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El-Gendi H, Salama A, El-Fakharany EM, Saleh AK. Optimization of bacterial cellulose production from prickly pear peels and its ex situ impregnation with fruit byproducts for antimicrobial and strawberry packaging applications. Carbohydr Polym 2023; 302:120383. [PMID: 36604061 DOI: 10.1016/j.carbpol.2022.120383] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/13/2022] [Accepted: 11/18/2022] [Indexed: 11/25/2022]
Abstract
Bacterial cellulose (BC) is currently among the most promising natural polymers. However, the production costs and biological inactivity are still challenges. The current study exploited the enzymatically hydrolyzed prickly pear peels (PPP) for BC production, which supported about 2.94 g/L as the sole production medium. The BC production was further optimized through a central composite design, where the maximum BC production was 6.01 g/L at 68 % PPPE at pH 4 after 11 days of incubation at 20 °C. The produced BC was characterized by FT-IR spectroscopy, XRD, and SEM analysis, and the results showed that PPPE is a promising carbon source for pure BC production. The BC membrane was separately loaded with several fruit byproduct extracts to enhance its biological activity for multiple applications. BC loaded with pomegranate peel extract (BC/PPE) revealed significant broad-spectrum antimicrobial activity, followed by BC loaded with pomegranate molasses (BC/PM). The BC/PPE membrane enhanced the shelf-life storage of strawberry fruits by about 5 days, with a reduction in the fruits' weight loss of 15 % compared to the uncovered group. The current study revealed the successful application of PPE for sustainable BC production with its packaging potential for enhancing strawberry shelf-life when loaded with PPE or PM.
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Affiliation(s)
- Hamada El-Gendi
- Bioprocess Development Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria 21934, Egypt.
| | - Ahmed Salama
- Cellulose and Paper Department, National Research Centre, El-Tahrir St., Dokki 12622, Giza, Egypt
| | - Esmail M El-Fakharany
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria 21934, Egypt
| | - Ahmed K Saleh
- Cellulose and Paper Department, National Research Centre, El-Tahrir St., Dokki 12622, Giza, Egypt.
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San León D, Nogales J. Toward merging bottom-up and top-down model-based designing of synthetic microbial communities. Curr Opin Microbiol 2022; 69:102169. [PMID: 35763963 DOI: 10.1016/j.mib.2022.102169] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/25/2022] [Accepted: 05/11/2022] [Indexed: 11/16/2022]
Abstract
The increasing interest of microbial communities as promising biocatalyst is leading an intense effort into the development of computational frameworks assisting the analysis and rational engineering of such complex ecosystems. Here, we critically review the recent computational and model-guided advances in the system-level engineering of microbiome, including both the rational bottom-up and the evolutionary top-down approaches. Furthermore, we highlight modeling and computational methods supporting both engineering paradigms. Finally, we discuss the advantages of combining both strategies into a hybrid top-down/bottom-up (middle-out) strategy to engineer synthetic microbial communities with improved performance and scope.
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Affiliation(s)
- David San León
- Department of Systems Biology, Centro Nacional de Biotecnología, CSIC, Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain.
| | - Juan Nogales
- Department of Systems Biology, Centro Nacional de Biotecnología, CSIC, Madrid, Spain; Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain.
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Hao Z, Zhang W, Wang X, Wang Y, Qin X, Luo H, Huang H, Su X. Identification of WxL and S-Layer Proteins from Lactobacillus brevis with the Ability to Bind Cellulose and Xylan. Int J Mol Sci 2022; 23:ijms23084136. [PMID: 35456954 PMCID: PMC9026416 DOI: 10.3390/ijms23084136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/27/2022] [Accepted: 04/07/2022] [Indexed: 01/01/2023] Open
Abstract
Xylanase releases xylo-oligosaccharides from dietary xylan, which stimulate the growth of the gut bacteria lactobacilli. Many lactobacilli adhere to dietary fibers, which may facilitate the assimilation of xylo-oligosaccharides and help them gain competence in the gut, but the underlying mechanisms remain elusive. Herein we report, from the highly abundant transcripts of Lactobacillus brevis cultured in wheat arabinoxylan supplemented with a xylanase, the identification of genes encoding four putative cell-surface WxL proteins (Lb630, Lb631, Lb632, and Lb635) and one S-layer protein (Lb1325) with either cellulose- or xylan-binding ability. The repetitively occurring WxL proteins were encoded by a gene cluster, among which Lb630 was chosen for further mutational studies. The analysis revealed three aromatic residues (F30, W61, and W156) that might be involved in the interaction of the protein with cellulose. A homology search in the genome of Enterococcus faecium identified three WxL proteins with conserved counterparts of these three aromatic residues, and they were also found to be able to bind cellulose and xylan. The findings suggested a role of the cell-surface WxL and S-layer proteins in assisting the cellular adhesion of L. brevis to plant cell wall polysaccharides.
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Current Progress in Production of Building-Block Organic Acids by Consolidated Bioprocessing of Lignocellulose. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7040248] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Several organic acids have been indicated among the top value chemicals from biomass. Lignocellulose is among the most attractive feedstocks for biorefining processes owing to its high abundance and low cost. However, its highly complex nature and recalcitrance to biodegradation hinder development of cost-competitive fermentation processes. Here, current progress in development of single-pot fermentation (i.e., consolidated bioprocessing, CBP) of lignocellulosic biomass to high value organic acids will be examined, based on the potential of this approach to dramatically reduce process costs. Different strategies for CBP development will be considered such as: (i) design of microbial consortia consisting of (hemi)cellulolytic and valuable-compound producing strains; (ii) engineering of microorganisms that combine biomass-degrading and high-value compound-producing properties in a single strain. The present review will mainly focus on production of organic acids with application as building block chemicals (e.g., adipic, cis,cis-muconic, fumaric, itaconic, lactic, malic, and succinic acid) since polymer synthesis constitutes the largest sector in the chemical industry. Current research advances will be illustrated together with challenges and perspectives for future investigations. In addition, attention will be dedicated to development of acid tolerant microorganisms, an essential feature for improving titer and productivity of fermentative production of acids.
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Sánchez Á, Vila JCC, Chang CY, Diaz-Colunga J, Estrela S, Rebolleda-Gomez M. Directed Evolution of Microbial Communities. Annu Rev Biophys 2021; 50:323-341. [PMID: 33646814 PMCID: PMC8105285 DOI: 10.1146/annurev-biophys-101220-072829] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Directed evolution is a form of artificial selection that has been used for decades to find biomolecules and organisms with new or enhanced functional traits. Directed evolution can be conceptualized as a guided exploration of the genotype-phenotype map, where genetic variants with desirable phenotypes are first selected and then mutagenized to search the genotype space for an even better mutant. In recent years, the idea of applying artificial selection to microbial communities has gained momentum. In this article, we review the main limitations of artificial selection when applied to large and diverse collectives of asexually dividing microbes and discuss how the tools of directed evolution may be deployed to engineer communities from the top down. We conceptualize directed evolution of microbial communities as a guided exploration of an ecological structure-function landscape and propose practical guidelines for navigating these ecological landscapes.
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Affiliation(s)
- Álvaro Sánchez
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
| | - Jean C C Vila
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
| | - Chang-Yu Chang
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
| | - Juan Diaz-Colunga
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
| | - Sylvie Estrela
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
| | - María Rebolleda-Gomez
- Department of Ecology & Evolutionary Biology and Microbial Sciences Institute, Yale University, New Haven, Connecticut 06520, USA; , , , , ,
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