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1.
The traditional process for the retting of melon pulp and microbiological characteristics in the recovery of melon seeds ( Colocynthis citrullus L.) were investigated. Melon pods were sliced open and exposed for seven days. The pulp underwent a natural fermentation that was characterised by the growth of microorganisms to 108–1010 cfu/g. The pH fluctuated between 4.8 and 5.1 with a lactic acid content of 0.72%. Bacillus subtilis, B. polymyxa, Lactobacillus fermentum, L. brevis and Streptococcus faecalis were the predominant microorganisms but, significant contributions were made by Staphylococcus saprophyticus and Enterobacter cloacae. Penicillium, Aspergillus and Rhizopus species including the yeasts, Sacharomyces cerevisiae Candida krusei and Deboromyces hansenii were isolated from the fermentation. Growth of microorganisms was completely inhibited in antibiotic-treated samples indicating that the melon pods were the main source of microorganisms for the fermentation. 相似文献
2.
Silages were made from the first cut of a predominantly perennial ryegrass sward. The silages were either untreated (W) or treated with formic acid (31 t−1 , F) or with 106 lactic acid bacteria (LAB) g−1 grass of each of three strains alone (A. Lactobacillus plantarum MTD1; B, Pediococcus species 6A2; C, L. plantarum 6A6) or in combination (AB. AC) to give seven treatments. The silage fermentation in 10-kg silos was followed chemically and microbiologically and the nutritive value of selected treatments evaluated using 2-t silos.
The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.
When fed to sheep, the intake of the formic acid-treated silage was significantly ( P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly ( P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter ( P < 0·001) and nitrogen ( P < 0·01) digestibilities of the formic acid-treated silage were also significantly lower than those of the other silages. 相似文献
The control silage (W) fermented well. Addition of formic acid restricted fermentation and produced a silage with a high ethanol concentration. After day 4, all inoculated silages had lower pH values and higher lactic acid concentrations and a higher ratio of lactic acid to acetic acid than the control silage. Chemically there was little difference between the inoculated silages in terms of final composition. Microbiologically the LAB applied in treatments B and C dominated the LAB populations in those silages when applied alone; however, they were suppressed when applied in combination with inoculant A.
When fed to sheep, the intake of the formic acid-treated silage was significantly ( P < 0·01) lower than that of the other silages and the intake of silage treated with inoculant A significantly ( P < 0·001) higher than that of silages treated with inoculants B and C. The apparent organic matter ( P < 0·001) and nitrogen ( P < 0·01) digestibilities of the formic acid-treated silage were also significantly lower than those of the other silages. 相似文献
3.
《Industrial Crops and Products》2000,11(2-3):129-137
Grass, clover and alfalfa are used for production of fodder pellets. In the green crop drying factories in the northern countries the drying is combined with pressing of the green crops resulting in production of large volumes of plant juices, green and brown juice. In order to get rid of these enormous amounts of plant juice, representing an environmental threat, it is our aim to convert the simple drying industry to a whole crop utilisation factory, a green biorefinery, where the plant juice can be used as raw material in a fermentation process. As the plant juice is very unstable, it has been necessary to develop a method for both conservation and utilisation of the juice. The plant juice is converted to a nice universal fermentation medium by lactic acid bacteria. A number of lactic acid producing strains have been tested. Among the most productive strains, Lactobacillus paracasei ssp. paracasei P4155 is found to be the most effective in utilising fructans and citric acid. Most carbohydrates and organic acids in the juice can be converted to lactic acid by two homofermentative lactobacilli. The highest lactic acid yield and productivity is reached when using not-heat sterilised brown or green juice as the fermentation medium. The amount of free amino acids in the juice is increased and the content of vitamins and other important growth factors kept unspoiled by the lactic acid fermentation. The fermented juice can be stored as it is or evaporated to a concentrated form and used in fermentation industries for production of amino acids, organic acids, enzymes etc. 相似文献
4.
