Lactic Acid Bacteria Inoculants Research Articles

Increasing Biogas Yield from Fodder by Microbial Stimulation of Propionic Acid Synthesis in Grass Silages

A new direction in the use of lactic acid bacteria inoculants is their application for renewable raw materials ensiling for biogas production. The aim of the study was to demonstrate the possibility of stimulating the synthesis of propionic acid in the process of co-fermentation of selected strains of Lactobacillus buchneri and L. diolivorans as well as L. buchneri and Pediococcus acidilactici. L. buchneri KKP 2047p and P. acidilactici KKP 2065p were characterized by the special capabilities for both synthesis and metabolism of 1,2-propanediol. L. diolivorans KKP 2057p stands out for the ability to metabolize 1,2-propanediol to propionic acid. As a result of the co-fermentation a concentration of propionic acid was obtained at least 1.5 times higher in the final stage of culture in comparison to cultivating individual species of bacteria separately. The results of in vitro experiments were applied in agricultural practice, by application of two lactic acid bacteria inoculants in ensiling of grass silage and improving its suitability for biogas production. Grass silages made with the addition of the inoculant were characterized by the content of 1,2-propanediol, 1-propanol and propionic acid ensured extension of the aerobic stability from 4 to 7 days in comparison to untreated silages. It was found that the use of both inoculants resulted in an approximately 10–30% increase in biogas yield from this raw material.

Effects of several lactic acid bacteria inoculants on fermentation and mycotoxins in corn silage

Effects of commercial and pure lactic acid bacteria (LAB) inoculants on fermentation and levels of aflatoxins and other mycotoxins in corn silage that was experimentally contaminated in the field with a toxigenic strain of Aspergillus flavus (ITEM 8069) were determined. Late-season corn hybrid plants were inoculated with A. flavus at silk emergence, and fresh-chopped corn was harvested at the ⅔ milk line stage (dry matter [DM]: 428 ± 6.5 g/kg) and ensiled directly (control, CTR) or after treatment with 9 LAB inoculants. Commercial inoculants contained Lactobacillus (L.) buchneri LB1819 and Lactococcus lactis O224 or Enterococcus faecium, Lactobacillus plantarum, Lactococcus lactis SR3.54 (respectively SiloSolve FC or SiloSolve MC, Chr. Hansen A/S, Hørsholm, Denmark), L. buchneri and L. plantarum (Pioneer brand 11C33, Pioneer Hi-Bred International, Des Moines, USA). One pure strain of L. brevis DSMZ 20054, two pure strains of L. plantarum (LP ATCC 8014 and LP PB) and three of L. rhamnosus (LR ATCC 7469, LR LR7 and LR RI) were also used. Each silage received an inoculant at final expected dose of approximately 250,000 CFU/g of freshly chopped forage, and was ensiled in 20 L mini-silos, compacted to density of 160 kg dry-mass/m3, stored at room temperature, and opened after 30 or 120 days. The commercial and pure inoculants had few effects on fermentation relative to CTR. Ensiling time and LAB treatment had no effect on silage pH. However SiloSolve FC silage had lower ethanol levels than CTR group, while 1,2 propanediol level doubled as ensiling time increased and the high values were with SiloSolve FC and Pioneer CFT. Aerobic stability increased with ensiling time, with the longest stability in SiloSolve FC and L. rhamnosus ATCC 7469 silage. Lowest aflatoxin B1 (AFB1) concentrations were in the L. rhamnosus LR7 and L. plantarum ATCC 8014 silages (about 8–10 μg/kg DM) and the highest concentration was in L. brevis DSMZ 20054 silage (34.2 μg/kg DM). Concluding, future investigations should be carried out to examine the relationship between LAB and mycotoxinegic fungi during ensiling.

