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The experiment aimed to compare the effects of citric acid residue (CAR) to that of three commonly used short‐chain fatty acids on the fermentation quality, aerobic stability and structural carbohydrate degradation of lucerne ensiled with lactic acid bacteria (LAB) inoculants. Fresh lucerne was ensiled with distilled water (control), LAB inoculant (L), CAR + LAB inoculant (CL), formic acid + LAB inoculant (FL), acetic acid + LAB inoculant (AL) and propanoic acid + LAB inoculant (PL) for 50 days. Chemical composition and microbial populations were determined after ensiling. The residual silages ensiled for 50 days were evaluated for aerobic stability. Compared with control, CL, FL, AL and PL treatments significantly (p < 0.05) decreased pH, ammonia nitrogen (NH3‐N) and butyric acid contents and increased lactic acid, acetic acid and propionic acid contents. Among them, CL silages had the lowest pH, dry matter and water‐soluble carbohydrate (WSC) content, whereas the population of LAB and the lactic acid contents were highest. Besides, CL outperformed in enhancing fibre degradation, CL silages significantly decreased (p < 0.05) neutral detergent fibre, acid detergent fibre, hemicellulose and cellulose contents compared with control and had the highest Flieg's point. All treated‐silages improved the aerobic stability compared with control, of which L improved 32 h, whereas CL, FL, AL and PL improved 46, 20, 46, >64 h, respectively. Applying a combination of CAR and LAB inoculant improved the fermentation quality and structural carbohydrate degradation of lucerne silage and had a similar effect on aerobic stability compared with other three short‐chain fatty acids. The CAR had a comparable effect on enhancing the fermentation quality compared with three short‐chain fatty acids. Thus, the combination of CAR and LAB inoculant might be used as an ideal additive for lucerne silage making with low WSC and high moisture content. [ABSTRACT FROM AUTHOR]

An experiment was conducted to investigate the effects of citric acid residue (CAR) and lactic acid bacteria (LAB) on fermentation quality and aerobic stability of alfalfa silage. Alfalfa was treated as follows: (1) control without additive (CON); (2) LAB (L); (3) 12 g/kg CAR (C); (4) 12 g/kg CAR + LAB (CL) and fermented for 3, 6, 9, 15, 30 and 45 days. The residual silages ensiled for 45 days were evaluated for aerobic stability. The results showed that addition of CAR with or without LAB inoculant decreased pH, acetic acid, ammonia nitrogen , neutral detergent fibre, hemicellulose contents and Enterobacteriaceae counts (p <.05) and increased dry matter and lactic acid contents (p <.05) after 45 days of ensiling. Whereas, the lower lactic acid and higher acetic acid contents were observed in L silages (p <.05) after 45 days of ensiling. During aerobic exposure, L and CL silages remained stable in pH, lactic and acetic acid contents, while the control and C silages showed higher pH, yeast and mould counts and lower lactic and acetic acid contents. Compared with the control, L and CL improved aerobic stability, whereas the poorer aerobic stability was shown in C silages (p <.05). In conclusion, applying a combination of CAR and LAB inoculant improved both fermentation quality and aerobic stability of alfalfa silage. Citric acid residue (CAR) was compared with a lactic acid bacteria (LAB) inoculant in ensiling alfalfa. The CAR improved fermentation quality compared to control and LAB treated silages. Aerobic stability improved when CAR was used in combination with LAB but not when used alone. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effect of lactic acid bacteria (LAB) on fermentation quality, mycotoxin concentrations, and microbial communities of whole-crop corn silages infested with mycotoxigenic fungi. Cultured spores (106 cfu/mL) of mycotoxigenic Aspergillus flavus and Fusarium graminearum were sprayed (5 mL) on corn forage on 27 July and 10 August 2018. On 21 August 2018, sprayed (FI; 3 plots) and unsprayed (NFI; 3 plots) corn forage were harvested at the 1/2 kernel milk line stage, followed by chopping and ensiling without inoculants (CON), or with Lactobacillus buchneri (LB, 1 × 106 cfu/g FW), Lactobacillus plantarum (LT, 1 × 106 cfu/g FW), or L. buchneri + L. plantarum (BT: both L. buchneri and L. plantarum applied at 0.5 × 106 cfu/g FW). After 90 d of ensiling, FI silages had a higher (p < 0.05) pH value and higher acetic acid (ACA), ethanol, and ammonia nitrogen (ammonia N) concentrations, but lower (p < 0.05) lactic acid (LA) concentrations than NFI silage. The inoculants decreased pH and increased LA concentration and LA/ACA compared with CON. The aflatoxin B1 (AFB1) was only detected in FI fresh corn and silages; ensiling decreased (p < 0.05) AFB1 concentration compared with fresh corn, and LB and BT decreased AFB1 concentration compared with CON. The zearalenone (ZEN), deoxynivalenol (DON), and fumonisin B1 (FB1) concentrations were similar (p < 0.05) for NFI silages, while ZEN concentration in BT was the lowest (p < 0.05) among all FI silages; DON