1
|
Li Y, Guo Z, Liu X, Xu L, Zhu W, Cheng Y, Longland AC, Theodorou MK. Bioaugmentation protocols involving Methanobrevibacter thaueri and Pecoramyces ruminantium for investigating lignocellulose degradation and methane production from alfalfa stalks. BIORESOURCE TECHNOLOGY 2024; 408:131172. [PMID: 39079572 DOI: 10.1016/j.biortech.2024.131172] [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: 06/10/2024] [Revised: 07/19/2024] [Accepted: 07/27/2024] [Indexed: 08/04/2024]
Abstract
Two protocols involving batch cultures were used to investigate the bioaugmentation of methane production by Pecoramyces ruminantium, and Methanobrevibacter thaueri. Protocol I examined the effect of altering the proportion of the microbial constituents in inoculum on alfalfa stalk fermentations and showed a 25 % improvement in dry matter loss in cultures where the inoculum contained just 30 % of co-culture and 70 % of fungal monoculture. Protocol II involved consecutive cultures and alternating inoculations. This protocol resulted in 17-22 mL/g DM methane production with co-cultures a 30 % increase in methane relative to the fungal monoculture. Both protocols indicate that the co-culture rapidly dominated and was more resilient than the monoculture. Synergistic interaction between fungus and methanogen, promoted more efficient lignocellulose degradation and higher methane yield. This study highlighted the potential of microbial co-cultures for enhancing methane production from lignocellulosic biomass, offering a promising bioaugmentation strategy for improving biogas yields and waste valorization.
Collapse
Affiliation(s)
- Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Ziqi Guo
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Xin Liu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Li Xu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China.
| | | | - Michael K Theodorou
- Department of Agriculture and Environment, Harper Adams University, Newport TF10 8NB, UK
| |
Collapse
|
2
|
Li K, Du H, Guo W, Na M, Na R. Alfalfa supplementation timing changes the rumen archaeal and fungal community composition and colonization in pre-weaning lambs. Front Microbiol 2024; 15:1380322. [PMID: 38784814 PMCID: PMC11112515 DOI: 10.3389/fmicb.2024.1380322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
The establishment of the rumen microbiota plays an important role in the rumen development. However, little is known about the effects of alfalfa supplementation time on rumen microbiota establishment. Here, a total of 42 Hu lambs, seven-day-old, were chosen for the study. After a week of adjustment, six lambs were sacrificed to establish a baseline. The remaining 36 lambs were randomly split into two groups: one receiving alfalfa hay at 14 days (EAF), the other at 42 days (LAF), both groups received milk replacer and starter pellets. Introducing alfalfa at 14 days of age significantly improved total dry matter intake between 28 and 42 days (p = 0.04) and average daily gain from both 14 to 28 days (p = 0.04) and 28 to 42 days (p < 0.01), but this effect disappears from 56 to 70 days (p > 0.05). At 42 days, the abundances of Naganishia, Ascochyta, and Neosetophoma in the EAF group were significantly higher (p < 0.05) than those in the LAF group (17.8% vs. 3.97, 10.89% vs. 1.77, and 1.27% vs. 0.09%, respectively). At 56 days, the abundances of Ascochyta, Wallemia, and Aspergillus in the EAF group were significantly lower (p < 0.05) than in the LAF group (3.53% vs. 16.40, 8.78% vs. 18.89, and 2.14% vs. 4.69%). At 70 days, Aspergillus abundance in the EAF group was significantly higher (p < 0.05) than in the LAF group (2.69% vs. 0.85%). The LEfSe analysis showed that Methanobrevibacter_smithii was the archaeal biomarker at 14 days in both groups. Methanobrevibacter_sp_AbM4 was enriched at 56 days in the LAF group. Compared to the LAF group, the specific fungal biomarkers in the EAF group included Sporobolomyces and Bullera at 14 days, Naganishia, Didymella, Cleistothelebolus, and Alloleptosphaeria at 42 days, Ascochyta, Neoascochyta, and Alfaria at 70 days. Correlation analysis results showed strong patterns of association both within and between archaea and fungi, which were influenced by alfalfa supplementation time. In summary, alfalfa supplementation at 14 days of age promotes the growth performance of lambs before weaning, and alfalfa supplementation timing significantly affects rumen archaeal and fungal communities and dynamical changes.
Collapse
Affiliation(s)
| | | | | | | | - Renhua Na
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot, China
| |
Collapse
|
3
|
Kyawt YY, Aung M, Xu Y, Zhou Y, Li Y, Sun Z, Zhu W, Cheng Y. Methane production and lignocellulosic degradation of wastes from rice, corn and sugarcane by natural anaerobic fungi-methanogens co-culture. World J Microbiol Biotechnol 2024; 40:109. [PMID: 38411737 DOI: 10.1007/s11274-024-03938-8] [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: 09/23/2023] [Accepted: 02/22/2024] [Indexed: 02/28/2024]
Abstract
Biomass from agriculture, forestry, and urban wastes is a potential renewable organic resource for energy generation. Many investigations have demonstrated that anaerobic fungi and methanogens could be co-cultured to degrade lignocellulose for methane generation. Thus, this study aimed to evaluate the effect of natural anaerobic fungi-methanogens co-culture on the methane production and lignocellulosic degradation of wastes from rice, corn and sugarcane. Hu sheep rumen digesta was used to develop a natural anaerobic fungi-methanogen co-culture. The substrates were rice straw (RS), rich husk (RH), corn stover (CS), corn cobs (CC), and sugarcane baggage (SB). Production of total gas and methane, metabolization rate of reducing sugar, glucose, and xylose, digestibility of hemicellulose and cellulose, activity of carboxymethylcellulase and xylanase, and concentrations of total acid and acetate were highest (P < 0.05) in CC, moderate (P < 0.05) in RS and CS, and lowest (P < 0.05) in SB and RH. The pH, lactate and ethanol were lowest (P < 0.05) in CC, moderate (P < 0.05) in RS and CS, and lowest (P < 0.05) SB and RH. Formate was lowest (P < 0.05) in CC, RS and CS, moderate (P < 0.05) in SB, and lowest (P < 0.05) in RH. Therefore, this study indicated that the potential of methane production and lignocellulosic degradation by natural anaerobic fungi-methanogens co-culture were highest in CC, moderate in RS and CS, and lowest in SB and RH.
Collapse
Affiliation(s)
- Yin Yin Kyawt
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw, 15013, Myanmar
| | - Min Aung
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw, 15013, Myanmar
| | - Yao Xu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yaqi Zhou
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China.
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China.
| |
Collapse
|
4
|
Leggieri PA, Blair EM, Lankiewicz TS, O'Malley MA. Continuous culture of anaerobic fungi enables growth and metabolic flux tuning without use of genetic tools. BIORESOURCE TECHNOLOGY 2024; 391:129854. [PMID: 37863334 DOI: 10.1016/j.biortech.2023.129854] [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: 07/29/2023] [Revised: 09/14/2023] [Accepted: 10/06/2023] [Indexed: 10/22/2023]
Abstract
Anaerobic gut fungi (AGF) have potential to valorize lignocellulosic biomass owing to their diverse repertoire of carbohydrate-active enzymes (CAZymes). However, AGF metabolism is poorly understood, and no stable genetic tools are available to manipulate growth and metabolic flux to enhance production of specific targets, e.g., cells, CAZymes, or metabolites. Herein, a cost-effective, Arduino-based, continuous-flow anaerobic bioreactor with online optical density control is presented to probe metabolism and predictably tune fluxes in Caecomyces churrovis. Varying the C. churrovis turbidostat setpoint titer reliably controlled growth rate (from 0.04 to 0.20 h-1), metabolic flux, and production rates of acetate, formate, lactate, and ethanol. Bioreactor setpoints to maximize production of each product were identified, and all continuous production rates significantly exceed batch rates. Formate spike-ins increased lactate flux and decreased acetate, ethanol, and formate fluxes. The bioreactor and turbidostat culture schemes demonstrated here offer tools to tailor AGF fermentations to application-specific hydrolysate product profiles.
Collapse
Affiliation(s)
- Patrick A Leggieri
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Elaina M Blair
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Thomas S Lankiewicz
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA; Joint BioEnergy Institute (JBEI), Emeryville, CA 94608, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA; Joint BioEnergy Institute (JBEI), Emeryville, CA 94608, USA; Biological Engineering Program, University of California, Santa Barbara, CA 93106, USA.
| |
Collapse
|
5
|
Peng C, May A, Abeel T. Unveiling microbial biomarkers of ruminant methane emission through machine learning. Front Microbiol 2023; 14:1308363. [PMID: 38143860 PMCID: PMC10749206 DOI: 10.3389/fmicb.2023.1308363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
Background Enteric methane from cow burps, which results from microbial fermentation of high-fiber feed in the rumen, is a significant contributor to greenhouse gas emissions. A promising strategy to address this problem is microbiome-based precision feed, which involves identifying key microorganisms for methane production. While machine learning algorithms have shown success in associating human gut microbiome with various human diseases, there have been limited efforts to employ these algorithms to establish microbial biomarkers for methane emissions in ruminants. Methods In this study, we aim to identify potential methane biomarkers for methane emission from ruminants by employing regression algorithms commonly used in human microbiome studies, coupled with different feature selection methods. To achieve this, we analyzed the microbiome compositions and identified possible confounding metadata variables in two large public datasets of Holstein cows. Using both the microbiome features and identified metadata variables, we trained different regressors to predict methane emission. With the optimized models, permutation tests were used to determine feature importance to find informative microbial features. Results Among the regression algorithms tested, random forest regression outperformed others and allowed the identification of several crucial microbial taxa for methane emission as members of the native rumen microbiome, including the genera Piromyces, Succinivibrionaceae UCG-002, and Acetobacter. Additionally, our results revealed that certain herd locations and feed composition markers, such as the lipid intake and neutral-detergent fiber intake, are also predictive features for methane emissions. Conclusion We demonstrated that machine learning, particularly regression algorithms, can effectively predict cow methane emissions and identify relevant rumen microorganisms. Our findings offer valuable insights for the development of microbiome-based precision feed strategies aiming at reducing methane emissions.
Collapse
Affiliation(s)
- Chengyao Peng
- Delft Bioinformatics Lab, Delft University of Technology, Delft, Netherlands
| | - Ali May
- dsm-firmenich, Science & Research, Delft, Netherlands
| | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, Delft, Netherlands
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, United States
| |
Collapse
|
6
|
Seid N, Ochsenreither K, Neumann A. Caproate production from Enset fiber in one-pot two-step fermentation using anaerobic fungi (Neocallimastix cameroonii strain G341) and Clostridium kluyveri DSM 555. Microb Cell Fact 2023; 22:216. [PMID: 37864174 PMCID: PMC10588050 DOI: 10.1186/s12934-023-02224-w] [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: 08/10/2023] [Accepted: 10/06/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Lignocellulosic biomass plays a crucial role in creating a circular bioeconomy and minimizing environmental impact. Enset biomass is a byproduct of traditional Ethiopian Enset food processing that is thrown away in huge quantities. This study aimed to produce caproate from Enset fiber using Neocallimastix cameroonii strain G341 and Clostridium kluyveri DSM 555 in one-pot two-step fermentation. RESULTS The process started by growing N. cameroonii on Enset fiber as a carbon source for 7 days. Subsequently, the fungal culture was inoculated with active C. kluyveri preculture and further incubated. The results showed that N. cameroonii grew on 0.25 g untreated Enset fiber as the sole carbon source and produced 1.16 mmol acetate, 0.51 mmol hydrogen, and 1.34 mmol formate. In addition, lactate, succinate, and ethanol were detected in small amounts, 0.17 mmol, 0.08 mmol, and 0.7 mmol, respectively. After inoculating with C. kluyveri, 0.3 mmol of caproate and 0.48 mmol of butyrate were produced, and hydrogen production also increased to 0.95 mmol compared to sole N. cameroonii fermentation. Moreover, after the culture was supplemented with 2.18 mmol of ethanol during C. kluyveri inoculation, caproate, and hydrogen production was further increased to 1.2 and 1.36 mmol, respectively, and the consumption of acetate also increased. CONCLUSION A novel microbial cell factory was developed to convert untreated lignocellulosic Enset fiber into the medium chain carboxylic acid caproate and H2 by a co-culture of the anaerobic fungi N. cameroonii and C. kluyveri. This opens a new value chain for Enset farmers, as the process requires only locally available raw materials and low-price fermenters. As the caproate production was mainly limited by the available ethanol, the addition of locally produced ethanol-containing fermentation broth ("beer") would further increase the titer.
