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Yao B, Kong X, Tian K, Zeng X, Lu W, Pang L, Sun S, Tian X. Initial Litter Chemistry and UV Radiation Drive Chemical Divergence in Litter during Decomposition. Microorganisms 2024; 12:1535. [PMID: 39203377 PMCID: PMC11356187 DOI: 10.3390/microorganisms12081535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/10/2024] [Accepted: 07/20/2024] [Indexed: 09/03/2024] Open
Abstract
Litter's chemical complexity influences carbon (C) cycling during its decomposition. However, the chemical and microbial mechanisms underlying the divergence or convergence of chemical complexity under UV radiation remain poorly understood. Here, we conducted a 397-day field experiment using 13C cross-polarization magic-angle spinning nuclear magnetic resonance (13C-CPMAS NMR) to investigate the interactions among the initial chemistry, microbial communities, and UV radiation during decomposition. Our study found that the initial concentrations of O-substituted aromatic C, di-O-alkyl C, and O-alkyl C in Deschampsia caespitosa were higher than those in Kobresia tibetica. Litter's chemical composition exhibited divergent patterns based on the initial chemistry, UV radiation, and decay time. Specifically, D. caespitosa consistently displayed higher concentrations of di-O-alkyl C and O-alkyl C compared to K. tibetica, regardless of the UV exposure and decay time. Additionally, litter's chemical complexity was positively correlated with changes in the extracellular enzyme activities, particularly those involved in lignin, cellulose, and hemicellulose degradation, which accounted for 9%, 20%, and 4% of the variation in litter's chemical complexity, respectively. These findings highlighted the role of distinct microbial communities in decomposing different C components through catabolism, leading to chemical divergence in litter. During the early decomposition stages, oligotrophic Planctomycetes and Acidobacteria metabolized O-alkyl C and di-O-alkyl C under UV-blocking conditions. In contrast, copiotrophic Actinobacteria and Chytridiomycota utilized these components under UV radiation exposure, reflecting their ability to thrive under UV stress conditions due to their rapid growth strategies in environments rich in labile C. Our study revealed that the inherent differences in the initial O-alkyl C and di-O-alkyl C contributed to the chemical divergence, while UV radiation further influenced this divergence by shifting the microbial community composition from oligotrophic to copiotrophic species. Thus, differences in the initial litter chemistry, microbial community, and UV radiation affected the quantity and quality of plant-derived C during decomposition.
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Affiliation(s)
- Bei Yao
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Xiangshi Kong
- Key Laboratory for Ecotourism of Hunan Province, School of Tourism, Jishou University, Jishou 416000, China;
| | - Kai Tian
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Xiaoyi Zeng
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Wenshuo Lu
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Lu Pang
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Shucun Sun
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
| | - Xingjun Tian
- School of Life Sciences, Nanjing University, Nanjing 210023, China; (B.Y.); (K.T.); (X.Z.); (W.L.); (L.P.); (S.S.)
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
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Peng L, Hou J, Zhang Y, Wang B, Zhang Y, Zhao K, Wang Q, Christie P, Liu W, Luo Y. Metagenomic analysis of a thermophilic bacterial consortium and its use in the bioremediation of a petroleum-contaminated soil. CHEMOSPHERE 2024; 360:142379. [PMID: 38777200 DOI: 10.1016/j.chemosphere.2024.142379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/16/2024] [Accepted: 05/17/2024] [Indexed: 05/25/2024]
Abstract
Biodegradation is difficult at high temperatures due to the limited capacity of microorganisms to survive and function outside their optimum temperature range. Here, a thermophilic petroleum-degrading consortium was enriched from compost at a temperature of 55 °C. 16S rDNA and metagenomic techniques were used to analyze the composition of the consortium and the mechanisms of degradation. The consortium degraded 17000 mg total petroleum hydrocarbons (TPHs) L-1 with a degradation efficiency of 81.5% in 14 days. The consortium utilized a range of substrates such as n-hexadecane, n-docosane, naphthalene and pyrene and grew well over a wide range of pH (4-10) and salinity (0-90 g L-1). The hydrocarbon-degrading extremophilic consortium contained, inter alia, (relative abundance >1%) Caldibacillus, Geobacillus, Mycolicibacterium, Bacillus, Chelatococcus, and Aeribacillus spp. Metagenomic analysis was conducted to discover the degradation and environmental tolerance functional genes of the consortium. Two alkane hydroxylase genes, alkB and ladA, were found. A microcosm study shows that the consortium promoted the bioremediation of soil TPHs. The results indicate that the consortium may be a good candidate for the high-temperature bioremediation of petroleum-contaminated soils.
