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Heliyon Jan 2023The present study evaluated efficiency of wheat straw (WS) hydrolysate obtained through fungal pre-treatment to produce ethanol and electricity in an electrochemical...
The present study evaluated efficiency of wheat straw (WS) hydrolysate obtained through fungal pre-treatment to produce ethanol and electricity in an electrochemical bioreactor. Three white rot fungi and were used to degrade WS for hydrolysate preparation, Lignocellulolytic enzyme production was also monitored during the pretreatment. Yeast was allowed to ferment all three hydrolysates up to 12 days. The yeast showed maximum electrochemical response as open circuit voltage (0.672 V), current density 542.42 mA m, and power density of 65.09 mW m on 12th day in the hydrolysate prepared using . Maximum ethanol production of 9.2% (w/v) was achieved on 7th day with a fermentation efficiency of about 62.1%. Further, the coulombic efficiency improved from 0.06 to 1.46% during 12 days of the experiment. Thus, the results indicated towards the possible conversion of lignocellulosic biomass into bioethanol along with bioelectricity generation.
PubMed: 36711303
DOI: 10.1016/j.heliyon.2023.e12951 -
Frontiers in Microbiology 2022The aim of this study was to investigate the influence of , alone or in combination with a214 or citric acid, on forage oat silage quality, bacterial and fungal...
The aim of this study was to investigate the influence of , alone or in combination with a214 or citric acid, on forage oat silage quality, bacterial and fungal microbiological profile during ensiling and aerobic exposure. With the exception of , all additives could improve silage quality of forage oat based on lower ammonia-nitrogen content and higher residual of water soluble carbohydrates during anaerobic fermentation compared to control silage, especially in combined with citric acid (CAPF). was the dominant bacteria in all silages, while CAPF group increased the relative abundance of and compared to control silage. The application of suppressed the relative abundance of yeasts such as and in response to aerobic exposure, especially in CAPF treatment, leading to high acetic acids and lower dry matter loss, as well as good aerobic stability. Therefore, , alone or in combination with citric acid, has potential to improve aerobic stability of forage oat silage by shifting bacterial and fungal community composition, and can be used as new additive to prepare high-quality silage for animal production.
PubMed: 36605512
DOI: 10.3389/fmicb.2022.1053933 -
Journal of Environmental Management Dec 2022Microbial fuel cells have emerged as a technique that can effectively treat wastewater with simultaneous electricity generation. The present study explored the...
Microbial fuel cells have emerged as a technique that can effectively treat wastewater with simultaneous electricity generation. The present study explored the performance of microbial fuel cell for decolorizing and degradation of azo dyes including, remazol brilliant blue (RBB), mordant blue 9 (MB9), acid red1 (AR1), and orange G (OG), while, simultaneously generating electricity. Wheat straw and its hydrolysate was used as a potential substrate in MFC. The hydrolysate was prepared through the degradation of wheat straw by P. floridensis, P. brevispora and P. chrysosporium, while the yeast Pichia fermentans was used as biocatalyst. Dye decolorization was carried out in a fungus-yeast mediated single-chambered MFC batch mode, U-shaped reactor, and bottle reactor in continuous mode. The maximum power density recorded in U shaped continuous reactor was 34.99 mW m on 21st day of the experiment. The best response of dye decolorization was observed in the case of MB9 (96%) with P. floridensis in the continuous electrochemical reactor followed by RBB (90-95%), OG (76%), and AR1 (38%). The toxicity of the treated wastewater was assessed using phytotoxicity analysis.
Topics: Azo Compounds; Benzenesulfonates; Bioelectric Energy Sources; Electricity; Electrodes; Saccharomyces cerevisiae; Triticum; Wastewater
PubMed: 36126599
DOI: 10.1016/j.jenvman.2022.116253 -
Food Research International (Ottawa,... Sep 2022There has been a growing interest in developing co-inoculum of Oenococcus oeni and Saccharomyces cerevisiae/non-Saccharomyces for simultaneous malolactic fermentation...
Effects of inoculation timing and mixed fermentation with Pichia fermentans on Oenococcus oeni viability, fermentation duration and aroma production during wine malolactic fermentation.
