1
|
Behringer MG, Ho WC, Miller SF, Worthan SB, Cen Z, Stikeleather R, Lynch M. Trade-offs, trade-ups, and high mutational parallelism underlie microbial adaptation during extreme cycles of feast and famine. Curr Biol 2024; 34:1403-1413.e5. [PMID: 38460514 PMCID: PMC11066936 DOI: 10.1016/j.cub.2024.02.040] [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: 10/04/2023] [Revised: 12/12/2023] [Accepted: 02/16/2024] [Indexed: 03/11/2024]
Abstract
Microbes are evolutionarily robust organisms capable of rapid adaptation to complex stress, which enables them to colonize harsh environments. In nature, microbes are regularly challenged by starvation, which is a particularly complex stress because resource limitation often co-occurs with changes in pH, osmolarity, and toxin accumulation created by metabolic waste. Often overlooked are the additional complications introduced by eventual resource replenishment, as successful microbes must withstand rapid environmental shifts before swiftly capitalizing on replenished resources to avoid invasion by competing species. To understand how microbes navigate trade-offs between growth and survival, ultimately adapting to thrive in environments with extreme fluctuations, we experimentally evolved 16 Escherichia coli populations for 900 days in repeated feast/famine conditions with cycles of 100-day starvation before resource replenishment. Using longitudinal population-genomic analysis, we found that evolution in response to extreme feast/famine is characterized by narrow adaptive trajectories with high mutational parallelism and notable mutational order. Genetic reconstructions reveal that early mutations result in trade-offs for biofilm and motility but trade-ups for growth and survival, as these mutations conferred positively correlated advantages during both short-term and long-term culture. Our results demonstrate how microbes can navigate the adaptive landscapes of regularly fluctuating conditions and ultimately follow mutational trajectories that confer benefits across diverse environments.
Collapse
Affiliation(s)
- Megan G Behringer
- Department of Biological Sciences, Vanderbilt University, 21st Avenue S, Nashville, TN 37232, USA; Department of Pathology Microbiology and Immunology, Vanderbilt University Medical Center, 21st Avenue S, Nashville, TN 37232, USA.
| | - Wei-Chin Ho
- Biodesign Center for Mechanisms of Evolution, Arizona State University, S McAllister Ave., Tempe, AZ 85281, USA; Department of Biology, University of Texas at Tyler, University Blvd., Tyler, TX 75799, USA.
| | - Samuel F Miller
- Biodesign Center for Mechanisms of Evolution, Arizona State University, S McAllister Ave., Tempe, AZ 85281, USA
| | - Sarah B Worthan
- Department of Biological Sciences, Vanderbilt University, 21st Avenue S, Nashville, TN 37232, USA
| | - Zeer Cen
- Department of Biological Sciences, Vanderbilt University, 21st Avenue S, Nashville, TN 37232, USA
| | - Ryan Stikeleather
- Biodesign Center for Mechanisms of Evolution, Arizona State University, S McAllister Ave., Tempe, AZ 85281, USA
| | - Michael Lynch
- Biodesign Center for Mechanisms of Evolution, Arizona State University, S McAllister Ave., Tempe, AZ 85281, USA
| |
Collapse
|
2
|
Hartono S, Meijerink MFA, Abee T, Smid EJ, van Mastrigt O. The stressostat: A novel approach in adaptive laboratory evolution to improve end-product resistance. N Biotechnol 2023; 78:123-130. [PMID: 37879567 DOI: 10.1016/j.nbt.2023.10.010] [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: 04/03/2023] [Revised: 09/18/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023]
Abstract
End-product inhibition in pH-controlled batch cultures, is the major limiting factor for bacterial biomass formation in the starter culture industry as well as in many other biotechnological processes. Adaptive laboratory evolution (ALE) has emerged over the past decades as a powerful tool for phenotype optimization, but none of the existing ALE methods could select for improved end-product resistance. Therefore, we developed the stressostat (STress Resistance Evolution in Substrate Surplus) as a novel continuous ALE method. Stressostat cultivation applies end-product concentrations as constant evolutionary pressure on microorganisms in the presence of substrate surplus. In this study, we improved the lactate resistance of Lactococcus lactis FM03P in 35 days of stressostat cultivations. The lactate concentrations increased over time from 530 to 675 mM, indicating the successful selection for variants with improved lactate resistance. Thirty-four variants were isolated and grouped into four clusters based on their growth rates at high lactate concentrations. In the high-throughput screening without pH control, most isolated variants could grow at high lactate concentrations (870-928 mM), while the wild type was completely inhibited. The variants grew slower than wild type at low lactate media indicating possible evolutionary trade-off. However, in pH-controlled batch cultivations, most variants produced more biomass than the wild type. In conclusion, stressostat cultivation is a valuable method to obtain L. lactis variants with improved end-product resistance and further characterization is needed to elucidate underlying resistance mechanisms and potential industrial applications.
Collapse
Affiliation(s)
- Sylviani Hartono
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Marlisa F A Meijerink
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Tjakko Abee
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Eddy J Smid
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands
| | - Oscar van Mastrigt
- Food Microbiology, Wageningen University & Research, P.O. Box 17, 6700AA Wageningen, the Netherlands.
| |
Collapse
|
3
|
Gonzalez JM, Aranda B. Microbial Growth under Limiting Conditions-Future Perspectives. Microorganisms 2023; 11:1641. [PMID: 37512814 PMCID: PMC10383181 DOI: 10.3390/microorganisms11071641] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/02/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Microorganisms rule the functioning of our planet and each one of the individual macroscopic living creature. Nevertheless, microbial activity and growth status have always been challenging tasks to determine both in situ and in vivo. Microbial activity is generally related to growth, and the growth rate is a result of the availability of nutrients under adequate or adverse conditions faced by microbial cells in a changing environment. Most studies on microorganisms have been carried out under optimum or near-optimum growth conditions, but scarce information is available about microorganisms at slow-growing states (i.e., near-zero growth and maintenance metabolism). This study aims to better understand microorganisms under growth-limiting conditions. This is expected to provide new perspectives on the functions and relevance of the microbial world. This is because (i) microorganisms in nature frequently face conditions of severe growth limitation, (ii) microorganisms activate singular pathways (mostly genes remaining to be functionally annotated), resulting in a broad range of secondary metabolites, and (iii) the response of microorganisms to slow-growth conditions remains to be understood, including persistence strategies, gene expression, and cell differentiation both within clonal populations and due to the complexity of the environment.
