Volkmar Passoth

Volkmar Passoth
Swedish University of Agricultural Sciences | SLU · Department of Molecular Sciences

PhD

About

154
Publications
19,087
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3,281
Citations
Citations since 2016
56 Research Items
1804 Citations
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Introduction
Focusing on oleaginous yeasts to replace fossile resources and vegetable oil to establish sustainable, circular processes for the production of food, feed and biochemicals. This involves applied research to convert raw materials to valuable compounds and fundamental science to understand physiology and genetics of non- conventional microorganisms. https://www.slu.se/en/ew-cv/volkmar-passoth/ ; https://www.slu.se/en/departments/molecular-sciences/research-groups/food-biotechnology/

Publications

Publications (154)
Article
Full-text available
Bioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio‐based products. Short‐rotation‐coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, an easy to manage cultivation system with vegetative propagation of plant material and multiple h...
Article
Full-text available
Production of carotenoids and lipids by Rhodotorula toruloides CBS 14 cultivated on wheat straw hydrolysate was investigated. An ultra-high-performance liquid chromatography (UHPLC) method for carotenoid quantification was developed and validated. Saponification effects on individual carotenoid quantification were identified, and lipid and caroteno...
Article
Full-text available
The genus Rhodotorula includes basidiomycetous oleaginous yeast species. Rhodotorula babjevae can produce compounds of biotechnological interest such as lipids, carotenoids, and bio- surfactants from low value substrates such as lignocellulose hydrolysate. High-quality genome assemblies are needed to develop genetic tools and to understand fungal e...
Preprint
Full-text available
The genus Rhodotorula includes basidiomycetous oleaginous yeast species. R. babjevae can produce compounds of biotechnological interest such as lipids, carotenoids and biosurfactants from low value substrates such as lignocellulose hydrolysate. High-quality genome assemblies are needed to develop genetic tools and to understand fungal evolution and...
Article
Full-text available
Diets low in fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) can help reduce symptoms in 50 to 80% of patients suffering from irritable bowel syndrome. Patients are, therefore, often advised to avoid products contributing to FODMAP intake, such as cereal grain products. However, these products are nutritious staple foods and avoi...
Article
Full-text available
Rhodotorula toruloides is an oleaginous yeast with high biotechnological potential. In order to understand the molecular physiology of lipid synthesis in Rhodosporidium toruloides and to advance metabolic engineering, a high-resolution genome is required. We constructed a genome draft of R. toruloides CBS 14, using a hybrid assembly approach, consi...
Article
Full-text available
Strains of the yeast genus Blastobotrys (subphylum Saccharomycotina) represent a valuable biotechnological resource for basic biochemistry research, single-cell protein, and heterologous protein production processes. Species of this genus are dimorphic, non-pathogenic, thermotolerant, and can assimilate a variety of hydrophilic and hydrophobic subs...
Article
Full-text available
Background Microbial oils, generated from lignocellulosic material, have great potential as renewable and sustainable alternatives to fossil-based fuels and chemicals. By unravelling the diversity of lipid accumulation physiology in different oleaginous yeasts grown on the various carbon sources present in lignocellulose hydrolysate (LH), new targe...
Preprint
Full-text available
Rhodotorula toruloides is an oleaginous yeast with high biotechnological potential. In order to understand the molecular physiology of lipid synthesis in R. toruloides and to advance metabolic engineering, a high-resolution genome is required. We constructed a genome draft of R. toruloides CBS 14, using a hybrid assembly approach, consisting of sho...
Article
Full-text available
Background Crude glycerol (CG) and hemicellulose hydrolysate (HH) are low—value side-products of biodiesel transesterification and pulp—and paper industry or lignocellulosic ethanol production, respectively, which can be converted to microbial lipids by oleaginous yeasts. This study aimed to test the ability of oleaginous yeasts to utilise CG and H...
Preprint
Full-text available
Background: Crude glycerol (CG) and hemicellulose hydrolysate (HH) are low- value side-products of biodiesel transesterification and pulp- and paper industry, respectively, which can be converted to microbial lipids by oleaginous yeasts. This study aimed to test the ability of oleaginous yeasts to utilise CG and HH and mixtures of them as carbon so...
Article
Full-text available
The production of microbial protein in the form of yeast grown on lignocellulosic sugars and nitrogen-rich industrial residues is an attractive approach for reducing dependency on animal and plant protein. Growth media composed of enzymatically saccharified sulfite-pulped spruce wood, enzymatic hydrolysates of poultry by-products and urea were used...
Article
Full-text available
Background: A possible future shortage of feed protein will force mankind to explore alternative protein sources that can replace conventional soymeal or fishmeal. Several large industrial organic side-streams could potentially be upgraded to feed protein using a fermentation process to generate single cell protein. Yeast is the most widely accept...
Article