Effects of different additives on fermentation quality and aerobic stability of Leymus chinensis silage 
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下载免费PDF全文 This study investigated the effects of different additives on fermentation quality and aerobic stability of Leymus chinensis silage. Treatments included (i) no additive, (ii) 3 mL kg?1 formic acid (FA), (iii) 6 mL kg?1 FA, (iv) 5 mL kg?1 acetic acid (AA), (v) 10 mL kg?1 AA, (vi) 2 mL kg?1 propionic acid (PA), (vii) 4 mL kg?1 PA, (viii) 5 mL kg?1 butyric acid (BA), (ix) 10 mL kg?1 BA, (x) 1.0 g kg?1 potassium sorbate (PS), (xi) 1.0 g kg?1 sodium benzoate (SB), (xii) 1 × 108 colony‐forming units (cfu) kg?1 Lactobacillus (Lb) plantarum LP (LP), (xiii) 1 × 108 cfu kg?1 Lb. brevis LB (LB) and (xiv) 1 × 108 cfu kg?1 Lb. buchneri NCIMB40788 (Fresh). Each additive treatment was based on fresh matter (FM). Results showed that all additives decreased pH values. All additives except Fresh decreased ammonia‐N content (p < .001). Both LP and LB increased lactic acid content (p < .001). Butyric acid content increased with FA (3 mL kg?1) and BA, but decreased with PA, PS, SB, FA (6 mL kg?1), AA, LP, LB (p < .001). FA (3 mL kg?1), AA (10 mL kg?1), PA, BA, PS, SB and Fresh improved aerobic stability (p < .001). After 8 days exposure to air, the pH value and yeast count were lower in FA (3 mL kg?1), BA (10 mL kg?1), SB treatments than in other treatments. Overall, AA outperformed all other additives in improving fermentation quality. Sodium benzoate and AA could be used as an effective additive to improve aerobic stability of L. chinensis silage. 相似文献
5.
The effects of stage of growth and additives with or without cellulase on fermentation and in vitro degradation characteristics of Leymus chinensis silage 下载免费PDF全文
下载免费PDF全文 This study evaluated the effects of different combinations of added lactic acid bacteria and cellulase applied at two growth stages on chemical composition and in vitro rumen digestibility of Leymus chinensis silage. Fresh grass was harvested at early heading stage (S1) and late heading stage (S2), respectively, and ensiled with five additives: 200 U cellulase (C) kg?1 fresh matter (FM), 1 × 105 colony‐forming units (cfu) Lactobacillus plantarum (LP) g?1 FM, 1 × 105 cfu Lb. casei (LC) g?1 FM, LP+C, LC+C and a control (CK). Four replicates of each treatment were weighed into 5‐L plastic buckets, and the mini silos were stored at ambient temperature (~30°C) for 60 d. Leymus chinensis harvested at S2 showed relatively higher neutral detergent fibre content, coliform bacteria count and lower crude protein content than S1. All additives decreased the pH and ammonia nitrogen (NH3‐N) content of L. chinensis silage (P < 0·001) except C. LP+C and LC+C decreased fibre content and increased water‐soluble carbohydrate content (P < 0·001). The silages were further anaerobically incubated in vitro at 39°C for 48 h with buffered rumen fluids of lactating cows. Leymus chinensis harvested at S2 showed lower in vitro dry‐matter disappearance, NH3‐N, total volatile fatty acid (VFA) content and higher average gas production rate (P < 0·05) than S1. In conclusion, Leymus chinensis should not be harvested too late. Compared with other treatments, a combination of Lb. casei (LC) with cellulase resulted in better fermented silage, but further testing is needed to confirm its efficacy. 相似文献
6.
