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Chen K, Deng X, Jiang D, Qin L, Lu M, Jiang W, Yang M, Zhang L, Jiang J, Lu L. Efficient conversion of distillers grains as feed ingredient by synergy of probiotics and enzymes. Front Microbiol 2024; 15:1403011. [PMID: 39027099 PMCID: PMC11254791 DOI: 10.3389/fmicb.2024.1403011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 06/25/2024] [Indexed: 07/20/2024] Open
Abstract
The direct feeding value of distillers grains is low due to the presence of higher cellulose, lignin and anti-nutritional factors such as mannan and xylan. In this study, complex enzymes and probiotic flora based on "probiotic enzyme synergy" technology were used to produce fermented distillers grains. The optimal substrate ratio, moisture content, fermentation time and temperature were determined. Subsequently, scale-up experiments were conducted to determine the performance of fermented feed. The results showed that multi-probiotic (Lactobacillus casei, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus oryzae) cooperated with complex enzymes (glucanase, mannanase, xylanase) showed excellent fermentation effect, crude protein, trichloroacetic acid soluble protein and fat increased by 31.25, 36.68, and 49.11% respectively, while crude fiber, acidic fiber and neutral fiber decreased by 34.24, 26.91, and 33.20%, respectively. The anti-nutritional factors mannan and arabinoxylan were reduced by 26.96 and 40.87%, respectively. Lactic acid, acetic acid, and propionic acid in the fermented organic acids increased by 240.93, 76.77, and 89.47%, respectively. Butyric acid increased significantly from scratch, and the mycotoxin degradation effect was not significant. This study provides a potential approach for high-value utilization of distillers grains.
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Affiliation(s)
- Kai Chen
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Xiangrong Deng
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
| | - Dahai Jiang
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Lanxian Qin
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
| | - Mengqi Lu
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
| | - Wenxuan Jiang
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Manqi Yang
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Liangliang Zhang
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
| | - Jianchun Jiang
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
- Institute of Chemical Industry of Forest Products, Nanjing, China
| | - Liming Lu
- Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen, China
- Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion, Huaqiao University, Xiamen, China
- College of Chemical Engineering, Huaqiao University, Xiamen, China
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Alebouyeh M, Almasian Tehrani N, Fallah F, Azimi L, Sadredinamin M, Yousefi N, Ghandchi G, Haji Molla Hoseini M. Protective effects of different lyoprotectants on survival of clinical bacterial isolates in a hospital biobank. Cryobiology 2024; 115:104891. [PMID: 38522663 DOI: 10.1016/j.cryobiol.2024.104891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 03/04/2024] [Accepted: 03/21/2024] [Indexed: 03/26/2024]
Abstract
Nowadays the significant role of biobanks in medical, diagnostic, industrial, and environmental research is well known. Bacterial biobanks could be used as a good resource for designing new treatments, biomedical and industrial researches, and laboratory diagnostics. To have a collection of bacteria from clinical samples and maintain their long-term viability, their preservation needs appropriate protective agents, like cryoprotectants and lyoprotectants. In this study, we collected and characterized Gram-negative and Gram-positive bacteria carrying important antibiotic resistance markers from different clinical samples of hospitalized children. Sucrose (10%), skimmed milk (10%), skimmed milk plus sodium glutamate (10% + 1%), and bovine serum albumin (BSA, 10%) were used as lyoprotectants during the freeze-drying procedure. The survival rate of the lyophilized samples was calculated by dilution plating and measuring the colony forming unit (CFU) after 3 months of storage. The culture analysis results indicated that 25 of the 27 studied bacterial genera (Dilutions 10-3 to 10-6), including Shigella, Methicillin-resistant S. aureus, Acinetobacter spp., Escherichia spp., Pseudomonas spp., Klebsiella spp., Enterococcus spp., were recovered in cultured fractions from all preservation conditions, while 2 genera were only detected in a single preservation condition (2/27, 7.4%). Based on the results, sucrose (10%) and skimmed milk (10%) presented the most protective features. The survival rates varied significantly according to types of the bacteria. Collectively, our results showed a diversity in the recovery of different bacterial genera after lyophilization. While statistically no significant difference was detected among the studied protective agents, sucrose (10%) and skimmed milk (10%) exhibited more effective lyoprotective properties for both Gram-positive and Gram-negative bacteria among the clinical isolates in our study.
