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Jung KM, Park J, Jang J, Jung SH, Lee SH, Kim SR. Characterization of Cold-Tolerant Saccharomyces cerevisiae Cheongdo Using Phenotype Microarray. Microorganisms 2021; 9:microorganisms9050982. [PMID: 33946617 PMCID: PMC8147183 DOI: 10.3390/microorganisms9050982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 01/29/2023] Open
Abstract
The cold-tolerant yeast Saccharomyces cerevisiae is industrially useful for lager fermentation, high-quality wine, and frozen dough production. S. cerevisiae Cheongdo is a recent isolate from frozen peach samples which has a good fermentation performance at low temperatures and desirable flavor profiles. Here, phenotype microarray was used to investigate industrial potentials of S. cerevisiae Cheongdo using 192 carbon sources. Compared to commercial wine yeast S. cerevisiae EC1118, Cheongdo showed significantly different growth rates on 34 substrates. The principal component analysis of the results highlighted that the better growth of Cheongdo on galactose than on EC1118 was the most significant difference between the two strains. The intact GAL4 gene and the galactose fermentation performance at a low temperatures suggested that S. cerevisiae Cheongdo is a promising host for industrial fermentation rich in galactose, such as lactose and agarose.
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Affiliation(s)
- Kyung-Mi Jung
- Cheongdo Peach Research Institute, Gyeongsangbuk-Do Agricultural Technology Administration, Cheongdo 38315, Korea;
| | - Jongbeom Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea; (J.P.); (J.J.); (S.-H.J.); (S.H.L.)
| | - Jueun Jang
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea; (J.P.); (J.J.); (S.-H.J.); (S.H.L.)
| | - Seok-Hwa Jung
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea; (J.P.); (J.J.); (S.-H.J.); (S.H.L.)
| | - Sang Han Lee
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea; (J.P.); (J.J.); (S.-H.J.); (S.H.L.)
| | - Soo Rin Kim
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Korea; (J.P.); (J.J.); (S.-H.J.); (S.H.L.)
- Correspondence: ; Tel.: +82-(53)-950-7769
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Refining Citrus Wastes: From Discarded Oranges to Efficient Brewing Biocatalyst, Aromatic Beer, and Alternative Yeast Extract Production. BEVERAGES 2021. [DOI: 10.3390/beverages7020016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Agro-industrial wastes can be valorized as biorefinery raw materials through innovative, environmentally friendly bioprocessing for added value products. In this study, a process for citrus waste valorization within the biorefinery concept is proposed, including the development of an effective biocatalyst, based on immobilized cells, for aromatic beer production, and an alternative yeast extract (AYE) production in the same unit. Specifically, orange pulp from discarded oranges was applied as an immobilization carrier of the alcohol-resistant and cryotolerant yeast strain S. cerevisiae AXAZ-1. The yeast culture was produced by minor nutrient supplementation using diluted molasses as substrate. An effective Citrus Waste Brewing Biocatalyst (CWBB) was produced and applied for beer fermentation. The aroma-related compounds in beer produced with free yeast cells or the CWBB were evaluated by solid-phase micro-extraction (SPME) gas chromatography–mass spectrometry (GC–MS). The analysis showed that the beers produced by the CWBB had a more complex volatile profile compared with beer fermented by the free cells. More specifically, the CWBB enhanced the formation of esters and terpenes by 5- and 27-fold, respectively. In the frame of the proposed multiprocessing biorefinery concept, the spent CWBB, after it has completed its cycle of brewing batches, was used as substrate for AYE production through autolysis. The produced AYE significantly affected the yeast growth when compared to commercial yeast extract (CYE). More specifically, it promoted the biomass productivity and biomass yield factor by 60–150% and 110–170%, respectively. Thus, AYE could be successfully used for industrial cell growth as an efficient and cheaper substitute of CYE. Within a circular economy framework, the present study highlights the potential use of citrus waste to produce aromatic beer combined with AYE production as an alternative way to valorize these wastes.
