Genome assembly and variant analysis of two Saccharomyces cerevisiae strains isolated from stingless bee pollen.

Products from stingless bees are rich reservoirs of microbial diversity, including yeasts with fermentative potential. Previously, two Saccharomyces cerevisiae strains, JP14 and IP9, were isolated from Jataí (Tetragonisca angustula) and Iraí (Nannotrigona testaceicornis) bees, respectively, aiming at mead production. Both strains presented great osmotic and sulfite tolerance, and ethanol production, although they have a high free amino nitrogen demand.

Effect of carbon and nitrogen concentrations on lipid accumulation and regulation of acetyl-CoA carboxylase in Papiliotrema laurentii.

Biodiesel is an interesting alternative to petroleum diesel as it is renewable, biodegradable, and has a low pollutant content. Yeast oils can be used for biodiesel production instead of edible oils, mitigating the use of arable land and water for biodiesel production. Maximum lipid accumulation is reached at 48 h of cultivation by the oleaginous yeast Papiliotrema laurentii UFV-1.

Identification of the main proteins secreted by Kluyveromyces marxianus and their possible roles in antagonistic activity against fungi.

Lytic enzymes secreted by Kluyveromyces marxianus can lyse Saccharomyces cerevisiae cells. Their ability to hydrolyze yeast cell walls can be used in biotechnological applications, such as the production of glucans and protoplasts, as well as a biological control agent against plant pathogenic fungi. Herein, 27 proteins secreted by K.

Bacterial cellulose: Strategies for its production in the context of bioeconomy.

Bacterial cellulose has advantages over plant-derived cellulose, which make its use for industrial applications easier and more profitable. Its intrinsic properties have been stimulating the global biopolymer market, with strong growth expectations in the coming years. Several bacterial species are capable of producing bacterial cellulose under different culture conditions; in this context, strategies aimed at metabolic engineering and several possibilities of carbon sources have provided opportunities for the bacterial cellulose's biotechnological exploration.

Papiliotrema laurentii: general features and biotechnological applications.

Papiliotrema laurentii, previously classified as Cryptococcus laurentii, is an oleaginous yeast that has been isolated from soil, plants, and agricultural and industrial residues. This variety of habitats reflects the diversity of carbon sources that it can metabolize, including monosaccharides, oligosaccharides, glycerol, organic acids, and oils. Compared to other oleaginous yeasts, such as Yarrowia lipolytica and Rhodotorula toruloides, there is little information regarding its genetic and physiological characteristics.

Physiological comparisons among Spathaspora passalidarum, Spathaspora arborariae, and Scheffersomyces stipitis reveal the bottlenecks for their use in the production of second-generation ethanol.

The microbial conversion of pentoses to ethanol is one of the major drawbacks that limits the complete use of lignocellulosic sugars. In this study, we compared the yeast species Spathaspora arborariae, Spathaspora passalidarum, and Sheffersomyces stipitis regarding their potential use for xylose fermentation. Herein, we evaluated the effects of xylose concentration, presence of glucose, and temperature on ethanol production.

Ethanol stress responses in Kluyveromyces marxianus: current knowledge and perspectives.

The rising concern with the emission of greenhouse gases has boosted new incentives for biofuels production, which are less polluting than fossil fuels. Special attention has been given to the second-generation ethanol, as it is produced from abundant feedstocks which do not compete with food production, such as lignocellulosic biomass and whey. Kluyveromyces marxianus stands out in second-generation ethanol production due to its capacity of assimilating lactose, the sugar found in whey, and tolerating high temperatures used in simultaneous saccharification processes.

Influence of glucose on xylose metabolization by Spathaspora passalidarum.

The yeast Spathaspora passalidarum is able to produce ethanol from D-xylose and D-glucose. However, it is not clear how xylose metabolism is affected by D-glucose when both sugars are available in the culture medium. The aims of this work were to evaluate the influence of D-glucose on D-xylose consumption, ethanol production, gene expression, and the activity of key xylose-metabolism enzymes under both aerobic and oxygen-limited conditions.

Adaptive responses of Kluyveromyces marxianus CCT 7735 to 2-phenylethanol stress: Alterations in membrane fatty-acid composition, ergosterol content, exopolysaccharide production and reduction in reactive oxygen species.

2-phenylethanol (2-PE) is a higher aromatic alcohol with a rose-like aroma used in the cosmetic and food industries as a flavoring and displays potential for application as an antifungal. Biotechnological production of 2-PE from yeast is an interesting alternative due to the non-use of toxic compounds and the generation of few by-products. Kluyveromyces marxianus CCT 7735 is a thermotolerant strain capable of producing high 2-PE titers from L-Phenylalanine; however, like other yeast species, its growth has been strongly inhibited by this alcohol.

Isolation of a new strain that displays capacity to achieve high lipid content from xylose.