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Affiliation(s)
- Masoud Alebouyeh
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasim Almasian Tehrani
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Fallah
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Leila Azimi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehrzad Sadredinamin
- Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Neda Yousefi
- Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ghazale Ghandchi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mostafa Haji Molla Hoseini
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Wu M, Pakroo S, Nadai C, Molinelli Z, Speciale I, De Castro C, Tarrah A, Yang J, Giacomini A, Corich V. Genomic and functional evaluation of exopolysaccharide produced by Liquorilactobacillus mali t6-52: technological implications. Microb Cell Fact 2024; 23:158. [PMID: 38812023 PMCID: PMC11138040 DOI: 10.1186/s12934-024-02431-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 05/20/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND This study explores the biosynthesis, characteristics, and functional properties of exopolysaccharide produced by the strain Liquorilactobacillus mali T6-52. The strain demonstrated significant EPS production with a non-ropy phenotype. RESULTS The genomic analysis unveiled genes associated with EPS biosynthesis, shedding light on the mechanism behind EPS production. These genes suggest a robust EPS production mechanism, providing insights into the strain's adaptability and ecological niche. Chemical composition analysis identified the EPS as a homopolysaccharide primarily composed of glucose, confirming its dextran nature. Furthermore, it demonstrated notable functional properties, including antioxidant activity, fat absorption capacity, and emulsifying activity. Moreover, the EPS displayed promising cryoprotective activities, showing notable performance comparable to standard cryoprotective agents. The EPS concentration also demonstrated significant freeze-drying protective effects, presenting it as a potential alternative cryoprotectant for bacterial storage. CONCLUSIONS The functional properties of L. mali T6-52 EPS reveal promising opportunities across various industrial domains. The strain's safety profile, antioxidant prowess, and exceptional cryoprotective and freeze-drying characteristics position it as an asset in food processing and pharmaceuticals.
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Affiliation(s)
- Manyu Wu
- Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Padova, Italy
| | - Shadi Pakroo
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Chiara Nadai
- Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Conegliano, TV, Italy
| | - Zeno Molinelli
- Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Conegliano, TV, Italy
| | - Immacolata Speciale
- Department of Agricultural Sciences, University of Napoli Federico II, Portici, NA, Italy
| | - Crisitina De Castro
- Department of Agricultural Sciences, University of Napoli Federico II, Portici, NA, Italy
| | - Armin Tarrah
- Canadian Research Institute for Food Safety, Department of Food Science, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Jijin Yang
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Alessio Giacomini
- Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Padova, Italy
| | - Viviana Corich
- Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Padova, Italy
- Interdepartmental Centre for Research in Viticulture and Enology (CIRVE), University of Padova, Conegliano, TV, Italy
- Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, Padova, Italy
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Pramanik S, Venkatraman S, Vaidyanathan VK. Development of engineered probiotics with tailored functional properties and their application in food science. Food Sci Biotechnol 2023; 32:453-470. [PMID: 36911322 PMCID: PMC9992677 DOI: 10.1007/s10068-023-01252-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 02/27/2023] Open
Abstract
The potential health benefits of probiotics may not be cognized because of the substantial curtailment in their viability during food storage and passage through the gastrointestinal system. Intestinal flora composition, and resistance against pathogens are among the health benefits associated with probiotic consumption. In the gastric environment, pH 2.0, probiotics dramatically lose their viability during the transit through the gastrointestinal system. The challenge remains to maintain cell viability until it reaches the large intestine. In extreme conditions, such as a decrease in pH or an increase in temperature, encapsulation technology can enhance the viability of probiotics. Probiotic bacterial strains can be encapsulated in a variety of ways. The methods are broadly systematized into two categories, liquid and solid delivery systems. This review emphasizes the technology used in the research and commercial sectors to encapsulate probiotic cells while keeping them alive and the food matrix used to deliver these cells to consumers. Graphical abstract
