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Park T. - Invited Review - Ruminal ciliates as modulators of the rumen microbiome. Anim Biosci 2024; 37:385-395. [PMID: 38186255 PMCID: PMC10838670 DOI: 10.5713/ab.23.0309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 11/22/2023] [Indexed: 01/09/2024] Open
Abstract
Ruminal ciliates are a fundamental constituent within the rumen microbiome of ruminant animals. The complex interactions between ruminal ciliates and other microbial guilds within the rumen ecosystems are of paramount importance for facilitating the digestion and fermentation processes of ingested feed components. This review underscores the significance of ruminal ciliates by exploring their impact on key factors, such as methane production, nitrogen utilization efficiency, feed efficiency, and other animal performance measurements. Various methods are employed in the study of ruminal ciliates including culture techniques and molecular approaches. This review highlights the pressing need for further investigations to discern the distinct roles of various ciliate species, particularly relating to methane mitigation and the enhancement of nitrogen utilization efficiency. The promotion of establishing robust reference databases tailored specifically to ruminal ciliates is encouraged, alongside the utilization of genomics and transcriptomics that can highlight their functional contributions to the rumen microbiome. Collectively, the progressive advancement in knowledge concerning ruminal ciliates and their inherent biological significance will be helpful in the pursuit of optimizing rumen functionality and refining animal production outcomes.
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Affiliation(s)
- Tansol Park
- Department of Animal Science and Technology, Chung-Ang University, Anseong 17546, Korea
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Cabral LDS, Weimer PJ. Megasphaera elsdenii: Its Role in Ruminant Nutrition and Its Potential Industrial Application for Organic Acid Biosynthesis. Microorganisms 2024; 12:219. [PMID: 38276203 PMCID: PMC10819428 DOI: 10.3390/microorganisms12010219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024] Open
Abstract
The Gram-negative, strictly anaerobic bacterium Megasphaera elsdenii was first isolated from the rumen in 1953 and is common in the mammalian gastrointestinal tract. Its ability to use either lactate or glucose as its major energy sources for growth has been well documented, although it can also ferment amino acids into ammonia and branched-chain fatty acids, which are growth factors for other bacteria. The ruminal abundance of M. elsdenii usually increases in animals fed grain-based diets due to its ability to use lactate (the product of rapid ruminal sugar fermentation), especially at a low ruminal pH (<5.5). M. elsdenii has been proposed as a potential dietary probiotic to prevent ruminal acidosis in feedlot cattle and high-producing dairy cows. However, this bacterium has also been associated with milk fat depression (MFD) in dairy cows, although proving a causative role has remained elusive. This review summarizes the unique physiology of this intriguing bacterium and its functional role in the ruminal community as well as its role in the health and productivity of the host animal. In addition to its effects in the rumen, the ability of M. elsdenii to produce C2-C7 carboxylic acids-potential precursors for industrial fuel and chemical production-is examined.