Collapse
Affiliation(s)
- Nebyat Seid
- Electrobiotechnology, Institute of Process Engineering in Life Science 2, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany.
- School of Chemical and Bio Engineering, Addis Ababa Institute of Technology, Addis Ababa University, P.O.B: 1176, Addis Ababa, Ethiopia.
| | - Katrin Ochsenreither
- Department of Chemical and Process Engineering, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany
| | - Anke Neumann
- Electrobiotechnology, Institute of Process Engineering in Life Science 2, Karlsruhe Institute of Technology (KIT), 76131, Karlsruhe, Germany.
| |
Collapse
|
7
|
Volmer JG, McRae H, Morrison M. The evolving role of methanogenic archaea in mammalian microbiomes. Front Microbiol 2023; 14:1268451. [PMID: 37727289 PMCID: PMC10506414 DOI: 10.3389/fmicb.2023.1268451] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/18/2023] [Indexed: 09/21/2023] Open
Abstract
Methanogenic archaea (methanogens) represent a diverse group of microorganisms that inhabit various environmental and host-associated microbiomes. These organisms play an essential role in global carbon cycling given their ability to produce methane, a potent greenhouse gas, as a by-product of their energy production. Recent advances in culture-independent and -dependent studies have highlighted an increased prevalence of methanogens in the host-associated microbiome of diverse animal species. Moreover, there is increasing evidence that methanogens, and/or the methane they produce, may play a substantial role in human health and disease. This review addresses the expanding host-range and the emerging view of host-specific adaptations in methanogen biology and ecology, and the implications for host health and disease.
Collapse
Affiliation(s)
- James G. Volmer
- Centre for Microbiome Research, School of Biomedical Sciences, Queensland University of Technology (QUT), Translational Research Institute, Woolloongabba, QLD, Australia
| | - Harley McRae
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, QLD, Australia
| | - Mark Morrison
- Faculty of Medicine, University of Queensland Frazer Institute, Translational Research Institute, Woolloongabba, QLD, Australia
| |
Collapse
|
8
|
Król B, Słupczyńska M, Wilk M, Asghar M, Cwynar P. Anaerobic rumen fungi and fungal direct-fed microbials
in ruminant feeding. JOURNAL OF ANIMAL AND FEED SCIENCES 2022. [DOI: 10.22358/jafs/153961/2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
9
|
Combined Biological and Chemical/Physicochemical Pretreatment Methods of Lignocellulosic Biomass for Bioethanol and Biomethane Energy Production—A Review. Appl Microbiol 2022. [DOI: 10.3390/applmicrobiol2040055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lignocellulosic biomass is a low-cost and environmentally-friendly resource that can be used to produce biofuels such as bioethanol and biogas, which are the leading candidates for the partial substitution of fossil fuels. However, the main challenge of using lignocellulosic materials for biofuel production is the low accessibility to cellulose for hydrolysis of enzymes and microorganisms, which can be overcome by pretreatment. Biological and chemical pretreatments have their own disadvantages, which could be reduced by combining the two methods. In this article, we review biological–chemical combined pretreatment strategies for biogas and bioethanol production. The synergy of fungal/enzyme–NaOH pretreatment is the only biological–chemical combination studied for biogas production and has proven to be effective. The use of enzyme, which is relatively expensive, has the advantage of hydrolysis efficiency compared to fungi. Nonetheless, there is vast scope for research and development of other chemical–biological combinations for biogas production. With respect to ethanol production, fungal–organosolv combination is widely studied and can achieve a maximum of 82% theoretical yield. Order of pretreatment is also important, as fungi may reduce the accessibility of cellulose made available by prior chemical strategies and suppress lignin degradation. The biofuel yield of similarly pretreated biomass can vary depending on the downstream process. Therefore, new strategies, such as bioaugmentation and genetically engineered strains, could help to further intensify biofuel yields.
Collapse
|
10
|
Stabel M, Haack K, Lübbert H, Greif M, Gorenflo P, Aliyu H, Ochsenreither K. Metabolic shift towards increased biohydrogen production during dark fermentation in the anaerobic fungus Neocallimastix cameroonii G341. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:96. [PMID: 36117170 PMCID: PMC9484062 DOI: 10.1186/s13068-022-02193-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 08/31/2022] [Indexed: 11/25/2022]
Abstract
Background Anaerobic fungi of the phylum Neocallimastigomycota have a high biotechnological potential due to their robust lignocellulose degrading capabilities and the production of several valuable metabolites like hydrogen, acetate, formate, lactate, and ethanol. The metabolism of these fungi, however, remains poorly understood due to limitations of the current cultivation strategies in still-standing bottles, thereby restricting the comprehensive evaluation of cultivation conditions. Results We describe the analysis of growth conditions and their influence on the metabolism of the previously isolated fungus Neocallimastix cameroonii G341. We established a bioreactor process in a stirred tank, enabling cultivation under defined conditions. The optimal growth temperature for the fungus was between 38.5 °C and 41.5 °C, while the optimal pH was 6.6–6.8. Like other dark fermentation systems, hydrogen production is dependent on the hydrogen partial pressure and pH. Shaking the bottles or stirring the fermenters led to an increase in hydrogen and a decrease in lactate and ethanol production. Regulation of the pH to 6.8 in the fermenter nearly doubled the amount of produced hydrogen. Conclusions Novel insights into the metabolism of Neocallimastix cameroonii were gained, with hydrogen being the preferred way of electron disposal over lactate and ethanol. In addition, our study highlights the potential application of the fungus for hydrogen production from un-pretreated biomass. Finally, we established the first cultivation of an anaerobic fungus in a stirred tank reactor system. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02193-z.
Collapse
|
11
|
Wei Y, Yang H, Wang Z, Zhao J, Qi H, Wang C, Zhang J, Yang T. Roughage biodegradation by natural co-cultures of rumen fungi and methanogens from Qinghai yaks. AMB Express 2022; 12:123. [PMID: 36121525 PMCID: PMC9485394 DOI: 10.1186/s13568-022-01462-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 09/10/2022] [Indexed: 11/10/2022] Open
Abstract
Anaerobic fungus–methanogen co-cultures from rumen liquids and faeces can degrade lignocellulose efficiently. In this study, 31 fungus–methanogen co-cultures were first obtained from the rumen of yaks grazing in Qinghai Province, China, using the Hungate roll-tube technique. The fungi were identified according to morphological characteristics and internal transcribed spacer (ITS) sequences. The methanogens associated with each fungus were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rRNA gene sequencing. They were five co-culture types: Neocallimastix frontalis + Methanobrevibacter ruminantium, Neocallimastix frontalis + Methanobrevibacter gottschalkii, Orpinomyces joyonii + Methanobrevibacter ruminantium, Caecomyces communis + Methanobrevibacter ruminantium, and Caecomyces communis + Methanobrevibacter millerae. Among the 31 co-cultures, during the 5-day incubation, the N. frontalis + M. gottschalkii co-culture YakQH5 degraded 59.0%–68.1% of the dry matter (DM) and 49.5%–59.7% of the neutral detergent fiber (NDF) of wheat straw, corn stalk, rice straw, oat straw and sorghum straw to produce CH4 (3.0–4.6 mmol/g DM) and acetate (7.3–8.6 mmol/g DM) as end-products. Ferulic acid (FA) released at 4.8 mg/g DM on corn stalk and p-coumaric acid (PCA) released at 11.7 mg/g DM on sorghum straw showed the highest values, with the following peak values of enzyme activities: xylanase at 12,910 mU/mL on wheat straw, ferulic acid esterase (FAE) at 10.5 mU/mL on corn stalk, and p-coumaric acid esterase (CAE) at 20.5 mU/mL on sorghum straw. The N. frontalis + M. gottschalkii co-culture YakQH5 from Qinghai yaks represents a new efficient combination for lignocellulose biodegradation, performing better than previously reported fungus–methanogen co-cultures from the digestive tract of ruminants.
Collapse
Affiliation(s)
- Yaqin Wei
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China. .,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China.
| | - Hui Yang
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Zhiye Wang
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Jiang Zhao
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Hongshan Qi
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Chuan Wang
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, 730000, People's Republic of China
| | - Jingrong Zhang
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| | - Tao Yang
- Key Laboratory of Microbial Resources Exploitation and Application of Gansu Province, Institute of Biology, Gansu Academy of Sciences, Lanzhou, 730000, People's Republic of China.,Center for Anaerobic Microbes, Institute of Biology, Gansu Academy of Sciences, No. 197 Dingxi South Road, Lanzhou, 730000, Gansu, People's Republic of China
| |
Collapse
|
12
|
Rumen eukaryotes are the main phenotypic risk factors for larger methane emissions in dairy cattle. Livest Sci 2022. [DOI: 10.1016/j.livsci.2022.105023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Xue Y, Shen R, Li Y, Sun Z, Sun X, Li F, Li X, Cheng Y, Zhu W. Anaerobic Fungi Isolated From Bactrian Camel Rumen Contents Have Strong Lignocellulosic Bioconversion Potential. Front Microbiol 2022; 13:888964. [PMID: 35928163 PMCID: PMC9345502 DOI: 10.3389/fmicb.2022.888964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/26/2022] [Indexed: 11/14/2022] Open
Abstract
This study aims to obtain anaerobic fungi from the rumen and fecal samples and investigates their potential for lignocellulosic bioconversion. Multiple anaerobic strains were isolated from rumen contents (CR1–CR21) and fecal samples (CF1–CF10) of Bactrian camel using the Hungate roll tube technique. After screening for fiber degradability, strains from rumen contents (Oontomyces sp. CR2) and feces (Piromyces sp. CF9) were compared with Pecoramyces sp. F1 (earlier isolated from goat rumen, having high CAZymes of GHs) for various fermentation and digestion parameters. The cultures were fermented with different substrates (reed, alfalfa stalk, Broussonetia papyrifera leaves, and Melilotus officinalis) at 39°C for 96 h. The Oontomyces sp. CR2 had the highest total gas and hydrogen production from most substrates in the in vitro rumen fermentation system and also had the highest digestion of dry matter, neutral detergent fiber, acid detergent fiber, and cellulose present in most substrates used. The isolated strains provided higher amounts of metabolites such as lactate, formate, acetate, and ethanol in the in vitro rumen fermentation system for use in various industrial applications. The results illustrated that anaerobic fungi isolated from Bactrian camel rumen contents (Oontomyces sp. CR2) have the highest lignocellulosic bioconversion potential, suggesting that the Bactrian camel rumen could be a good source for the isolation of anaerobic fungi for industrial applications.
