scholarly journals The Microbiota Dynamics of Alfalfa Silage During Ensiling and After Air Exposure, and the Metabolomics After Air Exposure Are Affected by Lactobacillus casei and Cellulase Addition

2020 ◽  
Vol 11 ◽  
Author(s):  
Zongfu Hu ◽  
Huaxin Niu ◽  
Qing Tong ◽  
Jie Chang ◽  
Jianhua Yu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Lactic Acid ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Lactobacillus Casei ◽  
Gas Chromatography Mass Spectrometry ◽  
Air Exposure ◽  
Fresh Matter ◽  
Alfalfa Silage

Both inoculants treatment and enzyme treatment promote the reproduction of lactic acid bacteria (LAB) to produce enough lactic acid to lower pH in silage. The present study investigated the microbial community and metabolome in cellulase, Lactobacillus casei, and air treated alfalfa silage. Chopped and wilted alfalfa (first cutting, 29% dry matter) was ensiled without (CON) or with L. casei (1 × 106 cfu g–1 fresh matter) (LC) or cellulase (20,000IU, 0.5% of fresh matter) (CE) for 56 days, then exposed to air for 3 days (PO). Greater ensiling quality was observed in LC and CE, which had lower pH and higher lactic acid content than CON at 56 days of ensiling and 3 days post-oxygen exposure. Air exposure was associated with decreased lactic acid concentrations and increased yeast and mold counts in all silages. SEM showed that the structure of leaf epicuticular wax crystals were intact in fresh alfalfa, totally decomposed in CON silage, and partly preserved in CE and LC silage. Gas chromatography mass spectrometry revealed that 196 metabolites and 95 differential concentration were present in the 3 days air exposure samples. Most of these metabolites, mainly organic acids, polyols, ketones, aldehydes, are capable of antimicrobial activity. The bacterial communities were obviously different among groups and Lactobacillus developed to a dominant status in all silages. Lactobacillus became dominant in bacterial communities of LC and CE silages from days 7 to 56, and their relative abundances reached 94.17–83.93% at day 56, respectively. For CON silage, until day 56, Lactobacillus dominated the bacterial community with abundance of 75.10%. After 3 days of oxygen exposure, Lactobacillus and Enterococcus were predominant in CON, and Lactobacillus remained dominant in LC and CE silages. The results indicated that, compared to untreated silages, L. casei could be a priority inoculant for alfalfa silage to boost Lactobacillus abundance and improve fermentation quality. Our high-throughput sequencing and gas chromatography mass spectrometry results provide a deep insight into the bacterial community and metabolites in alfalfa silage.

scholarly journals Comparison of Volatile and Nonvolatile Compounds in Rice Fermented by Different Lactic Acid Bacteria

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1183 ◽  
Author(s):  
Sang Lee ◽  
Young Hwang ◽  
Moon Kim ◽  
Myung Chung ◽  
Young-Suk Kim
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Volatile Compounds ◽  
Solid Phase ◽  
Principal Component ◽  
Gas Chromatography Mass Spectrometry ◽  
Flight Mass Spectrometry ◽  
Rice Samples

The production of rice-based beverages fermented by lactic acid bacteria (LAB) can increase the consumption of rice in the form of a dairy replacement. This study investigated volatile and nonvolatile components in rice fermented by 12 different LABs. Volatile compounds of fermented rice samples were analyzed using gas chromatography-mass spectrometry (GC-MS) combined with solid-phase microextraction (SPME), while nonvolatile compounds were determined using gas chromatography-time-of-flight/mass spectrometry (GC-TOF/MS) after derivatization. The 47 identified volatile compounds included acids, aldehydes, esters, furan derivatives, ketones, alcohols, benzene and benzene derivatives, hydrocarbons, and terpenes, while the 37 identified nonvolatile components included amino acids, organic acids, and carbohydrates. The profiles of volatile and nonvolatile components generally differed significantly between obligatorily homofermentative/facultatively heterofermentative LAB and obligatorily heterofermentative LAB. The rice sample fermented by Lactobacillus sakei (RTCL16) was clearly differentiated from the other samples on principal component analysis (PCA) plots. The results of PCA revealed that the rice samples fermented by LABs could be distinguished according to microbial strains.

scholarly journals Fermentation Enhanced Biotransformation of Compounds in the Kernel of Chrysophyllum albidum

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 6021
Author(s):  
Oluwatofunmi E. Odutayo ◽  
Emmanuel A. Omonigbehin ◽  
Tolulope D. Olawole ◽  
Olubanke O. Ogunlana ◽  
Israel S. Afolabi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Cultures ◽  
Gas Chromatography Mass Spectrometry ◽  
Bile Salt Hydrolase ◽  
Aqueous Extracts ◽  
Acidic Environment ◽  
African Star Apple

