The scale-up cultivation of Candida utilis in waste potato juice water with glycerol affects biomass and β(1,3)/(1,6)-glucan characteristic and yield

Microbial polysaccharides biosynthesis and their regulatory strategies

Microbial polysaccharides hold significant potential for various applications, including food, cosmetics, petroleum, and pharmaceuticals. A deeper understanding of their biosynthetic pathways and regulatory strategies is crucial for enhancing production efficiency and reducing associated costs. To summarize synthetic biological modification strategies for microbial polysaccharides from a hierarchical perspective, this review classifies these polymers into three categories based on the depths of carried out research regarding their biosynthetic pathways and regulatory strategies, i.e., (1) microbial polysaccharides with well-elucidated biosynthetic pathways, (2) microbial polysaccharides with well-elucidated precursor sugar biosynthetic pathways but synthase-encoding genes incompletely understood, and (3) those whose biosynthesis depends on a single synthetic enzyme. We systematically summarize the biosynthetic pathways of these three categories and provide insights into yield-improvement strategies. This review aims to serve as a valuable reference for metabolic regulation of microbial polysaccharides and to facilitate future advances in their production.

Blending polysaccharides from three edible mushrooms represents a promising approach for augmenting their anti-oxidant and anti-fatigue activities

It has been well documented that a number of polysaccharides with potent free-radical scavenging capability possess notable anti-fatigue activity. Interestingly, recent evidence also suggested mixed polysaccharides derived from multiple sources may yield augmented bioactivities compared to the polysaccharides from a single source. Therefore, in the current study, we investigated the anti-oxidant and anti-fatigue activities of a blend of polysaccharides isolated from three mushrooms. The optimal ratio of Pleurotus eryngii polysaccharide, Agrocybe aegerita polysaccharide, and Agaricus bisporus polysaccharide was firstly screened out by in vitro antioxidant assays with a Z-score comprehensive evaluation method. Then, the fatigue-reducing effects of the polysaccharide mixture at optimal ratio (1:2:2) were studied in mice. The results showed that the polysaccharide mixture exerted desirable fatigue-reducing effect evidence by significantly extended exhaustion time in the weight-loaded swimming assay (from 9.45 ± 3.06 min to 27.65 ± 19.84 min). Moreover, the observed fatigue-reducing effect may be attributed to its capacity to decrease fatigue-related metabolites, increase muscle glycogen reserves, and regulate energy metabolism-related transcripts in muscle tissue. Taken together, these findings highlighted the potential application of blending polysaccharides from multiple mushroom sources in mitigating fatigue.

Progress in the preparation, structure and bio-functionality of Dictyophora indusiata polysaccharides: A review

Dictyophora indusiata (D. indusiata) is an elegant fungus known as the "mushroom queen" because of its rich nutritional value and resemblance to dancers wearing clean white dresses. Due to the harsh growth environment, the yield of D. indusiata is relatively low. Polysaccharides are the most abundant component among them and it is valued for its unique physiological function. Multiple extraction and purification methods have been used to separate and purify polysaccharides from D. indusiata. These polysaccharides have demonstrated strong biological activities in vitro and in vivo, including anti-inflammatory, anti-tumour, immunomodulatory, antioxidant and anti-hyperlipidemic effects. In addition, D. indusiata polysaccharides have shown promising potential for development and application in the areas of food, healthcare products, pharmaceuticals, and cosmetics. Recent advances in the extraction, purification, structural characterization, biological activities and application prospects of D. indusiata polysaccharides were summarized. This review may enrich the knowledge about bioactive polysaccharides from D. indusiata and provide a theoretical basis. Due to diverse potential health-promoting properties of D. indusiata polysaccharides, further development for their application in functional foods and pharmaceuticals is expected.