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Affiliation(s)
- Shreyasi Pramanik
- Integrated Bioprocessing Laboratory, School of Bioengineering, Department of Biotechnology, SRM Institute of Science and Technology (SRM IST), Tamil Nadu 603 203 Kattankulathur, India
| | - Swethaa Venkatraman
- Integrated Bioprocessing Laboratory, School of Bioengineering, Department of Biotechnology, SRM Institute of Science and Technology (SRM IST), Tamil Nadu 603 203 Kattankulathur, India
| | - Vinoth Kumar Vaidyanathan
- Integrated Bioprocessing Laboratory, School of Bioengineering, Department of Biotechnology, SRM Institute of Science and Technology (SRM IST), Tamil Nadu 603 203 Kattankulathur, India
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Martins PMM, Batista NN, Santos LD, Dias DR, Schwan RF. Microencapsulation by spray drying of coffee epiphytic yeasts Saccharomyces cerevisiae CCMA 0543 and Torulaspora delbrueckii CCMA 0684. Braz J Microbiol 2022; 53:1565-1576. [PMID: 35676493 PMCID: PMC9433631 DOI: 10.1007/s42770-022-00776-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/28/2022] [Indexed: 11/02/2022] Open
Abstract
The objective of this work was to evaluate the microencapsulation feasibility of Saccharomyces cerevisiae CCMA 0543 and Torulaspora delbrueckii CCMA 0684 in three different compositions of wall material by spray-dryer. The yeasts (109 CFU mL-1) were microencapsulated separately using maltodextrin (15%), maltodextrin (15%) with sucrose (2%), or maltose (2%) as wall material. The viability was evaluated for 6 months at two different temperatures (7 and 25 °C). The yield, cell viability after spray drying, and characterization of the microcapsules were performed. Results indicate that cell viability ranged between 94.06 and 97.97%. After 6 months, both yeasts stored at 7 °C and 25 °C presented 107 and 102 CFU mL-1, respectively. Regarding Fourier-transform infrared spectroscopy analysis, all microencapsulated yeasts presented typical spectra footprints of maltodextrin. After 6 months of storage, S. cerevisiae CCMA 0543 obtained a 10.8% increase in cell viability using maltodextrin with maltose as wall material compared to maltodextrin and maltodextrin with sucrose. However, T. delbrueckii CCMA 0684 obtained a 13.5% increase in cell viability using only maltodextrin. The study showed that maltodextrin as a wall material was efficient in the microencapsulation of yeasts. It is possible to assume that maltose incorporation increased the cell viability of S. cerevisiae CCMA 0543 during storage.
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Affiliation(s)
| | | | - Líbia Diniz Santos
- Faculty of Chemical Engineering, Federal University of Uberlândia, Patos de Minas, MG, Brazil
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Dev MJ, Warke RG, Warke GM, Mahajan GB, Patil TA, Singhal RS. Advances in fermentative production, purification, characterization and applications of gellan gum. BIORESOURCE TECHNOLOGY 2022; 359:127498. [PMID: 35724911 DOI: 10.1016/j.biortech.2022.127498] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/11/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymers with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possibilities to develop cost-effective gellan gum bioprocess is desirable. This review focuses on details of upstream and downstream process of GG from an industrial perspective. It emphasizes on GG producing Sphingomonas spp., updates on biosynthesis, strain and media engineering, kinetic modeling, bioreactor design and scale-up considerations. Details of the downstream operations with possible modifications to make it cost-effective and environmentally sustainable have been discussed. The updated regulatory criteria for GG as a food ingredient and analytical tools required to validate the same have been briefly discussed. Derivatives of GG and their applications in various industrial segments have also been highlighted.
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Affiliation(s)
- Manoj J Dev
- Food Engineering and Technology Department, Institute of Chemical Technology, Mumbai, India
| | - Rahul G Warke
- Microbiology Division, Hi-Media Laboratories Pvt. Ltd., Mumbai, India
| | - Gangadhar M Warke
- Microbiology Division, Hi-Media Laboratories Pvt. Ltd., Mumbai, India
| | - Girish B Mahajan
- Microbiology Division, Hi-Media Laboratories Pvt. Ltd., Mumbai, India
| | - Tanuja A Patil
- Microbiology Division, Hi-Media Laboratories Pvt. Ltd., Mumbai, India
| | - Rekha S Singhal
- Food Engineering and Technology Department, Institute of Chemical Technology, Mumbai, India.