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Kazou M, Grafakou A, Tsakalidou E, Georgalaki M. Zooming Into the Microbiota of Home-Made and Industrial Kefir Produced in Greece Using Classical Microbiological and Amplicon-Based Metagenomics Analyses. Front Microbiol 2021; 12:621069. [PMID: 33584624 PMCID: PMC7876260 DOI: 10.3389/fmicb.2021.621069] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Accepted: 01/07/2021] [Indexed: 11/22/2022] Open
Abstract
Kefir is a high nutritional fermented dairy beverage associated with a wide range of health benefits. It constitutes a unique symbiotic association, comprising mainly lactic acid bacteria, yeasts, and occasionally acetic acid bacteria, which is strongly influenced by the geographical origin of the grains, the type of milk used, and the manufacture technology applied. Until recently, kefir microbiota has been almost exclusively studied by culture-dependent techniques. However, high-throughput sequencing, alongside omics approaches, has revolutionized the study of food microbial communities. In the present study, the bacterial, and yeast/fungal microbiota of four home-made samples (both grains and drinks), deriving from well spread geographical regions of Greece, and four industrial beverages, was elucidated by culture-dependent and -independent analyses. In all samples, classical microbiological analysis revealed varying populations of LAB and yeasts, ranging from 5.32 to 9.60 log CFU mL–1 or g–1, and 2.49 to 7.80 log CFU mL–1 or g–1, respectively, while in two industrial samples no yeasts were detected. Listeria monocytogenes, Salmonella spp. and Staphylococcus spp. were absent from all the samples analyzed, whereas Enterobacteriaceae were detected in one of them. From a total of 123 isolates, including 91 bacteria and 32 yeasts, Lentilactobacillus kefiri, Leuconostoc mesenteroides, and Lactococcus lactis as well as Kluvyeromyces marxianus and Saccharomyces cerevisiae were the mostly identified bacterial and yeast species, respectively, in the home-made samples. On the contrary, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, and Lacticaseibacillus rhamnosus along with Debaryomyces hansenii and K. marxianus were the main bacterial and yeast species, respectively, isolated from the industrial beverages. In agreement with the identification results obtained from the culture-dependent approaches, amplicon-based metagenomics analysis revealed that the most abundant bacterial genera in almost all home-made samples (both grains and drinks) were Lactobacillus and Lactococcus, while Saccharomyces, Kazachstania, and Kluvyeromyces were the predominant yeasts/fungi. On the other hand, Streptococcus, Lactobacillus, and Lactococcus as well as Kluvyeromyces and Debaryomyces dominated the bacterial and yeast/fungal microbiota, respectively, in the industrial beverages. This is the first report on the microbiota of kefir produced in Greece by a holistic approach combining classical microbiological, molecular, and amplicon-based metagenomics analyses.
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Affiliation(s)
- Maria Kazou
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
| | - Andriana Grafakou
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
| | - Effie Tsakalidou
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
| | - Marina Georgalaki
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Athens, Greece
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Robak K, Balcerek M. Current state-of-the-art in ethanol production from lignocellulosic feedstocks. Microbiol Res 2020; 240:126534. [PMID: 32683278 DOI: 10.1016/j.micres.2020.126534] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 01/08/2023]
Abstract
The renewable lignocellulosic biomass is a sustainable feedstock for the production of bioethanol, which shows the potential to replace fossil fuels. Due to the recalcitrant structure of plant cell wall made of cellulose, hemicellulose, and lignin, the biomass conversion process requires the use of efficient pretreatment process before enzymatic hydrolysis and fermentation to degrade the crystallinity of cellulose fibres and to remove lignin from biomass. Proper pretreatment techniques, economical production of cellulolytic enzymes, and effective fermentation of glucose and xylose in the presence of inhibitors are key challenges for the viable production of bioethanol. Although new strains capable of fermenting xylose are being designed, they are often not resistant to toxic compounds in hydrolysates. This paper provides an in-depth review of lignocellulosic bioethanol production via biochemical route, focusing on the most widely used pretreatment technologies and key operational conditions of enzymatic hydrolysis and fermentation considering sugar/ethanol yields. In addition, this review examines the relevant detoxification strategies for the removal of toxic substances and the importance of immobilization. The review also indicates potential usage of engineered microorganisms to improve glucose and xylose fermentation, cellulolytic enzymes production, and response to stress conditions.
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Affiliation(s)
- Katarzyna Robak
- Lodz University of Technology, Faculty of Biotechnology and Food Sciences, Institute of Fermentation Technology and Microbiology, Wólczańska 171/173, 90-924 Łódź, Poland.
| | - Maria Balcerek
- Lodz University of Technology, Faculty of Biotechnology and Food Sciences, Institute of Fermentation Technology and Microbiology, Wólczańska 171/173, 90-924 Łódź, Poland
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Unraveling the Microbiota of Natural Black cv. Kalamata Fermented Olives through 16S and ITS Metataxonomic Analysis. Microorganisms 2020; 8:microorganisms8050672. [PMID: 32384669 PMCID: PMC7284738 DOI: 10.3390/microorganisms8050672] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/02/2020] [Accepted: 05/04/2020] [Indexed: 11/23/2022] Open
Abstract
Kalamata natural black olives are one of the most economically important Greek varieties. The microbial ecology of table olives is highly influenced by the co-existence of bacteria and yeasts/fungi, as well as the physicochemical parameters throughout the fermentation. Therefore, the aim of this study was the identification of bacterial and yeast/fungal microbiota of both olives and brines obtained from 29 cv. Kalamata olive samples industrially fermented in the two main producing geographical regions of Greece, namely Aitoloakarnania and Messinia/Lakonia. The potential microbial biogeography association between certain taxa and geographical area was also assessed. The dominant bacterial family identified in olive and brine samples from both regions was Lactobacillaceae, presenting, however, higher average abundances in the samples from Aitoloakarnania compared to Messinia/Lakonia. At the genus level, Lactobacillus, Celerinatantimonas, Propionibacterium and Pseudomonas were the most abundant. In addition, the yeasts/fungal communities were less diverse compared to those of bacteria, with Pichiaceae being the dominant family and Pichia, Ogataea, and Saccharomyces being the most abundant genera. To the best of our knowledge, this is the first report on the microbiota of both olives and brines of cv. Kalamata black olives fermented on an industrial scale between two geographical regions of Greece using metagenomics analysis.