Collapse
Affiliation(s)
- Yihan Xue
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Rui Shen
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Zhanying Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Xiaoni Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Fengming Li
- College of Animal Science, Xinjiang Agricultural University, Ürümqi, China
| | - Xiaobin Li
- College of Animal Science, Xinjiang Agricultural University, Ürümqi, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Yanfen Cheng,
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
14
|
Kazemi Shariat Panahi H, Dehhaghi M, Guillemin GJ, Gupta VK, Lam SS, Aghbashlo M, Tabatabaei M. A comprehensive review on anaerobic fungi applications in biofuels production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 829:154521. [PMID: 35292323 DOI: 10.1016/j.scitotenv.2022.154521] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Anaerobic fungi (Neocallimastigomycota) are promising lignocellulose-degrading microorganisms that can be exploited by the biofuel industry. While natural production of ethanol by these microorganisms is very low, there is a greater potential for their use in the biogas industry. More specifically, anaerobic fungi can contribute to biogas production by either releasing holocellulose or reducing sugars from lignocelluloses that can be used as a substrate by bacteria and methanogens involved in the anaerobic digestion (AD) process or by metabolizing acetate and formate that can be directly consumed by methanogens. Despite their great potential, the appropriate tools for engineering anaerobic fungi have not been established yet. The first section of this review justifies how the biofuel industry can benefit from using anaerobic fungi and is followed by their taxonomy. In the third section, the possibility of using anaerobic fungi for the consolidated production of bioethanol is briefly discussed. Nevertheless, the main focus of this review is on the upstream and mainstream effects of bioaugmentation with anaerobic fungi on the AD process. The present review also scrutinizes the constraints on the way of efficient engineering of anaerobic rumen fungi. By providing this knowledge, this review aims to help research in this field with identifying the challenges that must be addressed by future experiments to achieve the full potentials of these promising microorganisms. To sum up, the pretreatment of lignocelluloses by anaerobic fungi can prevent carbohydrate loss due to respiration (compared to white-rot fungi). Following fungal mixed acid fermentation, the obtained slurry containing sugars and more susceptible holocellulose can be directly consumed by AD microorganisms (bacteria, methanogens). The bioaugmentation of anaerobic fungi into the AD process can increase methane biosynthesis by >3.3 times. Despite this, for the commercial AD process, novel genetic engineering techniques and kits must be developed to efficiently improve anaerobic fungi viability throughout the AD process.
Collapse
Affiliation(s)
- Hamed Kazemi Shariat Panahi
- Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; Biofuel Research Team (BRTeam), Terengganu, Malaysia
| | - Mona Dehhaghi
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; Biofuel Research Team (BRTeam), Terengganu, Malaysia; PANDIS.org, Australia
| | - Gilles J Guillemin
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, NSW, Australia; PANDIS.org, Australia
| | - Vijai Kumar Gupta
- Biorefining and Advanced Materials Research Center, SRUC, Kings Buildings, West Mains Road, Edinburgh EH9 3JG, UK; Centre for Safe and Improved Food, SRUC, Kings Buildings, West Mains Road, Edinburgh EH9 3JG, UK
| | - Su Shiung Lam
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China.
| | - Mortaza Aghbashlo
- Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran; Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China.
| | - Meisam Tabatabaei
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Henan Province Engineering Research Center for Forest Biomass Value-added Products, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Biofuel Research Team (BRTeam), Terengganu, Malaysia.
| |
Collapse
|
15
|
Hanafy RA, Dagar SS, Griffith GW, Pratt CJ, Youssef NH, Elshahed MS. Taxonomy of the anaerobic gut fungi ( Neocallimastigomycota): a review of classification criteria and description of current taxa. Int J Syst Evol Microbiol 2022; 72. [PMID: 35776761 DOI: 10.1099/ijsem.0.005322] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Members of the anaerobic gut fungi (Neocallimastigomycota) reside in the rumen and alimentary tract of larger mammalian and some reptilian, marsupial and avian herbivores. The recent decade has witnessed a significant expansion in the number of described Neocallimastigomycota genera and species. However, the difficulties associated with the isolation and maintenance of Neocallimastigomycota strains has greatly complicated comparative studies to resolve inter- and intra-genus relationships. Here, we provide an updated outline of Neocallimastigomycota taxonomy. We critically evaluate various morphological, microscopic and phylogenetic traits previously and currently utilized in Neocallimastigomycota taxonomy, and provide an updated key for quick characterization of all genera. We then synthesize data from taxa description manuscripts, prior comparative efforts and molecular sequence data to present an updated list of Neocallimastigomycota genera and species, with an emphasis on resolving relationships and identifying synonymy between recent and historic strains. We supplement data from published manuscripts with information and illustrations from strains in the authors' collections. Twenty genera and 36 species are recognized, but the status of 10 species in the genera Caecomyces, Piromyces, Anaeromyces and Cyllamyces remains uncertain due to the unavailability of culture and conferre (cf.) strains, lack of sequence data, and/or inadequacy of available microscopic and phenotypic data. Six cases of synonymy are identified in the genera Neocallimastix and Caecomyces, and two names in the genus Piromyces are rejected based on apparent misclassification.
Collapse
Affiliation(s)
- Radwa A Hanafy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Sumit S Dagar
- Bioenergy Group, Agharkar Research Institute, Pune, India
| | - Gareth W Griffith
- Institute of Biological, Environmental, and Rural Sciences (IBERS) Aberystwyth University, Aberystwyth, Wales, UK
| | - Carrie J Pratt
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Noha H Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| | - Mostafa S Elshahed
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA
| |
Collapse
|
16
|
Hua B, Cai Y, Cui Z, Wang X. Bioaugmentation with methanogens cultured in a micro-aerobic microbial community for overloaded anaerobic digestion recovery. Anaerobe 2022; 76:102603. [PMID: 35709936 DOI: 10.1016/j.anaerobe.2022.102603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 11/15/2022]
Abstract
Anaerobic digestion (AD) is widely used for conversion of waste materials into biogas, but inhibition of methane production caused by overloading can be a major problem. The micro-aerobic microbial community MC1 was used to successfully culture methanogens, Methanosarcina acetivorans C2A and Methanosaeta thermophila NBRC 101360. The maximum 16S rRNA gene concentrations of Methanosarcina acetivorans C2A and Methanosaeta thermophila NBRC101360 were 1.06 × 106 and 1.35 × 103 copies/mL, respectively. The five key bacteria in MC1 were quantified to assess the effect of inoculation on the abundances of the bacteria in the mixed culture. The original MC1 total 16S rRNA gene concentration was 1.93 × 108 copies/mL, and the total 16S rRNA gene concentration had increased to 4.79 × 109 copies/mL on day 9 (p < 0.05). The proportions of the key strains in MC1+MST had changed by day 9. Cells were harvested and used to bioaugment and increase the pH values of the high- and medium-temperature anaerobic systems. After bioaugmentation, thermophilic AD recovered well. The cumulative amounts of gas produced were 44.78% and 28.28% higher in the MC1+MST and MC1 groups, respectively, than the sterilized control. The MC1+MST group gave better results than the chemical addition control group (CaCO3). There was no clear effect of bioaugmentation in mesophilic AD. When compared with traditional pure culture of methanogens as inoculants, methanogen cultivation in MC1 was simple and there was no need to separate and purify the target strains. This simplified methanogenic bioaugmentation agent was useful to study the mechanism of bioaugmentation for the recovery from low pH inhibition, showing the potential for practical application.
Collapse
Affiliation(s)
- Binbin Hua
- National & Local Joint Engineering Research Center on Biomass Resource Utilization, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Yafan Cai
- School of Chemical Engineering, Zhengzhou University, Kexue Dadao 100, 450001, Zhengzhou, China
| | - Zongjun Cui
- Center of Biomass Engineering, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, PR China
| | - Xiaofen Wang
- Center of Biomass Engineering, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, PR China.
| |
Collapse
|
17
|
Bhujbal SK, Ghosh P, Vijay VK, Rathour R, Kumar M, Singh L, Kapley A. Biotechnological potential of rumen microbiota for sustainable bioconversion of lignocellulosic waste to biofuels and value-added products. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152773. [PMID: 34979222 DOI: 10.1016/j.scitotenv.2021.152773] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/05/2021] [Accepted: 12/25/2021] [Indexed: 06/14/2023]
Abstract
Lignocellulosic biomass is an abundant resource with untapped potential for biofuel, enzymes, and chemical production. Its complex recalcitrant structure obstructs its bioconversion into biofuels and other value-added products. For improving its bioconversion efficiency, it is important to deconstruct its complex structure. In natural systems like rumen, diverse microbial communities carry out hydrolysis, acidogenesis, acetogenesis, and methanogenesis of lignocellulosic biomass through physical penetration, synergistic and enzymatic actions enhancing lignocellulose degradation activity. This review article aims to discuss comprehensively the rumen microbial ecosystem, their interactions, enzyme production, and applications for efficient bioconversion of lignocellulosic waste to biofuels. Furthermore, meta 'omics' approaches to elucidate the structure and functions of rumen microorganisms, fermentation mechanisms, microbe-microbe interactions, and host-microbe interactions have been discussed thoroughly. Additionally, feed additives' role in improving ruminal fermentation efficiency and reducing environmental nitrogen losses has been discussed. Finally, the current status of rumen microbiota applications and future perspectives for the development of rumen mimic bioreactors for efficient bioconversion of lignocellulosic wastes to biofuels and chemicals have been highlighted.
Collapse
Affiliation(s)
- Sachin Krushna Bhujbal
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Pooja Ghosh
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, New Delhi 110016, India.
| | - Virendra Kumar Vijay
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Rashmi Rathour
- CSIR-National Environmental and Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India
| | - Manish Kumar
- CSIR-National Environmental and Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India
| | - Lal Singh
- CSIR-National Environmental and Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India
| | - Atya Kapley
- CSIR-National Environmental and Engineering Research Institute (CSIR-NEERI), Nagpur 440020, India
| |
Collapse
|
18
|
Brown JL, Swift CL, Mondo SJ, Seppala S, Salamov A, Singan V, Henrissat B, Drula E, Henske JK, Lee S, LaButti K, He G, Yan M, Barry K, Grigoriev IV, O'Malley MA. Co‑cultivation of the anaerobic fungus Caecomyces churrovis with Methanobacterium bryantii enhances transcription of carbohydrate binding modules, dockerins, and pyruvate formate lyases on specific substrates. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:234. [PMID: 34893091 PMCID: PMC8665504 DOI: 10.1186/s13068-021-02083-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/19/2021] [Indexed: 05/12/2023]
Abstract
Anaerobic fungi and methanogenic archaea are two classes of microorganisms found in the rumen microbiome that metabolically interact during lignocellulose breakdown. Here, stable synthetic co-cultures of the anaerobic fungus Caecomyces churrovis and the methanogen Methanobacterium bryantii (not native to the rumen) were formed, demonstrating that microbes from different environments can be paired based on metabolic ties. Transcriptional and metabolic changes induced by methanogen co-culture were evaluated in C. churrovis across a variety of substrates to identify mechanisms that impact biomass breakdown and sugar uptake. A high-quality genome of C. churrovis was obtained and annotated, which is the first sequenced genome of a non-rhizoid-forming anaerobic fungus. C. churrovis possess an abundance of CAZymes and carbohydrate binding modules and, in agreement with previous studies of early-diverging fungal lineages, N6-methyldeoxyadenine (6mA) was associated with transcriptionally active genes. Co-culture with the methanogen increased overall transcription of CAZymes, carbohydrate binding modules, and dockerin domains in co-cultures grown on both lignocellulose and cellulose and caused upregulation of genes coding associated enzymatic machinery including carbohydrate binding modules in family 18 and dockerin domains across multiple growth substrates relative to C. churrovis monoculture. Two other fungal strains grown on a reed canary grass substrate in co-culture with the same methanogen also exhibited high log2-fold change values for upregulation of genes encoding carbohydrate binding modules in families 1 and 18. Transcriptional upregulation indicated that co-culture of the C. churrovis strain with a methanogen may enhance pyruvate formate lyase (PFL) function for growth on xylan and fructose and production of bottleneck enzymes in sugar utilization pathways, further supporting the hypothesis that co-culture with a methanogen may enhance certain fungal metabolic functions. Upregulation of CBM18 may play a role in fungal-methanogen physical associations and fungal cell wall development and remodeling.
Collapse
Affiliation(s)
- Jennifer L Brown
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Candice L Swift
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Stephen J Mondo
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Susanna Seppala
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Asaf Salamov
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vasanth Singan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Bernard Henrissat
- DTU Bioengineering, Technical University of Denmark, 2800, Kgs. Lyngby, Denmark
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Elodie Drula
- Architecture Et Fonction Des Macromolécules Biologiques, CNRS/Aix-Marseille University, Marseille, France
- INRAE USC1408, AFMB, 13009, Marseille, France
| | - John K Henske
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Samantha Lee
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Guifen He
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mi Yan
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA.