The microorganisms associated with fermented African oil bean (Pentaclethra macrophylla Bentham) seed during ugba production was studied. Only bacteria were isolated from the ugba samples used. Although the bacteria included Bacillus spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp. and members of the family Enterobacteriaceae, only the Bacillus spp. were found to ferment African oil bean seeds to ugba. Bacillus spp. were the predominant microorganisms present, constituting over 95% of the total microbial population density. An increase in the number of Bacillus cells of about 2 log units daily, which attained a maximum density of log10 9.00 - log10 11.90 cfu/g after 3 days was observed. Contrarily, the Lactobacillus spp. increased minimally and attained a maximum value of log10 4.20 - log10 6.35 cfu/g within the same period. The Staphylococcus spp., Micrococcus spp. and the members of the family Enterobacteriaceae remained fairly steady in number for 24h, increased slightly till the 3rd day followed by exponential increases which attained maximum values of between log10 9.20 - log10 11.00, about the 7th day. Bacillus spp. cells also had the highest protease activities which were significantly (p < 0.05) higher than the values for the other bacterial isolates. The Bacillus spp. responsible for the fermentation of African oil bean seeds to ugba were identified as Bacillus coagulans, B. macerans, B. megaterium, B. pumilis and B. subtilis. 相似文献
7.
Vamanu A Vamanu E Popa O Câmpeanu G Albulescu R Drugulescu M Niţã S Bâbeani N 《Pakistan journal of biological sciences: PJBS》2008,11(4):613-617
This study presents the evolution of a Lactobacillus plantarum 2s strain and of a Lactobacillus acidophilus 1a strain on media containing pollen and honey. The following parameters were determined: CFU value, lactic acid production, sugar consumption and presentation of the final product. The researches were performed during 72 h, in tightly closed recipients, at a temperature of 37 degrees C, containing various quantities of milled or non-milled pollen (P1: 20 g non-milled pollen, 3 g honey, 5 mL distilled water; P2: 20 g milled pollen, 3 g honey, 5 mL distilled water; P3: 20% non-milled pollen, 3% honey; P4: 20% milled pollen, 3% honey). The media were very well homogenized before inoculation. The inoculation was made only after the medium gained a homogenous consistency. The inoculum consists of a 48 h culture of Lactobacillus plantarum 2s and Lactobacillus acidophilus, on LE medium, in equal proportions. The testing of the nutritive value of the symbiotic product was made on wistar rats, males and females, divided into lots of 10 animals each. The animals were administered symbiotic product every day, in their food, in intakes of 2 mg kg(-1) (lot I), 20 mg kg(-1) (lot II) and 200 mg kg(-1) (lot III), compared to a control. During the 4 weeks of the experiment, no lethality cases were recorded in any of lots, or in control. The animals involved in the experiment were examined daily and did not present changes of appetite, of behavior or clinical signs of disease. 相似文献
8.
Study was carried out to determine the spoilage association of traditionally fermented ugba, product of African oil bean seed. Samples were collected from three markets within Enugu metropolis in Eastern Nigeria. Microbial population of ugba was isolated, characterized and identified. Effect of time on product quality, total viable cell count and individual growth pattern of isolates was evaluated. Microorganisms isolated were Proteus sp., Klebsiella sp., Staphylococcus epidermidis, E. coli, Bacillus licheniformis and Bacillus subtilis. Initial viable cell count increased from 4.6 x 10(8) -6.2 x 10(8), 6.0 x 10(9) -6.9 x 10(9) and 3.9 x 10(8) -5 x 10(8) cfu g(-1) by the 4th day for samples from Mayor, Kenyatta and Garki markets, respectively. Organoleptic changes in texture and colour were seen to be a factor of time of storage. A decline in growth of Proteus sp., E. coli, Klebsiella sp. and S. epidermidis by the 4th day of storage was observed for all samples. Viable cells of B. licheniformis increased from 6.1 x 10(7) -17.7 x 10(7) cfu g(-1), 13.9 x 10(8) -20.0 x 10(8) and 8.7 x 10(7) -15.5 x 10(7) by the 4th day of storage for samples from Mayor, Kenyatta and Garki markets respectively. Growth of B. subtilis increased from 9.2 x 10(7) -19.9 x 10(7), 14.9 x 10(8) -21.2 x 10(8) and 11.5 x 10(7) -17.2 x 10(7) cfu g(-1) for samples from Mayor, Kenyatta and Garki markets respectively. Our results indicate that ugba spoilage is primarily a result of the continued activity of African oil bean seed fermentative organisms B. subtilis and B. licheniformis. 相似文献
9.