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Pistacia terebinthus Resin as Yeast Immobilization Support for Alcoholic Fermentation. Foods 2019; 8:foods8040127. [PMID: 30999587 PMCID: PMC6518291 DOI: 10.3390/foods8040127] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/09/2019] [Accepted: 04/12/2019] [Indexed: 01/01/2023] Open
Abstract
A natural resin retrieved from Pistacia terebinthus tree was evaluated as an immobilization carrier of Saccharomyces cerevisiae AXAZ-1 cells targeting successive fermentation batches of sugar synthetic mediums. Fermentation times below 54 h were recorded at temperatures 28–14 °C. In total, 147 compounds were detected using gas chromatography-mass spectrometry (GC-MS) analysis, including alcohols, esters, ketones, aldehydes, acids, and terpenes. Principal component analysis indicated that the state of cells (free/immobilized) and the fermentation temperature primarily affected terpenes’ composition. Importantly, no spoilage of the fermented beverages was noted during 90 days of storage at room temperature, most likely due to the high content of extracted terpenoids and phenols (up to 579.01 mg L−1 and 171.8 mg gallic acid equivalent L−1, respectively). Likewise, the developed novel biocatalyst (yeast cells immobilized within Pistacia terebinthus resin) was suitable for the production of low alcohol beverages with an enhanced aromatic profile. The obtained results revealed that the proposed bioprocess shows great commercialization potential in the new fast-growing low-alcohol beverages sector.
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Revealing new promoters in whey fermentation leads to a new research concept. Heliyon 2019; 5:e01262. [PMID: 30891511 PMCID: PMC6395786 DOI: 10.1016/j.heliyon.2019.e01262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/29/2022] Open
Abstract
The current investigation reveals new findings concerning the substantial promotional activity of orange juice, orange peel and molasses on whey fermentation using single cell culture of kefir microflora. Specifically, the addition in whey of only 1 % v/v orange juice or 1% v/v molasses - 4% w/v orange peel reduced the fermentation time to 10 from 70 hours. But the lowest fermentation time (9 h) was observed when a composite biocatalyst consisted of cells entrapped with orange peel in corn starch gel was used, where also the highest 14C-labeled lactose uptake rate by kefir was recorded. Bio-ethanol concentrations were increased using all the aforementioned promoters too and volatile byproducts such as esters were raised during the whey-orange juice mixtures fermentations, while terpenes by composite biocatalyst. The findings could be the base for new research projects for the rapid production of novel food stuffs and chemicals using whey as raw material.
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Nikolaou A, Kourkoutas Y. Exploitation of olive oil mill wastewaters and molasses for ethanol production using immobilized cells of Saccharomyces cerevisiae. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:7401-7408. [PMID: 29280099 DOI: 10.1007/s11356-017-1051-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/13/2017] [Indexed: 06/07/2023]
Abstract
An alcoholic fermentation process is described, involving molasses, the main by-product of the sugar industry, blended with crude olive oil mill wastewaters (OOMWs) and immobilized Saccharomyces cerevisiae cells on delignified cellulosic material (DCM). For comparison, fermentations with free cells were also carried out. Initially, the optimum blending mixture for molasses dilution was sought after, while at a second step repeated batch fermentations at a temperature range 5-30 °C were performed to monitor the operational stability of the system. A 1/1 ratio of OOMWs/tap water blending mixture and cell immobilization resulted in higher fermentation parameters. Ethanol concentration and daily productivity values recorded at temperatures ≥ 20 °C (up to 67.8 g L-1 and 67.6 g L-1 d-1, respectively) could be adopted by the industrial sector, although the decline in fermentation efficiency observed, probably due to the toxicity effects of OOMWs. Finally, the potential of OOMWs treatment for ethanol production is highlighted and assessed.
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Affiliation(s)
- Anastasios Nikolaou
- Laboratory of Applied Microbiology and Biotechnology, Department of Molecular Biology & Genetics, Democritus University of Thrace, 681 00, Alexandroupolis, Greece
| | - Yiannis Kourkoutas
- Laboratory of Applied Microbiology and Biotechnology, Department of Molecular Biology & Genetics, Democritus University of Thrace, 681 00, Alexandroupolis, Greece.
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Djelal H, Chniti S, Jemni M, Weill A, Sayed W, Amrane A. Identification of strain isolated from dates (Phœnix dactylifera L.) for enhancing very high gravity ethanol production. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:9886-9894. [PMID: 27838909 DOI: 10.1007/s11356-016-8018-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/28/2016] [Indexed: 06/06/2023]
Abstract
Ethanol production from by-products of dates in very high gravity was conducted in batch fermentation using two yeasts, Saccharomyces cerevisiae and Zygosaccharomyces rouxii, as well as a native strain: an osmophilic strain of bacteria which was isolated for the first time from the juice of dates (Phoenix dactylifera L.). The phylogenetic analysis based on the 16S ribosomal RNA and gyrB sequence and physiological analysis indicated that the strain identified belongs to the genus of Bacillus, B. amyloliquefaciens. The ethanol yields produced from the syrup of dates (175 g L-1 and 360 g L-1 of total sugar) were 40.6% and 29.5%, respectively. By comparing the ethanol production by the isolated bacteria to that obtained using Z. rouxii and S. cerevisiae, it can be concluded that B. amyloliquefaciens was suitable for ethanol production from the syrup of dates and can consume the three types of sugar (glucose, fructose, and sucrose). Using Z. rouxii, fructose was preferentially consumed, while glucose was consumed only after fructose depletion. From this, B. amyloliquefaciens was promising for the bioethanol industry. In addition, this latter showed a good tolerance for high sugar concentration (36%), allowing ethanol production in batch fermentation at pH 5.0 and 28 °C in date syrup medium. Promising ethanol yield produced to sugar consumed were observed for the two osmotolerant microorganisms, Z. rouxii and B. amyloliquefaciens, nearly 32-33%, which were further improved when they were cocultivated, leading to an ethanol to glucose yield of 42-43%.
