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Shrestha P, Karmacharya J, Kim KH, Han SR, Oh TJ. Exploration of novel trehalases from cold-adapted Variovorax sp. PAMC28711: Functional characterization. Int J Biol Macromol 2024; 271:132503. [PMID: 38768913 DOI: 10.1016/j.ijbiomac.2024.132503] [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: 11/06/2023] [Revised: 04/05/2024] [Accepted: 05/17/2024] [Indexed: 05/22/2024]
Abstract
The cold-adapted bacterium Variovorax sp. PAMC28711 possesses two distinct glycoside hydrolase (GH) families of trehalase, GH15 and GH37. While numerous studies have explored bacterial trehalase, the presence of two different trehalase genes within a single strain has not been reported until now. Interestingly, despite both GH37 and GH15 trehalases serving the same purpose of degrading trehalose, but do not share the sequence similarity. The substrate specificity assay confirmed that Vtre37 and Vtre15 displayed hydrolytic activity on α, α-trehalose. The key catalytic sites were identified as D280 and E469 in Vtre37 and E389 and E554 in Vtre15 through site-directed mutation and confirmed these two enzymes belong to trehalase. In addition, Vtre37 exhibited a relatively high level of enzyme activity of 1306.33 (±53.091) μmolmg-1, whereas Vtre15 showed enzyme activity of 408.39 (±12.503) μmolmg-1. Moreover, Vtre37 performed admirably showing resistance to ethanol (10 %), with high stable at acidic pH range. Furthermore, both prediction and experimental results indicate that validoxylamine A showed a potent inhibitory activity against Vtre37 trehalase with a Ki value of 16.85 nM. Therefore, we postulate that Vtre37 could be utilized as an ethanol enhancer and designed for screening inhibitors related to the trehalose degradation pathway. Additionally, we believe that characterizing these bacterial trehalase contributes to a better understanding of trehalose metabolism and its biological importance in bacteria.
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Affiliation(s)
- Prasansah Shrestha
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, South Korea; Genome-based Bio-IT Convergence Institute, Asan 31460, South Korea
| | - Jayram Karmacharya
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, South Korea
| | - Ki-Hwa Kim
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, South Korea; Genome-based Bio-IT Convergence Institute, Asan 31460, South Korea
| | - So-Ra Han
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, South Korea; Genome-based Bio-IT Convergence Institute, Asan 31460, South Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, South Korea
| | - Tae-Jin Oh
- Department of Life Science and Biochemical Engineering, Graduate School, SunMoon University, Asan 31460, South Korea; Genome-based Bio-IT Convergence Institute, Asan 31460, South Korea; Bio Big Data-based Chungnam Smart Clean Research Leader Training Program, SunMoon University, Asan 31460, South Korea; Department of Pharmaceutical Engineering and Biotechnology, SunMoon University, Asan 31460, South Korea.