Qiang Wang Liuliu Su Xuerong Fan Jiugang Yuan Li Cui Ping Wang 《Fibers and Polymers》2009,10(3):333-337
Two types of lipases, L3126 and Lipex 100L, were used to modify the surface of poly(lactic acid) (PLA) fiber by measuring
weight loss percentage and wettability of the fiber in this work. The influence factors were discussed and optimized based
on single-factor experiments. The optimal conditions for the modification of poly(lactic acid) fiber with lipases were determined
as follows: incubation with lipase L3126 of 0.5 g/l at 45 °C and pH 8.5 for 8 hours and incubation with lipase of 10 ml/l at 40 °C and pH 7.5 for 10 hours. Lipase L3126 showed higher biodegradation ability to poly(lactic acid) fiber than lipase
Lipex 100L. The scanning electron microscopy confirmed that both of the two lipases could lead to the formation of etching
characters on treated poly(lactic acid) fibers in comparison with the blank samples. Furthermore, the wettability of the fibers
treated with the lipases was evidently improved, especially Lipase L3126. 相似文献
10.
Efficacy of Bacillus subtilis MBI 600 Against Sheath Blight Caused by Rhizoctonia solani and on Growth and Yield of Rice 总被引：1，自引：0，他引：1
K.VIJAY KRISHNA KUMAR S.KR.YELLAREDDYGARI M.S.REDDY J.W.KLOEPPER K.S.LAWRENCE H.SUDINI D.E.GROTH S.KRISHNAM RAJU M.E.MILLER 《水稻科学》2012,19(1):55-63
Rice sheath blight disease(ShB),caused by Rhizoctonia solani,gives rise to significant grain yield losses.The present study evaluated the efficacy of Integral?,the commercial liquid formulation of Bacillus subtilis strain MBI 600,against rice ShB and for plant growth promotion.In greenhouse studies,four log concentrations of Integral(from 2.2×106 to 2.2×109 cfu/mL) were used as seed treatment(ST).After 25 d,seedlings were dipped(SD) into Integral prior to transplanting.At 30 d after transplanting(DAT),leaf sheaths were inoculated with immature sclerotia of the pathogen.At 45 DAT,a foliar spray(FS) with Integral was applied to some treatments.The fungicide control was 50% carbendazim at 1.0 g/L,and a nontreated control was also included.Overall,there were 10 treatments,each with five replications.ShB severity was rated at 52 DAT,and seedling height and number of tillers per plant were rated at 60 DAT.In 2009,two field trials evaluated Integral at 2.2×108 and 2.2×109 cfu/mL.Integral was applied as ST,and seedlings were produced in a nursery bed.After 32 d,seedlings were treated with Integral as SD and transplanted into 10 m2 blocks.Foliar sprays were given at 45 and 60 DAT.There were seven treatments,each with eight replications arranged as a factorial randomized complete block design.At 20 DAT,the plots were broadcast inoculated with R.solani produced on rice grains.Seedling height before transplanting,ShB severity at 90 DAT,and grain yield at harvest were recorded.Integral at 2.2×109 cfu/mL provided significant increase of seedling heights over other treatments under greenhouse conditions.The Integral treatments of ST + SD + FS at 2.2×109 cfu/mL significantly suppressed ShB over other treatments.In field studies,Integral provided significant increase of seedling height in nursery,and number of tillers per plant,compared with the control.ShB severity was significantly suppressed with higher concentrations of Integral compared to lower concentrations.Grain yield were the highest at an Integral concentration of 2.2×109 cfu/mL.Overall,Integral significantly reduced ShB severity,enhanced seedling growth,number of tillers per plant and grain yield as ST + SD + FS at the concentration of 2.2×109 cfu/mL under the conditions evaluated. 相似文献
11.
