Lactic Acid
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2021 ◽  
Vol 11 (21) ◽  
pp. 9867
Mihaela Dumitru ◽  
Dan Cristian Vodnar ◽  
Simon Elemer ◽  
Georgeta Ciurescu ◽  
Mihaela Habeanu ◽  

A total of 15 strains of lactic acid bacteria (LAB) were isolated from the broiler chicken’s gastrointestinal tract. All isolates were phenotypical and genetically identified. Among these isolates, only six were biochemical (API 50 CHL and ABIS soft) and genetically (16S rRNA sequencing) confirmed as Lactobacillus acidophilus, Limosilactobacillus fermentum, Levilactobacillus brevis, and Ligilactobacillus salivarius. Probiotic properties, including tolerance to pH (pH 2.0 and 3.0), bile salts (0.3% oxgall), hemolysis activity, and antibiotic susceptibility, were evaluated. Three isolates of the latter isolates showed high resistance at low pH values (73.74% to 98.20%) and bile salt concentrations (77.89% to 99.49%). The antibiotic test presented 100% resistance of LAB to gentamicin, lincomycin, enrofloxacin, and streptomycin lower than the 0.5 mm inhibition zone diameter. Selected strains (L. acidophilus IBNA 64, L. salivarius IBNA 33, and L. salivarius IBNA 41) were exposed to the spray-drying process based on observable probiotic potential. A maltodextrin-glucose solution was used as a thermoprotectant. After spray drying, a reduction in strain viability was noted (108 to 104 CFU/g). In conclusion, only L. salivarius (IBNA 33 and IBNA 41) could be used as a possible probiotic, and further studies are needed to ensure their safe application in the animal nutrition field with beneficial effects for improving performance and pathogen microorganism control from intestines equilibrating the microbiota composition.

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6286
Katarzyna Rucińska ◽  
Zbigniew Florjańczyk ◽  
Maciej Dębowski ◽  
Tomasz Gołofit ◽  
Rafał Malinowski

New organophilic montmorillonites with oligomers of lactic acid and other compounds such as citric acid, stearic acid, maleic anhydride, pentaerythritol and ε-caprolactone were synthesized. They were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), elemental analysis and swelling capacity in water. In all tested composites, an increase in the montmorillonite interlayer distance resulting from intercalation of the modifying substance in the montmorillonite was found by means of XRD. Elemental analysis and FTIR showed that all of the tested samples contained an organic segment in the montmorillonite structure. TGA studies revealed that composites modified with lactic acid oligomers, stearic acid or ε-caprolactone had the highest thermal stability. They also exhibited the lowest swelling capacity which was 2–3 times lower than that for unmodified sodium montmorillonite. Some preliminary studies on the mechanical properties of PLA/modified montmorillonite are also presented and discussed.

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2529
Cuicui Jiang ◽  
Mengyang Liu ◽  
Xu Yan ◽  
Ruiqi Bao ◽  
Aoxue Liu ◽  

This work investigated the effect of lipase addition on a Chinese traditional fermented fish product, Suanzhayu. The accumulation of lactic acid and the decrease of pH during the fermentation were mainly caused by the metabolism of Lactobacillus. The addition of lipase had little effect on pH and the bacterial community structure but promoted the growth of Proteus. The addition of lipase promotes the formation of volatile compounds, especially aldehydes and esters. The formation of volatile compounds is mainly divided into three stages, and lipase had accelerated the fermentation process. Lactobacillus, Enterococcus and Proteus played an important role not only in inhibition of the growth of Escherichia-Shigella, but also in the formation of flavor. This study provides a rapid fermentation method for the Suanzhayu process.