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| |
Collapse
|
19
|
Han Q, Guo H, Zhang J, Huang Z, Urynowicz MA, Ali MI. Methane Generation from Anthracite by Fungi and Methanogen Mixed Flora Enriched from Produced Water Associated with the Qinshui Basin in China. ACS OMEGA 2021; 6:31935-31944. [PMID: 34870016 PMCID: PMC8638023 DOI: 10.1021/acsomega.1c04705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Biogenic coalbed methane (CBM) is generally believed to be formed by anaerobic bacteria and methanogens, while a few studies took fungi into account. Here, the microflora consisting of fungi and methanogens was enriched from the produced water associated with the Qinshui Basin using anthracite as the only carbon source. The maximum methane yield of 231 μmol/g coal was obtained after 22 days of cultivation under the optimum temperature of 35 °C, pH of 8, salinity of 0-2%, particle size of 0.075-0.150 mm, and the solid-liquid ratio of 1:30. It could remain active even after exposure to air for 24 h. Miseq results showed that the archaea were mainly composed of Methanocella, a hydrogenotrophic methanogen, followed by acetoclastic methanogen Methanosaeta and Methanosarcina, which could use various methanogenic substrates. The fungal communities mainly included Amorphotheca, Alternaria, Aspergillus, and Penicilium, which are all able to degrade complex organics such as aromatics and lignin. After cultivation, the crystal structure of anthracite became looser, as shown by XRD results, which might be due to the swelling effect caused by the destruction of the aromatic ring structure of coal under the function of fungi. The stretching vibration intensity of each functional group in coal decreased with cultivation, as revealed by FTIR. The GC-MS results showed that the concentration of alkanes and alcohols decreased significantly, which are the products of ring-opening of aromatics by fungi. These results suggested that fungi and methanogens in the coalbed also can syntrophically degrade coal effectively, especially for aromatics in coal.
Collapse
Affiliation(s)
- Qing Han
- College
of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hongguang Guo
- College
of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
- Key
Lab of In-Situ Property-Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jinlong Zhang
- College
of Safety and Emergency Management and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Zaixing Huang
- School
of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
- Department
of Civil & Architectural Engineering, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Michael Allan Urynowicz
- Department
of Civil & Architectural Engineering, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Muhammad Ishtiaq Ali
- Environmental
Microbiology Lab, Department of Microbiology, Quaid-I-Azam University, Islamabad 45320, Pakistan
| |
Collapse
|
20
|
Yu X, Fu C, Cui Z, Chen G, Xu Y, Yang C. Inulin and isomalto-oligosaccharide alleviate constipation and improve reproductive performance by modulating motility-related hormones, short-chain fatty acids, and feces microflora in pregnant sows. J Anim Sci 2021; 99:6364795. [PMID: 34487146 DOI: 10.1093/jas/skab257] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/05/2021] [Indexed: 12/22/2022] Open
Abstract
Constipation in gestating and lactating sows is common and the inclusion of dietary fiber may help to alleviate this problem. We investigated the effects of inulin (INU) and isomalto-oligosaccharide (IMO), two sources of soluble dietary fiber, on gastrointestinal motility-related hormones, short-chain fatty acids (SCFA), fecal microflora, and reproductive performance in pregnant sows. On day 64 of gestation, 30 sows were randomly divided into three groups and fed as follows: a basal diet, a basal diet with 0.5% INU, and a basal diet with 0.5% IMO. We found that INU and IMO significantly modulated the levels of gastrointestinal motility-related hormones, as evidenced by an increase in substance P (P < 0.05), and a decrease in the vasoactive intestinal peptide concentrations (P < 0.05), indicating the capacity of INU and IMO to alleviate constipation. Furthermore, IMO enhanced the concentrations of acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids in the feces (P < 0.05). High-throughput sequencing showed that IMO and INU increased the fecal microflora α- and β-diversity (P < 0.05). Methanobrevibacter was more abundant (P < 0.05), whereas the richness of Turicibacter was lower in the INU and IMO groups than in the control group (P < 0.05). In addition, IMO significantly increased litter size (P < 0.05). Overall, our findings indicate that INU and IMO can relieve constipation, optimize intestinal flora, and promote reproductive performance in pregnant sows.
Collapse
Affiliation(s)
- Xiaorong Yu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| | - Chunsheng Fu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| | - Zhenchuan Cui
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| | - Guangyong Chen
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| | - Yinglei Xu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| | - Caimei Yang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Zhejiang Provincial Engineering Laboratory for Animal Health and Internet Technology, College of Animal Science and Technology·College of Veterinary Medcine, Zhejiang A & F University, Hangzhou 311300, China
| |
Collapse
|
21
|
Li Y, Meng Z, Xu Y, Shi Q, Ma Y, Aung M, Cheng Y, Zhu W. Interactions between Anaerobic Fungi and Methanogens in the Rumen and Their Biotechnological Potential in Biogas Production from Lignocellulosic Materials. Microorganisms 2021; 9:190. [PMID: 33477342 PMCID: PMC7830786 DOI: 10.3390/microorganisms9010190] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 11/29/2022] Open
Abstract
Anaerobic fungi in the digestive tract of herbivores are one of the critical types of fiber-degrading microorganisms present in the rumen. They degrade lignocellulosic materials using unique rhizoid structures and a diverse range of fiber-degrading enzymes, producing metabolic products such as H2/CO2, formate, lactate, acetate, and ethanol. Methanogens in the rumen utilize some of these products (e.g., H2 and formate) to produce methane. An investigation of the interactions between anaerobic fungi and methanogens is helpful as it provides valuable insight into the microbial interactions within the rumen. During the last few decades, research has demonstrated that anaerobic fungi stimulate the growth of methanogens and maintain methanogenic diversity. Meanwhile, methanogens increase the fiber-degrading capability of anaerobic fungi and stimulate metabolic pathways in the fungal hydrogenosome. The ability of co-cultures of anaerobic fungi and methanogens to degrade fiber and produce methane could potentially be a valuable method for the degradation of lignocellulosic materials and methane production.
Collapse
Affiliation(s)
- Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Zhenxiang Meng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Yao Xu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Yuping Ma
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Min Aung
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
- Department of Animal Nutrition, University of Veterinary Science, Nay Pyi Taw 15013, Myanmar
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; (Y.L.); (Z.M.); (Y.X.); (Q.S.); (Y.M.); (M.A.); (W.Z.)
| |
Collapse
|
22
|
The Effect of a High-Grain Diet on the Rumen Microbiome of Goats with a Special Focus on Anaerobic Fungi. Microorganisms 2021; 9:microorganisms9010157. [PMID: 33445538 PMCID: PMC7827659 DOI: 10.3390/microorganisms9010157] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 12/17/2022] Open
Abstract
This work investigated the changes of the rumen microbiome of goats switched from a forage to a concentrate diet with special attention to anaerobic fungi (AF). Female goats were fed an alfalfa hay (AH) diet (0% grain; n = 4) for 20 days and were then abruptly shifted to a high-grain (HG) diet (40% corn grain, 60% AH; n = 4) and treated for another 10 days. Rumen content samples were collected from the cannulated animals at the end of each diet period (day 20 and 30). The microbiome structure was studied using high-throughput sequencing for bacteria, archaea (16S rRNA gene) and fungi (ITS2), accompanied by qPCR for each group. To further elucidate unclassified AF, clone library analyses were performed on the ITS1 spacer region. Rumen pH was significantly lower in HG diet fed goats, but did not induce subacute ruminal acidosis. HG diet altered prokaryotic communities, with a significant increase of Bacteroidetes and a decrease of Firmicutes. On the genus level Prevotella 1 was significantly boosted. Methanobrevibacter and Methanosphaera were the most abundant archaea regardless of the diet and HG induced a significant augmentation of unclassified Thermoplasmatales. For anaerobic fungi, HG triggered a considerable rise in Feramyces observed with both ITS markers, while a decline of Tahromyces was detected by ITS2 and decrease of Joblinomyces by ITS1 only. The uncultured BlackRhino group revealed by ITS1 and further elucidated in one sample by LSU analysis, formed a considerable part of the AF community of goats fed both diets. Results strongly indicate that the rumen ecosystem still acts as a source for novel microorganisms and unexplored microbial interactions and that initial rumen microbiota of the host animal considerably influences the reaction pattern upon diet change.
Collapse
|
23
|
Hess M, Paul SS, Puniya AK, van der Giezen M, Shaw C, Edwards JE, Fliegerová K. Anaerobic Fungi: Past, Present, and Future. Front Microbiol 2020; 11:584893. [PMID: 33193229 PMCID: PMC7609409 DOI: 10.3389/fmicb.2020.584893] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 09/29/2020] [Indexed: 11/13/2022] Open
Abstract
Anaerobic fungi (AF) play an essential role in feed conversion due to their potent fiber degrading enzymes and invasive growth. Much has been learned about this unusual fungal phylum since the paradigm shifting work of Colin Orpin in the 1970s, when he characterized the first AF. Molecular approaches targeting specific phylogenetic marker genes have facilitated taxonomic classification of AF, which had been previously been complicated by the complex life cycles and associated morphologies. Although we now have a much better understanding of their diversity, it is believed that there are still numerous genera of AF that remain to be described in gut ecosystems. Recent marker-gene based studies have shown that fungal diversity in the herbivore gut is much like the bacterial population, driven by host phylogeny, host genetics and diet. Since AF are major contributors to the degradation of plant material ingested by the host animal, it is understandable that there has been great interest in exploring the enzymatic repertoire of these microorganisms in order to establish a better understanding of how AF, and their enzymes, can be used to improve host health and performance, while simultaneously reducing the ecological footprint of the livestock industry. A detailed understanding of AF and their interaction with other gut microbes as well as the host animal is essential, especially when production of affordable high-quality protein and other animal-based products needs to meet the demands of an increasing human population. Such a mechanistic understanding, leading to more sustainable livestock practices, will be possible with recently developed -omics technologies that have already provided first insights into the different contributions of the fungal and bacterial population in the rumen during plant cell wall hydrolysis.
Collapse
Affiliation(s)
- Matthias Hess
- Systems Microbiology & Natural Product Discovery Laboratory, Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - Shyam S. Paul
- Gut Microbiome Lab, ICAR-Directorate of Poultry Research, Indian Council of Agricultural Research, Hyderabad, India
| | - Anil K. Puniya
- Anaerobic Microbiology Lab, ICAR-National Dairy Research Institute, Dairy Microbiology Division, ICAR-National Dairy Research Institute, Karnal, India
| | - Mark van der Giezen
- Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, Stavanger, Norway
| | - Claire Shaw
- Systems Microbiology & Natural Product Discovery Laboratory, Department of Animal Science, University of California, Davis, Davis, CA, United States
| | - Joan E. Edwards
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Kateřina Fliegerová
- Laboratory of Anaerobic Microbiology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
24
|
Ma Y, Li Y, Li Y, Cheng Y, Zhu W. The enrichment of anaerobic fungi and methanogens showed higher lignocellulose degrading and methane producing ability than that of bacteria and methanogens. World J Microbiol Biotechnol 2020; 36:125. [PMID: 32712756 DOI: 10.1007/s11274-020-02894-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 07/12/2020] [Indexed: 12/20/2022]
Abstract
In this study, rumen content was used to obtain three enrichments of anaerobic fungi and methanogens (F + M enrichment), bacteria and methanogens (B + M enrichment), and whole rumen content (WRC enrichment), to evaluate their respective ability to degrade lignocellulose and produce methane. Among the treatments, F + M enrichment elicited the strongest lignocellulose degradation and methane production ability with both rice straw and wheat straw as substrates. Quantitative real-time PCR analysis and diversity analyses of methanogens in the three enrichment treatments demonstrated that F + M had larger number of 16S rRNA gene copies of methanogens and higher relative abundance of Methanobrevibacter, the predominant methanogen found in all enrichments. Caecomyces was the main anaerobic fungal genus for co-culturing to provide substrates for methanogens in this enrichment. Importantly, the F + M enrichment was stable and could be maintained with transfers supplied every 3 days, confirming its potential utility in anaerobic digestion for lignocellulose degradation and methane production.