Alan R. Langille K. L. Prouty W. A. Halteman 《American Journal of Potato Research》1993,70(10):735-741
In an attempt to improve nutritional qualities of the potato by exploiting variation associated with protoplast regeneration, Russet Burbank leaf protoplasts were cultured in cell layer (CL) medium containing the amino acid analog, 5-methyltryptophan (5-MT) at concentrations from 0 to 286 μM. At three day intervals, numbers of viable cells and dividing colonies were recorded to determine effects of 5-MT concentration on cell viability during the 14 day incubation period. Repeated count data were used in a computer program to construct survival profiles. Decline in cell populations was generally slight during the first 5 days in culture. Between day 5 and 11, survival rate dropped dramatically, averaging 10–12% per day regardless of concentration. As surviving cells began to divide, a leveling trend in the curves was noted between days 11 and 14. Reduced plating efficiency was only associated with the 103 and 286 μM treatments. No plants were regenerated from colonies exposed to 5-MT concentrations in CL greater than 34.4 μM nor were differences in free tryptophan found between tubers of protoclones and Russet Burbank. 相似文献
12.
Z. G. Weinberg G. Ashbell Y. Hen Y. Leshem† Y. S. Landau† I. Brukental‡ 《Grass and Forage Science》2002,57(2):184-187
Abstract The ensiling characteristics of safflower ( Carthamus tinctorius ) wilted to 290 and 411 g dry matter (DM) kg−1 fresh material were studied in 1·5 l glass jars. The experiment included a control and the application of Lactobacillus plantarum at 3·3 × 105 colony-forming units (cfu) per g of crop. After 60 days of ensiling, the pH of safflower silages was 4·6 and 4·0 in the control and inoculated silages respectively, with corresponding values for lactic acid, the major fermentation product, of 20 and 45 g kg−1 DM. The silages from the anaerobic jars were stable upon aerobic exposure. It is concluded the safflower silage has potential as an alternative fodder in semiarid regions. 相似文献
13.
Ramin M Alimon AR Panandam JM Sijam K Javanmard A Abdullah N 《Pakistan journal of biological sciences: PJBS》2008,11(4):583-588
The digestion and Volatile Fatty Acid (VFA) production from rice straw and oil palm fronds by cellulolytic bacteria isolated from the termite Coptotermes curvignathus were investigated. The bacteria were Acinetobacter strain Raminalimon, Enterobacter aerogenes strain Razmin C, Enterobacter cloacae strain Razmin B, Bacillus cereus strain Razmin A and Chryseobacterium kwangyangense strain Cb. Acinetobacter strain Raminalimon is an aerobic bacterium, while the other species are facultative anaerobes. There were significant differences (p<0.05) among the bacteria for Dry Matter (DM) lost and acetic acid production from rice straw and Acinetobacter strain Raminalimon showed the highest activity. The facultative bacteria C. kwangyangense strain Cb (cfu mL(-1) 231 x 10(-6), OD: 0.5), E. cloacae (cfu mL(-1) 68 x 10(-7), OD: 0.5) and E. aerogenes (cfu mL(-1) 33 x 10(-7), OD: 0.5) were used for digestion study with the rumen fluid microflora. The in vitro gas production technique was applied for the comparative study and the parameters measured were pH, gas (volume), dry matter lost, acetic acid, propionic acid and butyric acid concentrations. pH was not significantly (p<0.05) different among the five treatments. The bacterium C. kwangyangense strain Cb showed the highest activity (p<0.05) for DM lost, acetic acid, propionic acid and butyric acid production from rice straw when compared to the other bacterial activities. There was no significance (p<0.05) difference between the three bacteria for the dry matter lost of oil palm fronds but the production of Volatile Fatty Acids (VFA) was significantly (p<0.05) high in the treatment which was inoculated with C. kwangyangense strain Cb. The Gen Bank NCBI/EMBL accession numbers for the bacterial strains are EU332791, EU305608, EU305609, EU294508 and EU169201. 相似文献
14.
内生解淀粉芽孢杆菌TB2液体发酵条件的研究 总被引：3，自引：0，他引：3
采用单因素试验和正交试验对具有广谱拮抗作用的内生解淀粉芽孢杆菌TB2菌株的摇瓶发酵培养基和发酵条件进行优化。结果表明,最佳培养基组份为:玉米淀粉1.0%、豆粉1.0%、(NH4)2SO40.5%、MgSO4·7H2O0.1%、FeSO4·7H2O0.03%、K2HPO4·3H2O0.02%、KH2PO40.01%;培养条件为:初始pH值为7.5,温度35℃,接种量3%,装液量50mL/250mL三角瓶,摇床转速200r/min,发酵周期22～26h。优化条件下发酵水平活菌数达到8.52×1010cfu/mL。 相似文献
15.