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Mascelli GM, Garcia CA, Gardner JG. Genetic and enzymatic characterization of Amy13E from Cellvibrio japonicus reclassifies it as a cyclodextrinase also capable of α-diglucoside degradation. Appl Environ Microbiol 2024; 90:e0152123. [PMID: 38084944 PMCID: PMC10807414 DOI: 10.1128/aem.01521-23] [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: 09/01/2023] [Accepted: 10/31/2023] [Indexed: 01/25/2024] Open
Abstract
Cyclodextrinases are carbohydrate-active enzymes involved in the linearization of circular amylose oligosaccharides. Primarily thought to function as part of starch metabolism, there have been previous reports of bacterial cyclodextrinases also having additional enzymatic activities on linear malto-oligosaccharides. This substrate class also includes environmentally rare α-diglucosides such as kojibiose (α-1,2), nigerose (α-1,3), and isomaltose (α-1,6), all of which have valuable properties as prebiotics or low-glycemic index sweeteners. Previous genome sequencing of three Cellvibrio japonicus strains adapted to utilize these α-diglucosides identified multiple, but uncharacterized, mutations in each strain. One of the mutations identified was in the amy13E gene, which was annotated to encode a neopullulanase. In this report, we functionally characterized this gene and determined that it in fact encodes a cyclodextrinase with additional activities on α-diglucosides. Deletion analysis of amy13E found that this gene was essential for kojibiose and isomaltose metabolism in C. japonicus. Interestingly, a Δamy13E mutant was not deficient for cyclodextrin or pullulan utilization in C. japonicus; however, heterologous expression of the gene in E. coli was sufficient for cyclodextrin-dependent growth. Biochemical analyses found that CjAmy13E cleaved multiple substrates but preferred cyclodextrins and maltose, but had no activity on pullulan. Our characterization of the CjAmy13E cyclodextrinase is useful for refining functional enzyme predictions in related bacteria and for engineering enzymes for biotechnology or biomedical applications.IMPORTANCEUnderstanding the bacterial metabolism of cyclodextrins and rare α-diglucosides is increasingly important, as these sugars are becoming prevalent in the foods, supplements, and medicines humans consume that subsequently feed the human gut microbiome. Our analysis of a cyclomaltodextrinase with an expanded substrate range is significant because it broadens the potential applications of the GH13 family of carbohydrate active enzymes (CAZymes) in biotechnology and biomedicine. Specifically, this study provides a workflow for the discovery and characterization of novel activities in bacteria that possess a high number of CAZymes that otherwise would be missed due to complications with functional redundancy. Furthermore, this study provides a model from which predictions can be made why certain bacteria in crowded niches are able to robustly utilize rare carbon sources, possibly to gain a competitive growth advantage.
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Affiliation(s)
- Giulia M. Mascelli
- Department of Biological Sciences, University of Maryland, Baltimore, USA
| | - Cecelia A. Garcia
- Department of Biological Sciences, University of Maryland, Baltimore, USA
| | - Jeffrey G. Gardner
- Department of Biological Sciences, University of Maryland, Baltimore, USA
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Zhu L, Su Y, Ma Z, Guo L, Yang S, Yu H. Comparative proteomic analysis reveals differential protein expression of Hypsizygus marmoreus in response to different light qualities. Int J Biol Macromol 2022; 223:1320-1334. [PMID: 36395936 DOI: 10.1016/j.ijbiomac.2022.11.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 11/16/2022]
Abstract
Light is important environmental stress that influences the growth, development, and metabolism of Hypsizygus marmoreus (white var.). However, the molecular basis of the light effect on H. marmoreus remains unclear. In this study, a label-free comparative proteomic analysis was applied to investigate the global protein expression profile of H. marmoreus mycelia growing under white, red, green, and blue light qualities and darkness (control). Among 3149 identified proteins in H. marmoreus, 2288 were found to be expressed in all tested conditions. Data of Each light quality was compared with darkness for further analysis, numerous differentially expressed proteins (DEPs) were identified and the white light group showed the most. All the up-regulated and down-regulated DEPs were annotated and analyzed with the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The KEGG enrichment analysis revealed that light stress was associated with primary metabolism, glycolysis/gluconeogenesis, MAPK, proteasome, and carbohydrate-active enzyme pathways. This study advances valuable insights into the molecular mechanisms underlying the role of different light qualities in mushroom growth and development.
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Affiliation(s)
- Liping Zhu
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China
| | - Yao Su
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China
| | - Zhiheng Ma
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China
| | - Lizhong Guo
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China
| | - Song Yang
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China.
| | - Hao Yu
- Shandong Provincial Key Laboratory of Applied Mycology, School of Life Sciences, Qingdao Agricultural University, 700 Changcheng Road, Chengyang District, Qingdao 266109, Shandong Province, People's Republic of China.