Polyphasic identification of Rhizopus oryzae and evaluation of physical fermentation parameters in potato starch processing liquid waste for β-glucan production

Β-glucans are polysaccharide macromolecules that can be found in the cell walls of molds, such as Rhizopus oryzae. They provide functional properties in food systems and have immunomodulatory activity, anticancer, and prebiotic effects; reduce triglycerides and cholesterol; and prevent obesity, among others benefits. Furthermore, potato starch production requires a large amount of water, which is usually discharged into the environment, creating problems in soils and bodies of water. The physical parameters to produce β-glucans were determined, liquid waste from potato starch processing was used and native Rhizopus oryzae was isolated and identified from cereal grains. The isolates grew quickly on the three types of agars used at 25 °C and 37 °C, and they did not grow at 45 °C. Rhizopus oryzae M10A1 produced the greatest amount of β-glucans after six days of culture at 30 °C, pH 6, a stirring rate of 150 rpm and a fermentation volume of 250 mL. By establishing the physical fermentation parameters and utilizing the liquid waste from potato starch, Rhizopus oryzae M10A1 yielded 397.50 mg/100 g of β-glucan was obtained.

How do the carbon and nitrogen sources affect the synthesis of β-(1,3/1,6)-glucan, its structure and the susceptibility of Candida utilis yeast cells to immunolabelling with β-(1,3)-glucan monoclonal antibodies?

BACKGROUND

The need to limit antibiotic therapy due to the spreading resistance of pathogenic microorganisms to these medicinal substances stimulates research on new therapeutic agents, including the treatment and prevention of animal diseases. This is one of the goals of the European Green Deal and the Farm-To-Fork strategy. Yeast biomass with an appropriate composition and exposure of cell wall polysaccharides could constitute a functional feed additive in precision animal nutrition, naturally stimulating the immune system to fight infections.

RESULTS

The results of the research carried out in this study showed that the composition of Candida utilis ATCC 9950 yeast biomass differed depending on growth medium, considering especially the content of β-(1,3/1,6)-glucan, α-glucan, and trehalose. The highest β-(1,3/1,6)-glucan content was observed after cultivation in deproteinated potato juice water (DPJW) as a nitrogen source and glycerol as a carbon source. Isolation of the polysaccharide from yeast biomass confirmed the highest yield of β-(1,3/1,6)-glucan after cultivation in indicated medium. The differences in the susceptibility of β-(1,3)-glucan localized in cells to interaction with specific β-(1,3)-glucan antibody was noted depending on the culture conditions. The polymer in cells from the DPJW supplemented with glycerol and galactose were labelled with monoclonal antibodies with highest intensity, interestingly being less susceptible to such an interaction after cell multiplication in medium with glycerol as carbon source and yeast extract plus peptone as a nitrogen source.

CONCLUSIONS

Obtained results confirmed differences in the structure of the β-(1,3/1,6)-glucan polymers considering side-chain length and branching frequency, as well as in quantity of β-(1,3)- and β-(1,6)-chains, however, no visible relationship was observed between the structural characteristics of the isolated polymers and its susceptibility to immunolabeling in whole cells. Presumably, other outer surface components and molecules can mask, shield, protect, or hide epitopes from antibodies. β-(1,3)-Glucan was more intensely recognized by monoclonal antibody in cells with lower trehalose and glycogen content. This suggests the need to cultivate yeast biomass under appropriate conditions to fulfil possible therapeutic functions. However, our in vitro findings should be confirmed in further studies using tissue or animal models.

Magnesium Binding by Cyberlindnera jadinii Yeast in Media from Potato Wastewater and Glycerol