José R. Linares-Morales ◽  
Iván Salmerón-Ochoa ◽  
Blanca E. Rivera-Chavira ◽  
Néstor Gutiérrez-Méndez ◽  
Samuel B. Pérez-Vega ◽  

Azita Faraki ◽  
Fatemeh Rahmani

Probiotics and Lactic Acid Bacteria play important roles such as the production of antimicrobial compounds and other metabolites. So they have positive effects on human health. When reactive oxygen species generated in excess or cellular defenses are deficient, biomolecules can be damaged by the oxidative stress process. Various studies have shown that the best way to protect the human body from the effects of oxidation reactions is to avoid them, which can be accomplished by using antioxidants. Due to the damages of synthetic antioxidants, their usage has been discussed. Nowadays natural antioxidants derived from bio-resources have recently gained a lot of attention as a potential replacement for synthetic antioxidants. Probiotic bacteria are thought to defend against oxidative stress by restoring the gut microbiota, according to hypothesis of some scientists. This type of microorganisms indicated their antioxidant activity by producing and increasing antioxidant enzymes, production of secondary metabolites, small hydrolyzed peptides in food, resistance to the presence of hydrogen peroxide, and production of intracellular and extracellular compounds such as Exopolysaccharides. Also, they have shown their positive effect on in vivo models. In conclusion, according to the results of studies, lactic acid bacteria and probiotics are significant sources of natural antioxidants. Therefore, they have important research value and market development potential. Also, it should be noted that the mechanism of antioxidant activity of this group of microorganisms has not been fully investigated, this requires further research.

Lily Nguyen Trinh ◽  
Kelly C. McGuigan ◽  
Amar Gupta

AbstractTear trough deformity is a popular target for the treatment with filler injections. The side effects are generally mild and transient. However, delayed complications may occur. We aim to perform a thorough systematic review of the published literature related to delayed complications after tear trough filler injections. A search of published literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in June 2021 and included PubMed, ScienceDirect, and Embase databases. The Medical Subject Headings (MeSH) terms used included the following terms: delayed complications, nodules, granulomas, swelling, discoloration, dermal filler, hyaluronic acid (HA), polyacrylamide, calcium hydroxyapatite (CaHA), poly-L-lactic acid (PLLA), eyelid, periorbital, periocular, and tear trough. Twenty-eight articles consisting of 52 individual cases were included in the final analysis. 98% (51/52) of patients were female and had an average age of 48.3 years. HA was the most reported product (71.2%, 37/52), followed by PLLA (4/52, 7.7%), and CaHA (4/52, 7.7%). The most common delayed complication with any dermal filler was swelling (42.3%, 22/52) followed by lumps or nodules (25.0%, 13/52). Xanthelasma-like reaction (17.3%, 9/52), migration (7.7%, 4/52), discoloration (3%, 3/52) also occurred. The average time of onset of any complication was 16.8 months with xanthelasma-like reaction appearing soonest (mean: 10 months) and discoloration appearing latest (mean: 52 months). Most swelling cases were caused by HA. Semi-permanent fillers such as PMMA and synthetic fillers such as PLLA were more likely to be associated with lumps and nodules than other complications. It is important that clinicians who perform tear trough augmentation with dermal fillers have a thorough understanding of the risks of the procedure to diagnose and manage them promptly as well as provide patients with accurate information regarding the potential adverse effects.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Joel Romial Ngouénam ◽  
Pierre Marie Kaktcham ◽  
Chancel Hector Momo Kenfack ◽  
Edith Marius Foko Kouam ◽  
François Zambou Ngoufack

