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Hervelly, Djali M, Sukarminah E, Rialita T. The Effect of Fermentation Time and Consortium Starter Bacteria on Psycochemical Properties of Modified Purple Sweet Potato Flour. J FOOD PROCESS PRES 2022. [DOI: 10.1111/jfpp.16522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hervelly
- Student at Department of Food Technology, Faculty of Agriculture, Universitas Padjadjaran, Bandung, Indonesia, 2Promotor at Department of Food Technology, Laboratory of Food Processing Technology, Universitas Padjadjaran Bandung Indonesia
| | | | - Een Sukarminah
- Co‐promotor at Department of Food Technology, Universitas Padjadjaran Bandung Indonesia
| | - Tita Rialita
- Co‐promotor at Department of Food Technology, Universitas Padjadjaran Bandung Indonesia
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Harris A, Lindsay MA, Ganley ARD, Jeffs A, Villas-Boas SG. Sound Stimulation Can Affect Saccharomyces cerevisiae Growth and Production of Volatile Metabolites in Liquid Medium. Metabolites 2021; 11:605. [PMID: 34564421 PMCID: PMC8468475 DOI: 10.3390/metabo11090605] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 11/16/2022] Open
Abstract
The biological effect of sound on microorganisms has been a field of interest for many years, with studies mostly focusing on ultrasonic and infrasonic vibrations. In the audible range (20 Hz to 20 kHz), sound has been shown to both increase colony formation and disrupt microbial growth, depending upon the organism and frequency of sound used. In the brewer's yeast Saccharomyces cerevisiae, sound has been shown to significantly alter growth, increase alcohol production, and affect the metabolite profile. In this study, S. cerevisiae was exposed to a continuous 90 dB @ 20 μPa tone at different frequencies (0.1 kHz, 10 kHz, and silence). Fermentation characteristics were monitored over a 50-h fermentation in liquid malt extract, with a focus on growth rate and biomass yield. The profile of volatile metabolites at the subsequent stationary phase of the ferment was characterised by headspace gas chromatography-mass spectrometry. Sound treatments resulted in a 23% increase in growth rate compared to that of silence. Subsequent analysis showed significant differences in the volatilomes between all experimental conditions. Specifically, aroma compounds associated with citrus notes were upregulated with the application of sound. Furthermore, there was a pronounced difference in the metabolites produced in high- versus low-frequency sounds. This suggests industrial processes, such as beer brewing, could be modulated by the application of audible sound at specific frequencies during growth.
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Affiliation(s)
- Alastair Harris
- School of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Melodie A Lindsay
- School of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Austen R D Ganley
- School of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Andrew Jeffs
- School of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
| | - Silas G Villas-Boas
- School of Biological Sciences, University of Auckland, 3A Symonds Street, Auckland 1010, New Zealand
- Luxembourg Institute of Science and Technology, 5 rue Bommel, Z.A.E. Robert Steichen, L-4940 Luxembourg, Luxembourg
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Hamill PG, Stevenson A, McMullan PE, Williams JP, Lewis ADR, S S, Stevenson KE, Farnsworth KD, Khroustalyova G, Takemoto JY, Quinn JP, Rapoport A, Hallsworth JE. Microbial lag phase can be indicative of, or independent from, cellular stress. Sci Rep 2020; 10:5948. [PMID: 32246056 PMCID: PMC7125082 DOI: 10.1038/s41598-020-62552-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/16/2020] [Indexed: 01/01/2023] Open
Abstract
Measures of microbial growth, used as indicators of cellular stress, are sometimes quantified at a single time-point. In reality, these measurements are compound representations of length of lag, exponential growth-rate, and other factors. Here, we investigate whether length of lag phase can act as a proxy for stress, using a number of model systems (Aspergillus penicillioides; Bacillus subtilis; Escherichia coli; Eurotium amstelodami, E. echinulatum, E. halophilicum, and E. repens; Mrakia frigida; Saccharomyces cerevisiae; Xerochrysium xerophilum; Xeromyces bisporus) exposed to mechanistically distinct types of cellular stress including low water activity, other solute-induced stresses, and dehydration-rehydration cycles. Lag phase was neither proportional to germination rate for X. bisporus (FRR3443) in glycerol-supplemented media (r2 = 0.012), nor to exponential growth-rates for other microbes. In some cases, growth-rates varied greatly with stressor concentration even when lag remained constant. By contrast, there were strong correlations for B. subtilis in media supplemented with polyethylene-glycol 6000 or 600 (r2 = 0.925 and 0.961), and for other microbial species. We also analysed data from independent studies of food-spoilage fungi under glycerol stress (Aspergillus aculeatinus and A. sclerotiicarbonarius); mesophilic/psychrotolerant bacteria under diverse, solute-induced stresses (Brochothrix thermosphacta, Enterococcus faecalis, Pseudomonas fluorescens, Salmonella typhimurium, Staphylococcus aureus); and fungal enzymes under acid-stress (Terfezia claveryi lipoxygenase and Agaricus bisporus tyrosinase). These datasets also exhibited diversity, with some strong- and moderate correlations between length of lag and exponential growth-rates; and sometimes none. In conclusion, lag phase is not a reliable measure of stress because length of lag and growth-rate inhibition are sometimes highly correlated, and sometimes not at all.
