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Cao X, Cai R, Zuo S, Niu D, Yang F, Xu C. Enhanced lignin degradation by Irpex lacteus through expanded sterilization further improved the fermentation quality and microbial community during the silage preservation process. BIORESOUR BIOPROCESS 2024; 11:14. [PMID: 38647879 PMCID: PMC10992542 DOI: 10.1186/s40643-024-00730-2] [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: 11/12/2023] [Accepted: 01/10/2024] [Indexed: 04/25/2024] Open
Abstract
Traditional autoclaving, slow degradation rate and preservation of biomass treated by fungi are the main factors restricting biological treatment. In our previous studies, strains with high efficiency and selective lignin degradation ability were obtained. To further solve the limiting factors of biological treatment, this paper proposed a composite treatment technology, which could replace autoclaves for fungal treatment and improve the preservation and utilization of fungal-pretreated straw. The autoclaved and expanded buckwheat straw were, respectively, degraded by Irpex lacteus for 14 days (CIL, EIL), followed by ensiling of raw materials (CK) and biodegraded straw of CIL and EIL samples with Lactobacillus plantarum for different days, respectively (CP, CIP, EIP). An expansion led to lactic acid bacteria, mold, and yeast of the samples below the detection line, and aerobic bacteria was significantly reduced, indicating a positive sterilization effect. Expansion before I. lacteus significantly enhanced lignin selective degradation by about 6%, and the absolute content of natural detergent solute was about 5% higher than that of the CIL. Moreover, EIL decreased pH by producing higher organic acids. The combination treatment created favorable conditions for ensiling. During ensiling, EIP silage produced high lactic acid about 26.83 g/kg DM and the highest acetic acid about 22.35 g/kg DM, and the pH value could be stable at 4.50. Expansion before I. lacteus optimized the microbial community for ensiling, resulting in EIP silage co-dominated by Lactobacillus, Pediococcus and Weissella, whereas only Lactobacillus was always dominant in CP and CIP silage. Clavispora gradually replaced Irpex in EIP silage, which potentially promoted lactic acid bacteria growth and acetic acid production. In vitro gas production (IVGP) in EIL was increased by 30% relative to CK and was higher than 24% in CIL. The role of expansion was more significant after ensiling, the IVGP in EIP was increased by 22% relative to CP, while that in CIP silage was only increased by 9%. Silage of fungal-treated samples reduced methane emissions by 28% to 31%. The study demonstrated that expansion provides advantages for fungal colonization and delignification, and further improves the microbial community and fermentation quality for silage, enhancing the nutrition and utilization value. This has practical application value for scaling up biological treatment and preserving the fungal-treated lignocellulose.
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Affiliation(s)
- Xiaohui Cao
- College of Engineering, China Agricultural University, (East Campus), 17 Qing-Hua-Dong-Lu, Haidian District, Beijing, 100083, People's Republic of China
| | - Rui Cai
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, Hubei Province, China
| | - Sasa Zuo
- College of Engineering, China Agricultural University, (East Campus), 17 Qing-Hua-Dong-Lu, Haidian District, Beijing, 100083, People's Republic of China
| | - Dongze Niu
- Changzhou Key Laboratory of Biomass Green, Safe and High Value Utilization Technology, Institute of Urban and Rural Mining, Changzhou University, Changzhou, 213164, China
| | - Fuyu Yang
- College of Grassland Science and Technology, China Agricultural University, Beijing, 100093, People's Republic of China
| | - Chuncheng Xu
- College of Engineering, China Agricultural University, (East Campus), 17 Qing-Hua-Dong-Lu, Haidian District, Beijing, 100083, People's Republic of China.