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Identification and Characterization of a Novel Cold-Adapted GH15 Family Trehalase from the Psychrotolerant Microbacterium phyllosphaerae LW106. FERMENTATION 2022. [DOI: 10.3390/fermentation8100471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Psychrophiles inhabiting various cold environments are regarded as having evolved diverse physiological and molecular strategies, such as the accumulation of trehalose to alleviate cold stress. To investigate the possible contributions of trehalose metabolism-related enzymes to cold-adaption in psychrotrophic bacteria and enrich the resource bank of trehalose hydrolysis enzymes, a novel cold-adapted GH15 GA-like trehalase (MpTre15A) from psychrotolerant Microbacteriumphyllosphaerae LW106 isolated from glacier sediments was cloned and characterized. The recombinant MpTre15A from M. phyllosphaerae LW106 was expressed and purified in Escherichia coli BL21(DE3). The purified MpTre15A functioned as a hexamer and displayed maximal activity at pH 5.0 and 50 °C. Substrate specificity assay proved MpTre15A only showed hydrolytic activity toward α,α-trehalose. Site-directed mutation verified the key catalytic sites of Glu392 and Glu557 in MpTre15A. The kcat and kcat/Km values of MpTre15A at 4 °C (104.50 s−1 and 1.6 s−1 mM−1, respectively) were comparable to those observed for thermophilic GH15 trehalases at 50 °C, revealing its typical cold-adaptability. MpTre15A showed a trehalose conversion rate of 100% and 99.4% after 10 min and 15 min of incubation at 50 °C and 37 °C, respectively. In conclusion, this novel cold-adapted α,α-trehalase MpTre15A showed potential application for developing therapeutic enzymes, enzyme-based biosensors, and enzyme additives in the fermentation industry.
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Gardner JG, Schreier HJ. Unifying themes and distinct features of carbon and nitrogen assimilation by polysaccharide-degrading bacteria: a summary of four model systems. Appl Microbiol Biotechnol 2021; 105:8109-8127. [PMID: 34611726 DOI: 10.1007/s00253-021-11614-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 11/24/2022]
Abstract
Our current understanding of enzymatic polysaccharide degradation has come from a huge number of in vitro studies with purified enzymes. While this vast body of work has been invaluable in identifying and characterizing novel mechanisms of action and engineering desirable traits into these enzymes, a comprehensive picture of how these enzymes work as part of a native in vivo system is less clear. Recently, several model bacteria have emerged with genetic systems that allow for a more nuanced study of carbohydrate active enzymes (CAZymes) and how their activity affects bacterial carbon metabolism. With these bacterial model systems, it is now possible to not only study a single nutrient system in isolation (i.e., carbohydrate degradation and carbon metabolism), but also how multiple systems are integrated. Given that most environmental polysaccharides are carbon rich but nitrogen poor (e.g., lignocellulose), the interplay between carbon and nitrogen metabolism in polysaccharide-degrading bacteria can now be studied in a physiologically relevant manner. Therefore, in this review, we have summarized what has been experimentally determined for CAZyme regulation, production, and export in relation to nitrogen metabolism for two Gram-positive (Caldicellulosiruptor bescii and Clostridium thermocellum) and two Gram-negative (Bacteroides thetaiotaomicron and Cellvibrio japonicus) polysaccharide-degrading bacteria. By comparing and contrasting these four bacteria, we have highlighted the shared and unique features of each, with a focus on in vivo studies, in regard to carbon and nitrogen assimilation. We conclude with what we believe are two important questions that can act as guideposts for future work to better understand the integration of carbon and nitrogen metabolism in polysaccharide-degrading bacteria. KEY POINTS: • Regardless of CAZyme deployment system, the generation of a local pool of oligosaccharides is a common strategy among Gram-negative and Gram-positive polysaccharide degraders as a means to maximally recoup the energy expenditure of CAZyme production and export. • Due to the nitrogen deficiency of insoluble polysaccharide-containing substrates, Gram-negative and Gram-positive polysaccharide degraders have a diverse set of strategies for supplementation and assimilation. • Future work needs to precisely characterize the energetic expenditures of CAZyme deployment and bolster our understanding of how carbon and nitrogen metabolism are integrated in both Gram-negative and Gram-positive polysaccharide-degrading bacteria, as both of these will significantly influence a given bacterium's suitability for biotechnology applications.
