Pellicle formation, microbial succession and lactic acid utilisation during the aerobic deteriorating process of Sichuan pickle

Metagenomic studies about cocoa fermentation have mainly reported on the analysis of short reads for determination of Operational Taxonomic Units. However, it is also important to determine MAGs, which are genomes deriving from the assembly of metagenomics. For this research, all the cocoa metagenomes from public databases were downloaded, resulting in five datasets: one from Ghana and four from Brazil. Besides, in silico approaches were used to describe putative phenotypes and metabolic potential of MAGs. A total of 17 high-quality MAGs were recovered from these microbiomes, as follows: (i) fungi - Yamadazyma tenuis (n=1); (ii) lactic acid bacteria - Limosilactobacillus fermentum (n=5), Liquorilactobacillus cacaonum (n=1) , Liquorilactobacillus nagelli (n=1), Leuconostoc pseudomesenteroides (n=1) and Lactiplantibacillus plantarum subsp. plantarum (n=1); (iii) acetic acid bacteria - Acetobacter senegalensis (n=2) and Kozakia baliensis (n=1) and (iv) Bacillus subtilis (n=1) Brevundimonas sp. (n=2) and Pseudomonas sp. (n=1). Medium-quality MAGs were also recovered from cocoa microbiomes, including some detected for the first time in this environment ( Liquorilactobacillus vini , Komagataeibacter saccharivorans and Komagataeibacter maltaceti ) and other previously described ( Fructobacillus pseudoficulneus and Acetobacter pasteurianus ). Taken all together, the MAGs were useful to provide an additional description of the microbiome of cocoa fermentation, revealing previously overlooked microorganisms, with prediction of key phenotypes and biochemical pathways. Importance The production of chocolate starts with the harvesting of cocoa fruits and the spontaneous fermentation of the seeds, in a microbial succession that depends on yeasts, lactic acid bacteria and acetic acid bacteria in order to eliminate bitter and astringent compounds present in the raw material, which will be further roasted and grinded to originate the cocoa powder that will enter the food processing industry. The microbiota of cocoa fermentation is not completely know, and yet it advanced from culture-based studies to the advent of Next Generation DNA sequencing, with the generation of a myriad of data, that need bioinformatic approaches to be properly analysed. Although the majority metagenomic of studies have been based on short reads (OTUs), it is also important to analyse entire genomes to determine more precisely possible ecological roles of different species. Metagenome-assembled genomes (MAGs) are very useful for this purpose, and in this paper, MAGs from cocoa fermentation microbiomes were described, as well the possible implications of their phenotypic and metabolic potentials are discussed.

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MICROBIAL SUCCESS OF ETHANOL, LACTIC ACID AND ACETIC ACID DURING FERMENTATION OF COCOA SEEDS

10.31219/osf.io/hzecq ◽

2019 ◽

Author(s):

mulono apriyanto bin sugeng rijanto

Keyword(s):

Acetic Acid ◽

Lactic Acid ◽

Microbial Population ◽

Acetic Acid Bacteria ◽

Microbial Populations ◽

Cocoa Bean ◽

Microbial Succession ◽

Cocoa Beans ◽

Cocoa Bean Fermentation ◽

Fermentation Substrate

The objectives of the study are: 1) to determine the composition of the original cocoa bean pulp as a substrate for fermentation; 2) evaluating the effect of variations in random cocoa bean fermentation techniques on microbial populations. The stages of research carried out are as follows (1) testing the composition and moisture content of asalan cocoa beans as a fermentation substrate. (2) Fermented cocoa beans with 3 variations of fermentation techniques namely first treatment without addition of inoculum (control), second using S. cerevisiae (FNCC 3056) inoculum, L. lactis (FNC 0086) and A. aceti (FNCC 0016), respectively. - about 108 cfu / g is given simultaneously at the beginning of fermentation (IA). (3) gradual administration of inoculum yeast at the beginning of fermentation, lactic acid bacteria at 24 hours and acetic acid bacteria at 48 hours with a microbial population equal to the second treatment (IB). Fermentation is carried out for 120 hours. The temperature is set during fermentation, respectively 35 oC (first 24 hours), 45 oC (second 24 hours), 55 oC (third 24 hours) and 35 oC (last 48 hours). The results showed that during the fermentation of random cocoa beans showed that all treatments increased ethanol consumption in line with the increasing population of S. cerevisiae at the beginning of fermentation. Furthermore, L. lactis increases followed by lactic acid, at the end of A. aceti fermentation increases with acetic acid. From the results of this study it can be concluded that the rehydration of asalan cocoa beans can improve the composition of the pulp as a fermentation substrate. Microbial population shows that microbial succession has been demonstrated by the gradual addition of the inoculum.