Volatile organic compound modification by lactic acid bacteria in fermented chilli mash using GC-MS headspace extraction

This study was conducted to assess the volatile compound generated in fermented chili using the static headspace gas chromatography (GC-MS). Three types of lactic acid bacteria (LAB) inoculant were used; Lactobacillus plantarum Alo1, Lactobaciluss pentosus Alo2 and Lactobacillus platarum Au2 for the lactic acid fermented chili mash. Raw chili and natural fermented chili mash were served as negative and positive control. The volatile compound was grouped into 7 main compounds consist of ester, alcohol, alkane, acid, hydrocarbon, ether and nitrogen-containing group. Study showed that LAB inoculated chili mash has lower amount of ethanol as compared to naturally fermented chili mash. Besides, volatile compound generated among each inoculant was different. A compound known as n-Hexadecanoic acid was the primary compound detected in all LAB-inoculated chili mash. Result proved that LAB can be used as the potential starter culture in modifying the aroma of fermented chili mash.

Microbial and metabolite profiles of spontaneous and adjunct-inoculated cacao (Theobroma cacao L.) fermentation

The succession of the dominant microbial population during cacao fermentation with or without adjunct inoculation of yeast and lactic acid bacteria (LAB) were monitored on a laboratory scale using culture-dependent and culture-independent methods. Yeasts and acetic acid bacteria (AAB) population throughout a five-day fermentation process showed no significant differences but the LAB population increased through adjunct inoculation. Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) identification method showed the dominance of only Lactobacillus plantarum, one of the species used as the adjunct inoculum, which resulted in higher lactic acid production. On the other hand, Acetobacter spp. and Gluconobacter spp. were markedly observed in the spontaneously fermented set-up resulting in increased acetic acid production, significantly different (p>0.05) at three to five days of fermentation. LAB and yeast inoculation resulted in a more desirable temperature and pH of the fermenting mash which may result in better product quality.

Altering bacterial community: A possible way of lactic acid bacteria inoculants reducing CO2 production and nutrient loss during fermentation

CO2 production during ensiling is a source of greenhouse gases emissions and a cause of nutrient loss of silage. To investigate the influence of additives on CO2 production and relevant bacterial communities, stylo and rice straw were ensiled with sucrose and Lactobacillus plantarum (LP). After 30 days fermentation, LP reduced CO2 production (from 66.2 to 0 mL/100 g fresh matter in stylo, from 83.7 to 16.6 mL/100 g fresh matter in rice straw) and weight loss (from 2.71 to 1.72% in stylo, from 2.75 to 2.40% in rice straw). CO2 production was positively correlated (P < 0.05) with Lactococcus (0.99), Leuconostoc (0.55), Lachnoclostridium (0.45), Prevotella (0.23) and was negatively correlated (P < 0.05) with Serratia (-0.66), Sphingobacterium (-0.58), Pediococcus (-0.36). LP decreased the relative abundance of genera positively correlated with CO2 production and increased that of genera negatively correlated. In conclusion, LP could reduce CO2 production by altering bacterial community during ensiling.

Effects of Autochthonous Yeast Cultures on Some Quality Characteristics of Traditional Turkish Fermented Sausage “Sucuk”

The objective of this study was to determine the effects of yeast cultures (Candida zeylanoides and Debaryomyces hansenii) isolated from traditionally dry fermented Turkish sucuks, on some physicochemical and microbiological properties of the product. Eight different batches of the sucuks were produced by the inoculation of yeast and lactic acid bacteria (LAB) cultures (Lactobacillus curvatus, Lactobacillus plantarum and Lactobacillus sakei) in different combinations. The sucuks were ripened for 12 days and analyzed at 1st, 6th, and 12th days of ripening. Percent moisture content, pH, water activity (aw) and residual nitrite values of the sucuk inoculated with the yeast cultures were higher at the end of the ripening. The use of yeast cultures decreased hardness, gumminess, and chewiness values of the sucuk while increased adhesiveness values. Major volatile groups were aldehydes, terpenes, and sulphur compounds in the sucuk samples. The most noticeable results were for sensory properties of the sucuk that were positively improved by the yeast cultures.

Fermentation quality and aerobic stability of Napier grass ensiled with citric acid residue and lactic acid bacteria

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.