The aim of this study was to determine the magnesium-binding capacity of Cyberlindnera jadinii yeast in media prepared from potato wastewater and glycerol (after biodiesel production), supplemented with magnesium salt. The research was carried out in two stages. In the first, the ability to binding magnesium by yeast in media supplemented with various doses of this element was tested. In the second stage, after selecting the appropriate dose of magnesium, the culture was carried out in a bioreactor. The composition of the yeast biomass was also analysed in terms of lipids and protein content and amino acid composition. Studies have shown that this type of medium can be used as a culture medium for the growth of C. jadinii yeast. In the first stage of the study, the most magnesium (8.97 mg/gd.m.) was bound by yeast cells after 48 h of cultivation in a medium supplemented with the addition of magnesium at a dose of 2 g/L. In the second stage of the research, the highest magnesium content in the biomass (7.9 mg/gd.m.) was noted after 24 h of cultivation in the same medium. The lipid and protein contents in the biomass obtained after 24 h of cultivation in the bioreactor were 6.35 and 43.73%, respectively. The main fatty acids present in the yeast lipids were oleic acid (59.4%) and linoleic acid (8.6%). Analysis of the amino acid profile of the proteins showed the highest proportions were glutamic acid (13.7%) and aspartic acid (11%).

Food By-Products and Agro-Industrial Wastes as a Source of β-Glucans for the Formulation of Novel Nutraceuticals

Food and agro-industrial by-products provoke a great environmental and economic impact that must be minimized by adding value to these wastes within the framework of circular economy. The relevance of β-glucans obtained from natural sources (cereals, mushrooms, yeasts, algae, etc.), in terms of their interesting biological activities (hypocholesterolemic, hypoglycemic, immune-modulatory, antioxidant, etc.), has been validated by many scientific publications. Since most of these by-products contain high levels of these polysaccharides or can serve as a substrate of β-glucan-producing species, this work reviewed the scientific literature, searching for studies that utilized food and agro-industrial wastes to obtain β-glucan fractions, attending to the applied procedures for extraction and/or purification, the characterization of the glucans and the tested biological activities. Although the results related to β-glucan production or extraction using wastes are promising, it can be concluded that further research on the glucans' characterization, and particularly on the biological activities in vitro and in vivo (apart from antioxidant capacity), is required to reach the final goal of formulating novel nutraceuticals based on these molecules and these raw materials.

Efficient biosynthesis of exopolysaccharide in Candida glabrata by a fed-batch culture

Polysaccharides are important natural biomacromolecules. In particular, microbial exopolysaccharides have received much attention. They are produced by a variety of microorganisms, and they are widely used in the food, pharmaceutical, and chemical industries. The Candida glabrata mutant 4-C10, which has the capacity to produce exopolysaccharide, was previously obtained by random mutagenesis. In this study we aimed to further enhance exopolysaccharide production by systemic fermentation optimization. By single factor optimization and orthogonal design optimization in shaking flasks, an optimal fermentation medium composition was obtained. By optimizing agitation speed, aeration rate, and fed-batch fermentation mode, 118.6 g L⁻¹ of exopolysaccharide was obtained by a constant rate feeding fermentation mode, with a glucose yield of 0.62 g g⁻¹ and a productivity of 1.24 g L⁻¹ h⁻¹. Scaling up the established fermentation mode to a 15-L fermenter led to an exopolysaccharide yield of 113.8 g L⁻¹, with a glucose yield of 0.60 g g⁻¹ and a productivity of 1.29 g L⁻¹ h⁻¹.

Enhancing Red Yeast Biomass Yield and Lipid Biosynthesis by Using Waste Nitrogen Source by Glucose Fed-Batch at Low Temperature

This work reports the effect of simple feeding strategies and temperature to obtain high-cell-density cultures of Rhodotorula glutinis var. rubescens LOCKR13 maximizing the de novo lipid productivity using deproteinated potato wastewater (DPW) as a basic medium. Feeding DPW with glucose enables a high yield of Rhodotorula glutinis var. rubescens LOCKR13 biomass (52 g d.w. L−1) to be obtained. The highest values of lipid accumulation (34.15%, w/w), production (14.68 g L−1) and yield coefficients (YL/S: 0.242 g g−1), and volumetric productivity (PL: 0.1 g L−1 h−1) were reached by the strain in the two-stage fed-batch process at 20 °C. The lipid of yeast biomass was rich in oleic acid (Δ9C18:1) and palmitic acid (C16:0), and the lower temperature of incubation significantly increased the MUFA (especially oleic acid) content. For the first time, a unique set of thermal analyses of the microbial oil was performed. The isotherms of the oxidation kinetics (PDSC) showed that lipids extracted from the biomass of red yeast had high oxidative stability. This feature of the yeast oil can be useful for long-shelf-life food products and can be promising for the production of biodiesel.