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Affiliation(s)
- Luciano da Silva Cabral
- Department of Animal Science and Rural Extension, Agronomy and Animal Science School, Federal University of Mato Grosso, Cuiabá 780600-900, Mato Grosso, Brazil;
| | - Paul J. Weimer
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
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Guo W, Liu T, Neves ALA, Long R, Degen A, Zhou M, Chen X. Transmission of fungi and protozoa under grazing conditions from lactating yaks to sucking yak calves in early life. Appl Microbiol Biotechnol 2023:10.1007/s00253-023-12616-y. [PMID: 37341753 DOI: 10.1007/s00253-023-12616-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 06/22/2023]
Abstract
Microbiota from mothers is an essential source of microbes in early-life rumen microbiota, but the contribution of microbiota from different maternal sites to the rumen microbiota establishment in neonates needs more data. To fill this gap, we collected samples from the mouth, teat skin, and rumen of lactating yaks and from the rumen of sucking calves concomitantly on seven occasions between days 7 and 180 after birth under grazing conditions. We observed that the eukaryotic communities clustered based on sample sites, except for the protozoal community in the teat skin, with negative correlations between fungal and protozoal diversities in the rumen of calves. Furthermore, fungi in the dam's mouth, which is the greatest source of the calf's rumen fungi, accounted for only 0.1%, and the contribution of the dam's rumen to the calf's rumen fungi decreased with age and even disappeared after day 60. In contrast, the average contribution of the dam's rumen protozoa to the calf's rumen protozoa was 3.7%, and the contributions from the dam's teat skin (from 0.7 to 2.7%) and mouth (from 0.4 to 3.3%) increased with age. Thus, the divergence in dam-to-calf transmissibility between fungi and protozoa indicates that the foundation of these eukaryotic communities is shaped by different rules. This study provides the first measurements of the maternal contribution to the fungal and protozoal establishment in the rumen of sucking and grazing yak calves in early life, which could be beneficial for future microbiota manipulation in neonatal ruminants. KEY POINTS: • Dam to calf transfer of rumen eukaryotes occurs from multiple body sites. • A minor proportion of rumen fungi in calves originated from maternal sites. • The inter-generation transmission between rumen fungi and protozoa differs.
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Affiliation(s)
- Wei Guo
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University, Guiyang, 550025, China
- State Key Laboratory of Grassland Agro-Ecosystems, International Centre of Tibetan Plateau Ecosystem Management, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAlberta, AB, T6G 2P5, Canada
| | - Tingmei Liu
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University, Guiyang, 550025, China
| | - André Luis Alves Neves
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 3, 1870, Frederiksberg C, Denmark
| | - Ruijun Long
- State Key Laboratory of Grassland Agro-Ecosystems, International Centre of Tibetan Plateau Ecosystem Management, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Allan Degen
- Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 8410500, Beer Sheva, Israel
| | - Mi Zhou
- Department of Agricultural, Food and Nutritional Science, University of Alberta, EdmontonAlberta, AB, T6G 2P5, Canada.
| | - Xiang Chen
- Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University, Guiyang, 550025, China.
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Zhan A, Luo Y, Qin H, Lin W, Tian L. Hypomagnetic Field Exposure Affecting Gut Microbiota, Reactive Oxygen Species Levels, and Colonic Cell Proliferation in Mice. Bioelectromagnetics 2022; 43:462-475. [PMID: 36434792 DOI: 10.1002/bem.22427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 11/09/2022] [Indexed: 11/27/2022]
Abstract
The gut microbiota has been considered one of the key factors in host health, which is influenced by many environmental factors. The geomagnetic field (GMF) represents one of the important environmental conditions for living organisms. Previous studies have shown that the elimination of GMF, the so-called hypomagnetic field (HMF), could affect the physiological functions and resistance to antibiotics of some microorganisms. However, whether long-term HMF exposure could alter the gut microbiota to some extent in mammals remains unclear. Here, we investigated the effects of long-term (8- and 12-week) HMF exposure on the gut microbiota in C57BL/6J mice. Our results clearly showed that 8-week HMF significantly affected the diversity and function of the mouse gut microbiota. Compared with the GMF group, the concentrations of short-chain fatty acids tended to decrease in the HMF group. Immunofluorescence analysis showed that HMF promoted colonic cell proliferation, concomitant with an increased level of reactive oxygen species (ROS). To our knowledge, this is the first in vivo finding that long-term HMF exposure could affect the mouse gut microbiota, ROS levels, and colonic cell proliferation in the colon. Moreover, the changes in gut microbiota can be restored by returning mice to the GMF environment, thus the possible harm to the microbiota caused by HMF exposure can be alleviated. © 2022 Bioelectromagnetics Society.
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Affiliation(s)
- Aisheng Zhan
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.,France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yukai Luo
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.,France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Huafeng Qin
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
| | - Wei Lin
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.,France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
| | - Lanxiang Tian
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.,France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms, Chinese Academy of Sciences, Beijing, China
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