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An J, Sun L, Liu M, Dai R, Ge G, Wang Z, Jia Y. Influences of Growth Stage and Ensiling Time on Fermentation Characteristics, Nitrite, and Bacterial Communities during Ensiling of Alfalfa. PLANTS (BASEL, SWITZERLAND) 2023; 13:84. [PMID: 38202392 PMCID: PMC10780930 DOI: 10.3390/plants13010084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/05/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024]
Abstract
This study examined the impacts of growth stage and ensiling duration on the fermentation characteristics, nitrite content, and bacterial communities during the ensiling of alfalfa. Harvested alfalfa was divided into two groups: vegetative growth stage (VG) and late budding stage (LB). The fresh alfalfa underwent wilting until reaching approximately 65% moisture content, followed by natural fermentation. The experiment followed a completely randomized design, with samples collected after the wilting of alfalfa raw materials (MR) and on days 1, 3, 5, 7, 15, 30, and 60 of fermentation. The growth stage significantly influenced the chemical composition of alfalfa, with crude protein content being significantly higher in the vegetative growth stage alfalfa compared to that in the late budding stage (p < 0.05). Soluble carbohydrates, neutral detergent fiber, and acid detergent fiber content were significantly lower in the vegetative growth stage compared to the late budding stage (p < 0.05). Nitrite content, nitrate content, nitrite reductase activity, and nitrate reductase activity were all significantly higher in the vegetative growth stage compared to the late budding stage (p < 0.05). In terms of fermentation parameters, silage from the late budding stage exhibited superior characteristics compared to that from the vegetative growth stage. Compared to the alfalfa silage during the vegetative growth stage, the late budding stage group exhibited a higher lactate content and lower pH level. Notably, butyric acid was only detected in the silage from the vegetative growth stage group. Throughout the ensiling process, nitrite content, nitrate levels, nitrite reductase activity, and nitrate reductase activity decreased in both treatment groups. The dominant lactic acid bacteria differed between the two groups, with Enterococcus being predominant in vegetative growth stage alfalfa silage, and Weissella being predominant in late budding stage silage, transitioning to Lactiplantibacillus in the later stages of fermentation. On the 3rd day of silage fermentation, the vegetative growth stage group exhibited the highest abundance of Enterococcus, which subsequently decreased to its lowest level on the 15th day. Correlation analysis revealed that lactic acid bacteria, including Limosilactobacillus, Levilactobacillus, Loigolactobacillus, Pediococcus, Lactiplantibacillus, and Weissella, played a key role in nitrite and nitrate degradation in alfalfa silage. The presence of nitrite may be linked to Erwinia, unclassified_o__Enterobacterales, Pantoea, Exiguobacterium, Enterobacter, and Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium.
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Affiliation(s)
- Jiangbo An
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
| | - Lin Sun
- Inner Mongolia Academy of Agricultural & Animal Husbandry Sciences, Hohhot 010031, China;
| | - Mingjian Liu
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
| | - Rui Dai
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
| | - Gentu Ge
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
| | - Zhijun Wang
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
| | - Yushan Jia
- Key Laboratory of Forage Cultivation, Processing and High Efficient Utilization, Ministry of Agriculture, Inner Mongolia Agricultural University, Hohhot 010019, China; (J.A.); (M.L.); (R.D.); (G.G.); (Z.W.)
- Key Laboratory of Grassland Resources, Ministry of Education, Inner Mongolia Agricultural University, Hohhot 010019, China
- College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010019, China
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Lin J, Li G, Sun L, Wang S, Meng X, Sun L, Yuan L, Xu L. Varieties and ensiling: Impact on chemical composition, fermentation quality and bacterial community of alfalfa. Front Microbiol 2023; 13:1091491. [PMID: 36713170 PMCID: PMC9873995 DOI: 10.3389/fmicb.2022.1091491] [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: 11/07/2022] [Accepted: 12/15/2022] [Indexed: 01/13/2023] Open
Abstract
Introduction Six species of alfalfa commonly found in northern China were collected in the present study. Methods The chemical composition and epiphytic microbial communities during the ensiling were analyzed; and their effects on fermentation quality and silage bacterial communities were assessed. The effects of physicochemical characteristics of alfalfa on the bacterial community were also investigated in terms of nutritional sources of microbial growth and reproduction. Results and discussion The results showed that the chemical composition was significantly different in various alfalfa varieties, yet, the dominant genera attached to each variety of alfalfa was similar, except for pantoea (p<0.05). After ensiling, both the fermentation quality and microbial community changed obviously (p<0.05). Specifically, ZM2 had lower pH and ammonia nitrogen (NH3-N) content but higher LA content than other varieties of alfalfa silage. Beneficial bacteria such as Lentilactobacillus and Lactiplantibacillus were predominant in ZM2, which accounted for the higher fermentation quality. Significant correlations between the chemical composition of silage, fermentation quality and bacterial communities composition were observed. Moreover, variations in bacteria community structure during the fermentation of alfalfa were mainly influenced by water-soluble carbohydrates (36.79%) and dry matter (21.77%). Conclusion In conclusion, this study revealed the influence of chemical composition on microbial community and fermentation quality, laying the groundwork for future studies on high-quality silage.