β-Glucans from Yeast—Immunomodulators from Novel Waste Resources

β-glucans are a large class of complex polysaccharides with bioactive properties, including immune modulation. Natural sources of these compounds include yeast, oats, barley, mushrooms, and algae. Yeast is abundant in various processes, including fermentation, and they are often discarded as waste products. The production of biomolecules from waste resources is a growing trend worldwide with novel waste resources being constantly identified. Yeast-derived β-glucans may assist the host’s defence against infections by influencing neutrophil and macrophage inflammatory and antibacterial activities. β-glucans were long regarded as an essential anti-cancer therapy and were licensed in Japan as immune-adjuvant therapy for cancer in 1980 and new mechanisms of action of these molecules are constantly emerging. This paper outlines yeast β-glucans’ immune-modulatory and anti-cancer effects, production and extraction, and their availability in waste streams.

Antimicrobial and prebiotic activity of mannoproteins isolated from conventional and nonconventional yeast species-the study on selected microorganisms

Yeast mannoproteins are proposed as a paraprobiotics with antimicrobial and prebiotic properties. They can be used as biopreservatives in food and in diseases therapies. The knowledge about the specificity and/or capability of their influence on the growth of different microorganism is limited. The study determined the effect of mannoprotein preparations of Saccharomyces cerevisiae (S. cerevisiae) ATCC 7090 and nonconventional yeast origin [Metschnikowia reukaufii (M. reukaufii) WLP 4650 and Wickerhamomyces anomalus (W. anomalus) CCY 38-1-13] on the growth of selected bacteria of the genera: Lactobacilllus, Limosilatobacillus, Limosilatobacillus, Bifidobacterium, Staphylococcus, Enterococcus, Pseudomonas, Escherichia, Proteus and Salmonella. The degree of stimulation or growth inhibition of tested bacteria depended on the type and dose of the mannoprotein and the bacterial strain. The addition of the tested preparations in the entire range of applied concentrations had a positive effect especially on the growth of Lactobacillus arabinosus ATCC 8014 and Bifidobacterium animalis subsp. lactis B12. Mannoproteins isolated from S. cerevisiae limited the growth of the Escherichia coli (E. coli) ATCC 25922, Pseudomonas aureoginosa (P. aureoginosa) ATCC 27853, Proteus mirabilis ATCC 35659 and Salmonella Enteritidis ATCC 13076 to the greatest extent, while preparations of M. reukaufii and W. anomalus origin most effectively limited the growth of Staphylococcus aureus strains, E. coli and P. aureoginosa. The growth of Enterococcus faecalis was stimulated by the presence of all studied preparations in most of the concentrations used. Further research will determine how the purification process of studied mannoproteins or oligosaccharide fractions, its structure and composition influence on the growth of selected bacteria and what is the mechanism of its activity.

Influence of potato variety on polyphenol profile composition and glycoalcaloid contents of potato juice

The results of studies published in recent years indicate the broad biological activity of potato juice (PJ), which is a byproduct of the starch production process. Among the most frequently described activities are anti-inflammatory, antioxidant, and cytotoxic effects. Nevertheless, this waste juice is produced by the processing of many varieties of potatoes with different proportions, which does not allow to conclude on the biological activity of individual varieties. This article is a report on the antioxidant activity of PJ from seven selected potato varieties, their profile of polyphenolic compounds, and the content of glycoalkaloids (GAs). The use of similar cultivation conditions allowed to eliminate the influence of environmental factors on the content of the analyzed compounds. The influence of PJ on the growth of probiotic, commensal, and pathogenic bacteria was also assessed. It was shown that the varieties significantly influenced the differences in antioxidant activity as well as the content of GAs, but despite the observed differences, none of them showed antimicrobial activity. Therefore, it can be concluded that an appropriately selected variety will make it possible to obtain PJ that will be characterized by high antioxidant activity and, at the same time, will be safe from the toxicological point of view.

