1
|
Michoud G, Kohler TJ, Ezzat L, Peter H, Nattabi JK, Nalwanga R, Pramateftaki P, Styllas M, Tolosano M, De Staercke V, Schön M, Marasco R, Daffonchio D, Bourquin M, Busi SB, Battin TJ. The dark side of the moon: first insights into the microbiome structure and function of one of the last glacier-fed streams in Africa. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230329. [PMID: 37564072 PMCID: PMC10410210 DOI: 10.1098/rsos.230329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/20/2023] [Indexed: 08/12/2023]
Abstract
The glaciers on Africa's 'Mountains of the Moon' (Rwenzori National Park, Uganda) are predicted to disappear within the next decades owing to climate change. Consequently, the glacier-fed streams (GFSs) that drain them will vanish, along with their resident microbial communities. Despite the relevance of microbial communities for performing ecosystem processes in equatorial GFSs, their ecology remains understudied. Here, we show that the benthic microbiome from the Mt. Stanley GFS is distinct at several levels from other GFSs. Specifically, several novel taxa were present, and usually common groups such as Chrysophytes and Polaromonas exhibited lower relative abundances compared to higher-latitude GFSs, while cyanobacteria and diatoms were more abundant. The rich primary producer community in this GFS likely results from the greater environmental stability of the Afrotropics, and accordingly, heterotrophic processes dominated in the bacterial community. Metagenomics revealed that almost all prokaryotes in the Mt. Stanley GFS are capable of organic carbon oxidation, while greater than 80% have the potential for fermentation and acetate oxidation. Our findings suggest a close coupling between photoautotrophs and other microbes in this GFS, and provide a glimpse into the future for high-latitude GFSs globally where primary production is projected to increase with ongoing glacier shrinkage.
Collapse
Affiliation(s)
- Grégoire Michoud
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tyler J. Kohler
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Leïla Ezzat
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hannes Peter
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Juliet Kigongo Nattabi
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Rosemary Nalwanga
- Department of Zoology, Entomology and Fisheries Sciences (ZEFs), College of Natural Sciences, Makerere University, Kampala, Uganda
| | - Paraskevi Pramateftaki
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Michail Styllas
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Matteo Tolosano
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Vincent De Staercke
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Martina Schön
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Ramona Marasco
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Daniele Daffonchio
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Massimo Bourquin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Susheel Bhanu Busi
- Systems Ecology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Tom J. Battin
- River Ecosystems Laboratory, Alpine and Polar Environmental Research Center, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| |
Collapse
|
2
|
Wang ZK, Gong JS, Feng DT, Su C, Li H, Rao ZM, Lu ZM, Shi JS, Xu ZH. Geometric Remodeling of Nitrilase Active Pocket Based on ALF-Scanning Strategy To Enhance Aromatic Nitrile Substrate Preference and Catalytic Efficiency. Appl Environ Microbiol 2023; 89:e0022023. [PMID: 37191513 PMCID: PMC10304902 DOI: 10.1128/aem.00220-23] [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: 02/13/2023] [Accepted: 04/24/2023] [Indexed: 05/17/2023] Open
Abstract
Nitrilase can catalyze nitrile compounds to generate corresponding carboxylic acids. Nitrilases as promiscuous enzymes can catalyze a variety of nitrile substrates, such as aliphatic nitriles, aromatic nitriles, etc. However, researchers tend to prefer enzymes with high substrate specificity and high catalytic efficiency. In this study, we developed an active pocket remodeling (ALF-scanning) based on modulating the geometry of the nitrilase active pocket to alter substrate preference and improve catalytic efficiency. Using this strategy, combined with site-directed saturation mutagenesis, we successfully obtained 4 mutants with strong aromatic nitrile preference and high catalytic activity, W170G, V198L, M197F, and F202M, respectively. To explore the synergistic relationship of these 4 mutations, we constructed 6 double-combination mutants and 4 triple-combination mutants. By combining mutations, we obtained the synergistically enhanced mutant V198L/W170G, which has a significant preference for aromatic nitrile substrates. Compared with the wild type, its specific activities for 4 aromatic nitrile substrates are increased to 11.10-, 12.10-, 26.25-, and 2.55-fold, respectively. By mechanistic dissection, we found that V198L/W170G introduced a stronger substrate-residue π-alkyl interaction in the active pocket and obtained a larger substrate cavity (225.66 Å3 to 307.58 Å3), making aromatic nitrile substrates more accessible to be catalyzed by the active center. Finally, we conducted experiments to rationally design the substrate preference of 3 other nitrilases based on the substrate preference mechanism and also obtained the corresponding aromatic nitrile substrate preference mutants of these three nitrilases and these mutants with greatly improved catalytic efficiency. Notably, the substrate range of SmNit is widened. IMPORTANCE In this study, the active pocket was largely remodeled based on the ALF-scanning strategy we developed. It is believed that ALF-scanning not only could be employed for substrate preference modification but might also play a role in protein engineering of other enzymatic properties, such as substrate region selectivity and substrate spectrum. In addition, the mechanism of aromatic nitrile substrate adaptation we found is widely applicable to other nitrilases in nature. To a large extent, it could provide a theoretical basis for the rational design of other industrial enzymes.