Collapse
Affiliation(s)
- Juan M Gonzalez
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, IRNAS-CSIC, E-41012 Sevilla, Spain
| | - Beatriz Aranda
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, IRNAS-CSIC, E-41012 Sevilla, Spain
| |
Collapse
|
4
|
Camargo ARO, Van Mastrigt O, Bongers RS, Ben-Amor K, Knol J, Smid EJ, Abee T. Enhanced stress resistance of Bifidobacterium breve NRBB57 by induction of stress proteins at near-zero growth rates. Benef Microbes 2023; 14:85-94. [PMID: 36790092 DOI: 10.3920/bm2022.0074] [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: 02/16/2023]
Abstract
Bifidobacterium breve is a common habitant of the human gut and is used as probiotic in functional foods. B. breve has to cope with multiple stress conditions encountered during processing and passage through the human gut, including high temperature, low pH and exposure to oxygen. Additionally, during industrial processing and in the gut, B. breve could encounter nutrient limitation resulting in reduced growth rates that can trigger adaptive stress responses. For this reason, it is important to develop culture methods that elicit resistance to multiple stresses (robustness) encountered by the bacteria. To investigate the impact of caloric restriction on robustness of the probiotic B. breve NRBB57, this strain was grown in lactose-limited chemostat cultures and in retentostat for 21 days, at growth rates ranging from 0.4 h-1 to 0.00081 h-1. Proteomes of cells harvested at different growth rates were correlated to acid, hydrogen peroxide and heat stress survival capacity. Comparative proteome analysis showed that retentostat-grown cells had significantly increased abundance of a variety of stress proteins involved in protein quality maintenance and DNA repair (DnaJ, Hsp90, FtsH, ClpB, ClpP1, ClpC, GroES, RuvB, RecA), as well as proteins involved in oxidative stress defence (peroxiredoxin, ferredoxin, thioredoxin peroxidase, glutaredoxin and thioredoxin reductase). Exposure to three different stress conditions, 45 °C, pH 3, and 10 mM H2O2, showed highest stress resistance of retentostat cells sampled at week 2 and week 3 grown at 0.0018 and 0.00081 h-1. Our findings show that cultivation at near-zero growth rates induces higher abundance of stress defence proteins contributing to the robustness of B. breve NRBB57, thereby offering an approach that may support its production and functionality.
Collapse
Affiliation(s)
- A R Ortiz Camargo
- Food Microbiology, Wageningen University & Research, P.O. box 17, 6700 AA Wageningen, The Netherlands
| | - O Van Mastrigt
- Food Microbiology, Wageningen University & Research, P.O. box 17, 6700 AA Wageningen, The Netherlands
| | - R S Bongers
- Danone Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, the Netherlands
| | - K Ben-Amor
- Danone Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, the Netherlands
| | - J Knol
- Danone Nutricia Research, Uppsalalaan 12, 3584 CT Utrecht, the Netherlands.,Laboratory of Microbiology, Wageningen University & Research, P.O. Box 8033, 6700 EH Wageningen, the Netherlands
| | - E J Smid
- Food Microbiology, Wageningen University & Research, P.O. box 17, 6700 AA Wageningen, The Netherlands
| | - T Abee
- Food Microbiology, Wageningen University & Research, P.O. box 17, 6700 AA Wageningen, The Netherlands
| |
Collapse
|
5
|
The Pleiotropic Effects of Carbohydrate-Mediated Growth Rate Modifications in Bifidobacterium longum NCC 2705. Microorganisms 2023; 11:microorganisms11030588. [PMID: 36985162 PMCID: PMC10059941 DOI: 10.3390/microorganisms11030588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Bifidobacteria are saccharolytic bacteria that are able to metabolize a relatively large range of carbohydrates through their unique central carbon metabolism known as the “bifid-shunt”. Carbohydrates have been shown to modulate the growth rate of bifidobacteria, but unlike for other genera (e.g., E. coli or L. lactis), the impact it may have on the overall physiology of the bacteria has not been studied in detail to date. Using glucose and galactose as model substrates in Bifidobacterium longum NCC 2705, we established that the strain displayed fast and slow growth rates on those carbohydrates, respectively. We show that these differential growth conditions are accompanied by global transcriptional changes and adjustments of central carbon fluxes. In addition, when grown on galactose, NCC 2705 cells were significantly smaller, exhibited an expanded capacity to import and metabolized different sugars and displayed an increased acid-stress resistance, a phenotypic signature associated with generalized fitness. We predict that part of the observed adaptation is regulated by the previously described bifidobacterial global transcriptional regulator AraQ, which we propose to reflect a catabolite-repression-like response in B. longum. With this manuscript, we demonstrate that not only growth rate but also various physiological characteristics of B. longum NCC 2705 are responsive to the carbon source used for growth, which is relevant in the context of its lifestyle in the human infant gut where galactose-containing oligosaccharides are prominent.
Collapse
|