scholarly journals Effects of ferulic acid esterase-producing Lactobacillus fermentum and cellulase additives on the fermentation quality and microbial community of alfalfa silage

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7712 ◽  
Author(s):  
Rina Su ◽  
Kuikui Ni ◽  
Tianwei Wang ◽  
Xiaopan Yang ◽  
Jie Zhang ◽  
...  

Background Alfalfa (Medicago sativa) is an important forage material widely used for animal feed production. Ensiling is an effective method for preserving alfalfa, but it has shown some limitations in the production of high-quality alfalfa silage due to its low water soluble carbohydrates (WSC) content and high buffering capacity. Lactic acid bacteria (LAB) and cellulase are often used as silage additives to promote the ensiling process and enhance fermentation quality. Methods Experiments were conducted to investigate the effects of ferulic acid esterase (FAE)-producing Lactobacillus fermentum 17SD-2 (LF) and cellulase (CE) on the fermentation quality and microbial community of alfalfa silage. After 60 days of ensiling, analysis of fermentation quality and bacterial diversity in alfalfa silages were conducted using high-performance liquid chromatography and high-throughput sequencing methods. Results Alfalfa was ensiled with additives (LF, CE, and LF+CE) or without additives for 60 days. All additives increased lactic acid and decreased pH values and ammonia-N contents compared to control. Among all treatments, the combined addition of LF and CE showed lowest pH (4.66) and ammonia-N (NH3-N, 0.57% DM) content, highest contents of lactic acid (LA, 10.51% DM), dry matter (DM, 22.54%) and crude protein (CP, 24.60% DM). Combined addition of LF and CE performed better in reducing neutral detergent fiber (NDF, 29.76% DM) and acid detergent fiber (ADF, 22.86% DM) contents than the addition of LF (33.71, 27.39% DM) or CE (32.07, 25.45% DM) alone. Moreover, the microbial analysis indicated that LF+CE treatments increased the abundance of desirable Lactobacillus and inhibited the growth of detrimental Enterobacter and Clostridia in alfalfa silage. Discussion Combined addition of FAE-producing LF and CE is more effective than treatments of LF or CE alone in improving fermentation quality and nutrition values of alfalfa silage. This is likely due to a synergistic effect of CE and FAE produced by LF on plant cell wall degradation, indicating that these additives promote each other to improve fiber degradation and silage fermentation. In conclusion, combined addition of FAE-producing LF and CE could be a feasible way to improve alfalfa silage quality.

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1575
Author(s):  
Fuhou Li ◽  
Zitong Ding ◽  
Adegbola T. Adesogan ◽  
Wencan Ke ◽  
Yun Jiang ◽  
...  

The effects of two strains of class IIa bacteriocin-producing lactic acid bacteria, Lactobacillus delbrueckii F17 and Lactobacillus plantarum (BNCC 336943), or a non-bacteriocin Lactobacillus plantarum MTD/1 (NCIMB 40027), on fermentation quality, microbial counts, and aerobic stability of alfalfa silage were investigated. Alfalfa was harvested at the initial flowering stage, wilted to a dry matter concentration of approximately 32%, and chopped to 1 to 2 cm length. Chopped samples were treated with nothing (control, CON), Lactobacillus delbrueckii F17 (F17), Lactobacillus plantarum (BNCC 336943) (LPB), or Lactobacillus plantarum MTD/1 (NCIMB 40027) (LPN), each at an application rate of 1 × 106 colony-forming units/g of fresh weight. Each treatment was ensiled in quadruplicate in vacuum-sealed polyethylene bags packed with 500 g of fresh alfalfa per bag and ensiled at ambient temperature (25 ± 2 °C) for 3, 7, 14, 30, and 60 days. The samples were then subjected to an aerobic stability test after 60 days of ensiling. Compared with the CON silage, the inoculants reduced the pH after 14 days of ensiling. After 60 days, pH was lowest in the LPB-treated silage, followed by the F17 and LPN-treated silages. Inoculation of F17 increased concentrations of lactic acid in silages fermented for 7, 14, 30, and 60 days relative to other treatments, except for the LPN-treated silages ensiled for 30 and 60 days, in which the lactic acid concentrations were similar to that of F17 silage. Application of F17 and LPB decreased the number of yeast and mold relative to CON and LPN-treated silages. Compared with the CON silage, inoculant-treated silages had greater aerobic stability, water-soluble carbohydrate, and crude protein concentrations, and lower neutral detergent fiber, amino acid nitrogen, and ammonia nitrogen concentrations. The LPB-treated silage had the greatest aerobic stability followed by the F17-treated silage. Both class IIa bacteriocin producing inoculants improved alfalfa silage fermentation quality, reduced the growth of yeasts and molds, and improved the aerobic stability of the ensiled forage to a greater extent than the proven LPN inoculant. However, higher crude protein concentration and lower ammonia nitrogen concentration were observed in LPN-treated silage relative to other treatments.


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 518
Author(s):  
Vanessa P. Silva ◽  
Odilon G. Pereira ◽  
Eliana S. Leandro ◽  
Rosinea A. Paula ◽  
Mariele C. N. Agarussi ◽  
...  