and FB1 concentrations in LB, LT, and BT silages were significantly lower (p < 0.05) than those of CON in FI silages. The fungal infestation increased the bacterial and fungal diversity of silages compared with NFI silages. The FI silages had a higher relative abundance (RA) of Lactobacillus, Weissella, Wickerhamomyces, Pichia, and Epicoccum than the corresponding NFI silages. The RA of Aspergillus and Fusarium markedly decreased after 90 d of ensiling, and the inoculation expanded this trend irrespective of fungal infestation. The Penicillium in FI silages survived after 90 d of ensiling, while the inoculants decreased the RA of Penicillium. Inoculants mitigate the adverse effects of fungal infestation on corn silage quality by changing the bacterial and fungal communities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two microbial consortia with cellulolytic activities were enriched from yak rumen. • Application of two consortia improved fermentation quality of rice straw silages. • The microbial consortia accelerated the degradation of structural carbohydrates. • Rice straw ensiled with the microbial consortia enhanced ethanol production. The present study extracts and enriches cellulolytic microbial consortia from yak (Bos grunniens) and evaluates their effects on the fermentation profile and bioethanol yield in rice straw silage. Two microbial consortia (CF and PY) with high cellulolytic activity were isolated and observed to be prone to utilize natural carbon sources. Two consortia were introduced with and without combined lactic acid bacteria (CLAB) to rice straw for up to 60 days of ensiling, and their application notably decreased the levels of structural carbohydrates and pH values of rice straw silages. Treatments that combining microbial consortia and CLAB resulted in the highest levels of lactic acid, water soluble carbohydrates, mono- and disaccharides, and lignocellulose degradation, with PY + CLAB group yielding the highest bioethanol production. The microbial consortia identified herein exhibit great potential for degrading fibrous substrates, and their combination with CLAB provides a feasible way to efficiently use rice straw for bioethanol production. [ABSTRACT FROM AUTHOR]

• Lactobacillus plantarum altered the bacterial community of alfalfa silage. • Cocci lactic acid bacteria (LAB) and Citrobacter led to fat-soluble vitamins loss. • Cocci LAB and Citrobacter caused the appearance of undecanoic acid and trilinolein. • Lipase-producing- L. Plantarum reduced the losses of polyunsaturated fatty acids. • Specific bacteria relieved the losses of α-tocopherol and β-carotene during ensiling. The purpose of this study was to explore the diversity mechanism of fatty acids (FA) and the loss mechanisms of polyunsaturated FA (PUFA) and fat-soluble vitamins in alfalfa silages treated with molasses (ML), lipase-producing- Lactobacillus plantarum (LP), propionic acid (PA), sunflower seed oil (OL) and without additives as the control (CON) for 70 d. The results exhibited that natural ensiling led to the losses of PUFA, C18:3n3, α-tocopherol, and β-carotene and increased the FA diversity due to the appearances of C11:0 and C18:2 trans -912 relative to the fresh alfalfa material (FAM). Similar to the control silage, great PUFA losses were observed in ML- and OL-treated silages. In contrast, LP (P = 0.001 and P < 0.001) and PA (P = 0.053 and P = 0.044) reduced the losses of C18:3n3 and PUFA compared with the control. Adding LP increased the contents of C16:0 (P < 0.001), C18:1 trans -9 (P = 0.014), and C18:2n6 (P = 0.001) than FAM. Furthermore, ML, OL, PA and LP increased (P < 0.001) the C11:0 content relative to FAM, and LP- (P < 0.001) and PA-treated (P < 0.001) silages had lower C11:0 content than the control, ML- and OL-treated silages. Compared with the control, adding ML, OL and PA reduced (P < 0.001) the β-carotene loss, and PA (P < 0.001) and LP (P = 0.001) reduced the α-tocopherol loss. Adding LP slightly increased β-carotene (4.9 %) relative to FAM. Next-generation sequencing results showed that undesired Citrobacter and cocci lactic acid bacteria (LAB) included Weissella , Pediococcus and Lactococcus were predominant in the control, OL- and ML-treated silages. The low abundances of these bacteria were detected in PA- and LP-treated silages but they had high abundances of Lactobacillus (> 58.0 %). Spearman correlation and redundancy analyses revealed that these cocci LAB and Citrobacte r led to the increases of lipoxygenase activity, contents of C11:0, and C18:2 trans -912, and the losses of PUFA, C18:3n3, α-tocopherol, and β-carotene, while Lactobacillus altered these indexes oppositely. Moreover, Pantoea (r = -0.70 and -0.68), Sphingomonas (r = -0.81 and -0.76), Aureimonas (r = -0.81 and -0.78) and Devosia (r = -0.83 and -0.80) correlated negatively with the losses of α-tocopherol and β-carotene. In conclusion, ML, PA, and LP improved fermentation quality. Adding PA and LP altered the bacterial community in alfalfa silage, which in turn reduced the FA diversity and losses of PUFA, α-tocopherol, and β-carotene. [ABSTRACT FROM AUTHOR]