Microbiological and chemical profiles of elephant grass inoculated with and without Lactobacillus plantarum and Pediococcus acidilactici

Effects of Lactic Acid Bacteria on Fermentation and Nutritional Value of BRS Capiaçu Elephant Grass Silage at Two Regrowth Ages

The objective of this study was to evaluate the effects of lactic acid bacteria inoculation on the fermentation profile and nutritional value of BRS Capiaçu elephant grass silages harvested at two regrowth ages. The treatments were arranged in a 5 × 2 factorial scheme, with five inoculants (I) and two regrowth ages (A, 90 and 105 days), in a completely randomized design, with three replicates. There were I × A interactions (p < 0.05) on pH, acetic acid, and water-soluble carbohydrates. The silage treated with Kera-Sil showed a lower pH compared with the control silage. The highest ammonia nitrogen content was recorded in the silage treated with Yakult®. There were I × A interactions (p < 0.05) on the dry matter (DM) content, neutral detergent fiber (NDF), and in vitro digestibility of DM (IVDMD) and NDF (IVNDFD). Silages treated with Kera-Sil and Silo-Max at 90 days of regrowth showed a higher DM and higher IVDMD (p < 0.05). A higher NDF content and lower IVDMD and IVNDFD were recorded in silages produced with grass harvested at 105 days of regrowth (p < 0.05). The use of commercial microbial inoculants improved the fermentative and nutritional parameters of the silages.

Effects of ensiling sugarcane tops with bacteria-enzyme inoculants on growth performance, nutrient digestibility, and the associated rumen microbiome in beef cattle

Major challenges when ensiling sugarcane tops include fermentation that results in high quantities of alcohol and decrease in nutrient digestibility due to the accumulation of fiber components. Increased efforts to apply bacteria-enzyme inoculants in silage have the potential to improve nutrient digestibility. This study aimed to evaluate the effects of ensiling sugarcane tops with bacteria-enzyme inoculants or mixed bacterial inoculants on growth performance, nutrient digestibility, and rumen microbiome in beef cattle. Chopped sugarcane tops were ensiled in plastic bags for 60 d after application of 1) no inoculant (control check, CK); 2) bacteria-enzyme inoculants containing Pediococcus acidilactici, Saccharomyces cerevisiae, cellulase, and xylanase (T1, viable colony-forming units of each bacterial strain ≥108 CFU/g; enzyme activity of each enzyme ≥200 U/g); or 3) mixed bacterial inoculants containing Lactobacillus plantarum, Bacillus subtilis, and Aspergillus oryzae (T2, viable colony-forming units of each bacterial strain ≥107 CFU/g). Silages were fed to eighteen Holstein bull calves (n = 6/treatment) weighing 163.83 ± 7.13 kg to determine intake in a 49-d experimental period. The results showed that beef cattle-fed T1 silage or T2 silage had a significantly higher (P < 0.05) average daily gain than those fed CK silage, but the difference in dry matter intake was not significant (P > 0.05). The apparent digestibility of crude protein (CP) and acid detergent fiber (ADF) were higher (P < 0.05) for beef cattle-fed T1 silage or T2 silage than for those fed CK silage. The rumen bacterial community of beef cattle-fed T1 silage or T2 silage had a tendency to increase (P > 0.05) abundance of Firmicutes and Rikenellaceae_RC9_gut_group than those fed CK silage. Rumen fungal communities of beef cattle-fed T1 or T2 silage had a tendency to increase (P > 0.05) abundance of Mortierellomycota and of Mortierella than those fed CK silage. Spearman's rank correlation coefficient showed that the apparent digestibility of ADF for beef cattle was positively correlated with unclassified_p_Ascomycota of the fungal genera (P < 0.05). Neocalimastigomycota of the fungal phyla was strongly positively correlated with the apparent digestibility of neutral detergent fiber (NDF) (P < 0.05). Ruminococcus was positively correlated with the apparent digestibility of CP (P < 0.05). It was concluded that both T1 and T2 improved the growth performance of beef cattle by improving the ruminal apparent digestibility of CP and ADF, and had no significant impact on major rumen microbial communities in beef cattle.