Collapse
Affiliation(s)
- Zi-Kai Wang
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, People’s Republic of China
| | - Jin-Song Gong
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, People’s Republic of China
- Yixing Institute of Food and Biotechnology Co., Ltd., Yixing, People’s Republic of China
| | - Dan-Ting Feng
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, People’s Republic of China
| | - Chang Su
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, People’s Republic of China
- Yixing Institute of Food and Biotechnology Co., Ltd., Yixing, People’s Republic of China
| | - Hui Li
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, People’s Republic of China
| | - Zhi-Ming Rao
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, People’s Republic of China
| | - Zhen-Ming Lu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, People’s Republic of China
| | - Jin-Song Shi
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi, People’s Republic of China
- Yixing Institute of Food and Biotechnology Co., Ltd., Yixing, People’s Republic of China
| | - Zheng-Hong Xu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi, People’s Republic of China
- Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi, People’s Republic of China
- Yixing Institute of Food and Biotechnology Co., Ltd., Yixing, People’s Republic of China
| |
Collapse
|
3
|
Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2019-2020. MASS SPECTROMETRY REVIEWS 2022:e21806. [PMID: 36468275 DOI: 10.1002/mas.21806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2020. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. The review is basically divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of arrays. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other areas such as medicine, industrial processes and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. The reported work shows increasing use of incorporation of new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented nearly 40 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show little sign of diminishing.
Collapse
Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, UK
- Department of Chemistry, University of Oxford, Oxford, Oxfordshire, United Kingdom
| |
Collapse
|
4
|
Li J, Liang Y, He Z, Zhong M, Hu Z. Mutation of conserved residues in the laminarinase Lam1092 increases the antioxidant activity of the laminarin product hydrolysates. Enzyme Microb Technol 2022; 162:110135. [DOI: 10.1016/j.enzmictec.2022.110135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/28/2022] [Accepted: 09/23/2022] [Indexed: 10/14/2022]
|
5
|
Cheong KL, Li JK, Zhong S. Preparation and Structure Characterization of High-Value Laminaria digitata Oligosaccharides. Front Nutr 2022; 9:945804. [PMID: 35873409 PMCID: PMC9301192 DOI: 10.3389/fnut.2022.945804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/06/2022] [Indexed: 12/19/2022] Open
Abstract
Algae-derived marine oligosaccharides have been reported to be promising bioactive compounds because of their various properties with health benefits and potential significance in numerous applications in industrial biotechnology. In this study, laminaran oligosaccharides (LOs) with varying degrees of polymerization were obtained through partial acid hydrolysis of laminaran derived from Laminaria digitata. Based on response surface methodology, the optimum LOs yield was obtained for acid hydrolysis laminaran at a hydrolysis time of 55 min, temperature of 71°C, and acid concentration of 1.00 mol/L. The size-exclusion resin Bio-Gel P-2 was considered to be a better option for LOs purification. The structure of the purified oligosaccharides was analyzed through mass spectrometry and nuclear magnetic resonance. They demonstrated the main oligosaccharide structure corresponding to the connection of glucose with β-D-Glcp-(1→3)-β-D-Glcp, which was identified as laminaribiose (DP2), laminaritriose (DP3), laminaritetrose (DP4), and laminaripentaose (DP5). LOs demonstrate excellent antioxidant activities, as evidenced from their reactions with oxidizing free radicals, 1, 1-diphenyl-2-picryl-hydrazyl, and 2, 2′-azino-bis (3-etilbenzotiazoline-6-sulfonic acid) radicals. LOs exhibited a prebiotic effect on the growth of Bifidobacterium adolescentis and Lactobacillus plantarum. Therefore, we propose the development of LOs as natural antioxidants and prebiotics in the functional food and pharmaceutical industries.