In this work, we isolated and selected oleaginous yeasts from rock field soils from two National Parks in Brazil ( and ) with the potential to accumulate oil from xylose, the main pentose sugar found in lignocellulosic biomass. From the 126 isolates, two were selected based on their lipid contents. They were taxonomically identified as (UFV-1 and UFV-2).

Assessment of ethanol tolerance of Kluyveromyces marxianus CCT 7735 selected by adaptive laboratory evolution.

Kluyveromyces marxianus CCT 7735 shows potential for producing ethanol from lactose; however, its low ethanol tolerance is a drawback for its industrial application. The first aim of this study was to obtain four ethanol-tolerant K. marxianus CCT 7735 strains (ETS1, ETS2, ETS3, and ETS4) by adaptive laboratory evolution.

Isolation of xylose-assimilating yeasts and optimization of xylitol production by a new Meyerozyma guilliermondii strain.

Production of xylitol from lignocellulosic biomass is of interest to modern biorefineries, because this biomass should be processed into a spectrum of chemicals (bio-based products) and not only energy. The isolation of new yeast strains capable of efficiently converting xylose into xylitol and withstanding inhibitors released from biomass hydrolysis can contribute to making its production feasible in biorefineries. Forty-three out of 128 yeast strains isolated from the gut of Passalidae beetles were capable of assimilating xylose as the sole carbon source.

Ethanol stress responses of Kluyveromyces marxianus CCT 7735 revealed by proteomic and metabolomic analyses.

Kluyveromyces marxianus CCT 7735 offers advantages to ethanol production over Saccharomyces cerevisiae, including thermotolerance and the ability to convert lactose to ethanol. However, its growth is impaired at high ethanol concentrations. Herein we report on the protein and intracellular metabolite profiles of K.

Sugar transport systems in Kluyveromyces marxianus CCT 7735.

The pattern of glucose repression in most Kluyveromyces marxianus strains does not correlate with fermentative behaviour; however, glucose repression and fermentative metabolism appear to be linked to the kinetics of sugar uptake. In this work, we show that lactose transport in K. marxianus CCT 7735 by lactose-grown cells is mediated by a low-affinity H-sugar symporter.

Ploidy Variation in Separates Dairy and Non-dairy Isolates.

is traditionally associated with fermented dairy products, but can also be isolated from diverse non-dairy environments. Because of thermotolerance, rapid growth and other traits, many different strains are being developed for food and industrial applications but there is, as yet, little understanding of the genetic diversity or population genetics of this species. shows a high level of phenotypic variation but the only phenotype that has been clearly linked to a genetic polymorphism is lactose utilisation, which is controlled by variation in the gene.

Transcriptome analysis of the thermotolerant yeast Kluyveromyces marxianus CCT 7735 under ethanol stress.

The thermotolerant yeast Kluyveromyces marxianus displays a potential to be used for ethanol production from both whey and lignocellulosic biomass at elevated temperatures, which is highly alluring to reduce the cost of the bioprocess. Nevertheless, contrary to Saccharomyces cerevisiae, K. marxianus cannot tolerate high ethanol concentrations.

Applying functional metagenomics to search for novel lignocellulosic enzymes in a microbial consortium derived from a thermophilic composting phase of sugarcane bagasse and cow manure.

Environments where lignocellulosic biomass is naturally decomposed are sources for discovery of new hydrolytic enzymes that can reduce the high cost of enzymatic cocktails for second-generation ethanol production. Metagenomic analysis was applied to discover genes coding carbohydrate-depleting enzymes from a microbial laboratory subculture using a mix of sugarcane bagasse and cow manure in the thermophilic composting phase. From a fosmid library, 182 clones had the ability to hydrolyse carbohydrate.

Construction of recombinant Kluyveromyces marxianus UFV-3 to express dengue virus type 1 nonstructural protein 1 (NS1).

The yeast Kluyveromyces marxianus is a convenient host for industrial synthesis of biomolecules. However, despite its potential, there are few studies reporting the expression of heterologous proteins using this yeast. Here, we report expression of a dengue virus protein in K.

Oligonucleotide primers for specific detection of actinobacterial laccases from superfamilies I and K.

Although many putative laccase-like genes have been assigned to members of the phylum Actinobacteria, few of the related enzymes have been characterized so far. It is noteworthy, however, that this small number of enzymes has presented properties with industrial relevance. This observation, combined with the recognized biotechnological potential and the capability of this phylum to degrade recalcitrant soil polymers, has attracted attention for bioprospective approaches.

Cloning and expression of a functional core streptavidin in Pichia pastoris: strategies to increase yield.

Streptavidin is widely used as an analytical tool and affinity tag together with biotinylated surfaces or molecules. We report for the first time a simple strategy that yields high biomass of a Pichia pastoris strain containing a methanol induced core streptavidin (cStp) gene. Three factors were evaluated for biomass production: glycerol concentration, aeration, and feed flow rates in a bioreactor.