Fermentation By-products Research Articles

Algal Biomass Accumulation in Waste Digestate after Anaerobic Digestion of Wheat Straw

Cultivation of microalgae in waste digestate is a promising cost-effective and environmentally friendly strategy for algal biomass accumulation and valuable product production. Two different digestates obtained as by-products of the anaerobic fermentation at 35 °C and 55 °C of wheat straw as a renewable source for biogas production in laboratory-scale bioreactors were tested as cultivation media for microalgae after pretreatment with active carbon for clarification. The strains of microalgae involved were the red marine microalga Porphyridium cruentum, which reached 4.7 mg/mL dry matter when grown in thermophilic digestate and green freshwater microalga-Scenedesmus acutus, whose growth was the highest—7.3 mg/mL in the mesophilic digestate. During cultivation, algae reduced the available nutrient components in the liquid digestate at the expense of increasing their biomass. This biomass can find further applications in cosmetics, pharmacy, and feed. The nitrogen and phosphorus uptake from both digestates during algae cultivation was monitored and modeled. The results led to the idea of nonlinear dynamic approximations with an exponential character. The purpose was to develop relatively simple nonlinear dynamic models based on available experimental data, as knowing the mechanisms of the considered processes can permit creating protocols for industrial-scale algal production toward obtaining economically valuable products from microalgae grown in organic waste digestate.

Evaluation of dietary fermented tuna by-product meal as partial replacement for unprocessed tuna by-product meal in fishmeal-based diets for juvenile olive flounder Paralichthys olivaceus.

This study examined the effects of feeding fermented tuna by-product (FTBP) on the growth, non-specific immune response, liver and intestinal morphology, and disease resistance of olive flounder Paralichthys olivaceus. Olive flounders (n = 20; 2g) were randomly assigned into four dietary groups in triplicates. Fish were fed four test diets (50% crude protein; 10% crude lipid) for 10weeks in which unprocessed tuna by-product (TBP) meal was replaced (on a protein basis) with 0% (FTBP0 as the control diet), 15% (FTBP15), 30% (FTBP30), and 60% (FTBP60) of FTBP protein. Results showed that growth performance, blood parameters, and proximate composition were not influenced by FTBP inclusion. Non-specific immune parameters such as superoxide dismutase activity in the FTBP30 and FTBP60 groups were significantly higher than in the FTBP15 and the control groups, whereas lysozyme and myeloperoxidase activities were not different. Liver histopathology revealed normal architecture in groups fed FTBP0 and FTBP15 diets although mild alterations were noted in the FTBP30- and FTBP60-fed groups. Intestinal villi height and muscular thickness were not significantly altered with FTBP inclusion. Moreover, higher cumulative survival rate was observed in the FTBP60-fed group than fish fed with the other diets following the 13-day challenge with E. tarda. Together, these results demonstrate that fermented tuna by-product meal could be included at 60% in olive flounder diets.

Measurement and Characterization of Yeast Cell Size Using a Digital Optical Microscope

Yeast produces flavor components as by-products of fermentation. Such components, which account for considerable yeast quality value, may influence cell membrane fluidity and regulate cell size. In this study, yeast cell size was measured using various methods, and cell sizes were characterized for each strain of yeast. Herein, a method for measuring the cell size and automatically acquiring the cell area was proposed using inexpensive methylene blue staining and a versatile digital microscope to automatically acquire the cell area. To evaluate the efficiency, data on cell length and area were compared using the conventional and proposed methods. Additionally, the advantages of automated measurement and the ability to count cell numbers in the future are discussed through the acquisition of cell size data, which would be required for microfabrication and cell fabrication techniques. Although there are various candidate methods for evaluating the properties of each yeast strain, the present technique may be useful for evaluating the productivity of flavor components and selecting a yeast strain for producing food and drink products with high commodity values.

Novel chromatographic purification of succinic acid from whey fermentation broth by anionic exchange resins.

Replacement of the petroleum-based refineries with the biorefinery is regarded as an essential step towards a "zero" waste (circular) economy. Biobased succinic acid (SA) is listed by the United States Department of Energy among the top ten chemicals with the potential to replace chemicals from petroleum synthesis with renewable sources. Purification of bio-based succinic acid from fermentation by-products such as alcohols, formic acid, acetic acid and lactic is a major drawback of fermentative SA production. This study addresses this issue through a novel chromatographic separation using three distinct anionic resins: Amberlite IRA958 Cl (strong base anion exchange resin), Amberlite HPR 900 OH (strong base anion exchange resin) and Amberlyst A21 (week base anion exchange resin). The influence of process variables such as flow rate (0.18 BV/h, 0.42 BV/h and 0.84 BV/h), eluent concentration (1%, 5% and 10% HCl) and temperature (20, 30 and 40°C) were investigated. The results indicated SA separation efficiency of 76.1%, 69.3% and 81.2% for Amberlyst A21, Amberlite HPR 900 OH and Amberlite IRA958 Cl, respectively. As the regenerant HCl concentration increased from 1 to 10%, calculated succinic acid separation efficiencies decreased from 80.3 to 70.7%. Notably, as the regenerant strength increased from 1 to 10%, the total amount of organic acids desorbed from the resin sharply increased. At operation temperatures of 20, 30 and 40°C, SA separation efficacies were 81.2%, 73.9% and 76.4%, respectively. The insights from this study will be of great value in design of chromatographic separation systems for organic acids.