Amid known microbial bioethanol producers, the yeast Scheffersomyces (Pichia) stipitis is particularly promising in terms of alcoholic fermentation of both glucose and xylose, the main constituents of lignocellulosic biomass hydrolysates. However, the ethanol yield and productivity, especially from xylose, are still insufficient to meet the require...
Article
Full-text available
Brettanomyces naardenensis is a spoilage yeast with potential for biotechnological applications for production of innovative beverages with low alcohol content and high attenuation degree. Here, we present the first annotated genome of B. naardenensis CBS 7540. The genome of B. naardenensis CBS 7540 was assembled into 76 contigs, totaling 11,283,07...
Article
Full-text available
In a 10‐week study, we evaluated the effects of replacing 20%, 40% or 60% of fish‐ meal (present in control diet at 300 g/kg) on a digestible protein basis with yeast Saccharomyces cerevisiae or a yeast mixture of Wickerhamomyces anomalus and S. cer‐ evisiae on growth performance, nutrient digestibility, nutrient retention and intestinal health of...
Preprint
Full-text available
Biogas plants serve as hubs for the collection and utilization of highly nutritious waste streams from households and agriculture. However, their outputs (biogas and digestate) are of relatively low economic value. Here, we explore the co-production of yeast single cell protein, a potentially valuable feed ingredient for aquaculture and other anima...
Article
Full-text available
Straw is an agricultural residue of the production of e.g. cereals, rapeseed or sunflowers. It includes dried stalks, leaves, and empty ears and corncobs, which are separated from the grains during harvest. Straw is a promising lignocellulosic feedstock with a beneficial greenhouse gas balance for the production of biofuels and chemicals. Like all...
Article
Full-text available
Background: Lipid extraction for quantification of fat content in oleaginous yeasts often requires strong acids and harmful organic solvents; it is laborious and time-consuming. Therefore, in most cases just endpoint measurements of lipid accumulation are performed and kinetics of intracellular lipid accumulation is difficult to follow. To address...
Article
Full-text available
Background: Oleaginous yeasts are considered as a potential lipid source for food, feed and biofuel production. In order to make the yeast-based lipid production environmentally and economically sustainable, there is a need for screening studies in order to find the best yeast lipid producers on different substrates, and to optimize cultivation co...
Article
Full-text available
Here, we present the genome of the industrial ethanol production strain Brettanomyces bruxellensis CBS 11270. The nuclear genome was found to be diploid, containing four chro- mosomes with sizes of ranging from 2.2 to 4.0 Mbp. A 75 Kbp mitochondrial genome was also identified. Comparing the homologous chromosomes, we detected that 0.32% of nucle- o...
Data
List of genes without variants in CBS 11270. (TXT)
Data
Copy number variation in CBS 11270. (TXT)
Data
List of genes with reduced coverage. (TXT)
Data
Characterization of repeats in CBS 11270. (TXT)
Data
Characterization of variants in CBS 2499. (TXT)
Data
Clustering of genes with reduced coverage in CBS 11270. (DOCX)
Data
Haplotype sampling of CBS 11270. (DOCX)
Data
Distribution of SNPs per Kbp gene. (DOCX)
Data
Variation in coverage of chromosomes in CBS 11270. (DOCX)
Data
Characterization of variants in CBS 11270. (TXT)
Data
List of genes in CBS 11270 with variants. (TXT)
Data
List of genes in CBS 2499 with variants. (TXT)
Data
List of genes without variants in CBS 2499. (TXT)
Data
List of genes present in CBS 11270 but not in CBS 2499. (DOCX)
Data
Distribution of genes with different numbers of variants in heterozygous sites in the genome of CBS 11270 and between genomes of CBS 11270 and CBS 2499. (DOCX)
Data
List of genes present in CBS 2499 but not in CBS 11270. (DOCX)
Article
Full-text available
Enset (Ensete ventricosum) is the basis of the staple food consumed by about 20% of the Ethiopian population. Kocho is one of the food products generated from enset by spontaneous fermentation of decorticated and pulverized pseudostem and corm sections. We isolated culturable microbes associated with kocho from different stages of fermentation. Twe...
Article
Full-text available
Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce...
Article
Full-text available
This study investigates the replacement of vegetable oil (VO) in aquaculture feed for Arctic char (Salvelinus alpinus) with oil produced by the oleaginous yeast Lipomyces starkeyi grown in lignocellulose (wheat straw) hydrolysate. VO is extensively used to partially replace fish oil in aquaculture feed, which can be seen as non-sustainable. VO itse...
Article
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This study investigates biofuel production from wheat straw hydrolysate, from which furfural was extracted using a patented method developed at the Latvian State Institute of Wood Chemistry. The solid remainder after furfural extraction, corresponding to 67.6% of the wheat straw dry matter, contained 69.9% cellulose of which 4% was decomposed durin...
Article
Full-text available
Background Use of bio-based diesel is increasing in Europe. It is currently produced from oilseed crops, but can also be generated from lignocellulosic biomass such as straw. However, removing straw affects soil organic carbon (SOC), with potential consequences for the climate impact of the biofuel. This study assessed the climate impacts and energ...
Chapter