Improving ensiling characteristics by adding lactic acid bacteria modifies in vitro digestibility and methane production of forage-sorghum mixture silage

Improving the nutrition of livestock is an important aspect of global food production sustainability. This study verified whether lactic acid bacteria (LAB) inoculant could promote ensiling characteristics, nutritive value, and in vitro enteric methane (CH4) mitigation of forage sorghum (FS) mixture silage in attacking malnutrition in Zebu beef cattle. The FS at the soft dough stage, Cavalcade hay (CH), and cassava chip (CC) were obtained. The treatments were designed as a 4 × 2 factorial arrangement in a completely randomized design. Factor A was FS prepared without or with CH, CC, and CH + CC. Factor B was untreated or treated with Lactobacillus casei TH14. The results showed that all FS mixture silages preserved well with lower pH values below 4.0 and higher lactic acid contents above 56.4 g/kg dry matter (DM). Adding LAB boosted the lactic acid content of silages. After 24 h and 48 h of in vitro rumen incubation, the CC-treated silage increased in vitro DM digestibility (IVDMD) with increased total gas production and CH4 production. The LAB-treated silage increased IVDMD but decreased CH4 production. Thus, the addition of L. casei TH14 inoculant could improve lactic acid fermentation, in vitro digestibility, and CH4 mitigation in the FS mixture silages.

Effect of lactic acid bacteria on the ensiling characteristics and in vitro ruminal fermentation parameters of alfalfa silage

The objective of this study was to evaluate the effects of lactic acid bacteria (LAB) inoculants on fermentation quality and subsequent in vitro gas production, ruminal fermentation parameters, cellulolytic bacteria and their activities of alfalfa silage. Primary growth of alfalfa (Medicago sativa L.) was harvested at 50% flowering stage, inoculated without (control) or with Lactobacillus plantarum, Enterococcus mundtii and Enterococcus faecalis at 1.0 × 106 cfu/g of fresh weight (FW) in quadruplicate laboratory silos for 45 d. The silage inoculated with LAB were well preserved, indicated by the lower (p < .05) pH and ammonia-N content and the higher (p < .05) dry matter (DM), organic matter (OM), crude protein and lactic acid contents than the control silage. In vitro asymptotic gas and total volatile fatty acids production were higher in all LAB-treated silages (p < .05). All inoculants increased carboxymethyl-cellulase and β-glycosidase activities, and obtained higher DM and neutral detergent fibre degradability (p < .05) except E. mundtii. Similarly, L. plantarum and E. faecalis inoculants had higher (p < .05) Ruminococcus albus and Fibrobacter succinogenes relative proportions than the control. However, L. plantarum inoculants had lower (p < .05) percentage of methane (CH4) in 72 h gas production than the control and E. faecalis inoculants. These results suggested that L. plantarum were more effective in enhancing alfalfa silage utilisation by promoting forage digestibility and reducing ruminal CH4 emission than E. mundtii and E. faecalis. HIGHLIGHTS Lactic acid bacteria (LAB) inoculants improved alfalfa silage quality. Silage treated with Lactobacillus plantarum or Enterococcus mundtii increased gas production but reduced the percentage of methane in vitro. L. plantarum and Enterococcus faecalis promoted neutral detergent fibre digestibility by increased rumen cellulolytic bacteria proportion and cellulase activity.

Study on the bacterial community structure and fermentation characteristics of fresh and ensiled paper mulberry.

Two experiments were conducted to investigate the bacterial community of fresh and ensiled paper mulberry prepared with or without lactic acid bacteria (LAB) inoculants in South China. In Experiment 1, the bacterial community, chemical composition, and fermentation products of paper mulberry were analyzed. The results showed that fresh paper mulberry had high crude protein content, buffering capacity value, and amounts of uncultured bacteria. Ensiled paper mulberry showed poor fermentation with high pH value, ammonia-N content, and butyric acid content. In addition, Enterobacter was the dominant genus in silage, followed by Lactobacillus and Enterococcus. Water-soluble carbohydrates, ammonia-N, propionic acid, pH, and lactic acid (LA) were the main factors affecting bacterial community of silage. In Experiment 2, the BP17 (Lactobacillus plantarum) from natural fermented paper mulberry silage and two commercial inoculants (Silage-help [SH] and Chikuso-1 [CH]) were used as additives. Compared with other treatments, BP17 inoculant decreased (p < 0.05) pH and ammonia-N content and increased (p < 0.05) LA content of silage. Inoculation of BP17 also increased the dominance of desirable Lactobacillus and inhibited the growth of harmful bacteria in silage. These results confirmed that paper mulberry could be ensiled and epiphytic LAB inoculant can improve its fermentation quality.