Current approaches on the roles of lactic acid bacteria in crop silage

Lactic acid bacteria (LAB) play pivotal roles in the preservation and fermentation of forage crops in spontaneous or inoculated silages. Highlights of silage LAB over the past decades include the discovery of the roles of LAB in silage bacterial communities and metabolism and the exploration of functional properties. The present article reviews published literature on the effects of LAB on the succession, structure, and functions of silage microbial communities involved in fermentation. Furthermore, the utility of functional LAB in silage preparation including feruloyl esterase-producing LAB, antimicrobial LAB, lactic acid bacteria with high antioxidant potential, pesticide-degrading LAB, lactic acid bacteria producing 1,2-propanediol, and low-temperature-tolerant LAB have been described. Compared with conventional LAB, functional LAB produce different effects; specifically, they positively affect animal performance, health, and product quality, among others. In addition, the metabolic profiles of ensiled forages show that plentiful probiotic metabolites with but not limited to antimicrobial, antioxidant, aromatic, and anti-inflammatory properties are observed in silage. Collectively, the current knowledge on the roles of LAB in crop silage indicates there are great opportunities to develop silage not only as a fermented feed but also as a vehicle of delivery of probiotic substances for animal health and welfare in the future.

Evaluating the Effectiveness of Screened Lactic Acid Bacteria in Improving Crop Residues Silage: Fermentation Parameter, Nitrogen Fraction, and Bacterial Community

Ensiling characteristics of sweet potato vine (SPV) and peanut straw (PS), as well as the effects of lactic acid bacteria (LAB) strains, Lactococcus Lactis MK524164 (LL) and Lactobacillus farciminis MK524159 (LF), were investigated in this study. Fermentation parameters, nitrogen fractions, and bacterial community of SPV and PS were monitored at intervals during the ensiling process. The results showed that inoculating LAB increased lactate production (2.23 vs. 2.73%; 0.42 vs. 1.67% DM), accelerated pH decline (5.20 vs. 4.47; 6.30 vs. 5.35), and decreased butyrate (0.36% DM vs. not detected), ammonia-N (6.41 vs. 4.18% CP), or nonprotein-N (43.67 vs. 35.82% CP). Meanwhile, it altered the silage bacterial community, where the relative abundance of Lactobacillus was increased (6.67–32.03 vs. 45.27–68.43%; 0.53–10.45 vs. 38.37–68.62%) and that of undesirable bacteria such as Clostridium, Enterobacter, Methylobacterium, or Sphingomonas was much decreased. It is suggested that the screened LAB strains LL and LF can effectively improve the silage quality of SPV and PS silages.

Evaluation of biological and chemical additives on microbial community, fermentation characteristics, aerobic stability, and in vitro gas production of SuMu No. 2 elephant grass

BACKGROUND

The study was conducted to evaluate the effects of biological and chemical additives on microbial community, fermentation characteristics, aerobic stability, and in vitro gas production of SuMu No. 2 elephant grass.

RESULTS

Aerobic bacteria and yeast were not affected on days 5 and 7 but were significantly (P < 0.224) reduced on days 14, 30, and 60, whereas lactic acid and lactic acid bacteria were significantly (P > 0.001) higher in all ensiling days within all treatment groups. During the ensiling days, the pH, acetic acid, butyric acid, and yeast were decreased in all treatment groups, whereas the Lactobacillus plantarum group and L. plantarum + natamycin group were highly significantly (P > 0.001) decreased. During air exposure, the water-soluble carbohydrates, ammonia nitrogen, lactic acid, and acetic acid were not affected on days 1-4, whereas pH and aerobic bacteria (were significantly (P < 0.05) increased on days 2-4. The addition of Lactobacillus plantarum and natamycin increased the gas production, in vitro dry matter digestibility, and in vitro neutral detergent fiber of SuMu No. 2 elephant grass silages.

CONCLUSIONS

The addition of biological and chemical additives, such as L. plantrum alone and the combination with natamycin, affected the undesirable microbial community, fermentation characteristics, aerobic stability, and in vitro gas of SuMu No. 2 elephant grass. © 2021 Society of Chemical Industry.

Effect of endophytic Bacillus megaterium colonization on structure strengthening, microbial community, chemical composition and stabilization properties of Hybrid Pennisetum

BACKGROUND

This study was conducted to analyze the effects of endophytic Bacillus megaterium (BM 18-2) colonization on structure strengthening, microbial community, chemical composition and stabilization properties of Hybrid Pennisetum.