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Affiliation(s)
- Hayet Djelal
- Ecole des Métiers de l'Environnement, Campus de Ker Lann, 35 170, Bruz, France.
- Université de Rennes 1, ENSCR, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France.
| | - Sofien Chniti
- Ecole des Métiers de l'Environnement, Campus de Ker Lann, 35 170, Bruz, France
- Université de Rennes 1, ENSCR, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France
- Ecole Supérieure des Industries Alimentaires de Tunis, Université Carthage, et sis Avenue de la République, B. P 77, 1054, Amilcar, Tunisie
| | - Monia Jemni
- Centre Régional de Recherche en Agriculture Oasienne de Degueche, Laboratoire de technologies de dattes, Toreur, Tunisie
| | - Amélie Weill
- EQUASA Centre de Ressources en Qualité et Sécurité dans l'Agriculture et les Industries Agro-alimentaires, Technopole Brest-Iroise-Parvis Blaise Pascal, 29280, Plouzane, France
| | - Walaa Sayed
- Ecole des Métiers de l'Environnement, Campus de Ker Lann, 35 170, Bruz, France
| | - Abdeltif Amrane
- Université de Rennes 1, ENSCR, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France
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Scoma A, Coma M, Kerckhof FM, Boon N, Rabaey K. Efficient molasses fermentation under high salinity by inocula of marine and terrestrial origin. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:23. [PMID: 28163780 PMCID: PMC5282813 DOI: 10.1186/s13068-017-0701-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/05/2017] [Indexed: 05/14/2023]
Abstract
BACKGROUND Molasses is a dense and saline by-product of the sugar agroindustry. Its high organic content potentially fuels a myriad of renewable products of industrial interest. However, the biotechnological exploitation of molasses is mainly hampered by the high concentration of salts, an issue that is nowadays tackled through dilution. In the present study, the performance of microbial communities derived from marine sediment was compared to that of communities from a terrestrial environment (anaerobic digester sludge). The aim was to test whether adaptation to salinity represented an advantage for fermenting molasses into renewable chemicals such as volatile fatty acids (VFAs) although high sugar concentrations are uncommon to marine sediment, contrary to anaerobic digesters. RESULTS Terrestrial and marine microbial communities were enriched in consecutive batches at different initial pH values (pHi; either 6 or 7) and molasses dilutions (equivalent to organic loading rates (OLRs) of 1 or 5 gCOD L-1 d-1) to determine the best VFA production conditions. Marine communities were supplied with NaCl to maintain their native salinity. Due to molasses inherent salinity, terrestrial communities experienced conditions comparable to brackish or saline waters (20-47 mS cm-1), while marine conditions resembled brine waters (>47 mS cm-1). Enrichments at optimal conditions of OLR 5 gCOD L-1 d-1 and pHi 7 were transferred into packed-bed biofilm reactors operated continuously. The reactors were first operated at 5 gCOD L-1 d-1, which was later increased to OLR 10 gCOD L-1 d-1. Terrestrial and marine reactors had different gas production and community structures but identical, remarkably high VFA bioconversion yields (above 85%) which were obtained with conductivities up to 90 mS cm-1. COD-to-VFA conversion rates were comparable to the highest reported in literature while processing other organic leftovers at much lower salinities. CONCLUSIONS Although salinity represents a major driver for microbial community structure, proper acclimation yielded highly efficient systems treating molasses, irrespective of the inoculum origin. Selection of equivalent pathways in communities derived from different environments suggests that culture conditions select for specific functionalities rather than microbial representatives. Mass balances, microbial community composition, and biochemical analysis indicate that biomass turnover rather than methanogenesis represents the main limitation to further increasing VFA production with molasses. This information is relevant to moving towards molasses fermentation to industrial application.