Silage Additives Usage in Improving Fermentation Quality of Alfalfa Silage: A Review

Alfalfa is difficult to ensile due to its high protein content, low water-soluble carbohydrate level, low dry matter content, and high buffering capacity. Therefore, alfalfa has recently increased its efforts to make silage with additives. Silage additives have been used to enhancing the silage quality of alfalfa in recent years. This review covers research studies that have investigated the efficacy of silage additives on fermentation quality, the bacterial diversity of alfalfa silage using the Next-Generation Sequencing (NGS) technique, the effects of microbial inoculant on these bacterial communities, silage's antioxidant enzymes, and unsaturated fatty acid levels. In recent studies, more clear information about bacterial communities in silage fermentation has begun to be obtained with the use of NGS technique. In studies using these techniques, it was reported that lactic acid bacteria (LAB) organic acid additions to alfalfa silage caused Lactobacillus, Pediococcus and Sporolactobacillus species to increase relatively in silage environment, the ratio of unwanted species decreased and silage quality increased. Although the amount of alpha-tocopherol, and beta carotene decreased by half in pure silage compared to fresh alfalfa, it was observed that LAB inoculation increased the ratio of alpha tocopherol, beta carotene and also polyunsaturated fatty acids. Future silage additives are expected to determine effects fermentation quality, the bacterial community, the antioxidant enzymes, and unsaturated fatty acid levels.

Effect of Ensilage of Rye Treated with Formic Acid and Lactic Acid Bacteria Inoculant on Ruminal Fermentation Characteristics

Effect of Ensilage of Rye Treated with Formic Acid and Lactic Acid Bacteria Inoculant on Ruminal Fermentation Characteristics

111 Pathogenic Bacterial Levels in US Silages

Abstract Fresh forage crops have traditionally been preserved by fermentation, either based on the spontaneous fermentation by epiphytic lactic acid bacterial populations or driven by the addition of lactic acid bacteria inoculant cultures. Although this method of preservation is effective at retarding the spoilage and pathogenic bacteria it does not eliminate these organisms from the forage. Spore-forming and other bacteria are often able to survive the low pH and organic acid levels in the fermented forages and outgrow during feed-out and in the animal. The purpose of this research was to understand the levels and diversity of pathogens in silage systems as an important prerequisite to develop effective ways to control them. From February 2016 to December of 2019, 866 corn silage samples and 577 haylage samples were collected from 457 US dairy farms across 27 states to assess the pathogenic levels in silage. Results indicate the clostridia levels in the haylage samples averaged 9.4 x 103 cfu/g with a range of less than 10 cfu/g to 4.1 x 106 cfu/g. Corn silage had a significantly lower level of clostridia (p&amp;lt;0.05) averaging 2.3 x 103 cfu/g. Clostridium perfringens was the dominant species identified in both haylage and corn silage and accounted for more than 60% of all the clostridia isolates. The other major clostridia species identified were C. beijerinckii, Paraclostridium bifermentens and C. butyricum. E. coli levels were also determined in the haylage and corn silage samples. In haylage, the average E. coli level was 2.1 x 104 cfu/g and ranged from less than 10 cfu/g to 2.5 x 106 cfu/g and were significantly higher (p&amp;lt;0.05) than levels detected in corn silage (average of 5.4 x 101 cfu/g). Further work is underway to determine the source of these pathogens and methods of controlling through the fermentation process.