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Affiliation(s)
- Jianyu Lin
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Guanhua Li
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Lin Sun
- Inner Mongolia Key Laboratory of Microbial Ecology of Silage, Inner Mongolia Engineering Research Center of Development and Utilization of Microbial Resources in Silage, Inner Mongolia Academy of Agriculture and Animal Husbandry Sciences, Hohhot, China
| | - Shuang Wang
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xin Meng
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Licong Sun
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Lin Yuan
- Inner Mongolia Engineering Technology Research Center of Germplasm Resources Conservation and Utilization, School of Life Sciences, Inner Mongolia University, Hohhot, China,*Correspondence: Lin Yuan, ✉
| | - Linbo Xu
- Key Laboratory of Biohazard Monitoring and Green Prevention and Control for Artificial Grassland, Ministry of Agriculture and Rural Affairs, Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, China,*Correspondence: Lin Yuan, ✉
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Zhong H, Zhou J, Wang F, Wu W, Xiong H, Yin H, Li X. Isolation and identification of ligninolytic bacterium ( Bacillus cereus) from buffalo ( Bubalus bubalis) rumen and its effects on the fermentation quality, nutrient composition, and bacterial community of rape silage. Front Microbiol 2023; 14:1103652. [PMID: 37143543 PMCID: PMC10153755 DOI: 10.3389/fmicb.2023.1103652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 03/27/2023] [Indexed: 05/06/2023] Open
Abstract
This study aimed to isolate and identify a ligninolytic bacterium from the rumen of buffalo (Bubalus bubalis) and investigate its effects as a silage additive for whole-plant rape. Three lignin-degradation strains were isolated from the buffalo rumen, with AH7-7 being chosen for further experiments. Strain AH7-7, with acid tolerance and a 51.4% survival rate at pH 4, was identified as Bacillus cereus. It exhibited a lignin-degradation rate of 20.5% after being inoculated in a lignin-degrading medium for 8 days. We divided the rape into four groups according to the various additive compositions to examine the fermentation quality, nutritional value, and bacterial community after ensiling: Bc group (inoculated with B. cereus AH7-7 3.0 × 106 CFU g FW-1), Blac group (inoculated with B. cereus AH7-7 1.0 × 106 CFU g FW-1, L. plantarum 1.0 × 106 CFU g FW-1, and L. buchneri 1.0 × 106 CFU g FW-1), Lac group (inoculated with L. plantarum 1.5 × 106 CFU g FW-1 and L. buchneri 1.5 × 106 CFU g FW-1), and Ctrl group (no additives). After 60 days of fermentation, the application of B. cereus AH7-7 was potent in modulating the fermentation quality of silage, especially when combined with L. plantarum and L. buchneri, as indicated by lower dry matter loss and higher contents of crude protein, water-soluble carbohydrate, and lactic acid. Furthermore, treatments with the B. cereus AH7-7 additive decreased the contents of acid detergent lignin, cellulose, and hemicellulose. The B. cereus AH7-7 additive treatments reduced the bacterial diversity and optimized the bacterial community compositions of silage, with an increase in the relative abundance of beneficial Lactobacillus and a decrease in the relative abundance of undesirable Pantoea and Erwinia. Functional prediction revealed that inoculation with B. cereus AH7-7 could increase the cofactors and vitamins metabolism, amino acid metabolism, translation, replication and repair, and nucleotide metabolism, while decreasing the carbohydrate metabolism, membrane transport, and energy metabolism. In brief, B. cereus AH7-7 improved the microbial community, fermentation activity, and ultimately the quality of silage. The ensiling with B. cereus AH7-7, L. plantarum, and L. buchneri combination is an effective and practical strategy to improve the fermentation and nutrition preservation of rape silage.
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Affiliation(s)
- Huimin Zhong
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Jiayan Zhou
- National Center for International Research on Animal Genetics, Breeding and Reproduction (NCIRAGBR), Huazhong Agricultural University, Wuhan, China
| | - Fan Wang
- National Center for International Research on Animal Genetics, Breeding and Reproduction (NCIRAGBR), Huazhong Agricultural University, Wuhan, China
| | - Wenqing Wu
- National Center for International Research on Animal Genetics, Breeding and Reproduction (NCIRAGBR), Huazhong Agricultural University, Wuhan, China
| | - Haiqian Xiong
- Animal Husbandry, Huanggang Academy of Agricultural Sciences, Huanggang, Hubei, China
| | - Huaihui Yin
- Animal Husbandry, Huanggang Academy of Agricultural Sciences, Huanggang, Hubei, China
| | - Xiang Li
- National Center for International Research on Animal Genetics, Breeding and Reproduction (NCIRAGBR), Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, China
- Shennongjia Science and Technology Innovation Center, Huazhong Agricultural University, Shennongjia, China
- *Correspondence: Xiang Li
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