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Affiliation(s)
- Alberto Scoma
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
- Center for Geomicrobiology, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Marta Coma
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
- Centre for Sustainable Chemical Technologies (CSCT), University of Bath, Claverton Down, Bath, BA2 7AY UK
| | - Frederiek-Maarten Kerckhof
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
| | - Nico Boon
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
| | - Korneel Rabaey
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
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11
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Scoma A, Coma M, Kerckhof FM, Boon N, Rabaey K. Efficient molasses fermentation under high salinity by inocula of marine and terrestrial origin. BIOTECHNOLOGY FOR BIOFUELS 2017. [PMID: 28163780 DOI: 10.1186/s13068-017-0701-8%3fsite%3dbiotechnologyforbiofuels.biomedcentral.com] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
BACKGROUND Molasses is a dense and saline by-product of the sugar agroindustry. Its high organic content potentially fuels a myriad of renewable products of industrial interest. However, the biotechnological exploitation of molasses is mainly hampered by the high concentration of salts, an issue that is nowadays tackled through dilution. In the present study, the performance of microbial communities derived from marine sediment was compared to that of communities from a terrestrial environment (anaerobic digester sludge). The aim was to test whether adaptation to salinity represented an advantage for fermenting molasses into renewable chemicals such as volatile fatty acids (VFAs) although high sugar concentrations are uncommon to marine sediment, contrary to anaerobic digesters. RESULTS Terrestrial and marine microbial communities were enriched in consecutive batches at different initial pH values (pHi; either 6 or 7) and molasses dilutions (equivalent to organic loading rates (OLRs) of 1 or 5 gCOD L-1 d-1) to determine the best VFA production conditions. Marine communities were supplied with NaCl to maintain their native salinity. Due to molasses inherent salinity, terrestrial communities experienced conditions comparable to brackish or saline waters (20-47 mS cm-1), while marine conditions resembled brine waters (>47 mS cm-1). Enrichments at optimal conditions of OLR 5 gCOD L-1 d-1 and pHi 7 were transferred into packed-bed biofilm reactors operated continuously. The reactors were first operated at 5 gCOD L-1 d-1, which was later increased to OLR 10 gCOD L-1 d-1. Terrestrial and marine reactors had different gas production and community structures but identical, remarkably high VFA bioconversion yields (above 85%) which were obtained with conductivities up to 90 mS cm-1. COD-to-VFA conversion rates were comparable to the highest reported in literature while processing other organic leftovers at much lower salinities. CONCLUSIONS Although salinity represents a major driver for microbial community structure, proper acclimation yielded highly efficient systems treating molasses, irrespective of the inoculum origin. Selection of equivalent pathways in communities derived from different environments suggests that culture conditions select for specific functionalities rather than microbial representatives. Mass balances, microbial community composition, and biochemical analysis indicate that biomass turnover rather than methanogenesis represents the main limitation to further increasing VFA production with molasses. This information is relevant to moving towards molasses fermentation to industrial application.
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Affiliation(s)
- Alberto Scoma
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
- Center for Geomicrobiology, Aarhus University, Ny Munkegade 116, 8000 Aarhus C, Denmark
| | - Marta Coma
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
- Centre for Sustainable Chemical Technologies (CSCT), University of Bath, Claverton Down, Bath, BA2 7AY UK
| | - Frederiek-Maarten Kerckhof
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
| | - Nico Boon
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
| | - Korneel Rabaey
- Center of Microbial Ecology and Technology (CMET), University of Gent, Coupure Links 653, 9000 Ghent, Belgium
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Hydrosol of Thymbra capitata Is a Highly Efficient Biocide against Salmonella enterica Serovar Typhimurium Biofilms. Appl Environ Microbiol 2016; 82:5309-19. [PMID: 27342550 DOI: 10.1128/aem.01351-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/16/2016] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Salmonella is recognized as one of the most significant enteric foodborne bacterial pathogens. In recent years, the resistance of pathogens to biocides and other environmental stresses, especially when they are embedded in biofilm structures, has led to the search for and development of novel antimicrobial strategies capable of displaying both high efficiency and safety. In this direction, the aims of the present work were to evaluate the antimicrobial activity of hydrosol of the Mediterranean spice Thymbra capitata against both planktonic and biofilm cells of Salmonella enterica serovar Typhimurium and to compare its action with that of benzalkonium chloride (BC), a commonly used industrial biocide. In order to achieve this, the disinfectant activity following 6-min treatments was comparatively evaluated for both disinfectants by calculating the concentrations needed to achieve the same log reductions against both types of cells. Their bactericidal effect against biofilm cells was also comparatively determined by in situ and real-time visualization of cell inactivation through the use of time-lapse confocal laser scanning microscopy (CLSM). Interestingly, results revealed that hydrosol was almost equally effective against biofilms and planktonic cells, whereas a 200-times-higher concentration of BC was needed to achieve the same effect against biofilm compared to planktonic cells. Similarly, time-lapse CLSM revealed the significant advantage of the hydrosol to easily penetrate within the biofilm structure and quickly kill the cells, despite the three-dimensional (3D) structure of Salmonella biofilm. IMPORTANCE The results of this paper highlight the significant antimicrobial action of a natural compound, hydrosol of Thymbra capitata, against both planktonic and biofilm cells of a common foodborne pathogen. Hydrosol has numerous advantages as a disinfectant of food-contact surfaces. It is an aqueous solution which can easily be rinsed out from surfaces, it does not have the strong smell of the essential oil (EO) and it is a byproduct of the EO distillation procedure without any industrial application until now. Consequently, hydrosol obviously could be of great value to combat biofilms and thus to improve product safety not only for the food industries but probably also for many other industries which experience biofilm-related problems.