Hydrogen Availability Is Dependent on the Actions of Both Hydrogen-Producing and Hydrogen-Consuming Microbes.

Hydrogen gas (H2) is produced by H2-producing microbes in the gut during polysaccharide fermentation. Gut microbiome also includes H2-consuming microbes utilizing H2 for metabolism: methanogens producing methane, CH4, and sulfate-reducing bacteria producing hydrogen sulfide, H2S. H2S is not measured in the evaluation of gaseous byproducts of microbial fermentation. We hypothesize that the availability of measured H2 depends on both hydrogen producers and hydrogen consumers by measuring H2 invitro and invivo. In the invitro study, groups were Bacteroidesthetaiotaomicron (B.theta, H2 producers), Desulfovibriovulgaris (D.vulgaris, H2 consumers), and D.vulgaris + B.theta combined. Gas samples were collected at 2h and 24h after incubation and assayed for H2, CH4, and H2S. In the invivo study Sprague-Dawley rats were gavaged with suspended bacteria in four groups: B.theta, D.vulgaris, combined, and control. Gas was analyzed for H2 at 60min. In the invitro experiment, H2 concentration was higher in the combined group (188 ± 93.3ppm) compared with D.vulgaris (27.17 ± 9.6ppm) and B.theta groups (34.2 ± 29.8ppm; P < 0.05); H2S concentration was statistically higher in the combined group (10.32 ± 1.5ppm) compared with B.theta (0.19 ± 0.03ppm) and D.vulgaris group (3.46 ± 0.28ppm; P < 0.05). In the invivo study, H2 concentrations were significantly higher in the B.theta group (44.3 ± 6.0ppm) compared with control (31.8 ± 4.3) and the combined group (34.2 ± 8.7, P < 0.05). This study shows that sulfate-reducing bacteria could convert available H2 to H2S, leading to measured hydrogen levels that are dependent on the actions of both H2 producers and H2 consumers.

Milk Formula Enriched with Sodium Butyrate Influences Small Intestine Contractility in Neonatal Pigs.

Butyrate, a by-product of gut bacteria fermentation as well as the digestion of fat in mother’s milk, exerts a wide spectrum of beneficial effects in the gastrointestinal tissues. The present study aimed to determine the effects of sodium butyrate on small intestine contractility in neonatal piglets. Piglets were fed milk formula alone (group C) or milk formula supplemented with sodium butyrate (group B). After a 7-day treatment period, isometric recordings of whole-thickness segments of the duodenum and middle jejunum were obtained by electric field stimulation under the influence of increasing doses of Ach (acetylocholine) in the presence of TTX (tetrodotoxin) and atropine. Moreover, structural properties of the intestinal wall were assessed, together with the expression of cholinergic and muscarinic receptors (M1 and M2). In both intestinal segments (duodenum and middle jejunum), EFS (electric field stimulation) impulses resulted in increased contractility and amplitude of contractions in group B compared to group C. Additionally, exposure to dietary butyrate led to a significant increase in tunica muscularis thickness in the duodenum, while mitotic and apoptotic indices were increased in the middle jejunum. The expression of M1 and M2 receptors in the middle jejunum was significantly higher after butyrate treatment. The results indicate increased cholinergic signaling and small intestinal growth and renewal in response to feeding with milk formula enriched with sodium butyrate in neonatal piglets.

Isolation, Identification and Optimization of Natural Colorant Producing Soil-borne Aspergillus niger and Analysis of the Extracted Pigment

Natural colorants have been used in various applications throughout human history, including food, dyes, pharmaceuticals, cosmetics, and various other products. The objective of this study was to separate the naturally occurring filamentous fungus Aspergillus niger from the soil and get pigments for prospective industrial uses. Five different soil samples were taken on the campus (botanical garden, polyhouse, agricultural farm) of Padmashri Vikhe Patil College, Pravaranagar, India. By using standard techniques, the Aspergillus niger was isolated and identified from the soil samples (morphological &amp; microscopic characteristics). To produce pigment, Aspergillus niger was cultured in five different liquid media for 7 days under shaking conditions: potato dextrose broth (PDB), Czapek-Dox broth (CDB), yeast extract malt extract broth (YMB), Sabouraud dextrose broth (SDB), and nutrient broth (NB). The pigments were extracted from the biomass using an ethanol-based extraction technique, and the biomass was then concentrated using a rotary evaporator. Five samples allowed for the isolation of Aspergillus niger, and a yield estimate for the brown pigment that was recovered from Aspergillus niger was made. Utilizing a UV-VIS spectrophotometer, secondary metabolites testing, and spectroscopic analysis of the pigments, it was determined whether they had antibacterial efficacy against test organisms. The composition of the medium had an impact on the pigment. In this study, this species produces more pigment after eight days of culture under various circumstances, including 25°C and pH 4. Carbon and nitrogen are the sources that are necessary for the creation of secondary metabolites and biomass. Temperature, pH, carbon supply, aeration, and fermentation type all affect the pigments because they are by-products of fermentation (solid or submerged). As low-cost, fungi can be used as color production cell factories. The food, pharmaceutical, bio-paint, and textile industries all have emerging uses for fungal pigments.

