Effect of temperature on continuous fermentative lactic acid (LA) production and bacterial community, and development of LA-producing UASB reactor

2012 ◽  
Vol 119 ◽  
pp. 355-361 ◽  
Author(s):  
Dong-Hoon Kim ◽  
Wan-Taek Lim ◽  
Mo-Kwon Lee ◽  
Mi-Sun Kim
Keyword(s):  
Lactic Acid ◽  
Bacterial Community ◽  
Uasb Reactor ◽  
Effect Of Temperature

scholarly journals Dynamics of Fermentation Parameters and Bacterial Community in High-Moisture Alfalfa Silage with or without Lactic Acid Bacteria

2021 ◽  
Vol 9 (6) ◽  
pp. 1225
Author(s):  
Shanshan Zhao ◽  
Fengyuan Yang ◽  
Yuan Wang ◽  
Xiaomiao Fan ◽  
Changsong Feng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Community ◽  
Ph Value ◽  
Ammoniacal Nitrogen ◽  
High Concentration ◽  
High Moisture ◽  
Acid Accumulation ◽  
Alfalfa Silage ◽  
Fermentation Parameters

The aim of this study was to gain deeper insights into the dynamics of fermentation parameters and the bacterial community during the ensiling of high-moisture alfalfa. A commercial lactic acid bacteria (YX) inoculant was used as an additive. After 15 and 30 days of ensiling, the control silage (CK) exhibited a high pH and a high concentration of ammoniacal nitrogen (NH3-N); Enterobacter and Hafnia-Obesumbacterium were the dominant genera. At 60 d, the pH value and the concentration of NH3-N in CK silage increased compared with 15 and 30 d, propionic acid and butyric acid (BA) were detected, and Garciella had the highest abundance in the bacterial community. Compared with CK silage, inoculation of YX significantly promoted lactic acid and acetic acid accumulation and reduced pH and BA formation, did not significantly reduce the concentration of NH3-N except at 60 d, and significantly promoted the abundance of Lactobacillus and decreased the abundance of Garciella and Anaerosporobacter, but did not significantly inhibit the growth of Enterobacter and Hafnia-Obesumbacterium. In conclusion, high-moisture alfalfa naturally ensiled is prone to rot. Adding YX can delay the process of silage spoilage by inhibiting the growth of undesirable microorganisms to a certain extent.

Effect of temperature on bacterial community in petroleum hydrocarbon-contaminated and uncontaminated Antarctic soil

Polar Biology ◽  
2018 ◽  
Vol 41 (9) ◽  
pp. 1763-1775 ◽  
Author(s):  
C. W. Chong ◽  
S. Silvaraj ◽  
Y. Supramaniam ◽  
I. Snape ◽  
I. K. P. Tan
Keyword(s):  
Bacterial Community ◽  
Petroleum Hydrocarbon ◽  
Effect Of Temperature ◽  
Antarctic Soil

scholarly journals Microbial Community and Fermentation Characteristics of Native Grass Prepared Without or With Isolated Lactic Acid Bacteria on the Mongolian Plateau

2021 ◽  
Vol 12 ◽  
Author(s):  
Sihan You ◽  
Shuai Du ◽  
Gentu Ge ◽  
Tao Wan ◽  
Yushan Jia
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Community ◽  
Relative Abundance ◽  
Principal Coordinate Analysis ◽  
Water Soluble ◽  
Dry Matter Content ◽  
Mongolian Plateau ◽  
Native Grass ◽  
Grass Silage