Humoral immune responses against facultative pathogen Candida utilis in atopic patients with vulvovaginal candidiasis. Candida utilis glucomannan - New serologic biomarker

Vulvovaginal candidiasis is one of the most commonly reported female genital tract infections, affecting approximately 70-75% of childbearing age women at least once during their lifetime. Approximately 50% of patients have refractory episodes and in 5-10% of cases the disease has a chronic course. The fungal cell wall represents the important host-invader interface. Cell-wall polysaccharides represent biological response modifiers and the pathogen-associated molecular patterns and virulence factors. Glycans are sensed by germ-line encoded pattern recognition receptors and reactively participate in immune system cell signaling. The most dominant cell-wall antigenic structures of Candida species as ß-glucan, α- and ß-mannans, glucomannan and other immunogenic polysaccharides are of particular relevancy for specific in vitro diagnosis and long-term follow-up of the Candida infection. In this study we assessed the immunobiological activity of facultative pathogen Candida utilis cell glucomannan and its effectivity as in vitro serological marker for antibody testing. The novel serologic assay has been developed and optimized for C. utilis serodiagnosis. The comparison assays were performed to establish relationship between antibodies against C. utilis, C. albicans and S. cerevisiae main cell-wall antigens in patient sera. The study evaluates applicability of glucomannan as serodiagnostic antigen and as a trigger of antigenspecific IgG, IgM and IgA antibody isotypes in the cohort of 35 atopic female subjects with recurrent vulvovaginal candidiasis. Statistically significant sera values of specific anti-glycan IgM and IgA class antibodies were revealed. The results are suggestive for efficient serological application of C.utilis glucomannan as in vitro disease marker and prospectively for follow-up of the specific long-term antimycotic therapy.

Microbial production and recovery of hybrid biopolymers from wastes for industrial applications- a review

Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms. However, the use of biopolymers at industrial scale for the development of products with high added value, such as food or biomedical products, not only can compensate the primary costs of biopolymer production, but also improve local economies and environmental sustainability. The present review describes some of the most relevant aspects related to the synthesis of hybrid materials and nanocomposites based on biopolymers for the development of products with high-added value.

Increasing the Production of β-Glucan from Saccharomyces carlsbergensis RU01 by Using Tannic Acid

In this study, we increased β-glucan production from brewer's yeast, Saccharomyces carlsbergensis RU01, by using tannic acid. High-pressure freezing and transmission electron microscopy (HPF-TEM) revealed that the yeast cell wall obtained from yeast malt (YM) medium supplemented with 0.1% w/v tannic acid was thicker than that of yeast cultured in YM medium alone. The production of β-glucan from S. carlsbergensis RU01 was optimized in 3% w/v molasses and 0.1% w/v diammonium sulfate (MDS) medium supplemented with 0.1% w/v tannic acid. The results showed that MDS medium supplemented with 0.1% w/v tannic acid significantly increased the dry cell weight (DCW), and the β-glucan production was 0.28±0.01% w/v and 11.99±0.04% w/w. Tannic acid enhanced the β-glucan content by up to 42.23%. β-Glucan production in the stirred tank reactor (STR) was 1.4-fold higher than that in the shake flask (SF) culture. Analysis of the β-glucan composition by Fourier transform infrared (FTIR) spectroscopy showed that the β-glucan of S. carlsbergensis RU01 cultured in MDS medium supplemented with 0.1% w/v tannic acid had a higher proportion of polysaccharide than that of the control. In addition, β-glucans from brewer's yeast can be used as prebiotic and functional foods for human health and in animal feed.