Lipids are essential for any organism. They are hydrophobic compounds and include, for instance, acylglycerides, free fatty acids, sterols and isoprenoids. Their synthesis starts from acetyl-CoA, which is converted to lipids by a variety of complex biochemical reactions. Lipids consist of highly reduced molecules, and the redox factor providing ele...
Chapter
Liquid biofuels have great potential to replace fossil transportation fuels. Bioethanol, the current major biofuel, is mainly produced using the yeast Saccharomyces cerevisiae. However, present biofuels are largely generated from first generation, i.e. food grade, raw materials. Second generation, lignocellulosic biomass represents an abundant and...
Article
This study evaluated the effectiveness of solid-state fermentation with Arxula adeninivorans or Hypocrea jecorina to improve hygienic quality and digestibility of banana peels by mono-gastric animals. Green peels of cooking bananas (Musa AAA-group) were solid-state fermented in ziploc plastic bags for 14 d either non-inoculated or inoculated with A...
Article
Rainbow trout (Oncorhynchus mykiss) were fed for 10 weeks on a diet containing either 30% fish meal (FM) or with 20, 40 and 60% replacement of fish meal protein with Saccharomyces cerevisiae (SC) or a mixture of Wickerhamomyces anomalus and S. cerevisiae (WA). Luminal contents and mucosal tissue from the distal intestine were collected and analysed...
Article
Full-text available
BACKGROUND: Biodiesel is the main liquid biofuel in the EU and is currently mainly produced from vegetable oils. Alternative feedstocks are lignocellulosic materials, which provide several benefits compared with many existing feedstocks. This study examined a technical process and its mass and energy balances to gain a systems perspective of combi...
Article
This study investigated lipid production from the hemicellulosic fraction of birch wood by the oleaginous yeast Lipomyces starkeyi. Birch wood chips were thermochemically pretreated by hot water extraction, and the liquid phase, containing 45.1 g/l xylose as the major sugar, 13.1 g/l acetic acid and 4.7 g/l furfural was used for cultivations of L....
Article
Full-text available
Background It remains a challenge to perform de novo assembly using next-generation sequencing (NGS). Despite the availability of multiple sequencing technologies and tools (e.g., assemblers) it is still difficult to assemble new genomes at chromosome resolution (i.e., one sequence per chromosome). Obtaining high quality draft assemblies is extreme...
Article
Ethanol and biogas are energy carriers that could contribute to a future energy system independent of fossil fuels. Straw is a favorable bioenergy substrate as it does not compete with food or feed production. As straw is very resistant to microbial degradation, it requires a pretreatment to insure efficient conversion to ethanol and/or methane. Th...
Article
Dekkera bruxellensis is a non-conventional yeast normally considered a spoilage organism in wine (off flavours) and in the bioethanol industry. But it also has potential as production yeast. The species diverged from Saccharomyces cerevisiae 200 mya, before the whole genome duplication (WGD). However, it displays similar characteristics such as bei...
Article
Full-text available
This study combined moist airtight storage of moist grain with pig feed fermentation. Starter cultures with the potential to facilitate both technologies were added to airtight stored moist crimped cereal grain, and the impact on storage microflora and the quality of feed fermentations generated from the grain was investigated. Four treatments were...
Article
The study aimed at evaluating an effective sterilization–inoculation technique to facilitate silage research on the effect of forage microflora on fermentation variables. The sterilization effect of heating at 60°C for 3 h + 103°C for 15 h was tested on samples of grass, grass–clover, white clover and maize, pre-dried at 60°C to a dry-matter (DM) c...
Chapter
http://link.springer.com/chapter/10.1007%2F978-3-642-55013-3_9 Biofuels, such as ethanol, biodiesel and biogas, have the potential to replace a large proportion of transportation fuels that presently are mainly produced from fossil raw materials. Bioethanol, which is the product of the fermentative energy metabolism of yeasts, is currently the majo...
Article
Biofuels, such as ethanol, biodiesel and biogas, have the potential to replace a large proportion of transportation fuels that presently are mainly produced from fossil raw materials. Bioethanol, which is the product of the fermentative energy metabolism of yeasts, is currently the major biofuel on the global market. It is to a large extent generat...
Article
The fatty acid (FA) profiles of two strains of the yeasts Wickerhamomyces anomalus and Blastobotrys (Arxula) adeninivorans at cultivation temperatures from 15°C-30°C were characterised. Beside of the common even numbered C16 and C18 FAs, substantial proportions of the uneven numbered C17:1 were found in both species. C18:3 (n-3) (alpha linolenic ac...
Article
Adaptation of Dekkera bruxellensis to lignocellulose hydrolysate was investigated. Cells of D. bruxellensis were grown for 72 and 192 hours in batch and continuous culture, respectively (adapted cells). Cultivations in semisynthetic medium were run as controls (non-adapted cells). To test the adaptation, cells from these cultures were reinoculated...
Article
Sawdust can be used to make pellets (biofuel) and particle boards and as a potential lignocellulose feedstock in bioethanol production. Microbial activity can affect sawdust quality; hence, we monitored the microbial population in birch- and spruce sawdust after 3 months' storage at various temperatures. Species composition was similar on both mate...