The first part of the study aimed to isolate, characterize, and identify wild lactic acid bacteria (LAB) strains from alfalfa silage produced in a tropical area. LAB strains were isolated from alfalfa silage ensiled for 1, 3, 7, 14, 28, and 56 days (d) and were identified by sequencing the 16S rRNA gene. The second part aimed to investigate the effects of wild LAB strains on the nutritive and fermentative characteristics of alfalfa silage. This trial was conducted according to a completely randomized design in a 4 × 2 factorial scheme [four inoculants (I) × two harvests (H)], (n = 4). The inoculants were: (1) no inoculant (CTRL), (2) Lactobacillus pentosus (AV 14.17); (3) L. pentosus + Lactobacillus brevis + Pediococcus acidilactici (Combo); and (4) commercial inoculant (CI). Alfalfa forage (7 kg) was ensiled in 10 L buckets and opened after 90 d. Seventy-seven strains were isolated. Pediococcus, Lactobacillus, and Weissella represented 52.0, 24.7, and 20.8% of the isolates, respectively. For the first harvest, Combo, CI, and all inoculated silages showed lower acid detergent fiber ADF, neutral detergent fiber (NDF), and ammonia nitrogen (NH3-N), respectively. Silage fermented with AV14.17 presented greater residual water-soluble carbohydrate (WSC) in the second harvest and showed the lowest pH in both harvests. AV14.17 strain has potential as an inoculant for alfalfa silage production.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chao Peng ◽  
Wentao Sun ◽  
Xiang Dong ◽  
Lili Zhao ◽  
Jun Hao

AbstractThe study aimed to isolate and identify lactic acid bacteria (LAB) from silages and their application to improve the fermentation quality of alfalfa. Forty-nine LAB strains were isolated from silages, and two strains were screened for growth and acid production rates. Then two strains were selected for Physiological and morphological tests and 16S rRNA sequencing. They were Gram-positive and Catalase-negative and were able to grow at pH 3.5 and at 45 °C, were unable to grow different NaCl concentrations as 3.0% and 6.5%. Strain BDy3-10 was identified as Lactobacillus rhamnosus, while TSy1-3 was identified as L. buchneri. The selected strains were evaluated on fermentation of alfalfa silage. The highest crude protein content occurred in the BDy3-10 treatment group. The contents of neutral detergent fiber and acid detergent fiber in the TSy1-3 treatment were significantly lower than other treatment (P < 0.05). Compared to the control treatment, inoculation treatments deceased pH during ensiling (P < 0.001) and provided the most increased lactic acid content after ensiling for 10 days (P < 0.001). The acetic acid contents of all the inoculation groups were significantly increased (P < 0.001) during ensiling, and were lower than that of control group (P < 0.001). So, the TSy1-3 treatment most effectively improved the fermentation quality of alfalfa silage in warm and humid climate area.


2021 ◽  
Vol 9 (1) ◽  
pp. 52-59
Author(s):  
Xuxiong Tao ◽  
Chongwen Ji ◽  
Sifan Chen ◽  
Jie Zhao ◽  
Siran Wang ◽  
...  

This study was conducted to investigate the effects of adding citric acid residue (CAR) with or without lactic acid bacteria (LAB) to Napier grass (Cenchrus purpureus; syn. Pennisetum purpureum) cv. Sumu No. 2 at ensiling on the fermentation quality and aerobic stability of the resulting silage. Treatments included: Control (Napier grass forage without additives); and Napier grass inoculated with lactic acid bacteria (Lactobacillus plantarum and L. buchneri) at 1 × 106 cfu/gfresh weight (FW) forage (LAB) or 36 g citric acid residue/kg FW forage (CAR) or a mixture of CAR and LAB (CL). Forty-five days after ensiling the silages were tested for chemical and microbial composition and an aerobic stability test was conducted. The addition of CAR with or without LAB increased the DM and lactic acid concentrations in silage and decreased pH plus acetic acid, ammonia nitrogen (NH3-N), neutral detergent fiber and cellulose concentrations relative to Control. The pH in LAB silage was lower than in Control, while lactic acid concentration was higher. During the first 2 days of aerobic exposure, all additives increased the water-soluble carbohydrate (WSC) and lactic acid concentrations and decreased pH plus NH3-N and acetic acid concentrations. Moreover, CL silages had the highest WSC and the lowest NH3-N and acetic acid concentrations during aerobic exposure. However, all additives failed to improve the aerobic stability of the silage. While CAR with or without LAB inoculant improved the fermentation quality of silage made from Napier grass, more studies are warranted to identify additives which can improve aerobic stability of the silage after opening.


2021 ◽  
Vol 9 (12) ◽  
pp. 2614
Author(s):  
Xiaomiao Fan ◽  
Shanshan Zhao ◽  
Fengyuan Yang ◽  
Yuan Wang ◽  
Yanping Wang

To investigate the effects of lactic acid bacterial (LAB) inoculants and vacuuming on the fermentation quality and bacterial community, alfalfas were ensiled with or without a commercial LAB YX or Lactobacillus plantarum strain ZZUA493 for 10, 30, 60, and 90 days while undergoing either vacuum (V) or nonvacuum (NV) treatment. At 90 days, analysis of the microbial community by high-throughput sequencing was performed, and contents of aflatoxin B1 and deoxynivalenol (DON) mycotoxins in alfalfa silage were determined. In all inoculated alfalfa silage, irrespective of V or NV treatment, lactic acid (LA) content increased, pH (p < 0.05), and ammonia nitrogen (p < 0.05) content decreased, and no butyric acid was detected. Lactobacillus or Pediococcus became the dominant genus, and the abundance of Garciella decreased in alfalfa silage with the addition of either inoculant. The LAB inoculants YX and ZZUA493 helped reduce the mycotoxin content in alfalfa silage. The abundance of Garciella in the control and DON content in all alfalfa silage groups were higher (p < 0.05) in NV than V. In summary, LAB inoculants and vacuuming had a positive influence on alfalfa silage quality, and LAB inoculants were effective in reducing mycotoxins in silage alfalfa.


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