Effect of Selenium on the Growth and Lipid Accumulation of Yarrowia lipolytica Yeast

Nowadays, there is an increase attention on the effect of selenium (Se) on metabolic processes of microorganisms. Strains belonging to the genus of Yarrowia are of great biotechnological interest for various industries. In this study, we evaluated the effect of 10 mg/L of Se on the growth and lipid production of two Yarrowia lipolytica strains: the ACA DC 50109 and one more with increased oleagenicity, derived after ALE methodology (referred here as Y. lipolytica ALE_70). The presence of Se in the growth medium negatively affected both cell mass production and total lipid accumulation, for both Y. lipolytica strains. Fractionation of total lipids showed an inhibition on neutral lipid (NL) synthesis and consequently, an increase of polar lipids (glycolipids plus sphingolipids, and phospholipids) on the lipids of the Se-enriched ACA DC 50109 strain; however, the NL/polar ratio of the Se-enriched ALE_70 indicated that Se, apart from the inhibition of NL synthesis, provoked also the accumulation of polar lipids in this strain. In addition, the fatty acid (FA) composition was differently affected by Se. Se-enriched total lipids of the ALE_70 strain were enriched in linoleic acid (C18:2 n-6), which resulted in increase of the unsaturated index. On the other hand, Se-enriched lipids of the ACA DC 50109 strain were more saturated, as the percentage of palmitic (C16:0) and stearic (C18:0) acids increased in the total FAs. Moreover, it seems that Se influenced the activity or the expression of desaturases and elongase in both strains. Finally, the supplementation of growth medium with Se affected cell morphology, as well as the size and distribution of lipid droplets inside the yeast cells. According to our opinion, Se caused stress conditions and the consequence of that was the occurrence of metabolic disorders that affected cell mass, lipid content, and/or morphological structures. The results of the present study suggest that further research should be carried out to understand the background of the lipogenesis process in yeast cells cultured under stress conditions.

Membrane Filtration-Assisted Enzymatic Hydrolysis Affects the Biological Activity of Potato Juice

The results of recently published studies indicate that potato juice is characterized by interesting biological activity that can be particularly useful in the case of gastrointestinal symptoms. Moreover, the studies also described the high nutritional value of its proteins. This article is a report on the impact of the enzymatic hydrolysis of proteins combined with membrane filtration. The obtained potato juice protein hydrolysate (PJPH) and its concentrate (cPJPH) were characterized in terms of their nutritional value and biological activity. The amino acid profile and scoring, the content of mineral compounds, and the antioxidant and in vitro cytotoxic activity were assessed. The study proved that the antioxidant activity of PJPH is higher than that of fresh potato juice, and the cytotoxicity against human gastric carcinoma cell line (Hs 746T), human colon cancer cell line (Caco-2), human colorectal adenocarcinoma cell line (HT-29), and human normal colon mucosa cell line (CCD 841 CoN) showed biological activity specifically targeted against cancer cells. Therefore, it can be concluded that the membrane filtration-assisted enzymatic hydrolysis of potato juice proteins may increase their biological activity and allow for potato juice to be used in the production of medicinal preparations.

Biological Activity of High-Purity β-1,3-1,6-Glucan Derived from the Black Yeast Aureobasidium pullulans: A Literature Review

The black yeast Aureobasidium pullulans produces abundant soluble β-1,3-1,6-glucan-a functional food ingredient with known health benefits. For use as a food material, soluble β-1,3-1,6-glucan is produced via fermentation using sucrose as the carbon source. Various functionalities of β-1,3-1,6-glucan have been reported, including its immunomodulatory effect, particularly in the intestine. It also exhibits antitumor and antimetastatic effects, alleviates influenza and food allergies, and relieves stress. Moreover, it reduces the risk of lifestyle-related diseases by protecting the intestinal mucosa, reducing fat, lowering postprandial blood glucose, promoting bone health, and healing gastric ulcers. Furthermore, it induces heat shock protein 70. Clinical studies have reported the antiallergic and triglyceride-reducing effects of β-1,3-1,6-glucan, which are indicators of improvement in lifestyle-related diseases. The primary and higher-order structures of β-1,3-1,6-glucan have been elucidated. Specifically, it comprises a single highly-branched glucose residue with the β-1,6 bond (70% or more) on a backbone of glucose with 1,3-β bonds. β-Glucan shows a triple helical structure, and studies on its use as a drug delivery system have been actively conducted. β-Glucan in combination with anti-inflammatory substances or fullerenes can be used to target macrophages. Based on its health functionality, β-1,3-1,6-glucan is an interesting material as both food and medicine.

