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Saubade F, Cossec N, Giguelay Gesret L, Kouamé C, Ellouze M, Gérard C, Couvert O, Desriac N. Heat resistance of five spoilage microorganisms in a carbonated broth. Food Microbiol 2024; 122:104545. [PMID: 38839231 DOI: 10.1016/j.fm.2024.104545] [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: 01/23/2024] [Revised: 04/09/2024] [Accepted: 04/13/2024] [Indexed: 06/07/2024]
Abstract
Despite their acidic pH, carbonated beverages can be contaminated by spoilage microorganisms. Thermal treatments, before and/or after carbonation, are usually applied to prevent the growth of these microorganisms. However, the impact of CO2 on the heat resistance of spoilage microorganisms has never been studied. A better understanding of the combined impact of CO2 and pH on the heat resistance of spoilage microorganisms commonly found in carbonated beverages might allow to optimize thermal treatment. Five microorganisms were selected for this study: Alicyclobacillus acidoterrestris (spores), Aspergillus niger (spores), Byssochlamys fulva (spores), Saccharomyces cerevisiae (vegetative cells), and Zygosaccharomyces parabailii (vegetative cells). A method was developed to assess the impact of heat treatments in carbonated media on microbial resistance. The heat resistances of the five studied species are coherent with the literature, when data were available. However, neither the dissolved CO2 concentration (from 0 to 7 g/L), nor the pH (from 2.8 to 4.1) have an impact on the heat resistance of the selected microorganisms, except for As. niger, for which the presence of dissolved CO2 reduced the heat resistance. This study improved our knowledge about the heat resistance of some spoilage microorganisms in presence of CO2.
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Affiliation(s)
- Fabien Saubade
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29000, Quimper, France.
| | - Noëmie Cossec
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29000, Quimper, France.
| | - Luc Giguelay Gesret
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29000, Quimper, France.
| | - Christelle Kouamé
- NPTC Nestlé Waters, 1020 avenue Georges Clémenceau, F-88800, Vittel, France.
| | | | | | - Olivier Couvert
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29000, Quimper, France.
| | - Noémie Desriac
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29000, Quimper, France.
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Li Y, Luo L, Wang W, Hong B, Ma Y, Wang J. Characterization of a cell wall hydrolase with high activity against vegetative cells, spores and biofilm of Bacillus cereus. Int J Food Microbiol 2024; 414:110617. [PMID: 38335884 DOI: 10.1016/j.ijfoodmicro.2024.110617] [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: 08/08/2023] [Revised: 12/17/2023] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
Bacillus cereus is a prevalent foodborne pathogen that induces food poisoning symptoms such as vomiting and diarrhea. Its capacity to form spores and biofilm enables it to withstand disinfectants and antimicrobials, leading to persistent contamination during food processing. Consequently, it is necessary to develop novel and efficient antimicrobial agents to control B. cereus, its spores, and biofilms. Peptidoglycan hydrolases have emerged as a promising and eco-friendly alternative owing to their specific lytic activity against pathogenic bacteria. Here, we identified and characterized a Lysozyme-like cell wall hydrolase Lys14579, from the genome of B. cereus ATCC 14579. Recombinant Lys14579 specifically lysed B. cereus without affecting other bacteria. Lys14579 exhibited strong lytic activity against B. cereus, effectively lysing B. cereus cell within 20 min at low concentration (10 μg/mL). It also inhibited the germination of B. cereus spores and prevented biofilm formation at 12.5 μg/mL. Moreover, Lys14579 displayed good antimicrobial stability with negligible hemolysis in mouse red blood cells and no cytotoxicity against RAW264.7 cells. Notably, Lys14579 effectively inhibited B. cereus in boiled rice and minced meat in a dose-dependent manner. Furthermore, bioinformatics analysis and point mutagenesis experiments revealed that Glu-47 was the catalytic site, and Asp-57, Gln-60, Ser-61 and Glu-63 were active-site residues related with the cell wall lytic activity. Taken together, Lys14579 could be a promising biocontrol agent against vegetative cells, spores, and biofilm of B. cereus in food industry.
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Affiliation(s)
- Yanmei Li
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Lun Luo
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Wenhai Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Bin Hong
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China
| | - Yi Ma
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, China
| | - Jufang Wang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou 510006, China.