Although many aspects of grass silage have received intensive study, the changes that take place within the grass blades during ensilage have received little attention.
In two factorial experiments Italian ryegrass (cv. Lemtal) and cocksfoot (indigenous) were ensiled in laboratory silos (capacity 0·2 kg) with the grass under pressure (700 Pa) and subjected to two treatments (with or without 3·31 t-1 85% formic acid) and two silos from each treatment opened on eight sampling dates(1,2,3,4,7,10,14 and 21 d).
For each sampling date transverse sections of grass laminae were examined and changes in the cross sections of the protoplasts and of cells, as defined by the cell walls, were recorded. These data were used to calculate the ratios of protoplast to cell volumes at each sampling date.
Each silage was analysed for dry matter, pH, lactic acid, VFA, ammonia and glucose. The distance settled by the silage (a measure of decrease in silage volume) and the silage conductivity were also recorded.
Both of the untreated grasses yielded silages with typical lactic acid levels and pH values. In all of the silages there was a marked shrinkage of the plast within the space defined by the cell wall. The ratio of protoplast to cell volume eventually stabilized at 0·4. The formic acid-treated grasses reached this level by day 1 but a longer period was required by untreated grasses.
It is suggested that the decrease in silage volume is related to the lactic acid content of the liquid phase due to their close relationship in silages produced from untreated grasses ( r = 0·97***). 相似文献
In two factorial experiments Italian ryegrass (cv. Lemtal) and cocksfoot (indigenous) were ensiled in laboratory silos (capacity 0·2 kg) with the grass under pressure (700 Pa) and subjected to two treatments (with or without 3·31 t
For each sampling date transverse sections of grass laminae were examined and changes in the cross sections of the protoplasts and of cells, as defined by the cell walls, were recorded. These data were used to calculate the ratios of protoplast to cell volumes at each sampling date.
Each silage was analysed for dry matter, pH, lactic acid, VFA, ammonia and glucose. The distance settled by the silage (a measure of decrease in silage volume) and the silage conductivity were also recorded.
Both of the untreated grasses yielded silages with typical lactic acid levels and pH values. In all of the silages there was a marked shrinkage of the plast within the space defined by the cell wall. The ratio of protoplast to cell volume eventually stabilized at 0·4. The formic acid-treated grasses reached this level by day 1 but a longer period was required by untreated grasses.
It is suggested that the decrease in silage volume is related to the lactic acid content of the liquid phase due to their close relationship in silages produced from untreated grasses ( r = 0·97***). 相似文献
16.
Aderiye B. I. Ogunjobi A. A. 《Plant foods for human nutrition (Dordrecht, Netherlands)》1998,52(1):49-54
The microflora of white yam ( Dioscorea rotundata L.) slices fermented anaerobically in 1.5 percent brine for five days at room temperature were studied. The hydrolysis of the carbohydrate and the subsequent conversion of sugars and minerals by the fermenting microbes contributed much to the increased microbial load especially within the first 72 hours of fermentation. The organisms implicated in the fermentation include the species of Pediococcus, Lactobacillus and Pseudomonas, Bacillus subtilis and two other Gram negative coccal cells, yet to be identified. The decrease in microbial counts at the latter stage of fermentation was attributed to the high total acidity of the medium, which was about 2.67 times the initial value of 0.027% lactic acid. Meanwhile, the lactic acid bacteria increased continuously throughout the period of fermentation. 相似文献
17.
Gomathy M Thangaraju M Gunasekaran S Gopal NO Gopal H 《Pakistan journal of biological sciences: PJBS》2008,11(1):86-91
The survival of vegetative and sporulated cells of the Bacillus cultures on the seeds of the crop plants was tried in different combinations. One milliliter inoculum with 1 mL adhesive combination or sterile water showed better results followed by 1.5 mL inoculum with 0.5 mL adhesive or sterile water. The population of 5.5x10(5) cfu seed(-1) on black gram, 10.5x10(5) cfu seed(-1) on soybean and 6.5x10(5) cfu seed(-1) on maize were observed after 12 h of incubation in 1 mL sporulated inoculum mixed with 1 mL of rice gruel. The sporulated inoculum along with rice gruel favoured the adherence of the regenerated cells as rice gruel is rich in nutrient content. 相似文献
18.