Pentose-rich hydrolysate from oil palm empty fruit bunches for β-glucan production using Pichia jadinii and Cyberlindnera jadinii

Pentose-rich hydrolysate obtained from dilute acid pretreatment of oil palm empty fruit bunches was successfully consumed by pentose-consuming yeasts: Cyberlindnera jadinii (Cj) and Pichia jadinii (Pj). Nitrogen supplementation and no additional detoxification step were required. Pj produced 5.87 g/L of biomass using a C/N ratio of 14 after 120 h of fermentation, with xylose consumption of 71%. Cj produced 10.50 g/L of biomass after 96 h of fermentation with C/N ratio of 11.5, with maximum xylose consumption of 85%. β-glucans, high value-added macromolecules, were further extracted from the yeast biomass, achieving yields of 3.1 and 3.0% from Pj and Cj, respectively. The isolated polysaccharides showed a chemical structure of β-(1,3)-glucan with residues of other molecules. Additionally, β-(1,6) branches seems to have been broken during isolation process. Further studies assessing β-glucans production at industrial scale should be carried out looking for nitrogen sources and optimizing the β-glucan isolation method.

Revealing the Potential of Lipid and β-Glucans Coproduction in Basidiomycetes Yeast

Beta (β)-glucans are polysaccharides composed of D-glucose monomers. Nowadays, β-glucans are gaining attention due to their attractive immunomodulatory biological activities, which can be utilized in pharmaceutical or food supplementation industries. Some carotenogenic Basidiomycetes yeasts, previously explored for lipid and carotenoid coproduction, could potentially coproduce a significant amount of β-glucans. In the present study, we screened eleven Basidiomycetes for the coproduction of lipids and β-glucans. We examined the effect of four different C/N ratios and eight different osmolarity conditions on the coproduction of lipids and β-glucans. A high-throughput screening approach employing microcultivation in microtiter plates, Fourier Transform Infrared (FTIR) spectroscopy and reference analysis was utilized in the study. Yeast strains C. infirmominiatum CCY 17-18-4 and R. kratochvilovae CCY 20-2-26 were identified as the best coproducers of lipids and β-glucans. In addition, C. infirmominiatum CCY 17-18-4, R. kratochvilovae CCY 20-2-26 and P. rhodozyma CCY 77-1-1 were identified as the best alternative producers of β-glucans. Increased C/N ratio led to increased biomass, lipid and β-glucans production for several yeast strains. Increased osmolarity had a negative effect on biomass and lipid production while the β-glucan production was positively affected.

Technological and antioxidant properties of proteins obtained from waste potato juice

The article presents the technological and antioxidant properties of potato juice (PJ) protein concentrate obtained by the novel ultrafiltration method. Commercial products, obtained from waste PJ by the traditional method of acid coagulation of proteins, were studied for comparison. Functional properties such as water or oil absorption, foaming capacity, and foam stability (FS) as well as solubility at various pH were assessed. Moreover, the total phenolic compound content, antioxidant activity, and mineral composition were determined. The results showed that PJ protein concentrate obtained by ultrafiltration has good oil absorption properties (6.30 mL/g), which is more than two times higher than the commercial proteins used in the comparison (P2 = 2.33 mL/g and P3 = 2.67 mL/g). Moreover, the ability to create and stabilize foam was also higher (FS ranging from 20.0% at pH = 10 to 11.3% at pH = 2 after 60 min of testing). It had higher content of macro- and microelements and antioxidant activity compared to other samples. Therefore, it is possible to obtain interesting potato protein concentrate from the waste product of the starch production process, which may be an interesting raw material for enriching food.