Effect of Lactic Acid Bacteria on the Nutritive Value and In Vitro Ruminal Digestibility of Maize and Rice Straw Silage

A study was conducted to determine the effects of lactic acid bacteria (LAB) on nutritive value and in vitro rumen digestibility of maize and rice straw silages. Two identical experiments were carried out for each of the two silages. A total of five treatments were used for each experiment: (1) negative control (NC); (2) positive control (PC); (3) Lactobacillus plantarum (LPL); (4) L. paracasei (LPA); and (5) L. acidophilus (LA). Each treatment was then divided into four ensiling periods: 3, 7, 20, and 40 days with three replications. The LPL treatment had significantly higher dry matter (DM), lower ammonia-N, and a lower number of fungi on maize silage after 40 days (p &lt; 0.05). On the other hand, the LA treatment increased DM and CP content, reduced NDF and ADF contents compared to NC, and also produced more lactic acid compared to the other LAB-treated rice straw silages. Results of the in vitro rumen fermentation of maize silages showed no significant differences in DMD after LAB inoculation. However, higher DMD and ruminal ammonia-N were shown by rice straw ensiled with L. acidophilus. In conclusion, silage additives, which could improve the ensiling process of maize and rice straw, appeared to be different and substrate specific.

Effect of a low temperature tolerant lactic acid bacteria inoculant on the fermentation quality and bacterial community of oat round bale silage

The objective of this study was to investigate the effect of a low temperature tolerant lactic acid bacteria (LAB) inoculant on the fermentation characteristics and bacterial community of oat silage. Oats were harvested at the flowering stage and wilted to dry matter content of approximately 270 g/kg fresh weight. Wilted and chopped oats were used to make mini round bale silages. Silages were prepared without (control) or with a low temperature tolerant LAB inoculant including Lactobacillus plantarum BP18, Pediococcus pentosaceus HS1 and L. buchneri LP22 and then separately stored at different geographic locations (L, Chengdu Plain; H, Qinghai Tibetan Plateau) for 120 days. High contents of water soluble carbohydrate (WSC), crude protein (CP), neutral detergent fiber (aNDF) and acid detergent fiber (ADF) were found in LAB inoculated silage. Inoculation with LAB increased (P < 0.05) lactic acid and acetic acid contents, and decreased (P < 0.05) the final pH of silage stored at the H location. However, LAB inoculation reduced (P < 0.05) the bacterial operational taxonomic units (OTUs), richness index (Chao 1) and diversity index (Shannon) of silage stored at the L location. The dominant genera from silage samples were Lactobacillus, Leuconostoc and Clostridium, with a total relative abundance of 71∼93 %. LAB inoculation increased the abundance of desirable Lactobacillus and inhibited the growth of undesirable Clostridium in silage. Therefore, inoculation of low temperature tolerant LAB at ensiling could stimulate favorable fermentation and reconstruct the bacterial community for better preservation of high moist oat silage nutrients.

Microbiological and Physicochemical Qualities of Moo Som (Traditional Thai Fermented Meat) Inoculated with Lactic Acid Bacteria Starter

The effects of different strains of lactic acid bacteria (LAB) inoculation on the fermentation rates and qualities of moo som, a traditional Thai fermented pork, were evaluated. Lactobacillus plantarum KL102 (spontaneous starter) and L. plantarum TISIR543 (commercial starter) were used as starter cultures in the production of moo som. The decreased amounts of Staphylococcus aureus and coliforms in moo som inoculated with L. plantarum KL102 were at faster rates than those in Moo som inoculated with L. plantarum TISIR543. However, the final products of moo som inoculated with both LAB starters did not find S. aureus or and coliform loadings. Inoculation of both LAB starters could control growth of yeast in samples during fermentation. Furthermore, both starter cultures exhibited a higher rate of fermentation than the control (without inoculum), as demonstrated by the faster rate pH drop and acid production (p &lt; 0.05) during fermentation, while the fermentation of all samples were completed within 3 d. Due to higher acid production rate, texture, and especially hardness, gumminess and chewiness of inoculated moo som were higher than control moo som in the final products (p &lt; 0.05). From the results, the inoculation of LAB starter was more beneficial in color and in overall sensory evaluation (p &lt; 0.05). The overall quality was positively correlated with the color, odor, and texture of moo som (p &lt; 0.01). Based on microbiological and physicochemical qualities and sensory evaluation, KL102 is a potential LAB starter for moo som production.