RESULTS

The BM 18-2 had successfully colonized in the interior tissues in both leaf and stem of Hybrid Pennisetum. During ensiling, the levels of pH, acetic acid (AA), butyric acid (BA), propionic acid (PA), and the population of yeast and aerobic bacteria were significantly (P > 0.05) lower, while lactic acid bacteria (LAB) and lactic acid (LA) were significantly (P < 0.001) higher with the steps forward of ensiling in with BM 18-2 as compared to without BM 18-2 colonized of Hybrid Pennisetum. During the different ensiling days, at days 3, 6, 15, and 30, the genus Brevundimonas, Klebsiella, Lactococcus, Weissella, Enterobacter, Serratia, etc. population were significantly decreased, while genus Pediococcus acidilactici and Lactobacillus plantarum were significantly influenced in treated groups as compared to control. The genus Lactobacillus and Pediococcus were positively correlated with treatment groups.

CONCLUSIONS

It is concluded that the endophytic bacteria strain BM 18-2 significantly promoted growth characteristics and biomass yield before ensiling and after ensiling inoculated with or without Lactobacillus plantarum could improve the distinct changes of the undesirable microbial diversity, chemical composition, and stabilization properties in with BM 18-2 as compared to without BM 18-2 colonized Hybrid Pennisetum. © 2019 Society of Chemical Industry.

Integrated control of dry root rot of chickpea caused by Rhizoctoniabataticola under the natural field condition

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Bavistin® was effective in controlling dry root rot of chickpea.

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Among the chickpea cultivars, Karak-1 was found to be resistant as compared to other cultivars.

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The highest plant (64.1 cm), highest grain yield (1488 Kg/ha) in the integrated use of Karak-1 and Bavistin®, fungicide.

The study investigated the effect of three fungicides Bavistin®, Aliette®, and Biomagic® at the rate of 2 g/L were tested In vitro and In vivo to control dry root rot and their impact on yield were evaluated at the rate of 4 g/L against R. bataticola while varieties used were Karak-1, Karak-2, Karak-3, and Sheenghar. Disease severity was recorded lowest (19 %) and highest yield (1467 Kg/ha), plant height (47.5 cm), number of pods/plant (15.0) and number of grain/pods (1.66) were recorded in cultivar Karak-1. Among the fungicides drugs, the Bavistin®, significantly reduced the disease severity (5 %) and Kg/ha), highest plant height (64.1 cm), highest grain yield (1488 Kg/ha), number of pods/plant (24.5) and number of grain/pods (2.25). It is concluded that the integrated use of Karak-1 and Bavistin®, fungicide drugs gave promising results for controlling dry root rot of chickpea, and increased plant height, number of pods/plant and number of grain/pods.

Effects of Lactic Acid Bacteria Isolated From Rumen Fluid and Feces of Dairy Cows on Fermentation Quality, Microbial Community, and in vitro Digestibility of Alfalfa Silage

The objective of this study was to select lactic acid bacteria (LAB) isolated from the rumen fluid and feces of dairy cows, and evaluate their effects on silage quality of alfalfa after 30 or 60 days of ensiling. One hundred and four LAB strains were isolated from rumen fluid and feces of six dairy cows, of which four strains (Lactobacillus plantarum F1, L. plantarum F50, Lactobacillus salivarius L100, and Lactobacillus fermentum L120) and one commercial inoculant (GFG) isolated from forage were employed for further study. The silages treated with F1 had the lowest (P < 0.05) pH value and the highest (P < 0.05) lactic acid (LA) content in all treatments. Besides, higher (P < 0.05) in vitro digestibility was also observed in F1-treated silage after 60 days of ensiling. The microbial analysis showed that the Lactobacillus abundance in the F1-treated silages increased to 60.32%, higher than other treatments (5.12–47.64%). Our research indicated that strain F1 could be an alternative silage inoculant, and dairy cows could be a source for obtaining excellent LAB for ensiling.