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Dubey R, Jakeer S, Gaur NA. Screening of natural yeast isolates under the effects of stresses associated with second-generation biofuel production. J Biosci Bioeng 2016; 121:509-16. [DOI: 10.1016/j.jbiosc.2015.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 09/04/2015] [Accepted: 09/08/2015] [Indexed: 11/16/2022]
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Sarris D, Papanikolaou S. Biotechnological production of ethanol: Biochemistry, processes and technologies. Eng Life Sci 2016. [DOI: 10.1002/elsc.201400199] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Dimitris Sarris
- Laboratory of Food Microbiology and Biotechnology Department of Food Science and Human Nutrition, Agricultural University of Athens Athens Greece
| | - Seraphim Papanikolaou
- Laboratory of Food Microbiology and Biotechnology Department of Food Science and Human Nutrition, Agricultural University of Athens Athens Greece
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Pérez-Torrado R, Gamero E, Gómez-Pastor R, Garre E, Aranda A, Matallana E. Yeast biomass, an optimised product with myriad applications in the food industry. Trends Food Sci Technol 2015. [DOI: 10.1016/j.tifs.2015.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Schoina V, Terpou A, Angelika-Ioanna G, Koutinas A, Kanellaki M, Bosnea L. Use of Pistacia terebinthus resin as immobilization support for Lactobacillus casei cells and application in selected dairy products. JOURNAL OF FOOD SCIENCE AND TECHNOLOGY 2015; 52:5700-8. [PMID: 26344983 PMCID: PMC4554640 DOI: 10.1007/s13197-014-1627-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 10/16/2014] [Accepted: 10/23/2014] [Indexed: 10/24/2022]
Abstract
Resin from Pistacia terebinthus tree was used for the immobilization of L. casei ATCC 393 cells. The encapsulated L. casei cells biocatalysts were added as adjuncts during yogurt production at 45 °C and probiotic viability was assessed during storage at 4 °C. For comparison reasons yogurt with free L. casei cells were prepared. The effect of encapsulated bacteria as adjuncts in yogurt on pH, lactic acid, lactose and other physicochemical parameters were studied for 60 storage days at 4 °C. Samples were also tested for the microbiological and organoleptic characteristics during storage at 4 °C. Encapsulation matrix seems to sustain the viability of embedded L. casei cells at levels more than 7 logcfug(-1) after 60 days of storage at 4 °C. Furthermore, the absence of pathogens such as Salmonella, Staphylococci, Enterobacteriaceae and coliforms in the produced yogurts is noteworthy where spoilage microorganisms such as yeasts and molds seem to affect yogurt quality only in absence of Pistacia terebinthus resin. The effect of the resin on production of aroma-related compounds responsible for yogurt flavor was also studied using the solid phase microextraction gas chromatography/mass spectrometry technique. Alpha and beta- pinene were the major aroma compounds detected in produced yogurts (over 60 % of total aromatic compounds detected). Yogurts with immobilized cells on P.terebintus resin had a fine aroma and taste characteristic of the resin.
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Affiliation(s)
- Vasiliki Schoina
- Department of Chemistry, Food Biotechnology Group, University of Patras, Patras, Greece
| | - Antonia Terpou
- Department of Chemistry, Food Biotechnology Group, University of Patras, Patras, Greece
| | | | - Athanasios Koutinas
- Department of Chemistry, Food Biotechnology Group, University of Patras, Patras, Greece
| | - Maria Kanellaki
- Department of Chemistry, Food Biotechnology Group, University of Patras, Patras, Greece
| | - Loulouda Bosnea
- Department of Chemistry, Food Biotechnology Group, University of Patras, Patras, Greece
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Production of L-ornithine from sucrose and molasses by recombinant Corynebacterium glutamicum. Folia Microbiol (Praha) 2014; 60:393-8. [DOI: 10.1007/s12223-014-0371-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 12/11/2014] [Indexed: 01/02/2023]
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18
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Xu W, Liang L, Song Z, Zhu M. Continuous ethanol production from sugarcane molasses using a newly designed combined bioreactor system by immobilized Saccharomyces cerevisiae. Biotechnol Appl Biochem 2014; 61:289-96. [PMID: 24164318 DOI: 10.1002/bab.1175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 10/17/2013] [Indexed: 11/08/2022]
Abstract
Continuous ethanol fermentation using polyvinyl alcohol (PVA), immobilized yeast, and sugarcane molasses (22 and 35°Bx) with 8 g/L urea was run in a combined bioreactor system consisting of three-stage tubular bioreactors in series. The effect of the dilution rate (D) at 0.0037, 0.0075, 0.0117, 0.0145, 0.018, and 0.0282 H(-1) on continuous ethanol fermentation was investigated in this study. The results showed that D had a significant effect on fermentation efficiency, sugar-utilized rate, ethanol yield, and ethanol productivity in this designed continuous fermentation system. The D had a linear relationship with residual sugar and ethanol production under certain conditions. The highest fermentation efficiency of 83.26%, ethanol yield of 0.44 g/g, and the lowest residual sugar content of 6.50 g/L were achieved at 0.0037 H(-1) in the fermentation of 22°Bx molasses, indicating that the immobilization of cells using PVA, sugarcane pieces, and cotton towel is feasible and the established continuous system performs well.