Effect of Thermal Processing on Antioxidant Activity and Cytotoxicity of Waste Potato Juice

Potato juice (PJ), commonly considered a burdensome waste, is rich in various compounds with bioactive properties. It has long been considered a remedy for gastric problems in traditional folk medicine. If valorization of PJ through implementation in the production of functional foods is to be considered, stabilization methods must be developed to allow long-term storage of this seasonal product. It is important that such methods are chosen with regard to their effect on the bioactive value of the obtained product. In this study, the impact of four stabilization methods on the antioxidant and cytotoxic activities of PJ was investigated. Elevated temperatures were used in thermal deproteinization used to obtain DPJW (deproteinated potato juice water) and spray-drying of FPJ (fresh potato juice) that resulted in SDPJ. Freeze drying and cryoconcentration were the low temperature processing methods that yielded PJL (potato juice lyophilisate) and CPJ (cryocorncentrated potato juice), respectively. All processed materials were characterized chemically and compared with raw materials in terms of phenolic compounds content, antioxidant activity as well as cytotoxicity to human tumor cells isolated from the gastric mucosa (Hs476T cell line), colon (Caco-2 and HT-29 cell lines), and normal cells isolated from the small intestine and colon epithelium (IEC-6 and NCM460 cell lines). It was stated that high-temperature processes – thermal deproteinization and spray-drying – yielded products with increased antioxidant potential (TEAC) that also showed increased cytotoxic activity towards intestinal cancer cells. At the same time the cytotoxicity towards normal cells remained on par with that of fresh PJ (IEC-6 cells) or decreased (NCM460 cells). Thermal deproteinization significantly decreased the content of glycoalcaloids in the juice, while spray drying did not have such an effect. The two low-temperature processes investigated – cryoconcentration and freeze drying – did not affect the PJ cytotoxic activity towards any of the cell lines used in the tests, whereas they did affect the antioxidant properties and glycoalcaloids content of PJ.

Candida utilis ATCC 9950 Cell Walls and β(1,3)/(1,6)-Glucan Preparations Produced Using Agro-Waste as a Mycotoxins Trap

Mycotoxins are harmful contaminants of food and feed worldwide. Feed additives with the abilities to trap mycotoxins are considered substances which regulate toxin transfer from feed to tissue, reducing its absorption in animal digestive tract. Market analysis emphasizes growing interest of feed producers in mycotoxins binders obtained from yeast biomass. The aim of the study was to prescreen cell walls (CW) and β(1,3)/(1,6)-glucan (β-G) preparations isolated from Candida utilis ATCC 9950 cultivated on waste potato juice water with glycerol as adsorbents for aflatoxin B1 (AFB1), zearalenone (ZEN), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2) and fumonisin B1 (FB1). The adsorption was studied in single concentration tests at pH 3.0 and 6.0 in the presence of 1% of the adsorbent and 500 ng/mL of individual toxin. Evaluated CW and β-G preparations had the potential to bind ZEN, OTA and AFB1 rather than DON, NIV, T-2 toxin and FB1. The highest percentage of adsorption (about 83%), adsorption capacity (approx. 41 µg/ g preparation) and distribution coefficient (458.7mL/g) was found for zearalenone when CW preparation was used under acidic conditions. Higher protein content in CW and smaller particles sizes of the formulation could influence more efficient binding of ZEN, OTA, DON and T-2 toxin at appropriate pH compared to purified β-G. Obtained results show the possibility to transform the waste potato juice water into valuable Candida utilis ATCC 9950 preparation with mycotoxins adsorption properties. Further research is important to improve the binding capacity of studied preparations by increasing the active surface of adsorption.