This study aimed to isolate and identify lactic acid bacteria (LAB) from the native grass and naturally fermented silage from the Mongolian Plateau. The effect of selected strains on bacterial community and quality of native grass silage was also studied. Strains XM2, 265, and 842 could grow normally at 15°C–30°C, pH 4.0–8.0, and NaCl 3 and 6.5%; they were identified as Lactiplantibacillus plantarum subsp. plantarum, Pediococcus acidilactici, and Latilactobacillus graminis, by sequencing 16S rRNA, respectively. The three strains (XM2, 265, and 842) and one commercial additive (L) were used as inoculants and singularly added to the native grass. Compared to the control, the dry matter content was significantly (p < 0.05) lower in L and XM2 groups. The water-soluble carbohydrate content was significantly (p < 0.05) higher in control than in other groups. Compared with the control, the crude protein and ammonia nitrogen contents were significantly (p < 0.05) higher and lower in the LAB-treated groups, and the acid and detergent fiber contents were significantly (p < 0.05) reduced in the L and XM2 groups than those in other groups. There was a significant (p < 0.05) difference in the pH value, lactic acid content, and lactic acid-to-acetic acid ratio in L and XM2 groups than in other groups. Compared with the control, the number of LAB was significantly (p < 0.05) higher in LAB-treated silages, whereas no significant (p > 0.05) differences were observed in yeast and aerobic bacteria in all groups. Compared to the control, the Shannon index was significantly (p < 0.05) reduced. Simpson and Chao1 were significantly (p < 0.05) increased. Principal coordinate analysis based on the unweighted UniFrac distance showed clear separation of the bacterial community in fresh materials and LAB-treated silages. Besides, compared to the control, the principal coordinate analysis of LAB-treated silages was also separate. After 30 days of fermentation, the relative abundance of Firmicutes increased and was the primary phylum in all silages. Compared with the control, the abundance of Firmicutes and Proteobacteriawas significantly (p < 0.05) higher and lower in L and XM2 groups. In contrast, no significant differences were observed among control, 265, and 842 groups. At the genus level, the relative abundance of Lactobacillus, Enterobacter, Pediococcus, and Weissella was increased and dominated the native grass fermentation. Compared with the control, the abundance of Lactobacillus was significantly (p < 0.05) higher in L, XM2, and 842 groups, while no significant (p > 0.05) differences were observed between the control and 265 groups. The abundance of Pediococcus was higher than that in other groups. Consequently, the results demonstrated that LAB significantly influenced silage fermentation by reconstructing microbiota, and Lactobacillus was the dominant genus in the native grass silages. Furthermore, the results showed that strain XM2 could effectively improve the silage quality, and it is considered a potential starter for the native grass silage.

Modeling and Predicting the Growth of Lactic Acid Bacteria in Lightly Preserved Seafood and Their Inhibiting Effect on Listeria monocytogenes

2007 ◽  
Vol 70 (11) ◽  
pp. 2485-2497 ◽  
Author(s):  
OLE MEJLHOLM ◽  
PAW DALGAARD
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Chemical Characterization ◽  
Effect Of Temperature ◽  
Inhibiting Effect ◽  
Smoked Salmon ◽  
Boundary Model ◽  
Parameter Values ◽  
Separate Product

A cardinal parameter model was developed to predict the effect of diacetate, lactate, CO2, smoke components (phenol), pH, NaCl, temperature, and the interactions between all parameters on the growth of lactic acid bacteria (LAB) in lightly preserved seafood. A product-oriented approach based on careful chemical characterization and growth of bacteria in ready-to-eat seafoods was used to develop this new LAB growth model. Initially, cardinal parameter values for the inhibiting effect of diacetate, lactate, CO2, pH, and NaCl–water activity were determined experimentally for a mixture of LAB isolates or were obtained from the literature. Next, these values and a cardinal parameter model were used to model the effect of temperature (Tmin) and smoke components (Pmax). The cardinal parameter model was fitted to data for growth of LAB (μmax values) in lightly preserved seafood including cold-smoked and marinated products with different concentrations of naturally occurring and added organic acids. Separate product validation studies of the LAB model resulted in average bias and accuracy factor values of 1.2 and 1.5, respectively, for growth of LAB (μmax values) in lightly preserved seafood. Interaction between LAB and Listeria monocytogenes was predicted by combining the developed LAB model and an existing growth and growth boundary model for the pathogen (O. Mejlholm and P. Dalgaard, J. Food Prot. 70:70–84). The performance of the existing L. monocytogenes model was improved by taking into account the effect of microbial interaction with LAB. The observed and predicted maximum population densities of L. monocytogenes in inoculated lightly preserved seafoods were 4.7 and 4.1 log CFU g−1, respectively, whereas for naturally contaminated vacuum-packed cold-smoked salmon the corresponding values were 0.7 and 0.6 log CFU g−1 when a relative lag time of 4.5 was used for the pathogen.

scholarly journals Changes in ruminal bacterial community composition following feeding of alfalfa ensiled with a lactic acid bacterial inoculant

2012 ◽  
Vol 95 (1) ◽  
pp. 328-339 ◽  
Author(s):  
R. Mohammed ◽  
D.M. Stevenson ◽  
K.A. Beauchemin ◽  
R.E. Muck ◽  
P.J. Weimer
Keyword(s):  
Lactic Acid ◽  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Composition

scholarly journals Silage Fermentation, Bacterial Community, and Aerobic Stability of Total Mixed Ration Containing Wet Corn Gluten Feed and Corn Stover Prepared with Different Additives

Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1775
Author(s):  
Guangning Zhang ◽  
Xinpeng Fang ◽  
Guanzhi Feng ◽  
Yang Li ◽  
Yonggen Zhang
Keyword(s):  
Lactic Acid ◽  
Bacterial Community ◽  
Corn Stover ◽  
Total Mixed Ration ◽  
Aerobic Stability ◽  
Corn Gluten ◽  
Corn Gluten Feed ◽  
Fermentation Quality ◽  
Wet Corn Gluten Feed ◽  
Gluten Feed

The objective of this study was to investigate the effects of different additives on the fermentation quality, bacterial community, and aerobic stability of total mixed ration (TMR) silage containing wet corn gluten feed (WCGF) and corn stover. The TMR was ensiled with four treatments: (1) no additive (control); (2) lactic acid bacteria (LAB); (3) fibrolytic enzyme (EN); (4) LAB + EN. The EN and LAB + EN decreased the neutral detergent fiber and acid detergent fiber contents. Additives led to a higher lactic acid (LA) content (p < 0.0001) compared to control at all ensiling times. Silages inoculated with LAB and LAB + EN had higher dry matter (p = 0.0007), LA (p < 0.0001) and acetic acid (AA) contents (p < 0.0001) compared to control. The LAB and LAB + EN had significantly lowest ammonia nitrogen among the treatments, while no significant difference occurred after days 7 of ensiling. Silages treated with LAB and LAB + EN had a higher LAB count (p < 0.0001) and a lower pH, yeast, and mold counts compared to other silages. The LAB and LAB + EN greatly increased the portions of Firmicutes and Lactobacillus (p < 0.0001, and p < 0.0001, respectively) and reduced undesirable bacteria. Inoculation with LAB + EN and LAB improved aerobic stability of TMR silages indicated by higher and more stable LA and AA contents, smaller rise in pH, and yeast count than other silages. The LAB + EN and LAB reduced microbial diversity and improved the fermentation quality and aerobic stability of TMR silage containing WCGF and corn stover.

Selection and characterization of potential probiotic Lactobacilli spp isolated from chicken feces may be used as a potent antibacterial agent

2016 ◽  
Vol 35 (1) ◽  
Author(s):  
Nazila Aazami ◽  
Enayatollah Kalantar ◽  
Helen Poormazaheri ◽  
Nassimeh Setayesh vali Pour ◽  
Gholamreza Salehi Jouzan
Keyword(s):  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Tolerance ◽  
Resistance Test ◽  
Effect Of Temperature ◽  
Rdna Sequencing

<italic>Lactobacillus</italic> strains commonly used as probiotics which possess some properties such as resistance to gastric acidity and bile salts, production of antimicrobial compounds, the ability to modulate immune responses, and adhesion to gut tissues. This study aimed to isolate, identify, production and characterization of the probiotic strains. Total of 10 digestive tracts of chickens fed without antibiotics for presence of <italic>Lactobacillus spp</italic> was evaluated. All isolates were grown with different conditions like effect of temperature, pH, pepsine, bile, sodium chloride tolerance, aggregation, adhesion and antibiotic resistance test tested and then antibacterial activity was determined.In this study, 34 lactic acid bacteria were investigated as putative probiotic candidates. Based on the molecular identification using 16S rDNA sequencing the isolates belonged to <italic>Lactobacillus</italic> species. The strains showed potent antibacterial activity. The results on acid tolerance showed that all the strains tested survived at pH 2.0 to 5.5. <italic>L. agilis</italic> strain M18, <italic>L. salivarius</italic> strain M10, <italic>L.vaginalis</italic> strains M8 and M19, and <italic>L. crispatus</italic> strains Or2 and M10 showed the lowest sensitivity to pepsine. All the studied Lactobacillus strains were able to grow at both 15 and 45°C . Five Lactobacillus strains adhered well to the Caco-2 cells. The result of antibiotic resistance test of 34 lactic acid bacteria showed that most of them were resistant or intermediate. Based on 34 <italic>Lactobacillus</italic> strains, <italic>L. vaginalis</italic> strain M8 and <italic>L. reuteri</italic> strain M6 were selected for the further in vivo assays and possible eventual use as prophylactic and therapeutic agent.

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