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Affiliation(s)
- Philip G Hamill
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Andrew Stevenson
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Phillip E McMullan
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - James P Williams
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Abiann D R Lewis
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Sudharsan S
- Department of Chemistry, PGP College of Arts and Science, NH-7, Karur Main Road, Paramathi, Namakkal, Tamil Nadu, 637 207, India
| | - Kath E Stevenson
- Special Collections and Archives, McClay Library, Queen's University Belfast, 10 College Park Avenue, Belfast, BT7 1LP, Northern Ireland
| | - Keith D Farnsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Galina Khroustalyova
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - Jon Y Takemoto
- Utah State University, Department of Biology, 5305 Old Main Hill, Logan, UT, 84322, USA
| | - John P Quinn
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland
| | - Alexander Rapoport
- Laboratory of Cell Biology, Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas Str., 1-537, LV-1004, Riga, Latvia
| | - John E Hallsworth
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, Northern Ireland.
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Stevenson A, Hamill PG, O'Kane CJ, Kminek G, Rummel JD, Voytek MA, Dijksterhuis J, Hallsworth JE. Aspergillus penicillioidesdifferentiation and cell division at 0.585 water activity. Environ Microbiol 2017; 19:687-697. [DOI: 10.1111/1462-2920.13597] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/03/2016] [Accepted: 11/16/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Andrew Stevenson
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Philip G. Hamill
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Callum J. O'Kane
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
| | - Gerhard Kminek
- Independent Safety Office; European Space Agency; 2200 AG Noordwijk The Netherlands
| | | | | | - Jan Dijksterhuis
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8; Utrecht CT 3584 The Netherlands
| | - John E. Hallsworth
- Institute for Global Food Security; School of Biological Sciences, MBC, Queen's University Belfast; Belfast BT9 7BL Northern Ireland
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Wu WJ, Liu SL, Yung PT. Effect of static magnetic field on endospore germination. Bioelectromagnetics 2016; 38:121-127. [PMID: 27862061 DOI: 10.1002/bem.22017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 10/19/2016] [Indexed: 11/09/2022]
Abstract
This work investigated the effect of static magnetic field (SMF) on Bacillus atrophaeus endospore germination. Germination was triggered by L-alanine in 1.3-T SMF and characterized by ion release, Ca2+ -dipicolinic acid release, and water influx. These events were monitored by electrical conductivity, Tb-DPA fluorescence, and optical density, respectively. Culturability of endospore germinated in SMF exposure was evaluated by CFU enumeration. Results indicated that 1.3-T SMF failed to significantly affect endospore germination and culturability, suggesting that the three aforementioned processes were not sensitive to SMF. Bioelectromagnetics. 38:121-127, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Wen Jie Wu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Si Li Liu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Pun To Yung
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong, China
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Ning T, Wang H, Zheng M, Niu D, Zuo S, Xu C. Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2016; 30:171-180. [PMID: 27165015 PMCID: PMC5205603 DOI: 10.5713/ajas.16.0046] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/17/2016] [Accepted: 04/21/2016] [Indexed: 11/27/2022]
Abstract
Objective This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.
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Affiliation(s)
- Tingting Ning
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Huili Wang
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Mingli Zheng
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Dongze Niu
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Sasa Zuo
- College of Engineering, China Agricultural University, Beijing 100083, China
| | - Chuncheng Xu
- College of Engineering, China Agricultural University, Beijing 100083, China
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