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Casas-Godoy L, Arellano-Plaza M, Kirchmayr M, Barrera-Martínez I, Gschaedler-Mathis A. Preservation of non-Saccharomyces yeasts: Current technologies and challenges. Compr Rev Food Sci Food Saf 2021; 20:3464-3503. [PMID: 34096187 DOI: 10.1111/1541-4337.12760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 03/05/2021] [Accepted: 03/29/2021] [Indexed: 11/30/2022]
Abstract
There is a recent and growing interest in the study and application of non-Saccharomyces yeasts, mainly in fermented foods. Numerous publications and patents show the importance of these yeasts. However, a fundamental issue in studying and applying them is to ensure an appropriate preservation scheme that allows to the non-Saccharomyces yeasts conserve their characteristics and fermentative capabilities by long periods of time. The main objective of this review is to present and analyze the techniques available to preserve these yeasts (by conventional and non-conventional methods), in small or large quantities for laboratory or industrial applications, respectively. Wine fermentation is one of the few industrial applications of non-Saccharomyces yeasts, but the preservation stage has been a major obstacle to achieve a wider application of these yeasts. This review considers the preservation techniques, and clearly defines parameters such as culturability, viability, vitality and robustness. Several conservation strategies published in research articles as well as patents are analyzed, and the advantages and disadvantages of each technique used are discussed. Another important issue during conservation processes is the stress to which yeasts are subjected at the time of preservation (mainly oxidative stress). There is little published information on the subject for non-Saccharomyces yeast, but it is a fundamental point to consider when designing a preservation strategy.
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Affiliation(s)
- Leticia Casas-Godoy
- Industrial Biotechnology Unit, National Council for Science and Technology-Center for Research and Assistance in Technology and Design of the State of Jalisco, Zapopan, Mexico
| | - Melchor Arellano-Plaza
- Industrial Biotechnology Unit, Center for Research and Assistance in Technology and Design of the State of Jalisco, Zapopan, Mexico
| | - Manuel Kirchmayr
- Industrial Biotechnology Unit, Center for Research and Assistance in Technology and Design of the State of Jalisco, Zapopan, Mexico
| | - Iliana Barrera-Martínez
- Industrial Biotechnology Unit, National Council for Science and Technology-Center for Research and Assistance in Technology and Design of the State of Jalisco, Zapopan, Mexico
| | - Anne Gschaedler-Mathis
- Industrial Biotechnology Unit, Center for Research and Assistance in Technology and Design of the State of Jalisco, Zapopan, Mexico
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Comparison of Preservation Methods of Staphylococcus aureus and Escherichia coli Bacteria. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2020. [DOI: 10.22207/jpam.14.3.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One of the most important problems faced by microbiologists is to preserve bacterial isolates in the best state to study and further diagnosis. The current study aims to provide a summary of experimental results to maintain two species of bacteria alive after being stored by using some additives. This study found that the best temperature to preserve Staphylococcus aureus was -20°C for a year, while for Escherichia coli it was the same temperature except in using Glycerol (G) 100% and Food oil (FO) methods. The optimum method to preserve S. aureus was by using Normal Saline (NS), while Distilled Water (DW) was the optimum method to preserve E. coli at temperatures (4, 25 and -20)°C for a year, the phenotypic patterns for examining bacteria were maintained except in NS at 4°C for S. aureus after a year ago. Glycerol was used alone at concentrations (100, 50, 30 and 15)%, and another group used G+NS in the same volumes, good results were achieved when it used alone or with NS to preserve bacteria for six months at 4°C except for methods of G100% and (G100% + NS) for examining bacteria. FO has never been used as preservation liquid, it is successful to survive S. aureus at -20°C for a year, and when it was added to NS, E. coli survived for a year at three temperatures (4, 25 and -20)°C, while S. aureus didn’t survive for a year when FO+NS method used at room temperature. The precipitation method was used for bacterial suspension, then added the preserving liquid, but the results were not effective compared to the First method.