There has been a growing interest in developing co-inoculum of Oenococcus oeni and Saccharomyces cerevisiae/non-Saccharomyces for simultaneous malolactic fermentation (MLF) and alcoholic fermentation (AF) of wines. This study sought to elucidate the effects of two crucial factors (inoculation timing and paired yeast) on the fermentation performance and aroma production of Merlot wine. O. oeni used for MLF was concurrently or sequentially inoculated with two yeast cultures (i.e., single S. cerevisiae and mixed S. cerevisiae /Pichia fermentans H5Y-28) used for AF. Inoculation timing determined the overall vinification duration, and conditioned the production of principle higher alcohols, terpene and O. oeni-mediated volatiles. In contrast, paired yeast improved O. oeni viability, and showed significant effect on aromatic esters and volatile fatty acids. Possibly due to lower ethanol stress, co-inoculum allowed O. oeni to initiate MLF during AF, resulting in 45% reduction of total fermentation time. Meanwhile, O. oeni growth was stimulated by P. fermentans, with 1.7-fold of the maximum population higher than that in co-fermentation without P. fermentans. Such stimulation of O. oeni growth also occurred in sequential fermentation where P. fermentans had been replaced by S. cerevisiae. Only in sequential inoculum, P. fermentans induced high levels of 3-methylbutyl acetate, ethyl 3-methylbutanoate, ethyl hexanoate and ethyl octanoate, which may result in enhanced fresh fruity trait of wines. These findings suggested a positive effect of P. fermentans H5Y-28 on O. oeni and MLF. This work provides an alternative approach to improve wine MLF and aroma outcomes using friendly non-Saccharomyces yeast with appropriate inoculation strategy.
Topics: Fermentation; Odorants; Oenococcus; Pichia; Saccharomyces cerevisiae; Wine
PubMed: 35940798
DOI: 10.1016/j.foodres.2022.111604 -
Letters in Applied Microbiology Nov 2022Milk kefir is a fermented dairy product with numerous attributed health benefits due to the presence of a complex eukaryotic and prokaryotic microbiota. In this study, a...
Milk kefir is a fermented dairy product with numerous attributed health benefits due to the presence of a complex eukaryotic and prokaryotic microbiota. In this study, a total number of 26 yeast isolates were obtained from eight kefir samples from three different cities of Iran. The isolates belonged to Kluyveromyces marxianus, Saccharomyces cerevisiae, Pichia fermentans and P. kudriavzevii. The potential probiotic characteristics of the isolates were evaluated based on their ability to tolerate the stimulated condition of the gastrointestinal tract. In addition, hemolytic activity, adherence to different solvents, auto-aggregation, adhesion to the epithelial intestine-derived cells and antimicrobial activity of the selected isolates were evaluated. Overall, four yeast strains (three strains of S. cerevisiae and one strain of P. fermentans) showed resistance and survival ability against the gastrointestinal physiological conditions including acidic pH, presence of bile salt and digestive enzymes. They were able to grow at 37°C and had the capacity to adhere to epithelial intestine-derived cells. These results suggest that the selected strains can be proper candidates as probiotic yeast strains for the development of novel functional foods.
Topics: Kefir; Iran; Saccharomyces cerevisiae; Probiotics; Cultured Milk Products; Bile Acids and Salts; Anti-Infective Agents; Solvents
PubMed: 35879830
DOI: 10.1111/lam.13794 -
Frontiers in Nutrition 2022Crataegi Fructus, a medicinal and edible herb in China, has been considered a popular dietary supplement globally. It is used for the treatment of dyspepsia and chronic...
Crataegi Fructus, a medicinal and edible herb in China, has been considered a popular dietary supplement globally. It is used for the treatment of dyspepsia and chronic heart failure according to the Chinese Pharmacopoeia (2020). However, fungal contamination in Crataegi Fructus affects its quality and safety, thus preventing its global promotion. In this study, we comprehensively studied the fungal community in processed products of Crataegi Fructus by high-throughput sequencing. A total of 21 Crataegi Fructus samples were collected from five provinces in China, and the samples were divided into five groups based on collection areas, as well as into three groups based on processing methods. We then targeted the internal transcribed spacer 2 sequence through the Illumina Miseq PE300 platform to investigate fungal composition and diversity. Results showed that all 21 samples were detected with fungal contamination, and Ascomycota was dominant at the phylum level. In the groups based on collection areas, Dothideomycetes, Pleosporaceae, and were dominant at the class, family, and genus levels, respectively. In the groups based on processing methods, Dothideomycetes, Aspergillaceae, and were the most abundant at the class, family, and genus levels, respectively. Differences in fungal communities between various groups were also observed. Furthermore, a total of 115 species were identified, among which seven were potential toxigenic, namely, , , , , , , and . In conclusion, this study reveals great fungal richness and diversity of Crataegi Fructus, providing references for the prevention and control of fungal contamination of Crataegi Fructus in practical production.
PubMed: 35634418
DOI: 10.3389/fnut.2022.883698 -
Food Research International (Ottawa,... Mar 2022Hutai-8 grape (Vitis vinifera × Vitis labrusca) was fermented into rose wine with Saccharomyces cerevisiae to characterize the key aroma compounds by sensomics...