Collapse
Affiliation(s)
- Kit-Leong Cheong
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, China
- Department of Biology, College of Science, Shantou University, Shantou, China
| | - Jia-Kang Li
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, China
- Department of Biology, College of Science, Shantou University, Shantou, China
| | - Saiyi Zhong
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, China
- *Correspondence: Saiyi Zhong,
| |
Collapse
|
6
|
Kumagai Y, Kishimura H, Lang W, Tagami T, Okuyama M, Kimura A. Characterization of an Unknown Region Linked to the Glycoside Hydrolase Family 17 β-1,3-Glucanase of Vibrio vulnificus Reveals a Novel Glucan-Binding Domain. Mar Drugs 2022; 20:md20040250. [PMID: 35447923 PMCID: PMC9026390 DOI: 10.3390/md20040250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/27/2023] Open
Abstract
The glycoside hydrolase family 17 β-1,3-glucanase of Vibrio vulnificus (VvGH17) has two unknown regions in the N- and C-termini. Here, we characterized these domains by preparing mutant enzymes. VvGH17 demonstrated hydrolytic activity of β-(1→3)-glucan, mainly producing laminaribiose, but not of β-(1→3)/β-(1→4)-glucan. The C-terminal-truncated mutants (ΔC466 and ΔC441) showed decreased activity, approximately one-third of that of the WT, and ΔC415 lost almost all activity. An analysis using affinity gel containing laminarin or barley β-glucan revealed a shift in the mobility of the ΔC466, ΔC441, and ΔC415 mutants compared to the WT. Tryptophan residues showed a strong affinity for carbohydrates. Three of four point-mutations of the tryptophan in the C-terminus (W472A, W499A, and W542A) showed a reduction in binding ability to laminarin and barley β-glucan. The C-terminus was predicted to have a β-sandwich structure, and three tryptophan residues (Trp472, Trp499, and Trp542) constituted a putative substrate-binding cave. Linker and substrate-binding functions were assigned to the C-terminus. The N-terminal-truncated mutants also showed decreased activity. The WT formed a trimer, while the N-terminal truncations formed monomers, indicating that the N-terminus contributed to the multimeric form of VvGH17. The results of this study are useful for understanding the structure and the function of GH17 β-1,3-glucanases.
Collapse
Affiliation(s)
- Yuya Kumagai
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan;
- Correspondence: (Y.K.); (A.K.)
| | - Hideki Kishimura
- Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan;
| | - Weeranuch Lang
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Takayoshi Tagami
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Masayuki Okuyama
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
| | - Atsuo Kimura
- Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; (W.L.); (T.T.); (M.O.)
- Correspondence: (Y.K.); (A.K.)
| |
Collapse
|
7
|
Koteshwara A. Simple Methods for the Preparation of Colloidal Chitin, Cell Free Supernatant and Estimation of Laminarinase. Bio Protoc 2021; 11:e4176. [PMID: 34722823 DOI: 10.21769/bioprotoc.4176] [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: 03/22/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 11/02/2022] Open
Abstract
Colloidal chitin (CC) is a common substrate used in research work involving chitin-active enzymes (chitinases). Cell free supernatant (CFS) is prepared from fermented broth. Preparation of CC and CFS usually involve large amounts of liquid, which must be separated from the solids. This necessitates the use of a large volume centrifugation facility, which may not be accessible to everyone. Filtration is a viable alternative to centrifugation, and several filter elements are described in the literature. Each of those elements has its own set of disadvantages like non-availability, high cost, fragility, and non-reusability. Here we describe the use of lab coat clothing material (LCCM) for the preparation of CC and CFS. For filtration purposes, the LCCM was found to be functional, rugged, reusable, and cost-effective. Also described here is a new method for the estimation of laminarinase using a laminarin infused agarose gel plate. An easily available optical fabric brightener (OFB) was used as a stain for the agarose plate. The laminarin infused agarose plate assay is simple, inexpensive, and was found to be impervious to high amounts of ammonium sulfate (AS) in enzyme precipitates.
Collapse
Affiliation(s)
- Ananthamurthy Koteshwara
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences (MCOPS), Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India
| |
Collapse
|
8
|
Koteshwara A, Philip NV, Aranjani JM, Hariharapura RC, Volety Mallikarjuna S. A set of simple methods for detection and extraction of laminarinase. Sci Rep 2021; 11:2489. [PMID: 33510321 PMCID: PMC7844030 DOI: 10.1038/s41598-021-81807-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/04/2020] [Indexed: 11/08/2022] Open
Abstract
A carefully designed ammonium sulfate precipitation will simplify extraction of proteins and is considered to be a gold standard among various precipitation methods. Therefore, optimization of ammonium sulfate precipitation can be an important functional step in protein purification. The presence of high amounts of ammonium sulphate precludes direct detection of many enzymatically active proteins including reducing sugar assays (e.g. Nelson-Somogyi, Reissig and 3,5-dinitrosalicylic acid methods) for assessing carbohydrases (e.g. laminarinase (β (1-3)-glucanohydrolase), cellulases and chitinases). In this study, a simple method was developed using laminarin infused agarose plate for the direct analysis of the ammonium sulphate precipitates from Streptomyces rimosus AFM-1. The developed method is simple and convenient that can give accurate results even in presence of ammonium sulfate in the crude precipitates. Laminarin is a translucent substrate requiring the use of a stain to visualize the zones of hydrolysis in a plate assay. A very low-cost and locally available fluorescent optical fabric brightener Tinopal CBS-X has been used as a stain to detect the zones of hydrolysis. We also report simple methods to prepare colloidal chitin and cell free supernatant in this manuscript.
Collapse
Affiliation(s)
- Ananthamurthy Koteshwara
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Udupi, Karnataka, 576104, India
| | - Nancy V Philip
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Udupi, Karnataka, 576104, India
| | - Jesil Mathew Aranjani
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Udupi, Karnataka, 576104, India
| | - Raghu Chandrashekhar Hariharapura
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Udupi, Karnataka, 576104, India
| | - Subrahmanyam Volety Mallikarjuna
- Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Udupi, Karnataka, 576104, India.
| |
Collapse
|