Effects of combining two lactic acid bacteria as a starter culture on model kimchi fermentation

This study aimed to establish a mixed starter culture to standardize the flavor of kimchi, a traditional Korean food. Leuconostoc mesenteroides and Lactobacillus sakei were selected for the culture based on their key roles in kimchi fermentation. The effects of various starter culture mixing ratios on the overall fermentation process were investigated. Fermentation was carried out at 15 °C for 72 h. In the microbial community analysis, a similar ratio to the initial mixed inoculated ratio was observed in the microbial environments. Treatment with high-rate L. mesenteroides inoculation, exhibiting hetero-fermentative characteristics, led to the production of mannitol (1393.11 mg/100 g), acetic acid (57.70 mg/kg), and lactic acid (1141.90 mg/kg), in addition to the induction of a rapid increase in the number of viable cells, thereby reducing the pH (pH 3.9). Conversely, treatment with high-rate L. sakei inoculation, exhibiting homo-fermentative characteristics, led to the production of less mannitol and acetic acid, with more lactic acid. Principal component analysis score plots showed a distinct difference in kimchi metabolites depending on the lactic acid bacteria (LAB) starter culture. Therefore, by using mixed LAB starter strains, this study demonstrated the value of various characteristics and standardized manufacturing of kimchi. LAB types and inoculation ratios greatly affected the types and concentration of metabolites in kimchi fermentation.

Evaluation of the bioprotectivity of Lactobacillus binary/ternary cultures in yogurt.

The attempts toward addition of biocontrol agents in dairy products have gained popularity. Here, we worked on analysing the antifungal activity of binary and ternary combinations of three Lactic Acid Bacteria (LAB) against five spoilage yeasts in yogurt. The yogurt samples were characterized in terms of pH, acidity, WHC, textural parameters, viscosity, survivability and antifungal activity of LAB and sensorial properties during cold storage. The results showed that the inoculation of LAB in yogurt gave rise in significant reduction of pH throughout cold storage while titrable acidity and WHC decreased (p < .05). Inoculation of LAB resulted in significant increase in hardness and adhesiveness while springiness remained constant. On the other hand, apparent viscosity of all samples experienced a profound increase up to the 10th day of storage followed by a reduction trend for the rest of storage period. Analysis of inhibitory activity of LAB showed an efficient barrier against all five yeasts, in which the most activity was recorded for Lactobacillus reuteri followed by Lactobacillus acidophilus. On the other hand, the most resistance yeast was Kluyveromyces marxianus followed by Rhodotorula mucilaginosa. Sensorial analysis revealed that addition of LAB in yogurt brought about a profound improvement in textural quality of samples. Inoculation of LAB cultures in yogurt at 5% (v/v) not only could improve the physicochemical and sensorial properties of yogurt, but also could introduce a strategy toward substituting of chemical preservatives with biocontrol agents.

Fermentation of barley and wheat with lactic acid bacteria and exogenous enzyme on nutrient composition, microbial count, and fermentative characteristics

Characteristics of wheat and barley inoculated with a homo-fermentative (HO) or hetero-fermentative (HE) lactic acid bacteria (LAB) were investigated in separate 97 d studies conducted using a 3 × 2 factorial arrangement comparing inoculants (no inoculant, HO or HE) and multi-enzyme (no or yes) addition. The pH declined (P &lt; 0.05) to below 4.5 by day 6, coinciding with peaks in lactobacilli and yeast counts. A more rapid decline (P &lt; 0.05) in pH and lactobacilli count but higher (P &lt; 0.05) yeast count was observed with HO relative to HE. Enzyme addition reduced pH in inoculated grains only, particularly with HE (inoculant × enzyme effect; P &lt; 0.05). Higher dry matter losses (P &lt; 0.05) were observed with HE, most apparent in barley. Lactate was generally highest in HO and was increased by enzyme addition. Acetate was higher (P &lt; 0.05) in HE. Ethanol and ammonia were lowest (P &lt; 0.05) in HO. Wheat neutral detergent fibre (NDF) was reduced by both inoculants compared with control, whereas enzyme addition reduced NDF content in both grains. In conclusion, although not marked, fermentation responses appeared greater in wheat than barley although either LAB inoculant improved grain fermentation characteristics. The multi-enzyme appeared active during fermentation.

Effects of citric acid residue and lactic acid bacteria on fermentation quality and aerobic stability of alfalfa silage

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. Highlights 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.