Hutai-8 grape (Vitis vinifera × Vitis labrusca) was fermented into rose wine with Saccharomyces cerevisiae to characterize the key aroma compounds by sensomics approach, and fermented with selected Pichia fermentans and S. cerevisiae for aroma enhancement. In total, 82 odorants were detected in single-fermentation Hutai-8 rose wine, 22 aroma active compounds, mainly varietal odorants and fruity esters, were further quantitated for aroma reconstitution tests, and successfully mimicked sweet, floral, and fruity traits. Omission tests excluded the importance of isobutyl acetate, ethyl butyrate, 1-nonanol for aroma development. Furthermore, the successfully recombined co-fermentation Hutai-8 rose wine revealed 21 aroma active compounds identified from 79 odorants. The complexity of wine fruity/floral characteristics was improved through increased levels of inactive odorants and decreased levels of off-odorants. Moreover, rose wine made by co-inoculation had greater color stability compared to single-fermentation. This work provides insights into the understanding of mechanisms underlying modulation of co-fermentation for improved wine quality.
Topics: Fermentation; Odorants; Pichia; Saccharomyces cerevisiae; Wine
PubMed: 35227481
DOI: 10.1016/j.foodres.2022.110959 -
Bioresource Technology Dec 2021Hemicellulosic sugars, the overlooked fraction of lignocellulosic residues can serve as potential and cost-effective raw material that can be exploited for xylitol...
Hemicellulosic sugars, the overlooked fraction of lignocellulosic residues can serve as potential and cost-effective raw material that can be exploited for xylitol production. Xylitol is a top platform chemical with applications in food and pharmaceutical industries. Sugarcane bagasse (SCB) and olive pits (OP) are the major waste streams from sugar and olive oil industries, respectively. The current study evaluated the potential of Pichia fermentans for manufacturing of xylitol from SCB and OP hydrolysates through co-fermentation strategy. The highest xylitol accumulation was noticed with a glucose and xylose ratio of 1:10 followed by feeding with xylose alone. The fed-batch cultivation using pure xylose, SCB, and OP hydrolysates, resulted in xylitol accumulation of 102.5, 86.6 and 71.9 g/L with conversion yield of 0.78, 0.75 and 0.74 g/g, respectively. The non-pathogenic behaviour and ability to accumulate high xylitol levels from agro-industrial residues demonstrates the potential of P. fermentans as microbial cell factory.
Topics: Cellulose; Fermentation; Hydrolysis; Olea; Pichia; Saccharum; Xylitol; Xylose
PubMed: 34592613
DOI: 10.1016/j.biortech.2021.126005 -
The Science of the Total Environment Jan 2022The eco-sustainability of industrial processes relies on the proper exploitation of by-products and wastes. Recently, brewers' spent grain (BSG), the main by-product of...
The eco-sustainability of industrial processes relies on the proper exploitation of by-products and wastes. Recently, brewers' spent grain (BSG), the main by-product of brewing, was successfully recycled through vermicomposting to produce an organic soil conditioner. However, the pre-processing step there applied (oven-drying) resulted in high costs and the suppression of microbial species beneficial for soil fertility. To overcome these limitations, a low-input pre-processing step was here applied to better exploit BSG microbiota and to make BSG suitable for vermicomposting. During 51 days of pre-treatment, the bacterial and fungal communities of BSG were monitored by denaturing gradient gel electrophoresis (DGGE). Chemical (carbon, nitrogen, ammonium, nitrate content, dissolved organic carbon) and biochemical (dehydrogenase activity) parameters were also evaluated. Mature vermicompost obtained from pre-processed BSG was characterized considering its legal requirements (e.g., absence of pathogens and mycotoxins, lack of phytotoxicity on seeds), microbiota composition, and chemical properties. Results obtained showed that throughout the pre-process, the BSG microbiota was enriched in bacterial and fungal species of significant biotechnological and agronomic potential, including lactic acid bacteria (Weissella, Pediococcus), plant growth-promoting bacteria (Bacillus, Pseudomonas, Pseudoxhantomonas), and biostimulant yeasts (Pichia fermentans, Trichoderma reesei, Beauveria bassiana). Pre-processing increased the suitability of BSG for earthworms' activity to produce high-quality mature vermicompost.
Topics: Animals; Edible Grain; Hypocreales; Lactobacillales; Oligochaeta; Pichia
PubMed: 34464790
DOI: 10.1016/j.scitotenv.2021.149792 -
Biochemistry and Biophysics Reports Mar 2021pH ) , 0 g/L97 g/L43 g/L 20 g/L and 37 g/L 43 g/L pH pH . .
pH ) , 0 g/L97 g/L43 g/L 20 g/L and 37 g/L 43 g/L pH pH . .
PubMed: 33490643
DOI: 10.1016/j.bbrep.2020.100886