Chrysophyllum albidum Linn (African star apple) is a fruit with extensive nutritional and medicinal benefits. The fruit and kernel in the seed are both edible. Strains of lactic acid bacteria (LAB) were isolated from fermented seeds and assessed for probiotic characteristics. The extracts in both the unfermented and the fermented aqueous extracts from the kernels obtained from the seeds of C. albidum were subjected to analysis using the gas chromatography/mass spectrometry (GC-MS) method. This analysis identified the bioactive compounds present as possible substrate(s) for the associated organisms inducing the fermentation and the resultant biotransformed products formed. Three potential probiotic LAB strains identified as Lactococcus raffinolactis (ProbtA1), Lactococcus lactis (ProbtA2a), and Pediococcus pentosaceus (ProbtA2b) were isolated from the fermented C. albidum seeds. All strains were non hemolytic, which indicated their safety, Probt (A1, A2a, and A2b) grew in an acidic environment (pH 3.5) during the 48-h incubation time, and all three strains grew in 1% bile, and exhibited good hydrophobicity and auto-aggregation properties. Mucin binding proteins was not detected in any strain, and bile salt hydrolase was detected in all the strains. l-lactic acid (28.57%), norharman (5.07%), formyl 7E-hexadecenoate (1.73%), and indole (1.51%) were the four major constituents of the fermented kernel of the C. albidum, while 2,5-dimethylpyrazine (C1, 1.27%), 3,5-dihydroxy-6-methyl-2,3-dihydropyran-4-one (C2, 2.90%), indole (C3, 1.31%), norharman (C4, 3.01%), and methyl petroselinate (C5, 4.33%) were the five major constituents of the unfermented kernels. The isolated LAB are safe for consumption. The fermenting process metabolized C1, C2, and C5, which are possible starter cultures for the growth of probiotics. Fermentation is an essential tool for bioengineering molecules in foods into safe and health beneficial products.

scholarly journals Chemical Feedstock Recovery via the Pyrolysis of Electronically Heated Tobacco Wastes

2021 ◽  
Vol 13 (22) ◽  
pp. 12856
Author(s):  
Yejin Choi ◽  
Sangjae Jeong ◽  
Young-Kwon Park ◽  
Huijeong Kim ◽  
Se-Jeong Lim ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Cellulose Acetate ◽  
Gas Chromatography Mass Spectrometry ◽  
Poly Lactic Acid ◽  
Tobacco Leaves ◽  
Ms Analysis ◽  
Apparent Activation Energies

The pyrolysis of waste electronically heated tobacco (EHT), consisting of tobacco leaves (TL), a poly-lactic acid (PLA) filter, and a cellulose acetate (CA) filter, was investigated using thermogravimetric (TG) and pyrolyzer–gas chromatography/mass spectrometry (Py-GC/MS) analysis. The pyrolytic properties of waste EHT obtained after smoking were comparable to those of fresh EHT. Although the maximum decomposition temperatures (TmaxS) of waste TL and CA were similar to those of fresh EHT components, the Tmax of waste PLA was slightly higher than that of fresh PLA due to smoldering. The Tmaxs of PLA and CA were lowered when they were co-pyrolyzed with TL due to interactions between pyrolysis intermediates. The apparent activation energies for the non-isothermal pyrolysis of waste EHT components were higher than those of fresh EHT components. Py-GC/MS analysis results indicated that considerable amounts of chemical feedstocks, such as nicotine and limonene from TL, caprolactone and lactide from PLA, and acetic acid and triacetin from CA, can be recovered by simple pyrolysis of EHT. Co-pyrolysis of TL, PLA, and CA revealed that the experimental amount of lactide was much larger than the calculated value, suggesting its synergistic formation.

scholarly journals Exometabolites of some anaerobic microorganisms of human microflora

2011 ◽  
Vol 57 (1) ◽  
pp. 95-105 ◽  
Author(s):  
N.V. Beloborodova ◽  
I.T. Bairamov ◽  
A.Yu. Olenin ◽  
N.I. Fedotcheva
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Lactic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Hydroxybutyric Acid ◽  
Anaerobic Microorganisms ◽  
Chromatography Mass Spectrometry ◽  
Hydroxyglutaric Acid ◽  
Anaerobic Microflora

Some exometabolites produced by basic representatives of human anaerobic microflora were investigated, detected by gas chromatography - mass spectrometry (GC-MS). In vitro besides lactic acid Bifidobacterium and Lactobacillus generate substantial amounts of phenyllactic and p-hydroxyphenyllactic acids. Clostridium produced 2-hydroxybutyric acid and to a lesser extent lactic and phenyllactic acids. In contrast to С. perfringens, C. sporogenes generates substantial amount of phenylpropionic and p-hydroxyphenylpropionic acids and less p-hydroxyphenyllactic acid. С. perfringens produced minor amounts of 2-hydroxyglutaric acid. Bacteroids are potent producers of succinic and fumaric acids; they also contribute to production of significant portion of lactic acid. E. lentum generate lactic, phenyllactic and succinic acids and form a characteristic only for ones (from studied microorganisms) 2-hydroxyhexanic and 2-hydroxy-3-methylbutyric acids.

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