Effects of natamycin and Lactobacillus plantarum on the chemical composition, microbial community, and aerobic stability of Hybrid pennisetum at different temperatures

This study evaluated the effects of natamycin and Lactobacillus plantarum on the chemical composition, microbial community, and aerobic stability of Hybrid pennisetum at different temperatures. Different concentrations of natamycin (0.50 g L⁻¹, 1.00 g L⁻¹, and 1.50 mg L⁻¹) significantly (p > 0.05) reduced the growth of undesirable microorganisms. During the ensiling periods the pH, ammonia nitrogen (NH₃–N), acetic acid (AA), butyric acid (BA), aerobic bacteria (AB), and yeast were significantly (p > 0.05) reduced, while the lactic acid and lactic acid bacteria were significantly (p < 0.05) influenced in the SLP and SLNP groups as compared to the SP and SNP groups at high temperature (29–30 °C). During air exposure, water-soluble carbohydrate, ammonia nitrogen (NH₃–N), lactic acid (LA), and acetic acid (AA) were not influenced, while pH and aerobic bacteria were significantly (p < 0.05) enhanced after three days (72 hours) of air exposure, and lactic acid bacteria were significantly (p > 0.05) reduced at ambient temperature (9–10 °C). It is concluded that the addition of L. plantarum CICC 20765 alone and in combination with natamycin reduced the content of AA, pH, NH₃–N, BA, and undesirable microbial community, and enhanced the chemical composition, fermentation quality, and air exposure. Natamycin alone did not significantly enhance the organic acid profile but improved the air exposure. Furthermore, more effort is needed to evaluate the effects on silage preservation on a large scale and on animal performance.

The inoculation of L. plantarum and natamycin influenced the fermentation quality. Natamycin and L. plantarum reduced the undesirable microbial community. During ensiling process, the LA and LABs was significantly enhanced.

Effects of probiotics and nutrients addition on the microbial community and fermentation quality of peanut hull

The objective of this study was to develop a new type of feedstuff by utilizing probiotics to transform agricultural byproducts to meet the livestock feed shortage. In this study, peanut hull powder (PHP) was used as the fermentation substrate, which was inoculated with 18 kinds of feed probiotics combined with two kinds of nutritional additives. The desired value formula was used to select the strains suitable for fermentation of PHP, and the strains were combined as multi-culture starters. We compared the changes of the chemical composition and bacterial flora before and after the fermentation, which provided a theoretical basis for the establishment and quality evaluation of the system of PHP fermentation. The result shows that inoculation with CM6 together with nutrients co-fermenting clearly raised the content of organic acid, CP and WSC in the PHP and effectively inhibited the growth of harmful microorganisms such as Enterobacter and Fusarium.

Isolation and molecular identification of lactic acid bacteria from King grass and their application to improve the fermentation quality of sweet Sorghum

The aim of the present study was isolation and molecular identification of lactic acid bacteria from King grass and their application to improve the fermentation quality of sweet Sorghum. Seventy-six strains of LAB were isolated; five strains were selected for Physiological and morphological tests and 16S rRNA sequencing. All five strains grew at different pH 3.5-8.0, different temperature 35, 40, 45, 50 °C and different NaCl concentrations 3, 6.5, 9.5%. Strains HDASK were identified Lactobacillus plantarum and SK3907, SK2A32, SK3A42 and ASKDD Pediococcus acidilactici. Three isolated strains and one commercial strain were added to sweet sorghum. Silage was prepared of four treatments and one control with three replicates as control (SKC, adding 2 ml/kg sterilizing water), L. plantarum commercial bacteria (SKP), L. plantarum (HDASK) isolated from King grass (SKA), P. acidilactici (SK3907) isolated from King grass (SKB) and P. acidilactici (ASKDD) isolated from King grass (SKD). All silage were prepared using polyethylene terephthalate bottles, and incubated at room temperature for different ensiling days. The level of pH, acetic acid, NH3-N, water soluble carbohydrate and butyric acid was significantly (P < 0.05) decreased. Lactic acid, ethanol and propionic acid (PA) was significantly (P < 0.05) increased in treatments compared to control. The dry matter, propionic acid neutral detergent fiber, acid detergent fiber did not significantly (P < 0.05) differ among the treatments but the values were increased and decreased. The number of yeast, mold and LAB were significantly (P < 0.05). It is suggested that the supplementation of LAB could enhanced the fermentation quality of sweet Sorghum silage.