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Affiliation(s)
- Li Peng
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210008, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jinyu Hou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yufeng Zhang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210008, China
| | - Beibei Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yun Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ke Zhao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Qingling Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Peter Christie
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Wuxing Liu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Yongming Luo
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
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Rajeswari G, Kumar V, Jacob S. A concerted enzymatic de-structuring of lignocellulosic materials using a compost-derived microbial consortia favoring the consolidated pretreatment and bio-saccharification. Enzyme Microb Technol 2024; 174:110393. [PMID: 38219439 DOI: 10.1016/j.enzmictec.2023.110393] [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: 08/30/2023] [Revised: 11/24/2023] [Accepted: 12/29/2023] [Indexed: 01/16/2024]
Abstract
The robustness of microbial consortia isolated from compost habitat encompasses the complementary metabolism that aids in consolidated bioprocessing (CBP) of lignocellulosic biomass (LCB) by division of labor across the symbionts. Composting of organic waste is deemed to be an efficient way of carbon recycling, where the syntrophic microbial population exerts a concerted action of lignin and polysaccharide (hemicellulose and cellulose) component of plant biomass. The potential of this interrelated microorganism could be enhanced through adaptive laboratory evolution (ALE) with LCB for its desired functional capabilities. Therefore, in this study, microbial symbionts derived from organic compost was enriched on saw dust (SD) (woody biomass), aloe vera leaf rind (AVLR) (agro-industrial waste) and commercial filter paper (FP) (pure cellulose) through ALE under different conditions. Later, the efficacy of enriched consortium (EC) on consolidated pretreatment and bio-saccharification was determined based on substrate degradation, endo-enzymes profiling and fermentable sugar yield. Among the treatment sets, AVLR biomass treated with EC-5 has resulted in the higher degradation rate of lignin (47.01 ± 0.66%, w/w) and polysaccharides (45.87 ± 1.82%, w/w) with a total sugar yield of about 60.01 ± 4.24 mg/g. In addition, the extent of structural disintegration of substrate after EC-treatment was clearly deciphered by FTIR and XRD analysis. And the factors of Pearson correlation matrix reinforces the potency of EC-5 by exhibiting a strong positive correlation between AVLR degradation and the sugar release. Thus, a consortium based CBP could promote the feasibility of establishing a sustainable second generation biorefinery framework.
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Affiliation(s)
- Gunasekaran Rajeswari
- Department of Biotechnology, School of Bioengineering, College of Engineering and Technology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Chengalpattu District, Kattankulathur 603203, Tamil Nadu, India
| | - Vinod Kumar
- School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
| | - Samuel Jacob
- Department of Biotechnology, School of Bioengineering, College of Engineering and Technology, Faculty of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Chengalpattu District, Kattankulathur 603203, Tamil Nadu, India.
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Wang Y, Wang C, Chen Y, Cui M, Wang Q, Guo P. Heterologous Expression of a Thermostable α-Galactosidase from Parageobacillus thermoglucosidasius Isolated from the Lignocellulolytic Microbial Consortium TMC7. J Microbiol Biotechnol 2022; 32:749-760. [PMID: 35637170 PMCID: PMC9628905 DOI: 10.4014/jmb.2201.01022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 12/15/2022]
Abstract
α-Galactosidase is a debranching enzyme widely used in the food, feed, paper, and pharmaceuticals industries and plays an important role in hemicellulose degradation. Here, T26, an aerobic bacterial strain with thermostable α-galactosidase activity, was isolated from laboratory-preserved lignocellulolytic microbial consortium TMC7, and identified as Parageobacillus thermoglucosidasius. The α-galactosidase, called T26GAL and derived from the T26 culture supernatant, exhibited a maximum enzyme activity of 0.4976 IU/ml when cultured at 60°C and 180 rpm for 2 days. Bioinformatics analysis revealed that the α-galactosidase T26GAL belongs to the GH36 family. Subsequently, the pET-26 vector was used for the heterologous expression of the T26 α-galactosidase gene in Escherichia coli BL21 (DE3). The optimum pH for α-galactosidase T26GAL was determined to be 8.0, while the optimum temperature was 60°C. In addition, T26GAL demonstrated a remarkable thermostability with more than 93% enzyme activity, even at a high temperature of 90°C. Furthermore, Ca2+ and Mg2+ promoted the activity of T26GAL while Zn2+ and Cu2+ inhibited it. The substrate specificity studies revealed that T26GAL efficiently degraded raffinose, stachyose, and guar gum, but not locust bean gum. This study thus facilitated the discovery of an effective heat-resistant α-galactosidase with potent industrial application. Meanwhile, as part of our research on lignocellulose degradation by a microbial consortium, the present work provides an important basis for encouraging further investigation into this enzyme complex.
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Affiliation(s)
- Yi Wang
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
| | - Chen Wang
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
- College of Biology and Pharmacy, Three Gorges University, Yichang 443002, P.R. China
| | - Yonglun Chen
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
- College of Biology and Pharmacy, Three Gorges University, Yichang 443002, P.R. China
| | - MingYu Cui
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
- College of Biology and Pharmacy, Three Gorges University, Yichang 443002, P.R. China
| | - Qiong Wang
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
| | - Peng Guo
- Institute of Agricultural Products Processing and Nuclear Agriculture Technology Research, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R. China
- College of Biology and Pharmacy, Three Gorges University, Yichang 443002, P.R. China
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Chen J, Yang Y, Ke Y, Chen X, Jiang X, Chen C, Xie S. Anaerobic sulfamethoxazole-degrading bacterial consortia in antibiotic-contaminated wetland sediments identified by DNA-stable isotope probing and metagenomics analysis. Environ Microbiol 2022; 24:3751-3763. [PMID: 35688651 DOI: 10.1111/1462-2920.16091] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/31/2022] [Indexed: 11/29/2022]
Abstract
Anaerobic degradation has been demonstrated as an important pathway for the removal of sulfonamide (SA) in contaminated environments, and identifying the microorganisms responsible for the degradation of SA is a key step in developing bioaugmentation approaches. In this study, we investigated the anaerobic degradation activity of three SA [sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX)] and the associated bacterial community in wetland sediments contaminated by aquaculture (in Fujian Province, coded with FJ), livestock farming (in Sichuan Province, coded with SC), or rural wastewaters (in Guangdong Province, coded with GD). Additionally, the combination of DNA-stable isotope probing (SIP) with metagenomics was further applied to assess the active SA-degrading microbes using SMX as a model SA. Among SDZ, SMZ and SMX, only SMX could be effectively dissipated, and the degradation of SMX was relatively fast in the microcosms of sediments with higher levels of SA contamination (FJ and SC). The anaerobic biotransformation pathway of SMX was initiated by hydrogenation with the cleavage of the N-O bond on the isoxazole ring. DNA-SIP revealed that the in situ active anaerobic SMX-degraders (5, 18 and 3 genera in sediments FJ, SC and GD respectively) were dominated by Proteobacteria in sediments FJ and SC, but by Firmicutes (two Family XVIII members) in sediment GD. Mycobacterium, unclassified Burkholderiaceae and Rhodocyclaceae were identified as the dominant active SMX-degrading bacteria in both sediments FJ and SC. Higher proportions of antibiotic resistance gene and genes involved in various functional categories were observed in sediments FJ and SC.
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Affiliation(s)
- Jianfei Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Yuyin Yang
- South China Institute of Environmental Sciences (SCIES), Ministry of Ecology and Environment (MEE), Guangzhou, 510655, China
| | - Yanchu Ke
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Xiuli Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Xinshu Jiang
- State Key Joint Laboratory of Environment Simulation and Pollution Control (SKJLESPC), Beijing Key Laboratory for Emerging Organic Contaminants Control (BKLEOC), School of Environment, POPs Research Center, Tsinghua University, Beijing, 100084, China
| | - Chao Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Shuguang Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
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