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Zhang W, Mao G, Zhuang J, Yang H. The co-inoculation of Pseudomonas chlororaphis H1 and Bacillus altitudinis Y1 promoted soybean [ Glycine max (L.) Merrill] growth and increased the relative abundance of beneficial microorganisms in rhizosphere and root. Front Microbiol 2023; 13:1079348. [PMID: 36699592 PMCID: PMC9868396 DOI: 10.3389/fmicb.2022.1079348] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/16/2022] [Indexed: 01/10/2023] Open
Abstract
Currently, plant growth-promoting rhizobacteria (PGPR) microbial inoculants are heavily used in agricultural production among which Pseudomonas sp. and Bacillus sp. are two excellent inoculum strains, which are widely used in plant growth promotion and disease control. However, few studies have been conducted on the combined use of the two bacteria. The aim of this study was to investigate the effects of co-inoculation of these two bacteria on soybean [Glycine max (L.) Merrill] growth and physiological indexes and further study the effect of microbial inoculants on native soil bacterial communities and plant endophyte microbiota, especially microorganisms in rhizosphere and root. A pot experiment was conducted and four treatments were designed: group without any strain inoculant (CK); group inoculated with Pseudomonas chlororaphis H1 inoculant (J); group inoculated with Bacillus altitudinis Y1 inoculant (Y) and group inoculated with equal volume of P. chlororaphis H1 inoculant and B. altitudinis Y1 inoculant (H). Compared with CK, the three inoculant groups J, Y, and H exhibited improved soybean growth and physiological indexes, and group H was the most significant (p < 0.05). In terms of rhizosphere bacterial community structure, the relative abundance of native Luteimonas (9.31%) was higher in the H group than in the J (6.07%), Y (3.40%), and CK (5.69%) groups, which has potential value of disease suppression. Besides, compared with bacterial communities of the other three groups in soybean roots, group H increased the abundance of beneficial bacterial community for the contents of Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Devosia, and Methylobacillus significantly increased (p < 0.05). In conclusion, we found that the composite inoculum of Pseudomonas chlororaphis H1 and Bacillus altitudinis Y1 could effectively promote soybean growth, increase yield and improve the beneficial bacterial community in root and rhizosphere and have certain value for soil improvement.
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Affiliation(s)
- Wentao Zhang
- Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, China,College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Guohao Mao
- Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, China,College of Forestry, Nanjing Forestry University, Nanjing, China
| | - Jiayao Zhuang
- Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, China,College of Forestry, Nanjing Forestry University, Nanjing, China,*Correspondence: Jiayao Zhuang, ✉
| | - Hao Yang
- Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Nanjing Forestry University, Nanjing, China,College of Forestry, Nanjing Forestry University, Nanjing, China
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Prakash AA, Sathishkumar K, AlSalhi MS, Devanesan S, Mani P, Kamala-Kannan S, Vijayanand S, Rajasekar A. Integrated approach of photo-assisted electrochemical oxidation and sequential biodegradation of textile effluent. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119412. [PMID: 35568287 DOI: 10.1016/j.envpol.2022.119412] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/12/2022] [Accepted: 05/01/2022] [Indexed: 06/15/2023]
Abstract
Synthetic azo dyes are extensively used in the textile industries, which are being released as textile effluent into the environment presence of azo dyes in the environment is great environmental concern therefore treatment of textile effluent is crucial for proper release of the effluent into the environment. Electrochemical oxidation (EO) is extensively used in the degradation of pollutants because of its high efficiency. In this study, photo-assisted electrooxidation (PEO) followed by biodegradation of the textile effluent was evaluated. The pretreatment of textile effluent was conducted by EO and PEO in a tubular flow cell with TiO2-Ti/IrO2-RuO2 anode and titanium cathode under different current densities (10, 15, and 20 mA cm-2). The chemical oxygen demand level reduced from 3150 mg L-1 to 1300 and 600 mg L-1under EO and PEO, respectively. Furthermore, biodegradation of EO and PEO pretreated textile effluent shows reduction in chemical oxygen demand (COD) from 1300 mg L-1 to 900 mg L-1and 600 mg L-1to 110 mg L-1, respectively. The most abundant genera were identified as Acetobacter, Achromobacter, Acidaminococcus, Actinomyces, and Acetomicrobium from the textile effluent. This study suggests that an integrated approach of PEO and subsequent biodegradation might be an effective and eco-friendly method for the degradation of textile effluent.
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Affiliation(s)
- Arumugam Arul Prakash
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India
| | - Kuppusamy Sathishkumar
- Rhizosphere Biology Laboratory, Department of Microbiology, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Mohamad S AlSalhi
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box: 2455, Riyadh, 11451, Saudi Arabia
| | - Sandhanasamy Devanesan
- Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box: 2455, Riyadh, 11451, Saudi Arabia
| | - Panagal Mani
- Department of Biotechnology, Annai College of Arts and Science, Kumbakonam, Thanjavur District, Affiliated to Bharathidasan University, Tiruchirappalli, Tamil Nadu, 612503, India
| | - Seralathan Kamala-Kannan
- Division of Biotechnology Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Science, Jeonbuk National University, Iksan, 54596, South Korea
| | - Selvaraj Vijayanand
- Bioresource Technology Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India
| | - Aruliah Rajasekar
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India.
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