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Changes Occurring in Spontaneous Maize Fermentation: An Overview

Fermentation ◽

10.3390/fermentation6010036 ◽

2020 ◽

Vol 6 (1) ◽

pp. 36 ◽

Cited By ~ 3

Author(s):

Clemencia Chaves-López ◽

Chiara Rossi ◽

Francesca Maggio ◽

Antonello Paparella ◽

Annalisa Serio

Keyword(s):

Acetic Acid ◽

Lactic Acid ◽

Nutritional Value ◽

Acetic Acid Bacteria ◽

Antimicrobial Compounds ◽

Microbial Succession ◽

Positive Effects ◽

The World ◽

Bacillus Spp ◽

The Impact

Maize and its derived fermented products, as with other cereals, are fundamental for human nutrition in many countries of the world. Mixed cultures, principally constituted by lactic acid bacteria (LAB) and yeasts, are responsible for maize fermentation, thus increasing its nutritional value and extending the products’ shelf-life. Other microorganisms involved, such as molds, acetic acid bacteria, and Bacillus spp. can contribute to the final product characteristics. This review gives an overview of the impact of the activities of this complex microbiota on maize product development and attributes. In particular, starting from amylolytic activity, which is able to increase sugar availability and influence the microbial succession and production of exopolysaccharides, vitamins, and antimicrobial compounds, which improve the nutritional value. Further activities are also considered with positive effects on the safety profile, such as phytates detoxification and mycotoxins reduction.

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Decrease Polyphenols, Ethanol, Lactic Acid, and Acetic Acid during Fermentation with Addition of Cocoa Beans Innoculum

10.31219/osf.io/53fzq ◽

2019 ◽

Author(s):

mulono apriyanto bin sugeng rijanto

Keyword(s):

Acetic Acid ◽

Lactic Acid ◽

Microbial Population ◽

Acetic Acid Bacteria ◽

Cocoa Bean ◽

Microbial Succession ◽

Cocoa Beans ◽

Third Stage ◽

Seed Fermentation ◽

Fermentation Substrate

The research objectives were: 1) to know the composition of cocoa bean pulp as substrate for fermentation; 2) evaluate the effect of variationof cocoa seed fermentation technique on microbial population. Stages of research conducted are as follows (1) testing the composition and water content of cocoa bean pulp as a fermentation substrate. (2) Fermented cocoa beans with 3 variations of fermentation technique ie first treatment withoutaddition of inoculum (control), both using inoculum S. cerevisiae (FNCC 3056), L. lactis (FNC 0086) and A. aceti (FNCC 0016), respectively - about 108cfu/g is given simultaneously at the beginning of fermentation (IA). (3) gradual inoculum administration of yeast at the begi nning of fermentation, lacticacid bacteria at 24 hours and acetic acid bacteria at 48 h with microbial population equal to second treatment (IB). Fermentation is carried out for 120hours. Temperatures are adjusted during fermentation, respectively 35 oC (first 24 hours), 45 oC (24 second hours), 55 oC (24 hours three) and 35 oC(last 48 hours). The third stage of fermented cocoa beans from the three treatments was roasted and analyzed for their volati le compounds. The resultsshowed that during the fermentation of cocoa beans showed that all treatments increased the ethanol kosentarsi in line with the increasing population ofS. cerevisiae at the beginning of fermentation. Next L. lactis increased followed by lactic acid, at the end of A. aceti fermentation increased followed byacetic acid. From the results of this study it can be concluded that the rehydration of cocoa bean pulp can improve the composition of pulp asfermentation substrate. The microbial population indicated that there was a microbial succession shown in the gradual addition of inoculum treatment.