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Affiliation(s)
- Jeffrey G Gardner
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA.
| | - Harold J Schreier
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA.,Department of Marine Biotechnology, Institute of Marine and Environmental Technology, University of Maryland, Baltimore County, Baltimore, MD, USA
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Garcia CA, Gardner JG. Bacterial α-diglucoside metabolism: perspectives and potential for biotechnology and biomedicine. Appl Microbiol Biotechnol 2021; 105:4033-4052. [PMID: 33961116 PMCID: PMC8237927 DOI: 10.1007/s00253-021-11322-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/20/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022]
Abstract
In a competitive microbial environment, nutrient acquisition is a major contributor to the survival of any individual bacterial species, and the ability to access uncommon energy sources can provide a fitness advantage. One set of soluble carbohydrates that have attracted increased attention for use in biotechnology and biomedicine is the α-diglucosides. Maltose is the most well-studied member of this class; however, the remaining four less common α-diglucosides (trehalose, kojibiose, nigerose, and isomaltose) are increasingly used in processed food and fermented beverages. The consumption of trehalose has recently been shown to be a contributing factor in gut microbiome disease as certain pathogens are using α-diglucosides to outcompete native gut flora. Kojibiose and nigerose have also been examined as potential prebiotics and alternative sweeteners for a variety of foods. Compared to the study of maltose metabolism, our understanding of the synthesis and degradation of uncommon α-diglucosides is lacking, and several fundamental questions remain unanswered, particularly with regard to the regulation of bacterial metabolism for α-diglucosides. Therefore, this minireview attempts to provide a focused analysis of uncommon α-diglucoside metabolism in bacteria and suggests some future directions for this research area that could potentially accelerate biotechnology and biomedicine developments. KEY POINTS: • α-diglucosides are increasingly important but understudied bacterial metabolites. • Kinetically superior α-diglucoside enzymes require few amino acid substitutions. • In vivo studies are required to realize the biotechnology potential of α-diglucosides.
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Affiliation(s)
- Cecelia A Garcia
- Department of Biological Sciences, University of Maryland-Baltimore County, Baltimore, MD, USA
| | - Jeffrey G Gardner
- Department of Biological Sciences, University of Maryland-Baltimore County, Baltimore, MD, USA.
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Monge EC, Gardner JG. Efficient chito-oligosaccharide utilization requires two TonB-dependent transporters and one hexosaminidase in Cellvibrio japonicus. Mol Microbiol 2021; 116:366-380. [PMID: 33735458 DOI: 10.1111/mmi.14717] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/13/2021] [Accepted: 03/14/2021] [Indexed: 11/29/2022]
Abstract
Chitin utilization by microbes plays a significant role in biosphere carbon and nitrogen cycling, and studying the microbial approaches used to degrade chitin will facilitate our understanding of bacterial strategies to degrade a broad range of recalcitrant polysaccharides. The early stages of chitin depolymerization by the bacterium Cellvibrio japonicus have been characterized and are dependent on one chitin-specific lytic polysaccharide monooxygenase and nonredundant glycoside hydrolases from the family GH18 to generate chito-oligosaccharides for entry into metabolism. Here, we describe the mechanisms for the latter stages of chitin utilization by C. japonicus with an emphasis on the fate of chito-oligosaccharides. Our systems biology approach combined transcriptomics and bacterial genetics using ecologically relevant substrates to determine the essential mechanisms for chito-oligosaccharide transport and catabolism in C. japonicus. Using RNAseq analysis we found a coordinated expression of genes that encode polysaccharide-degrading enzymes. Mutational analysis determined that the hex20B gene product, predicted to encode a hexosaminidase, was required for efficient utilization of chito-oligosaccharides. Furthermore, two gene loci (CJA_0353 and CJA_1157), which encode putative TonB-dependent transporters, were also essential for chito-oligosaccharides utilization. This study further develops our model of C. japonicus chitin metabolism and may be predictive for other environmentally or industrially important bacteria.
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Affiliation(s)
- Estela C Monge
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
| | - Jeffrey G Gardner
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD, USA
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