Anti-inflammation and gut microbiota regulation properties of fatty acids derived from fermented milk in mice with dextran sulfate sodium-induced colitis.

The by-products of milk fermentation by lactic acid bacteria provide potential health benefits to the balance of host intestinal microflora. In this study, the anti-inflammatory properties of fatty acids from monoculture-strain (Lactiplantibacillusplantarum A3) and multiple-strain (Streptococcus thermophilus, Lactobacillus bulgaricus, and L. plantarum A3 1:1:2) fermented milk were evaluated in a mouse model of dextran sulfate sodium-induced colitis, and the gut microbiota regulation properties of the fatty acids were also investigated. Results showed that fatty acids can attenuate the inflammatory response by inhibiting the expression of inflammatory factors IL-6 and tumor necrosis factor-α, and blocking the phosphorylation of the JNK in MAPK signal pathway. In addition, the relative abundance of the taxa Akkermansia and Lactobacillus were both enriched after the fatty acid intervention. This finding suggests that fatty acids from the milk fermentation with mixed lactic acid bacteria starters can reduce the severity of dextran sulfate sodium-induced colitis and enhance the abundance of the probiotics in the mice intestinal tract.

The Effect of Yogurt and Kefir Starter Cultures on Bioactivity of Fermented Industrial By-Product from Cannabis sativa Production—Hemp Press Cake

Cannabis sativa (hemp) is a plant considered to be abundant in bioactive compounds. The increasing production of hemp oil is leaving considerable amounts of hemp press cakes (HPC), which have not been sufficiently managed so far. One of the directions of development of plant-based food is the use of by-products of the agri-food industry in accordance with the idea of zero waste and the circular economy, so the purpose of this study was to determine the possibility of HPC fermentation using yogurt and kefir cultures and to determine the effect of the type of starter on the properties of the products. In the present study, starter cultures of yogurt (YO 122) and kefir (commercial grains) were used for HPC fermentation. Changes in lactic acid bacteria (LAB) and yeast population, pH, acidity, the content of bioactive compounds by spectrophotometric methods (proteins, amino acids, polyphenols, flavonoids, reducing sugars) and antioxidant activity (DDPH, ABTS, FRAP and reducing power) were determined. The results showed that it was possible to develop high-value beverages based on HPC with high fermentation efficiency: survivability of LAB and yeast (&gt;106 CFU/g) and acidification (pH in a range of 4.82–6.36 and 5.34–6.49 for yogurt and kefir culture, respectively). Moreover, the stability of hemp protein, with its variable free amino acid composition, antioxidant potential and presented changes in polyphenolic content, was observed during storage. The presented results show a new way to manage HPC as an oil industry residue by using it as a raw material for the development of a bioactive food product and illustrate the relationship between applied starter culture, the direction of fermentation and changes in the content of bioactive compounds.

Functional Food-drunk Crab with High GABA Production Obtained by Inoculating Fermentation Broth of &lt;i&gt;Lactobacillus brevisZ-215&lt;/i&gt; and Crab by-products into Drunk Crab

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the central nervous system and has various physiological functions. Recently, researchers have become interested in GABA-rich functional food design. Our laboratory obtained a strain named Lactobacillus brevisZ-215 with a high GABA production, which was used in previous studies. In this paper, we attempted to develop a GABA-rich drunk crab product using L. brevisZ-215 and crab by-products fermentation broth. The results revealed that the drunk crab products with the addition of bacterial and fermentation broths have high GABA content, close to 3 mg/mL. Furthermore, we improved the nutrition and flavor of the functional drunk crab. Additionally, we analyzed the shelf-life of drunken crabs by measuring the GABA content, pH, total volatile basic nitrogen, thiobarbituric acid, biogenic amine content, and colony count. The results of the measurements showed that the shelf-life was significantly longer compared to the uninoculated drunken crab and that the biogenic amine content was significantly suppressed.

In-depth investigation of the bioethanol and biogas production from organic and mineral acid pretreated sugarcane bagasse: Comparative and optimization studies

Organic acid pretreatment has generated much interest as one of the high potential methods for promoting enzymatic saccharification of lignocellulosic materials. