these yeasts to produce extracellular enzymes, and other metabolites (carotenoids and mycosporines). Cold-adapted yeasts from Patagonian glaciers were able to hydrolyze natural polymers (casein, lipids, starch, pectin and carboxymethylcellulose) at low temperatures and some were able to produce photo-protective compounds. These results suggest a significant ecological role of these organisms as organic matter decomposers and nutrient cyclers, also reveal that some of these yeasts could be used for further metabolic, ecological and biotechnological studies. The objective of this review is to summarize all the findings related to cold adapted yeasts from glacial environments of the South Hemisphere (outside Antarctica), also to highlight the importance of continental ice masses from the microbiological perspective.&#x0D; Keywords: yeasts, psychrophilic, glaciers, extracellular enzymes.

Microbiological Quality and Enzymes Activity of Refrigerated Bolti Fish ( Tilapia Nilotica ) Pretreated with Organic Acids

This study was carried out to evaluate the microbiological quality and enzymes activity of whole Nile bolti fish (Tilapia nilotica) stored under refrigeration at 4±1°C after immersing in aqueous solutions of acetic acid (1%), citric acid (3%) and mixture of acetic acid (1%) with citric acid (3%) for 5 minutes. Changes in microbiological quality criteria, (total viable bacterial counts (TVBC), psychrophilic bacterial counts (PBC), yeast and mold counts and total coliform count) and activity of catalase and protease enzymes were evaluated during 12 days of storage. Results indicated that, the aqueous solutions of used acids reduced various criteria of spoilage microorganisms. On the other hand, by increasing the storage time of fresh bolti fish at 4±1°C, the microbial counts and both of catalase and protease activity were gradually increased. Whereas, the combination of acetic acid and citric acid are the most effective treatment for reducing catalase and protease activity during storage time up to 12 days. In conclusion, the results found that acetic acid and citric acid solutions, especially in combinations, can be utilized as safe organic preservatives for bolti fish under refrigerated storage up to 12 days.

Effect of Pretreatment and Modified Atmosphere Packaging on Quality of dry Coleslaw mix

The aim of the study was to determine the effect of soaking in chlorinated water (100 ppm chlorine) or mild thermal treatment in water (55°C; 3 min) and modified atmosphere packaging on the quality and shelf life of dry coleslaw stored for 12 days at 4°C. Samples were packaged in low‐barrier film in modified atmosphere containing: 5/10/85, 20/25/55, 50/30/20, 70/30/0 %O2/% CO2/% N2, and air atmosphere. In‐pack gas levels, sensory quality, microbial counts and cell permeability were determined.In comparison to non‐processed coleslaw, pretreatment of coleslaw, both consisting in soaking in chlorine solution and a mild thermal processing, resulted in a reduction by approx. 1 logarithmic cycle for counts of psychrophilic and lactic acid bacteria as well as mesophilic and psychrophilic yeasts, by 1 and 1.7 logarithmic cycle for coliform bacteria and by 2 up to 3 logarithmic cycles for Pseudomonas bacteria. Modified atmosphere (irrespective of its composition) used in product packaging was found to have no effect on the count of mesophilic bacteria. An elevated content of carbon dioxide in modified atmosphere (10, 25 or 30%) inhibited growth of psychrophilic bacteria and Pseudomonas bacteria up to 6 days of storage. In the case of coliform bacteria growth inhibition during storage was recorded both in the samples packaged in air atmosphere and in the atmosphere of 50/30/20 and 70/30/0 %O2/% CO2/% N2. In samples packaged in the atmosphere of 70% O2 and 30% CO2 after 12 days the greatest cell permeability was recorded, which was connected with a deterioration of their microbiological quality. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Physiological adaptations of yeasts living in cold environments and their potential applications

Yeasts, widely distributed across the Earth, have successfully colonized cold environments despite their adverse conditions for life. Lower eukaryotes play important ecological roles, contributing to nutrient recycling and organic matter mineralization. Yeasts have developed physiological adaptations to optimize their metabolism in low-temperature environments, which affect the rates of biochemical reactions and membrane fluidity. Decreased saturation of fatty acids helps maintain membrane fluidity at low temperatures and the production of compounds that inhibit ice crystallization, such as antifreeze proteins, helps microorganisms survive at temperatures around the freezing point of water. Furthermore, the production of hydrolytic extracellular enzymes active at low temperatures allows consumption of available carbon sources. Beyond their ecological importance, interest in psychrophilic yeasts has increased because of their biotechnological potential and industrial uses. Long-chain polyunsaturated fatty acids have beneficial effects on human health, and antifreeze proteins are attractive for food industries to maintain texture in food preserved at low temperatures. Furthermore, extracellular cold-active enzymes display unusual substrate specificities with higher catalytic efficiency at low temperatures than their mesophilic counterparts, making them attractive for industrial processes requiring high enzymatic activity at low temperatures. In this minireview, we describe the physiological adaptations of several psychrophilic yeasts and their possible biotechnological applications.

Vertical distribution of the soil microbiota along a successional gradient in a glacier forefield.

Spatial patterns of microbial communities have been extensively surveyed in well-developed soils, but few studies investigated the vertical distribution of micro-organisms in newly developed soils after glacier retreat. We used 454-pyrosequencing to assess whether bacterial and fungal community structures differed between stages of soil development (SSD) characterized by an increasing vegetation cover from barren (vegetation cover: 0%/age: 10 years), sparsely vegetated (13%/60 years), transient (60%/80 years) to vegetated (95%/110 years) and depths (surface, 5 and 20 cm) along the Damma glacier forefield (Switzerland). The SSD significantly influenced the bacterial and fungal communities. Based on indicator species analyses, metabolically versatile bacteria (e.g. Geobacter) and psychrophilic yeasts (e.g. Mrakia) characterized the barren soils. Vegetated soils with higher C, N and root biomass consisted of bacteria able to degrade complex organic compounds (e.g. Candidatus Solibacter), lignocellulolytic Ascomycota (e.g. Geoglossum) and ectomycorrhizal Basidiomycota (e.g. Laccaria). Soil depth only influenced bacterial and fungal communities in barren and sparsely vegetated soils. These changes were partly due to more silt and higher soil moisture in the surface. In both soil ages, the surface was characterized by OTUs affiliated to Phormidium and Sphingobacteriales. In lower depths, however, bacterial and fungal communities differed between SSD. Lower depths of sparsely vegetated soils consisted of OTUs affiliated to Acidobacteria and Geoglossum, whereas depths of barren soils were characterized by OTUs related to Gemmatimonadetes. Overall, plant establishment drives the soil microbiota along the successional gradient but does not influence the vertical distribution of microbiota in recently deglaciated soils.

Bioinformatics survey of the metal usage by psychrophilic yeast Glaciozyma antarctica PI12.

Metal ions are one of the essential elements which are extensively involved in many cellular activities. With rapid advancements in genome sequencing techniques, bioinformatics approaches have provided a promising way to extract functional information of a protein directly from its primary structure. Recent findings have suggested that the metal content of an organism can be predicted from its complete genome sequences. Characterizing the biological metal usage of cold-adapted organisms may help to outline a comprehensive understanding of the metal-partnerships between the psychrophile and its adjacent environment. The focus of this study is targeted towards the analysis of the metal composition of a psychrophilic yeast Glaciozyma antarctica PI12 isolated from sea ice of Antarctica. Since the cellular metal content of an organism is usually reflected in the expressed metal-binding proteins, the putative metal-binding sequences from G. antarctica PI12 were identified with respect to their sequence homologies, domain compositions, protein families and cellular distribution. Most of the analyses revealed that the proteome was enriched with zinc, and the content of metal decreased in the order of Zn > Fe > Mg > Mn, Ca > Cu. Upon comparison, it was found that the metal compositions among yeasts were almost identical. These observations suggested that G. antarctica PI12 could have inherited a conserved trend of metal usage similar to modern eukaryotes, despite its geographically isolated habitat.

Molecular cloning, expression and characterisation of Afp4, an antifreeze protein from Glaciozyma antarctica

Antifreeze proteins (AFPs) are proteins with affinity towards ice and contribute to the survival of psychrophiles in subzero environment. Limited studies have been conducted on how AFPs from psychrophilic yeasts interact with ice. In this study, we describe the functional properties of an antifreeze protein from a psychrophilic Antarctic yeast, Glaciozyma antarctica. A cDNA encoding the antifreeze protein, AFP4, from G. antarctica PI12 was amplified from the mRNA extracted from cells grown at 4 °C. Sequence characterisation of Afp4 showed high similarity to fungal AFPs from Leucosporidium sp. AY30, LeIBP (93 %). The 786-bp cDNA encodes a 261-amino-acid protein with a theoretical pI of 4.4. Attempts to produce the recombinant Afp4 in Escherichia coli resulted in the formation of inclusion bodies (IB). The IB were subsequently denatured and refolded by dilution. Gel filtration confirmed that the refolded recombinant Afp4 is monomeric with molecular mass of ~25 kDa. Thermal hysteresis (TH) and recrystallisation inhibition assays confirmed the function of Afp4 as an antifreeze protein. In the presence of Afp4, ice crystals were modified into hexagonal shapes with TH values of 0.08 °C and smaller ice grains were observed compared with solutions without AFP. Structural analyses via homology modelling showed that Afp4 folds into β-helices with three distinct faces: a, b and c. Superimposition analyses predicted the b-face as the ice-binding surface of Afp4, whereby the mechanism of interaction is driven by hydrophobic interactions and the flatness of surface. This study may contribute towards an understanding of AFPs from psychrophilic yeasts.

English

More than 70% of earth’s surface is covered by cold ecosystems and these ecosystems have been colonized by a class of extremophilic microorganisms called as psychrophiles. Thus psychrophiles are true extremophiles that has the ability to live in extremely low temperature conditions. Psychrophilic yeasts are important due to their physiological adaptation at low temperature and they have potential application in biotechnology. Psychrophilic yeast produces cold-active enzymes having numerous applications in textile, medical and pharmaceuticals, fine chemical synthesis, food industry, domestic and environmental applications. Psychrophilic enzymes from yeast have attracted attention of researchers to explore the new application of these enzymes because of their high activity at low and moderate temperatures. The present review describes various immune biotechnological applications of different cold-active enzymes produced by psychrophilic yeast in different industries. Key words: Extremophilic microorganisms, cold-active enzymes, environmental applications.