Collapse
Affiliation(s)
- Yuping Ma
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuanfei Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, 210095, China
| |
Collapse
|
25
|
Li Y, Hou Z, Shi Q, Cheng Y, Zhu W. Methane Production From Different Parts of Corn Stover via a Simple Co-culture of an Anaerobic Fungus and Methanogen. Front Bioeng Biotechnol 2020; 8:314. [PMID: 32426337 PMCID: PMC7204275 DOI: 10.3389/fbioe.2020.00314] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 03/23/2020] [Indexed: 12/27/2022] Open
Abstract
To determine ways to improve the utilization of corn stover, this study investigated methane production from different parts of corn stover using a simple co-culture of an anaerobic fungus (Pecoramyces species) and methanogen (Methanobrevibacter species). The simple co-culture was incubated with the stem pith, leaf blade, or stem bark of corn stover (as substrates) at 39°C for 72 h. The results showed that the stem bark had the lowest (P < 0.05) digestibility (38.0 ± 1.36%) and neutral detergent solubles, that is, cell solubles (31.6 ± 0.45%), and the highest (P < 0.05) lignin content (4.8 ± 0.56%). The leaf blade had a significantly higher methane conversion rate (56.6 ± 0.76 mL/g digested substrate) than the stem pith (49.2 ± 1.60 mL/g digested substrate), even though they showed similar levels of methane production (42.4 ± 1.0 mL and 40.9 ± 1.35 mL, respectively). Both the leaf blade and stem pith of corn stover have the potential to produce methane in a simple co-culture of an anaerobic fungus and methanogen.
Collapse
Affiliation(s)
- Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Zhesheng Hou
- College of Mechanical and Electrical Engineering, Jilin Institute of Chemical Technology, Jilin, China
| | - Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
- Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agriculture University, Nanjing, China
| |
Collapse
|
26
|
Vinzelj J, Joshi A, Insam H, Podmirseg SM. Employing anaerobic fungi in biogas production: challenges & opportunities. BIORESOURCE TECHNOLOGY 2020; 300:122687. [PMID: 31926794 DOI: 10.1016/j.biortech.2019.122687] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 12/21/2019] [Accepted: 12/23/2019] [Indexed: 05/24/2023]
Abstract
Anaerobic fungi (AF, phylum Neocallimastigomycota) are best known for their ability to efficiently break down lignocellulosic biomass. Their unique combination of mechanical and enzymatic attacks on recalcitrant plant structures bears great potential for enhancement of the anaerobic digestion (AD) process. Although scientists in this field have long agreed upon the potential of AF for biotechnology, research is only recently gaining traction. This delay was largely due to difficulties in culture-dependent and culture-independent analysis of those high-maintenance organisms with their still unknown complex growth requirements. In this review, we will summarize current research efforts on bioaugmentation with AF and further point out, how the lack of basic knowledge on AF nutritional needs hampers their implementation on an industrial scale. Through this, we hope to further kindle interest into basic research on AF in order to advance their stable integration into biotechnological processes.
Collapse
Affiliation(s)
- Julia Vinzelj
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Akshay Joshi
- ZHAW School of Life Sciences and Facility Management, Einsiedlerstrasse 31, CH-8820 Wädenswil, Switzerland
| | - Heribert Insam
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Sabine Marie Podmirseg
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| |
Collapse
|
27
|
Li Y, Sun M, Li Y, Cheng Y, Zhu W. Co-cultured methanogen improved the metabolism in the hydrogenosome of anaerobic fungus as revealed by gas chromatography-mass spectrometry analysis. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2020; 33:1948-1956. [PMID: 32054157 PMCID: PMC7649409 DOI: 10.5713/ajas.19.0649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 01/06/2020] [Indexed: 11/27/2022]
Abstract
Objective The purpose of this study was to reveal the metabolic shift in the fungus co-cultured with the methanogen (Methanobrevibacter thaueri). Methods Gas chromatography-mass spectrometry was used to investigate the metabolites in anaerobic fungal (Pecoramyces sp. F1) cells and the supernatant. Results A total of 104 and 102 metabolites were detected in the fungal cells and the supernatant, respectively. The partial least squares-discriminant analysis showed that the metabolite profiles in both the fungal cell and the supernatant were distinctly shifted when co-cultured with methanogen. Statistically, 16 and 30 metabolites were significantly (p<0.05) affected in the fungal cell and the supernatant, respectively by the co-cultured methanogen. Metabolic pathway analysis showed that co-culturing with methanogen reduced the production of lactate from pyruvate in the cytosol and increased metabolism in the hydrogenosomes of the anaerobic fungus. Citrate was accumulated in the cytosol of the fungus co-cultured with the methanogen. Conclusion The co-culture of the anaerobic fungus and the methanogen is a good model for studying the microbial interaction between H2-producing and H2-utilizing microorganisms. However, metabolism in hydrogenosome needs to be further studied to gain better insight in the hydrogen transfer among microorganisms.
Collapse
Affiliation(s)
- Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Meizhou Sun
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanfei Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
28
|
Lillington SP, Leggieri PA, Heom KA, O'Malley MA. Nature's recyclers: anaerobic microbial communities drive crude biomass deconstruction. Curr Opin Biotechnol 2019; 62:38-47. [PMID: 31593910 DOI: 10.1016/j.copbio.2019.08.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/25/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022]
Abstract
Microbial communities within anaerobic ecosystems have evolved to degrade and recycle carbon throughout the earth. A number of strains have been isolated from anaerobic microbial communities, which are rich in carbohydrate active enzymes (CAZymes) to liberate fermentable sugars from crude plant biomass (lignocellulose). However, natural anaerobic communities host a wealth of microbial diversity that has yet to be harnessed for biotechnological applications to hydrolyze crude biomass into sugars and value-added products. This review highlights recent advances in 'omics' techniques to sequence anaerobic microbial genomes, decipher microbial membership, and characterize CAZyme diversity in anaerobic microbiomes. With a focus on the herbivore rumen, we further discuss methods to discover new CAZymes, including those found within multi-enzyme fungal cellulosomes. Emerging techniques to characterize the interwoven metabolism and spatial interactions between anaerobes are also reviewed, which will prove critical to developing a predictive understanding of anaerobic communities to guide in microbiome engineering.
Collapse
Affiliation(s)
- Stephen P Lillington
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Patrick A Leggieri
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Kellie A Heom
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, United States.
| |
Collapse
|
29
|
Shi Q, Li Y, Li Y, Cheng Y, Zhu W. Effects of steam explosion on lignocellulosic degradation of, and methane production from, corn stover by a co-cultured anaerobic fungus and methanogen. BIORESOURCE TECHNOLOGY 2019; 290:121796. [PMID: 31319215 DOI: 10.1016/j.biortech.2019.121796] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 05/23/2023]
Abstract
The aim of this study was to investigate the effects of steam explosion on lignocellulose digestibility of, and methane production from corn stover by a co-culture of anaerobic fungus and methanogen. The cumulative methane production at 72 h of incubation from the steam-exploded corn stover was 32.2 ± 1.74 mL, which not significantly different (P > 0.05) from that of the untreated corn stover (37.1 ± 1.09 mL). However, steam explosion decreased the hemicellulose contents of corn stover by 28.0 ± 0.39% and increased the neutral detergent solute by 23.5 ± 0.25%. While this treatment did not affect the dry matter digestibility (64.1 ± 0.26%, and 64.1 ± 0.28%, respectively). In conclusion, the co-culture of anaerobic fungus and methanogen can degrade the crude fibrous portion of corn stover without any pretreatments. It possesses promising biotechnological prospects for conversion of crop residue based straw resources to obtain biofuel in the form of methane.
Collapse
Affiliation(s)
- Qicheng Shi
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanfei Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China.
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China
| |
Collapse
|
30
|
Co-cultivation of the anaerobic fungus Anaeromyces robustus with Methanobacterium bryantii enhances transcription of carbohydrate active enzymes. J Ind Microbiol Biotechnol 2019; 46:1427-1433. [PMID: 31089985 DOI: 10.1007/s10295-019-02188-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/07/2019] [Indexed: 12/18/2022]
Abstract
Anaerobic gut fungi are biomass degraders that form syntrophic associations with other microbes in their native rumen environment. Here, RNA-Seq was used to track and quantify carbohydrate active enzyme (CAZyme) transcription in a synthetic consortium composed of the anaerobic fungus Anaeromyces robustus with methanogen Methanobacterium bryantii. Approximately 5% of total A. robustus genes were differentially regulated in co-culture with M. bryantii relative to cultivation of A. robustus alone. We found that 105 CAZymes (12% of the total predicted CAZymes of A. robustus) were upregulated while 29 were downregulated. Upregulated genes encode putative proteins with a wide array of cellulolytic, xylanolytic, and carbohydrate transport activities; 75% were fused to fungal dockerin domains, associated with a carbohydrate binding module, or both. Collectively, this analysis suggests that co-culture of A. robustus with M. bryantii remodels the transcriptional landscape of CAZymes and associated metabolic pathways in the fungus to aid in lignocellulose breakdown.
Collapse
|
31
|
Li Y, Li Y, Jin W, Sharpton TJ, Mackie RI, Cann I, Cheng Y, Zhu W. Combined Genomic, Transcriptomic, Proteomic, and Physiological Characterization of the Growth of Pecoramyces sp. F1 in Monoculture and Co-culture With a Syntrophic Methanogen. Front Microbiol 2019; 10:435. [PMID: 30894845 PMCID: PMC6414434 DOI: 10.3389/fmicb.2019.00435] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/19/2019] [Indexed: 11/13/2022] Open
Abstract
In this study, the effects of a syntrophic methanogen on the growth of Pecoramyces sp. F1 was investigated by characterizing fermentation profiles, as well as functional genomic, transcriptomic, and proteomic analysis. The estimated genome size, GC content, and protein coding regions of strain F1 are 106.83 Mb, 16.07%, and 23.54%, respectively. Comparison of the fungal monoculture with the methanogen co-culture demonstrated that during the fermentation of glucose, the co-culture initially expressed and then down-regulated a large number of genes encoding both enzymes involved in intermediate metabolism and plant cell wall degradation. However, the number of up-regulated proteins doubled at the late-growth stage in the co-culture. In addition, we provide a mechanistic understanding of the metabolism of this fungus in co-culture with a syntrophic methanogen. Further experiments are needed to explore this interaction during degradation of more complex plant cell wall substrates.
Collapse
Affiliation(s)
- Yuanfei Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Yuqi Li
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China
| | - Wei Jin
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing, China
| | - Thomas J Sharpton
- Department of Microbiology - Department of Statistics, Oregon State University, Corvallis, OR, United States
| | - Roderick I Mackie
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Isaac Cann
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States.,Department of Microbiology, University of Illinois at Urbana-Champaign, Champaign, IL, United States.,Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing, China
| | - Weiyun Zhu
- Laboratory of Gastrointestinal Microbiology, National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.,Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
32
|
Lan W, Yang C. Ruminal methane production: Associated microorganisms and the potential of applying hydrogen-utilizing bacteria for mitigation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:1270-1283. [PMID: 30841400 DOI: 10.1016/j.scitotenv.2018.11.180] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 05/16/2023]
Abstract
Methane emission from ruminants not only causes serious environmental problems, but also represents a significant source of energy loss to animals. The increasing demand for sustainable animal production is driving researchers to explore proper strategies to mitigate ruminal methanogenesis. Since hydrogen is the primary substrate of ruminal methanogenesis, hydrogen metabolism and its associated microbiome in the rumen may closely relate to low- and high-methane phenotypes. Using candidate microbes that can compete with methanogens and redirect hydrogen away from methanogenesis as ruminal methane mitigants are promising avenues for methane mitigation, which can both prevent the adverse effects deriving from chemical additives such as toxicity and resistance, and increase the retention of feed energy. This review describes the ruminal microbial ecosystem and its association with methane production, as well as the effects of interspecies hydrogen transfer on methanogenesis. It provides a scientific perspective on using bacteria that are involved in hydrogen utilization as ruminal modifiers to decrease methanogenesis. This information will be helpful in better understanding the key role of ruminal microbiomes and their relationship with methane production and, therefore, will form the basis of valuable and eco-friendly methane mitigation methods while improving animal productivity.
Collapse
Affiliation(s)
- Wei Lan
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China; MoE Key Laboratory of Molecular Animal Nutrition, China
| | - Chunlei Yang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China; MoE Key Laboratory of Molecular Animal Nutrition, China.
| |
Collapse
|
33
|
The biotechnological potential of anaerobic fungi on fiber degradation and methane production. World J Microbiol Biotechnol 2018; 34:155. [PMID: 30276481 DOI: 10.1007/s11274-018-2539-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 09/26/2018] [Indexed: 01/16/2023]
Abstract
Anaerobic fungi (phylum Neocallimastigomycota), an early branching family of fungi, are commonly encountered in the digestive tract of mammalian herbivores. To date, isolates from ten described genera have been reported, and several novel taxonomic groupings are detected using culture-independent molecular methods. Anaerobic fungi are recognized as playing key roles in the decomposition of lignocellulose (up to 50% of the ingested and untreated lignocellulose), with their physical penetration and extracellular enzymatical secretion of an unbiased diverse repertoire of cell-wall-degrading enzymes. The secreted cell-wall-degrading enzymes of anaerobic fungi include both free enzymes and extracellular multi-enzyme complexes called cellulosomes, both of which have potential as fiber degraders in industries. In addition, anaerobic fungi can provide large amounts of substrates such as hydrogen, formate, and acetate for their co-cultured methanogens. Consequently, large amounts of methane can be produced. And thus, it is promising to use the co-culture of anaerobic fungi and methanogens in the biogas process to intensify the biogas yield owing to the efficient and robust degradation of recalcitrant biomass by anaerobic fungi and improved methane production from co-cultures of anaerobic fungi and methanogens.
Collapse
|
34
|
Vaidya JD, van den Bogert B, Edwards JE, Boekhorst J, van Gastelen S, Saccenti E, Plugge CM, Smidt H. The Effect of DNA Extraction Methods on Observed Microbial Communities from Fibrous and Liquid Rumen Fractions of Dairy Cows. Front Microbiol 2018; 9:92. [PMID: 29445366 PMCID: PMC5797766 DOI: 10.3389/fmicb.2018.00092] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 01/16/2018] [Indexed: 12/01/2022] Open
Abstract
DNA based methods have been widely used to study the complexity of the rumen microbiota, and it is well known that the method of DNA extraction is a critical step in enabling accurate assessment of this complexity. Rumen fluid (RF) and fibrous content (FC) fractions differ substantially in terms of their physical nature and associated microorganisms. The aim of this study was therefore to assess the effect of four DNA extraction methods (RBB, PBB, FDSS, PQIAmini) differing in cell lysis and/or DNA recovery methods on the observed microbial diversity in RF and FC fractions using samples from four rumen cannulated dairy cows fed 100% grass silage (GS100), 67% GS and 33% maize silage (GS67MS33), 33% GS and 67% MS (GS33MS67), or 100% MS (MS100). An ANOVA statistical test was applied on DNA quality and yield measurements, and it was found that the DNA yield was significantly affected by extraction method (p < 0.001) and fraction (p < 0.001). The 260/280 ratio was not affected by extraction (p = 0.08) but was affected by fraction (p = 0.03). On the other hand, the 260/230 ratio was affected by extraction method (p < 0.001) but not affected by fraction (p = 0.8). However, all four extraction procedures yielded DNA suitable for further analysis of bacterial, archaeal and anaerobic fungal communities using quantitative PCR and pyrosequencing of relevant taxonomic markers. Redundancy analysis (RDA) of bacterial 16S rRNA gene sequence data at the family level showed that there was a significant effect of rumen fraction (p = 0.012), and that PBB (p = 0.012) and FDSS (p = 0.024) also significantly contributed to explaining the observed variation in bacterial community composition. Whilst the DNA extraction method affected the apparent bacterial community composition, no single extraction method could be concluded to be ineffective. No obvious effect of DNA extraction method on the anaerobic fungi or archaea was observed, although fraction effects were evident for both. In summary, the comprehensive assessment of observed communities of bacteria, archaea and anaerobic fungi described here provides insight into a rational basis for selecting an optimal methodology to obtain a representative picture of the rumen microbiota.
Collapse
Affiliation(s)
- Jueeli D. Vaidya
- Top Institute Food and Nutrition, Wageningen, Netherlands
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| | - Bartholomeus van den Bogert
- Top Institute Food and Nutrition, Wageningen, Netherlands
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| | - Joan E. Edwards
- Top Institute Food and Nutrition, Wageningen, Netherlands
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| | | | - Sanne van Gastelen
- Top Institute Food and Nutrition, Wageningen, Netherlands
- Animal Nutrition Group, Wageningen University and Research, Wageningen, Netherlands
| | - Edoardo Saccenti
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Wageningen, Netherlands
| | - Caroline M. Plugge
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| |
Collapse
|
35
|
Wei YQ, Yang HJ, Long RJ, Wang ZY, Cao BB, Ren QC, Wu TT. Characterization of natural co-cultures of Piromyces with Methanobrevibacter ruminantium from yaks grazing on the Qinghai-Tibetan Plateau: a microbial consortium with high potential in plant biomass degradation. AMB Express 2017; 7:160. [PMID: 28789484 PMCID: PMC5545993 DOI: 10.1186/s13568-017-0459-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/20/2017] [Indexed: 11/10/2022] Open
Abstract
Anaerobic fungi reside in the gut of herbivore and synergize with associated methanogenic archaea to decompose ingested plant biomass. Despite their potential for use in bioconversion industry, only a few natural fungus–methanogen co-cultures have been isolated and characterized. In this study we identified three co-cultures of Piromyces with Methanobrevibacter ruminantium from the rumen of yaks grazing on the Qinghai Tibetan Plateau. The representative co-culture, namely (Piromyces + M. ruminantium) Yak-G18, showed remarkable polysaccharide hydrolase production, especially xylanase. Consequently, it was able to degrade various lignocellulose substrates with a biodegrading capability superior to most previously identified fungus or fungus–methanogen co-culture isolates. End-product profiling analysis validated the beneficial metabolic impact of associated methanogen on fungus as revealed by high-yield production of methane and acetate and sustained growth on lignocellulose. Together, our data demonstrated a great potential of (Piromyces + M. ruminantium) Yak-G18 co-culture for use in industrial bioconversion of lignocellulosic biomass.
Collapse
|
36
|
Edwards JE, Forster RJ, Callaghan TM, Dollhofer V, Dagar SS, Cheng Y, Chang J, Kittelmann S, Fliegerova K, Puniya AK, Henske JK, Gilmore SP, O'Malley MA, Griffith GW, Smidt H. PCR and Omics Based Techniques to Study the Diversity, Ecology and Biology of Anaerobic Fungi: Insights, Challenges and Opportunities. Front Microbiol 2017; 8:1657. [PMID: 28993761 PMCID: PMC5622200 DOI: 10.3389/fmicb.2017.01657] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/15/2017] [Indexed: 11/25/2022] Open
Abstract
Anaerobic fungi (phylum Neocallimastigomycota) are common inhabitants of the digestive tract of mammalian herbivores, and in the rumen, can account for up to 20% of the microbial biomass. Anaerobic fungi play a primary role in the degradation of lignocellulosic plant material. They also have a syntrophic interaction with methanogenic archaea, which increases their fiber degradation activity. To date, nine anaerobic fungal genera have been described, with further novel taxonomic groupings known to exist based on culture-independent molecular surveys. However, the true extent of their diversity may be even more extensively underestimated as anaerobic fungi continue being discovered in yet unexplored gut and non-gut environments. Additionally many studies are now known to have used primers that provide incomplete coverage of the Neocallimastigomycota. For ecological studies the internal transcribed spacer 1 region (ITS1) has been the taxonomic marker of choice, but due to various limitations the large subunit rRNA (LSU) is now being increasingly used. How the continued expansion of our knowledge regarding anaerobic fungal diversity will impact on our understanding of their biology and ecological role remains unclear; particularly as it is becoming apparent that anaerobic fungi display niche differentiation. As a consequence, there is a need to move beyond the broad generalization of anaerobic fungi as fiber-degraders, and explore the fundamental differences that underpin their ability to exist in distinct ecological niches. Application of genomics, transcriptomics, proteomics and metabolomics to their study in pure/mixed cultures and environmental samples will be invaluable in this process. To date the genomes and transcriptomes of several characterized anaerobic fungal isolates have been successfully generated. In contrast, the application of proteomics and metabolomics to anaerobic fungal analysis is still in its infancy. A central problem for all analyses, however, is the limited functional annotation of anaerobic fungal sequence data. There is therefore an urgent need to expand information held within publicly available reference databases. Once this challenge is overcome, along with improved sample collection and extraction, the application of these techniques will be key in furthering our understanding of the ecological role and impact of anaerobic fungi in the wide range of environments they inhabit.
Collapse
Affiliation(s)
- Joan E. Edwards
- Laboratory of Microbiology, Wageningen University & ResearchWageningen, Netherlands
| | - Robert J. Forster
- Lethbridge Research and Development Centre, Agriculture and Agri-Food CanadaLethbridge, AB, Canada
| | - Tony M. Callaghan
- Department for Quality Assurance and Analytics, Bavarian State Research Center for AgricultureFreising, Germany
| | - Veronika Dollhofer
- Department for Quality Assurance and Analytics, Bavarian State Research Center for AgricultureFreising, Germany
| | | | - Yanfen Cheng
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural UniversityNanjing, China
| | - Jongsoo Chang
- Department of Agricultural Science, Korea National Open UniversitySeoul, South Korea
| | - Sandra Kittelmann
- Grasslands Research Centre, AgResearch Ltd.Palmerston North, New Zealand
| | - Katerina Fliegerova
- Institute of Animal Physiology and Genetics, Czech Academy of SciencesPrague, Czechia
| | - Anil K. Puniya
- College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences UniversityLudhiana, India
- Dairy Microbiology Division, ICAR-National Dairy Research InstituteKarnal, India
| | - John K. Henske
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Sean P. Gilmore
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Michelle A. O'Malley
- Department of Chemical Engineering, University of California, Santa BarbaraSanta Barbara, CA, United States
| | - Gareth W. Griffith
- Institute of Biological Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, United Kingdom
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University & ResearchWageningen, Netherlands
| |
Collapse
|
37
|
Li Y, Jin W, Mu C, Cheng Y, Zhu W. Indigenously associated methanogens intensified the metabolism in hydrogenosomes of anaerobic fungi with xylose as substrate. J Basic Microbiol 2017; 57:933-940. [PMID: 28791723 DOI: 10.1002/jobm.201700132] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/22/2017] [Accepted: 06/25/2017] [Indexed: 01/14/2023]
Abstract
Anaerobic fungi are potent lignocellulose degraders, but have not yet been exploited in this capacity, largely owing to their poor metabolic characterization. In the current study, a time course of fermentation was conducted to study the effect of the co-cultured methanogens on xylose metabolism by anaerobic fungi. The fermentation end-products from anaerobic fungal monoculture were H2 (6.7 ml), CO2 (65.7 ml), formate (17.90 mM), acetate (9.00 mM), lactate (11.89 mM), ethanol, and malate after 96 h fermentation. Compared to the monoculture, the end-products of co-culture shifted to more CO2 (71.8 ml) and acetate (15.20 mM), methane (14.9 ml), less lactate (5.28 mM), and hardly detectable formate and H2 at the end of fermentation. After 48 h, accumulated formate was remarkably consumed by co-cultured methanogens, accompanied by significantly increased acetate, CO2 and pH, and decreased lactate and malate. Xylose utilization, in both cultures, was similar during fermentation. However, the relative flux of carbon in hydrogenosomes in the co-culture was higher than that in the monoculture. In conclusion, the co-culture with methanogens enhanced "energy yields" of anaerobic fungi by removing the accumulated formate, decreased the metabolism in cytosol, for example, the lactate pathway, and increased the metabolism in hydrogenosomes, for example, the acetate pathway.