Evangelos S. Lazos George Aggelousis Michael Bratakos 《Plant foods for human nutrition (Dordrecht, Netherlands)》1993,44(1):45-62
The fermented food, trahanas (a milk-wheat flour combination prepared in Greece), was studied to determine the microbiological and chemical changes that occur during fermentation. It is a lactic acid bacterial fermentation in whichStreptococcus lactis, Streptococcus diacetylactis, Leuconostoc cremoris, Lactobacillus lactis, Lactobacillus casei, Lactobacillus bulgaricus andLactobacillus acidophilus play the major acid- and aroma-producing role. The whole fermentation lasts about 50 hours. The pH of the final dried trahanas was 4.07–4.75, the acidity 0.60–1.00%, the moisture content 8.6–11.5% and the protein content 10.4–13.6%. The product offers possibilities as an increased nutritive value or high-protein food. 相似文献
19.
The effect of adding Lactobacillus buchneri 40788, a heterofermentative lactobacilli, to whole‐plant maize and its effect on fermentation and aerobic stability of the resulting silage were evaluated. Whole‐plant maize (380 g DM kg–1 fresh weight) was ensiled in laboratory silos after the following treatments: untreated, L. buchneri 40788 at 1 × 105, 2·5 × 105, 5 × 105, and 1 × 106 colony forming units g–1 of fresh forage or, a commercial inoculant containing homolactic acid bacteria, a single species of propionibacteria and enzymes. Addition of L. buchneri 40788 resulted in a decrease in lactic acid concentration but increased the concentration of acetic acid in silage and markedly decreased the numbers of yeasts present in the silage. All levels of L. buchneri 40788, increased the aerobic stability of silages but the effect was greatest for the two highest levels of inoculation. Treatment with the commercial inoculant had no effect on the fermentation or aerobic stability of silage. On‐farm treatment of maize silage with L. buchneri 40788, stored in a bag silo, resulted in changes in fermentation that were similar to those observed in laboratory silos. Treatment decreased the numbers of yeast in silage and increased aerobic stability (+25 h) of the silage when exposed to air. Treatment had no effect on the dry‐matter intake of silage fed to sheep. These results showed that treating silage with L. buchneri 40788 can increase the aerobic stability of maize silage in laboratory and farm silos. 相似文献
20.
Nicoline Vermeulen Michael Czerny Michael G. Gänzle Peter Schieberle Rudi F. Vogel 《Journal of Cereal Science》2007
(E)-2-Nonenal and (E,E)-2,4-decadienal are key aroma compounds in wheat bread crumb. The fate of these unsaturated aldehydes in sourdoughs fermented with homo- and heterofermentative lactobacilli or baker's yeast was investigated, and the metabolic pathways in these microorganisms identified. Clear differences were observed between homofermentative lactobacilli, heterofermentative lactobacilli and Saccharomyces cerevisiae. Heterofermentative strains rapidly reduced the concentrations of these aldehydes in dough, whereas S. cerevisiae displayed a lower activity. Lactobacillus sanfranciscensis reduced the aldehydes to the corresponding unsaturated alcohols, whereas S. cerevisiae reduced both the aldehyde moiety and the double bond, resulting in the formation of the corresponding saturated alcohols. S. cerevisiae first reduced the aldehyde moiety and then the double bond. In L. sanfranciscensis, the reduction of aldehydes is coupled to the oxidation of NADH to NAD+, which enables this heterofermentative strain to produce additional ATP from glucose. L. sakei, a strain that produces only lactic acid during sourdough fermentation, did not metabolise the unsaturated aldehydes at all. Both L. sakei and S. cerevisiae appeared to enhance aldehyde formation during the first hours of dough fermentation, probably due to the hydrogen peroxide production by these two strains. 相似文献