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Microbial succesion, fermentation end-products, aerobic stability of guinea grass ensiled with various doses of additive containing bacterial inoculant and fibrolytic enzymes.

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v85i3-4.3069 ◽

1969 ◽

Vol 85 (3-4) ◽

pp. 151-164

Author(s):

Abner A. Rodríguez ◽

José L. Martínez ◽

Raúl Macchiavelli ◽

Ernesto O. Riquelme

Keyword(s):

Lactic Acid ◽

Chemical Composition ◽

Dry Matter ◽

Microbial Populations ◽

Soluble Carbohydrate ◽

Microbial Succession ◽

Grass Silage ◽

Aerobic Stability ◽

End Products ◽

Guinea Grass

An experiment was conducted to evaluate the effect of three application rates (0,1 and 2 times the recommended rate) of a commercial additive containing a lactic acid-producing bacterial inoculant as well as plant cell walldegrading enzymes, on the microbial succession, fermentation end-products, and aerobic stability of guinea grass (Panicum maximum var. Jacq.) silage. Vegetative material was harvested at 30% dry matter (DM) and chopped into 2.5-cm pieces. At ensiling, three treatments were imposed: no additive (control), additive applied at recommended rate, and at 2x the recommended rate. Three silos per treatment were opened after 0, 2, 4, 7, 14, 28, and 56 d of fermentation, and siiage was analyzed for pH, microbial succession, chemical composition, fermentation end-products and aerobic stability. For aerobic stability determination, three silos per treatment were opened at the end of the fermentation period, and silage (400 g) was exposed to air for three days in Styrofoam containers lined with plastic. After 0 , 1 , and 3 d of aerobic exposure, silage was analyzed for pH, microbial populations (total bacteria, yeast and molds), water soluble carbohydrate content, fermentation end-products and in vitro dry matter degradability (IVDMD). Temperature was monitored daily and dry matter recovery (DMR) was calculated after 1 and 3 d of aerobic exposure. The addition of the commercial additive, applied one or two times the recommended rate, increased (P < 0.05) the lactic acid producing bacterial population and decreased (P < 0.05) conforms during early stages of the fermentation process, but did not influence the yeast and mold populations or the chemical composition of the resulting silage. Use of the inoculant-enzyme mixture also resulted in siiage with higher lactic acid content 56 days post ensiling. The silage additive did not inffuence pH, temperature, microbial populations, soluble carbohydrate content, IVDMD or DMR of guinea grass silage after exposure to air. In summary, use of the commercial additive applied at the recommended rate partially improved the fermentation characteristics of guinea grass silage, but did not enhance its aerobic stability. Increasing the application rate to twice the recommended rate did not result in better fermentation.

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Demonstration of Retinal Glycogen with Silver Methenamine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066875 ◽

1971 ◽

Vol 29 ◽

pp. 564-565

Author(s):

A. W. Sedar ◽

G. H. Bresnick

Keyword(s):

Lactic Acid ◽

Chromic Acid ◽

Periodic Acid ◽

Müller Cell ◽

External Limiting Membrane ◽

Electron Microscope Level ◽

Reactive Process ◽

Inner Limiting Membrane ◽

Muller Cell ◽

And Migration

After experimetnal damage to the retina with a variety of procedures Müller cell hypertrophy and migration occurs. According to Kuwabara and others the reactive process in these injuries is evidenced by a marked increase in amount of glycogen in the Müller cells. These cells were considered originally supporting elements with fiber processes extending throughout the retina from inner limiting membrane to external limiting membrane, but are known now to have high lactic acid dehydrogenase activity and the ability to synthesize glycogen. Since the periodic acid-chromic acid-silver methenamine technique was shown to demonstrate glycogen at the electron microscope level, it was selected to react with glycogen in the fine processes of the Müller cell that ramify among the neural elements in various layers of the retina and demarcate these cells cytologically. The Rhesus monkey was chosen as an example of a well vascularized retina and the rabbit as an example of a avascular retina to explore the possibilities of the technique.

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