Collapse
Affiliation(s)
- Yuanfei Li
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Wei Jin
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Chunlong Mu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yanfen Cheng
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Weiyun Zhu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, Jiangsu, China
| |
Collapse
|
38
|
da Silva RR, Pedezzi R, Souto TB. Exploring the bioprospecting and biotechnological potential of white-rot and anaerobic Neocallimastigomycota fungi: peptidases, esterases, and lignocellulolytic enzymes. Appl Microbiol Biotechnol 2017; 101:3089-3101. [PMID: 28314873 DOI: 10.1007/s00253-017-8225-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/26/2017] [Accepted: 03/04/2017] [Indexed: 11/28/2022]
Abstract
Fungi constitute an invaluable natural resource for scientific research, owing to their diversity; they offer a promising alternative for bioprospecting, thus contributing to biotechnological advances. For a long time, extensive information has been exploited and fungal products have been tested as a source of natural compounds. In this context, enzyme production remains a field of interest, since it offers an efficient alternative to the hazardous processes of chemical transformations. Owing to their vast biodiversity and peculiar biochemical characteristics, two fungal categories, white-rot and anaerobic Neocallimastigomycota, have gathered considerable attention for biotechnological applications. These fungi are known for their ability to depolymerize complex molecular structures and are used in degradation of lignocellulosic biomass, improvement of animal feed digestibility, biogas and bioethanol production, and various other applications. However, there are only limited reports that describe proteolytic enzymes and esterases in these fungi and their synergistic action with lignocellulolytic enzymes on degradation of complex polymers. Thus, in this minireview, we focus on the importance of these organisms in enzyme technology, their bioprospecting, possibility of integration of their enzyme repertoire, and their prospects for future biotechnological innovation.
Collapse
Affiliation(s)
- Ronivaldo Rodrigues da Silva
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n Campus Universitário da USP, Ribeirão Preto, São Paulo, 14040-903, Brazil.
| | - Rafael Pedezzi
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n Campus Universitário da USP, Ribeirão Preto, São Paulo, 14040-903, Brazil
| | - Tatiane Beltramini Souto
- Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo (IFES), Nova Venécia, ES, Brazil
| |
Collapse
|
39
|
Patra A, Park T, Kim M, Yu Z. Rumen methanogens and mitigation of methane emission by anti-methanogenic compounds and substances. J Anim Sci Biotechnol 2017; 8:13. [PMID: 28149512 PMCID: PMC5270371 DOI: 10.1186/s40104-017-0145-9] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 01/13/2017] [Indexed: 11/25/2022] Open
Abstract
Methanogenic archaea reside primarily in the rumen and the lower segments of the intestines of ruminants, where they utilize the reducing equivalents derived from rumen fermentation to reduce carbon dioxide, formic acid, or methylamines to methane (CH4). Research on methanogens in the rumen has attracted great interest in the last decade because CH4 emission from ruminants contributes to global greenhouse gas emission and represents a loss of feed energy. Some DNA-based phylogenetic studies have depicted a diverse and dynamic community of methanogens in the rumen. In the past decade, researchers have focused on elucidating the underpinning that determines and affects the diversity, composition, structure, and dynamics of methanogen community of the rumen. Concurrently, many researchers have attempted to develop and evaluate interventions to mitigate enteric CH4 emission. Although much work has been done using plant secondary metabolites, other approaches such as using nitrate and 3-nitrooxy propanol have also yielded promising results. Most of these antimethanogenic compounds or substances often show inconsistent results among studies and also lead to adverse effects on feed intake and digestion and other aspects of rumen fermentation when fed at doses high enough to achieve effective mitigation. This review provides a brief overview of the rumen methanogens and then an appraisal of most of the antimethanogenic compounds and substances that have been evaluated both in vitro and in vivo. Knowledge gaps and future research needs are also discussed with a focus on methanogens and methane mitigation.
Collapse
Affiliation(s)
- Amlan Patra
- Department of Animal Sciences, The Ohio State University, 2029 Fyffe Road, Columbus, OH 43210 USA.,Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, 37 K. B. Sarani, Belgachia, Kolkata, 700037 India
| | - Tansol Park
- Department of Animal Sciences, The Ohio State University, 2029 Fyffe Road, Columbus, OH 43210 USA
| | - Minseok Kim
- Animal Nutrition and Physiology Team, National Institute of Animal Science, Rural Development Administration, Wanju, 55365 Republic of Korea
| | - Zhongtang Yu
- Department of Animal Sciences, The Ohio State University, 2029 Fyffe Road, Columbus, OH 43210 USA
| |
Collapse
|
40
|
Wei YQ, Yang HJ, Luan Y, Long RJ, Wu YJ, Wang ZY. Isolation, identification and fibrolytic characteristics of rumen fungi grown with indigenous methanogen from yaks (Bos grunniens) grazing on the Qinghai-Tibetan Plateau. J Appl Microbiol 2016; 120:571-87. [PMID: 26910857 DOI: 10.1111/jam.13035] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 11/27/2022]
Abstract
AIM To obtain co-cultures of anaerobic fungi and their indigenously associated methanogens from the rumen of yaks grazing on the Qinghai-Tibetan Plateau and investigate their morphology features and ability to degrade lignocellulose. METHODS AND RESULTS Twenty fungus-methanogen co-cultures were obtained by Hungate roll-tube technique. The fungi were identified as Orpinomyces, Neocallimastix and Piromyces genera based on the morphological characteristics and internal transcribed spacer 1 sequences analysis. All methanogens were identified as Methanobrevibacter sp. by 16S rRNA gene sequencing. There were four types of co-cultures: Neocallimastix with Methanobrevibacter ruminantium, Orpinomyces with M. ruminantium, Orpinomyces with Methanobrevibacter millerae and Piromyces with M. ruminantium among 20 co-cultures. In vitro studies with wheat straw as substrate showed that the Neocallimastix with M. ruminantium co-cultures and Piromyces with M. ruminantium co-cultures exhibited higher xylanase, filter paper cellulase (FPase), ferulic acid esterase, acetyl esterase activities, in vitro dry matter digestibility, gas, CH4 , acetate production, ferulic acid and p-coumaric acid releases. The Neocallimastix frontalis Yak16 with M. ruminantium co-culture presented the strongest lignocellulose degradation ability among 20 co-cultures. CONCLUSIONS Twenty fungus-methanogen co-cultures were obtained from the rumen of grazing yaks. The N. frontalis with M. ruminantium co-cultures were highly effective combination for developing a fermentative system that bioconverts lignocellulose to high activity fibre-degrading enzyme, CH4 and acetate. SIGNIFICANCE AND IMPACT OF THE STUDY The N. frontalis with M. ruminantium co-cultures from yaks grazing on the Qinghai-Tibetan Plateau present great potential in lignocellulose biodegradation industry.
Collapse
Affiliation(s)
- Y-Q Wei
- School of Life Sciences, Lanzhou University, Lanzhou, China.,Institute of Biological Research, Gansu Academy of Sciences, Lanzhou, China
| | - H-J Yang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University (CAU), Beijing, China
| | - Y Luan
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University (CAU), Beijing, China
| | - R-J Long
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Y-J Wu
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Z-Y Wang
- Institute of Biological Research, Gansu Academy of Sciences, Lanzhou, China
| |
Collapse
|
41
|
Peng X“N, Gilmore SP, O’Malley MA. Microbial communities for bioprocessing: lessons learned from nature. Curr Opin Chem Eng 2016. [DOI: 10.1016/j.coche.2016.09.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
42
|
Impact of different antibiotics on methane production using waste-activated sludge: mechanisms and microbial community dynamics. Appl Microbiol Biotechnol 2016; 100:9355-9364. [DOI: 10.1007/s00253-016-7767-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 07/28/2016] [Indexed: 10/21/2022]
|
43
|
Li Y, Jin W, Cheng Y, Zhu W. Effect of the Associated Methanogen Methanobrevibacter thaueri on the Dynamic Profile of End and Intermediate Metabolites of Anaerobic Fungus Piromyces sp. F1. Curr Microbiol 2016; 73:434-441. [PMID: 27287262 DOI: 10.1007/s00284-016-1078-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 05/29/2016] [Indexed: 01/31/2023]
Abstract
Although the scheme of metabolic pathways involved in the production of the major end products has been described, the dynamic profile of metabolites of anaerobic fungi co-cultured with methanogens is limited, especially for the intermediate metabolites. In the present study, the fermentation of the co-culture of Piromyces sp. F1 and Methanobrevibacter thaueri on glucose was investigated. The presence of methanogens shortened the growth lag time of anaerobic fungi and enhanced the total gas production. The occurrence of the maximum cell dry weight and the disappearance of most of the substrate were observed at 24 h for the co-culture and 48 h for the fungal mono-culture. In the co-culture, hydrogen was detected at a very low level during fermentation, and formate transitorily accumulated at 24 h and disappeared at 48 h, resulting in an increase of pH. Acetate was higher during the fermentation in the co-culture (P < 0.05), while lactate and ethanol were higher only in the initial stage of fermentation (P < 0.05). After 48 h, lactate in the mono-culture became much higher than that in the co-culture (P < 0.05), and ethanol tended to remain the same in both cultures. Moreover, malate tended to be exhausted in the co-culture, while it accumulated in the mono-culture. Citrate was also detected in both co-culture and mono-culture. Collectively, these results suggest that methanogen enhanced the malate pathway and weakened the lactate pathway of anaerobic fungus.
Collapse
Affiliation(s)
- Yuanfei Li
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wei Jin
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanfen Cheng
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Weiyun Zhu
- Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, 210095, China
| |
Collapse
|
44
|
Fiber degradation potential of natural co-cultures of Neocallimastix frontalis and Methanobrevibacter ruminantium isolated from yaks (Bos grunniens) grazing on the Qinghai Tibetan Plateau. Anaerobe 2016; 39:158-64. [PMID: 26979345 DOI: 10.1016/j.anaerobe.2016.03.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 11/23/2022]
Abstract
Several natural anaerobic fungus-methanogen co-cultures have been isolated from rumen and feces source of herbivores with strong fiber degrading ability. In this study, we isolated 7 Neocallimastix with methanogen co-cultures from the rumen of yaks grazing on the Qinghai Tibetan Plateau. Based on morphological characteristics and internal transcribed spacer 1 sequences (ITS1), all the fungi were identified as Neocallimastix frontalis. The co-cultures were confirmed as the one fungus - one methanogen pattern by the PCR-denatured gradient gel electrophoresis (DGGE) assay. All the methanogens were identified as Methanobrevibacter ruminantium by 16s rRNA gene sequencing. We investigated the biodegrading capacity of the co-culture (N. frontalis + M. ruminantium) Yaktz1 on wheat straw, corn stalk and rice straw in a 7 days-incubation. The in vitro dry matter digestibility (IVDMD), acid detergent fiber digestibility (ADFD) and neural detergent fiber digestibility (NDFD) values of the substrates in the co-culture were significantly higher than those in the mono-culture N. frontalis Yaktz1. The co-culture exhibited high polysaccharide hydrolase (xylanase and FPase) and esterase activities. The xylanase in the co-culture reached the highest activity of 12500 mU/ml on wheat straw at the day 3 of the incubation. At the end of the incubation, 3.00 mmol-3.29 mmol/g dry matter of methane were produced by the co-culture. The co-culture also produced high level of acetate (40.00 mM-45.98 mM) as the end-product during the biodegradation. Interestingly, the N. frontalis Yaktz1 mono-culture produced large amount of lactate (8.27 mM-11.60 mM) and ethanol (163.11 mM-242.14 mM), many times more than those recorded in the previously reported anaerobic fungi. Our data suggests that the (N. frontalis + M. ruminantium) Yaktz1 co-culture and the N. frontalis Yaktz1 mono-culture both have great potentials for different industrial use.