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Affiliation(s)
- Wanxia Xu
- School of Bioscience and Bioengineering, South China University of Technology, Panyu, Guangzhou, People's Republic of China
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Improvement of cell growth and L-lysine production by genetically modified Corynebacterium glutamicum during growth on molasses. J Ind Microbiol Biotechnol 2013; 40:1423-32. [PMID: 24029876 DOI: 10.1007/s10295-013-1329-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 08/06/2013] [Indexed: 12/14/2022]
Abstract
Fructose-1,6-bisphosphatase (FBPase) and fructokinase (ScrK) have important roles in regenerating glucose-6-phosphate in the pentose phosphate pathway (PPP), and thus increasing L-lysine production. This article focuses on the development of L-lysine high-producing strains by heterologous expression of FBPase gene fbp and ScrK gene scrK in C. glutamicum lysC (fbr) with molasses as the sole carbon source. Heterologous expression of fbp and scrK lead to a decrease of residual sugar in fermentation broth, and heterologous expression of scrK prevents the fructose efflux. Heterologous expression of fbp and scrK not only increases significantly the activity of corresponding enzymes but also improves cell growth during growth on molasses. FBPase activities are increased tenfold by heterologous expression of fbp, whereas the FBPase activity is only increase fourfold during co-expression of scrK and fbp. Compared with glucose, the DCW of heterologous expression strains are higher on molasses except co-expression of fbp and scrK strain. In addition, heterologous expression of fbp and scrK can strongly increase the L-lysine production with molasses as the sole carbon source. The highest increase (88.4 %) was observed for C. glutamicum lysC (fbr) pDXW-8-fbp-scrK, but the increase was also significant for C. glutamicum lysC (fbr) pDXW-8-fbp (47.2 %) and C. glutamicum lysC (fbr) pDXW-8-scrK (36.8 %). By-products, such as glycerol and dihydroxyacetone, are decreased by heterologous expression of fbp and scrK, whereas trehalose is only slightly increased. The strategy for enhancing L-lysine production by regeneration of glucose-6-phosphate in PPP may provide a reference to enhance the production of other amino acids during growth on molasses or starch.
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Jin M, Sarks C, Gunawan C, Bice BD, Simonett SP, Avanasi Narasimhan R, Willis LB, Dale BE, Balan V, Sato TK. Phenotypic selection of a wild Saccharomyces cerevisiae strain for simultaneous saccharification and co-fermentation of AFEX™ pretreated corn stover. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:108. [PMID: 23890073 PMCID: PMC3729497 DOI: 10.1186/1754-6834-6-108] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 07/25/2013] [Indexed: 05/09/2023]
Abstract
BACKGROUND Simultaneous saccharification and co-fermentation (SSCF) process involves enzymatic hydrolysis of pretreated lignocellulosic biomass and fermentation of glucose and xylose in one bioreactor. The optimal temperatures for enzymatic hydrolysis are higher than the standard fermentation temperature of ethanologenic Saccharomyces cerevisiae. Moreover, degradation products resulting from biomass pretreatment impair fermentation of sugars, especially xylose, and can synergize with high temperature stress. One approach to resolve both concerns is to utilize a strain background with innate tolerance to both elevated temperatures and degradation products. RESULTS In this study, we screened a panel of 108 wild and domesticated Saccharomyces cerevisiae strains isolated from a wide range of environmental niches. One wild strain was selected based on its growth tolerance to simultaneous elevated temperature and AFEX™ (Ammonia Fiber Expansion) degradation products. After engineering the strain with two copies of the Scheffersomyces stipitis xylose reductase, xylitol dehydrogenase and xylulokinase genes, we compared the ability of this engineered strain to the benchmark 424A(LNH-ST) strain in ethanol production and xylose fermentation in standard lab medium and AFEX pretreated corn stover (ACS) hydrolysates, as well as in SSCF of ACS at different temperatures. In SSCF of 9% (w/w) glucan loading ACS at 35°C, the engineered strain showed higher cell viabilities and produced a similar amount of ethanol (51.3 g/L) compared to the benchmark 424A(LNH-ST) strain. CONCLUSION These results validate our approach in the selection of wild Saccharomyces cerevisiae strains with thermo-tolerance and degradation products tolerance properties for lignocellulosic biofuel production. The wild and domesticated yeast strains phenotyped in this work are publically available for others to use as genetic backgrounds for fermentation of their pretreated biomass at elevated temperatures.
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Affiliation(s)
- Mingjie Jin
- Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
| | - Cory Sarks
- Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
| | - Christa Gunawan
- Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
| | - Benjamin D Bice
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 1552 University Ave, Madison, WI 53726, USA
| | - Shane P Simonett
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - Ragothaman Avanasi Narasimhan
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 1552 University Ave, Madison, WI 53726, USA
| | - Laura B Willis
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 1552 University Ave, Madison, WI 53726, USA
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
- U.S. Department of Agriculture, Forest Products Laboratory, 1 Gifford Pinchot Dr, Madison, WI 53726, USA
| | - Bruce E Dale
- Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
| | - Venkatesh Balan
- Biomass Conversion Research Laboratory (BCRL), Department of Chemical Engineering and Materials Science, Michigan State University, 3900 Collins Road, Lansing, MI 48910, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824, USA
| | - Trey K Sato
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, 1552 University Ave, Madison, WI 53726, USA
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Kwon YJ, Wang F, Li Q, Liu CZ. Effect of temperature on ethanol tolerance of thermotolerantIsshatchenkia orientalisIPE100. Eng Life Sci 2012. [DOI: 10.1002/elsc.201100205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
| | - Feng Wang
- National Key Laboratory of Biochemical Engineering; Institute of Process Engineering; Chinese Academy of Sciences; Beijing; P. R. China
| | | | - Chun-Zhao Liu
- National Key Laboratory of Biochemical Engineering; Institute of Process Engineering; Chinese Academy of Sciences; Beijing; P. R. China
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Golfinopoulos A, Soupioni M, Kopsahelis N, Tsaousi K, Koutinas AA. Lactose uptake rate measurements by 14C-labelled lactose reveals promotional activity of porous cellulose in whey fermentation by kefir yeast. Food Chem 2012; 134:1973-81. [DOI: 10.1016/j.foodchem.2012.03.126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 03/17/2012] [Accepted: 03/28/2012] [Indexed: 11/24/2022]
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Zheng C, Sun X, Li L, Guan N. Scaling up of ethanol production from sugar molasses using yeast immobilized with alginate-based MCM-41 mesoporous zeolite composite carrier. BIORESOURCE TECHNOLOGY 2012; 115:208-214. [PMID: 22154581 DOI: 10.1016/j.biortech.2011.11.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 11/14/2011] [Accepted: 11/16/2011] [Indexed: 05/31/2023]
Abstract
Microporous and mesoporous zeolites, including ZSM-5, H-β, H-Y, and MCM-41, were modified with 3-aminopropyl-triethoxysilane (APTES), then inorganic fillers, such as abovementioned zeolites or mesoporous materials, (α-AlOOH or γ-Al(2)O(3)), were mixed with alginate embedded with yeast; and finally these carriers were cross-linked through the double oxirane. The alginate-based immobilized yeast with MCM-41 exhibited much shorter fermentation time and higher ethanol concentration than pure alginate and other composite carriers with the highest cell concentration of 4.8×10(9) cells/mL. The composite carrier maintains the highest ethanol productivity of 6.55 g/L/h for 60 days in continuous fermentation process, implying good operational durability for commercial applications. The reason for the higher bio-catalytical function of the immobilized yeast might lay in the uniformly yeast distribution in the bio-reactor and high yeast cell concentration, which contributed by the improved transmission of fermentation media and combined effects of yeast adsorption by MCM-41 and embedment by alginate.