Lactic acid (LA) is used in food, cosmetic, chemical, and pharmaceutical industries and has recently attracted much attention in the production of biodegradable polymers. The expensive substances including carbon and nitrogen sources involved in its fermentative synthesis and the increasing market demand of LA have prompted scientists to look for inexpensive raw materials from which it can be produced. This research was aimed at determining the optimum conditions of lactic acid (LA) production from pineapple by-products and an inexpensive nitrogen source using Lactiplantibacillus plantarum strain 4O8. After collection and preparation of the carbon source (pineapple by-products) and nitrogen sources (by-products from fish, chicken, and beer brewing industries), they were used for the formulation of 4 different media in terms of nitrogen sources. Then, the proximate compositions of promising nitrogen sources were determined. This was followed by the screening of factors (temperature, carbon source, nitrogen source, MgSO4, MnSO4, FeSO4, KH2PO4, and KHPO4) influencing the production of LA using the definitive plan. Lastly, the optimization process was done using the central composite design. The highest LA productions ( 14.64 ± 0.05   g / l and 13.4 ± 0.02   g / l ) were obtained in production medium supplemented with chicken and fish by-products, respectively, making them the most promising sources of nitrogen. The proximate analysis of these nitrogen sources revealed that their protein contents were 83.00 ± 1.41 % DM and 74.00 ± 1.41 % DM for chicken by-products and fish by-products, respectively. Concerning the screening of factors, temperature, nitrogen source, and carbon source were the factors that showed a major impact on LA production in the production medium containing chicken by-products as nitrogen source. A pineapple by-product concentration of 141.75 g/l, a nitrogen source volume of 108.99 ml/l, and a temperature of 30.89°C were recorded as the optimum conditions for LA production. The optimization led to a 2.73-fold increase in LA production when compared with the production medium without nitrogen source. According to these results, chicken by-products are a promising and an inexpensive nitrogen source that can be an alternative to yeast extract in lactic acid production.

2021 ◽  
María Carla Groff ◽  
Gustavo Scaglia ◽  
Oscar A. Ortiz ◽  
Sandra E. Noriega

Abstract Objectives To obtain a mathematical model that adequately describes the time lag between biomass generation and lactic acid production of lactic fermentations. Methods Seven experimental kinetics from other research works were studied to validate our proposal: four studies of Fungal Submerged Fermentation and three cases of Bacterial Submerged Fermentation, including the data recollected by Luedeking and Piret. Results We introduce a modification to the Luedeking and Piret model that consist in the introduction of a time delay parameter in the model, this parameter would account for the lag time that exists between the production of biomass and lactic acid. It is possible to determine this time delay in a simple way by approximating the biomass and product formation considering that they behave as a first order plus dead time system. The duration of this phenomenon, which is not described with the classical Luedeking and Piret model, is a function of microorganism physiology (ease of biomass growth), environment (nutrients) and type of inoculum. Conclusion The Luedeking and Piret with delay model applications reveal an increase of the R2 in all cases, evidencing the quality of fit and the simplicity of the method proposed. These model would improve the accuracy of bioprocess scaling up.

2021 ◽  
Lucas von Gastrow ◽  
Remy Amelot ◽  
Diego Segond ◽  
Stephane Guezennec ◽  
Florence Valence ◽  

Understanding how microbes disperse in ecosystems is critical to understand the dynamics and evolution of microbial communities. However, microbial dispersal is difficult to study because of uncertainty about the vectors that may contribute to their migration. This applies to both microbial communities in natural and human-associated environments. Here, we studied microbial dispersal among French sourdoughs and flours used to make bread. Sourdough is a naturally fermented mixture of flour and water. It hosts a community of bacteria and yeasts whose origins are only partially known. We analyzed whether flour is a carrier of sourdough yeast and bacteria and studied whether microbial migration occurs between sourdoughs. The microbial community of a collection of 46 sourdough samples, as well as that of the flour from which each was made, was studied by 16S rDNA and ITS1 metabarcoding. No sourdough yeast species were detected in the flours. Sourdough lactic acid bacteria (LAB) were found in only five flour samples, and they did not have the same amplicon sequence variant (ASV) as found in the corresponding sourdough. The species shared between the sourdough and flour samples are commonly found on plants and are not known to be alive in sourdough. Thus, the flour microorganisms did not appear to grow in the sourdough microbial community. Dispersal between sourdoughs was also studied. Sourdoughs shared no yeast ASV, except in few cases where groups of three to five bakers shared some. These results suggest that there is little migration between sourdoughs, except in a few situations where bakers may exchange sourdough or be vectors of yeast dispersal themselves.

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