Collapse
|
45
|
McAllister TA, Meale SJ, Valle E, Guan LL, Zhou M, Kelly WJ, Henderson G, Attwood GT, Janssen PH. RUMINANT NUTRITION SYMPOSIUM: Use of genomics and transcriptomics to identify strategies to lower ruminal methanogenesis. J Anim Sci 2016; 93:1431-49. [PMID: 26020166 DOI: 10.2527/jas.2014-8329] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Globally, methane (CH4) emissions account for 40% to 45% of greenhouse gas emissions from ruminant livestock, with over 90% of these emissions arising from enteric fermentation. Reduction of carbon dioxide to CH4 is critical for efficient ruminal fermentation because it prevents the accumulation of reducing equivalents in the rumen. Methanogens exist in a symbiotic relationship with rumen protozoa and fungi and within biofilms associated with feed and the rumen wall. Genomics and transcriptomics are playing an increasingly important role in defining the ecology of ruminal methanogenesis and identifying avenues for its mitigation. Metagenomic approaches have provided information on changes in abundances as well as the species composition of the methanogen community among ruminants that vary naturally in their CH4 emissions, their feed efficiency, and their response to CH4 mitigators. Sequencing the genomes of rumen methanogens has provided insight into surface proteins that may prove useful in the development of vaccines and has allowed assembly of biochemical pathways for use in chemogenomic approaches to lowering ruminal CH4 emissions. Metagenomics and metatranscriptomic analysis of entire rumen microbial communities are providing new perspectives on how methanogens interact with other members of this ecosystem and how these relationships may be altered to reduce methanogenesis. Identification of community members that produce antimethanogen agents that either inhibit or kill methanogens could lead to the identification of new mitigation approaches. Discovery of a lytic archaeophage that specifically lyses methanogens is 1 such example. Efforts in using genomic data to alter methanogenesis have been hampered by a lack of sequence information that is specific to the microbial community of the rumen. Programs such as Hungate1000 and the Global Rumen Census are increasing the breadth and depth of our understanding of global ruminal microbial communities, steps that are key to using these tools to further define the science of ruminal methanogenesis.
Collapse
|
46
|
Few highly abundant operational taxonomic units dominate within rumen methanogenic archaeal species in New Zealand sheep and cattle. Appl Environ Microbiol 2014; 81:986-95. [PMID: 25416771 DOI: 10.1128/aem.03018-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Sequencing and analyses of 16S rRNA gene amplicons were performed to estimate the composition of the rumen methanogen community in 252 samples from eight cohorts of sheep and cattle, separated into 16 different sample groups by diet, and to determine which methanogens are most prominent in the rumens of farmed New Zealand ruminants. Methanobacteriales (relative abundance ± standard deviation, 89.6% ± 9.8%) and Methanomassiliicoccales (10.4% ± 9.8%) were the two major orders and contributed 99.98% (±0.1%) to the rumen methanogen communities in the samples. Sequences from Methanobacteriales were almost entirely from only four different species (or clades of very closely related species). Each was detectable in at least 89% of the samples. These four species or clades were the Methanobrevibacter gottschalkii clade and Methanobrevibacter ruminantium clade with a mean abundance of 42.4% (±19.5% standard deviation) and 32.9% (±18.8%), respectively, and Methanosphaera sp. ISO3-F5 (8.2% ± 6.7%) and Methanosphaera sp. group5 (5.6% ± 5.7%). These four species or clades appeared to be primarily represented by only one or, in one case, two dominant sequence types per species or clade when the sequences were grouped into operational taxonomic units (OTUs) at 99% sequence identity. The mean relative abundance of Methanomassiliicoccales in the samples was relatively low but exceeded 40% in some of the treatment groups. Animal feed affected the apparent methanogen community structure of both orders, as evident from differences in relative abundances of the major OTUs in animals under different feeding regimens.
Collapse
|
47
|
Cheng YF, Jin W, Mao SY, Zhu WY. Production of Citrate by Anaerobic Fungi in the Presence of Co-culture Methanogens as Revealed by (1)H NMR Spectrometry. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2014; 26:1416-23. [PMID: 25049725 PMCID: PMC4093067 DOI: 10.5713/ajas.2013.13134] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/26/2013] [Accepted: 04/30/2013] [Indexed: 11/27/2022]
Abstract
The metabolomic profile of the anaerobic fungus Piromyces sp. F1, isolated from the rumen of goats, and how this is affected by the presence of naturally associated methanogens, was analyzed by nuclear magnetic resonance spectroscopy. The major metabolites in the fungal monoculture were formate, lactate, ethanol, acetate, succinate, sugars/amino acids and α-ketoglutarate, whereas the co-cultures of anaerobic fungi and associated methanogens produced citrate. This is the first report of citrate as a major metabolite of anaerobic fungi. Univariate analysis showed that the mean values of formate, lactate, ethanol, citrate, succinate and acetate in co-cultures were significantly higher than those in the fungal monoculture, while the mean values of glucose and α-ketoglutarate were significantly reduced in co-cultures. Unsupervised principal components analysis revealed separation of metabolite profiles of the fungal mono-culture and co-cultures. In conclusion, the novel finding of citrate as one of the major metabolites of anaerobic fungi associated with methanogens may suggest a new yet to be identified pathway exists in co-culture. Anaerobic fungal metabolism was shifted by associated methanogens, indicating that anaerobic fungi are important providers of substrates for methanogens in the rumen and thus play a key role in ruminal methanogenesis.
Collapse
Affiliation(s)
- Yan Fen Cheng
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Wei Jin
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Sheng Yong Mao
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Wei-Yun Zhu
- Laboratory of Gastrointestinal Microbiology, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| |
Collapse
|
48
|
Jin W, Cheng YF, Mao SY, Zhu WY. Discovery of a novel rumen methanogen in the anaerobic fungal culture and its distribution in the rumen as revealed by real-time PCR. BMC Microbiol 2014; 14:104. [PMID: 24758319 PMCID: PMC4017770 DOI: 10.1186/1471-2180-14-104] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 04/17/2014] [Indexed: 12/11/2022] Open
Abstract
Background The novel archaea belonging to Rumen Cluster C (RCC), which may play an important role in methane production in the rumen have received increased attention. However, the present information on RCC in the rumen is limited by the unsuccessful isolation of axenic pure RCC from the rumen. In the present study, RCC grown in anaerobic fungal subcultures was identified by the molecular and culture methods. Results A novel RCC species existing in the fungal subcultures was identified and demonstrated by the 16S rRNA gene clone library. Interestingly, the novel RCC species survived in the fungal cultures over all the subculture transferring, even in the 62nd subculture, in contrast to the other methanogens, which disappeared during subcultures. Further work showed that subculture transfer frequency significantly affected the relative abundance of the novel RCC species in the fungal subcultures. The five-day and seven-day transfer frequencies increased the relative abundance of the RCC species (P<0.05). In addition, quantitative real-time PCR revealed that high concentrate diets did not affect the abundance of archaea, but numerically reduced the abundance of the novel RCC species in the rumen. In addition, the relative abundance of the RCC species was numerically higher in the rumen liquid fraction than in the rumen epithelium and solid fractions. Finally, a purified fungal culture containing the RCC species was successfully obtained. PCR and sequencing analysis showed that the novel RCC species contained a mcrA gene, which is known to play a crucial role in methanogenesis, and thus could be identified as a methanogen. Conclusion In this study, a novel RCC species was identified as a methanogen and closely associated with anaerobic fungi. This novel approach by using co-culture with anaerobic fungi may provide a feasible way to culture and investigate not yet identified methanogens.
Collapse
Affiliation(s)
| | | | | | - Wei Yun Zhu
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, 210095 Nanjing, China.
| |
Collapse
|
49
|
Influence of cell disruption and elution on cellulase release of Clostridium straminisolvens (CSK1). Appl Biochem Biotechnol 2014; 173:510-21. [PMID: 24728761 DOI: 10.1007/s12010-014-0857-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 03/10/2014] [Indexed: 10/25/2022]
Abstract
Clostridium straminisolvens (CSK1) is a novel cellulolytic bacterium isolated from a cellulose-degrading bacterial community MC1. In this study, the influence of the following cell disruption and elution methods on CSK1cellulase release was investigated: (1) freezing-thawing, (2) ultrasonication, (3) elution, (4) freezing-thawing following elution, (5) ultrasonication following elution, and lastly (6) high-pressure homogenization following elution. The activity of the cellulases CMCase, β-glucosidase, Avicelase, FPase, and xylanase in crude extracts increased 81.5, 23.8, 87.7, 46.3, and 51.7 %, respectively, with an observed optimal treatment method for each cellulase type. The release of protein from CSK1 cells increased following either cell disruption or elution and was highest at 88.3 % in the homogenization high pressure following elution treatment. A newly observed protein was present following cell elution. The performance of cell elution as determined by real time-PCR indicated that the first time cell elution removed more than 90 % of the CSK1 cells from the substrate. These findings demonstrate that cell disruption and elution are effective methods for inducing cellulase release, and elution is the key step for CSK1. To our knowledge, this study presents the first evidence of optimal treatments for induction of cellulase release of Clostridium straminisolvens. This information will be of great value for use in subsequent efforts to better understand the cellulase characteristics of CSK1 and cellulose degradation mechanisms of the MC1 community.
Collapse
|
50
|
Leis S, Dresch P, Peintner U, Fliegerová K, Sandbichler AM, Insam H, Podmirseg SM. Finding a robust strain for biomethanation: anaerobic fungi (Neocallimastigomycota) from the Alpine ibex (Capra ibex) and their associated methanogens. Anaerobe 2013; 29:34-43. [PMID: 24384307 DOI: 10.1016/j.anaerobe.2013.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 12/04/2013] [Accepted: 12/19/2013] [Indexed: 10/25/2022]
Abstract
Anaerobic fungi occupy the rumen and digestive tract of herbivores, where they play an important role in enzymatic digestion of lignocellulosic and cellulosic substrates, i.e. organic material that their hosts are unable to decompose on their own. In this study we isolated anaerobic fungi from a typical alpine herbivore, the Alpine ibex (C. ibex). Three fungal strains, either as pure culture (ST2) or syntrophic co-culture with methanogens (ST3, ST4) were successfully obtained and morphologically characterised by different microscopy- and staining-techniques and by rDNA ITS gene sequencing. The isolated fungi were identified as Neocallimastix frontalis (ST2) and Caecomyces communis (ST3 and ST4). We introduce a novel field of application for lactofuchsin-staining, combined with confocal laser scanning microscopy. This approach proved as an effective method to visualize fungal structures, especially in the presence of plant biomass, generally exhibiting high autofluorescence. Moreover, we could demonstrate that fungal morphology is subject to changes depending on the carbon source used for cultivation. Oxygen tolerance was confirmed for both, C. communis-cultures for up to three, and for the N. frontalis-isolate for up to 12 h, respectively. With PCR, FISH and an oligonucleotide microarray we found associated methanogens (mainly Methanobacteriales) for C. communis, but not for N. frontalis.
Collapse
Affiliation(s)
- Stefanie Leis
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Philipp Dresch
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Ursula Peintner
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Katerina Fliegerová
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Videnska 1083, Prague, Czech Republic
| | | | - Heribert Insam
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria
| | - Sabine Marie Podmirseg
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, A-6020 Innsbruck, Austria.
| |
Collapse
|