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Affiliation(s)
- Chunming Zheng
- State Key Laboratory of Hollow-fiber Membrane Materials and Membrane Processes, School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387, PR China
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Kopsahelis N, Bosnea L, Kanellaki M, Koutinas AA. Volatiles formation from grape must fermentation using a cryophilic and thermotolerant yeast. Appl Biochem Biotechnol 2012; 167:1183-98. [PMID: 22328258 DOI: 10.1007/s12010-012-9582-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 01/20/2012] [Indexed: 11/30/2022]
Abstract
Grape must fermentation performance and volatiles formation by simultaneously cryophilic and thermotolerant yeast (strain AXAZ-1), isolated from grapes in Greece, was evaluated in a wide temperature range (5-40°C). Yeast strain was immobilized on brewer's spent grains (BSG) and the formed biocatalyst was introduced into a Multi-Stage Fixed Bed Tower (MFBT) bioreactor. Almost complete sugar utilization from the aforementioned biocatalyst was observed in a wide temperature spectrum, ranging from 5 °C to 37 °C, while at 40 °C residual sugar was up to 29 g/l. Time to complete fermentation with the immobilized yeast ranged from 290 h at 5 °C and 120 h at 40 °C to 25 h at 33 °C. The daily ethanol productivity reached maximum (88.6 g/l) and minimum (5.6 g/l) levels at 33 °C and 5 °C, respectively. The aroma-related compounds' profiles of immobilized cells at different fermentation temperatures were evaluated by using solid phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS). Must fermentation resulted in a high-quality fermentation product due to the low concentrations of higher and amyl alcohols at all temperatures tested. AXAZ-1 is a very promising strain for quality wine production, as it is capable of performing fermentations of high ethanol concentration and productivities in both low and high temperatures.
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Affiliation(s)
- Nikolaos Kopsahelis
- Food Biotechnology Group, Section of Analytical Environmental and Applied Chemistry, Department of Chemistry, University of Patras, 26500 Patras, Greece.
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Golfinopoulos A, Kopsahelis N, Tsaousi K, Koutinas AA, Soupioni M. Research perspectives and role of lactose uptake rate revealed by its study using 14C-labelled lactose in whey fermentation. BIORESOURCE TECHNOLOGY 2011; 102:4204-4209. [PMID: 21232943 DOI: 10.1016/j.biortech.2010.12.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 12/11/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
The present investigation examines the effect of pH, temperature and cell concentration on lactose uptake rate, in relation with kinetics of whey fermentation using kefir and determines the optimum conditions of these parameters. Lactose uptake rate was measured by adding (14)C-labelled lactose in whey. The results reveal the role of lactose uptake rate, being the main factor that affects the rate of fermentation, in contrast to the activity of the enzymes involved in lactose bioconversion process. Lactose uptake rate results discussion showed that mainly Ca(2+) is responsible for the reduced whey fermentation rate in comparison with fermentations using synthetic media containing lactose. Likewise, the results draw up perspectives on whey fermentation research to improve whey fermentation rate. Those perspectives are research to remove Ca(2+) from whey, the use of nano and microtubular biopolymers and promoters such as γ-alumina pellets and volcan foaming rock kissiris in order to accelerate whey fermentation.
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Affiliation(s)
- Aristidis Golfinopoulos
- Food Biotechnology Group, Department of Chemistry, University of Patras, GR-26500 Patras, Greece
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Ouyang G, Vuckovic D, Pawliszyn J. Nondestructive Sampling of Living Systems Using in Vivo Solid-Phase Microextraction. Chem Rev 2011; 111:2784-814. [DOI: 10.1021/cr100203t] [Citation(s) in RCA: 369] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Gangfeng Ouyang
- MOE Key Laboratory of Aquatic Product Safety/KLGHEI of Environment and Energy Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Dajana Vuckovic
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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