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Nascimento CRSD, Souto ADSS, Galvão RM, Lazéra MDS, Trilles L. Genotypic and Phenotypic Stability of Mixed Primary Isolates of Cryptococcus gattii and Cryptococcus neoformans: A Comparative Analysis of Four Preservation Methods. Biopreserv Biobank 2020; 18:196-203. [PMID: 32213084 DOI: 10.1089/bio.2019.0096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The choice of a suitable preservation method is critical for long-term microorganisms' viability. The strains should be preserved for long periods using reliable and reproducible methods that minimize genotypic and phenotypic variations and viability losses. The methodologies are usually designed for a better performance in isolated microorganisms. However, atypical primary isolates of Cryptococcus neoformans or Cryptococcus gattii, such as mixed species or even different species of a species complex, are a challenge for long-term preservation and taxonomic review studies. The aim of this study was to evaluate which of the four preservation methods tested presented better performance in the preservation of simulated coexistence strains of C. neoformans and C. gattii. Two environmental strains, one C. gattii and one C. neoformans, were mixed in vitro to test four different preservation methods (freezing at -20°C, -80°C, -196°C, and freeze-drying). The colony-forming units from each preservation method were evaluated, and colonies were randomly selected and cultivated in canavanine glycine bromothymol blue (CGB) agar to evaluate the amounts of CGB-positive (C. gattii) and CGB-negative (C. neoformans) colonies resulting from each preservation method after 1 week, 15 days, 1 month, 6 months, and 1 year. According to our results, cryopreservation at -20°C demonstrated was preferable for C. neoformans species, and further studies after long-term storage are necessary. Recovery of yeast cells after freeze-dried preservation in skim milk is better for both species. Ultrafreezing methods evaluated (-80°C and -196°C) also showed better results in the maintenance of C. gattii. Freeze-drying should be preferred for the maintenance of multilineage isolates from the C. neoformans and C. gattii species complexes.
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Affiliation(s)
- Carlos Roberto Sobrinho do Nascimento
- Microbiology Department, National Institute for Quality Control in Health, Fiocruz, Rio de Janeiro, Brazil.,Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, Fiocruz, Rio de Janeiro, Brazil
| | | | - Raíssa Maria Galvão
- Microbiology Department, National Institute for Quality Control in Health, Fiocruz, Rio de Janeiro, Brazil
| | - Marcia Dos Santos Lazéra
- Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, Fiocruz, Rio de Janeiro, Brazil
| | - Luciana Trilles
- Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, Fiocruz, Rio de Janeiro, Brazil
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Hernández A, Larsson CU, Sawicki R, van Niel EWJ, Roos S, Håkansson S. Impact of the fermentation parameters pH and temperature on stress resilience of Lactobacillus reuteri DSM 17938. AMB Express 2019; 9:66. [PMID: 31102098 PMCID: PMC6525219 DOI: 10.1186/s13568-019-0789-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/02/2019] [Indexed: 11/10/2022] Open
Abstract
This study was undertaken to investigate the impact of culture pH (4.5-6.5) and temperature (32-37 °C) on the stress resilience of Lactobacillus reuteri DSM 17938 during freeze-drying and post freeze-drying exposure to low pH (pH 2) and bile salts. Response-surface methodology analysis revealed that freeze-drying survival rates [Formula: see text] were linearly related to pH with the highest survival rate of 80% when cells were cultured at pH 6.5 and the lowest was 40% when cells were cultured at pH 4.5. The analysis further revealed that within the chosen temperature range the culture temperature did not significantly affect the freeze-drying survival rate. However, fermentation at pH 4.5 led to better survival rates when rehydrated cells were exposed to low pH shock or bile salts. Thus, the effect of pH on freeze-drying survival was in contrast to effects on low pH and bile salts stress tolerance. The rationale behind this irreconcilability is based on the responses being dissimilar and are not tuned to each other. Culturing strain DSM 17938 at pH values higher than 5.5 could be a useful option to improve the survivability and increase viable cell numbers in the final freeze-dried product. However, the dissimilar responses for the process- and application parameters tested here suggest that an optimal compromise has to be found in order to obtain the most functional probiotic product possible.
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Long-term preservation of Leptospira spp.: challenges and prospects. Appl Microbiol Biotechnol 2018; 102:5427-5435. [PMID: 29736823 DOI: 10.1007/s00253-018-9047-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 10/17/2022]
Abstract
Preservation of leptospiral cultures is tantamount to success in leptospiral diagnostics, research, and development of preventive strategies. Each Leptospira isolate has imperative value not only in disease diagnosis but also in epidemiology, virulence, pathogenesis, and drug development studies. As the number of circulating leptospires is continuously increasing and congruent with the importance to retain their original characteristics and properties, an efficient long-term preservation is critically needed to be well-established. However, the preservation of Leptospira is currently characterized by difficulties and conflicting results mainly due to the biological nature of this organism. Hence, this review seeks to describe the efforts in developing efficient preservation methods, to discover the challenges in preserving this organism and to identify the factors that can contribute to an effective long-term preservation of Leptospira. Through the enlightenment of the previous studies, a potentially effective method has been suggested. The article also attempts to evaluate novel strategies used in other industrial and biotechnological preservation efforts and consider their potential application to the conservation of Leptospira spp.
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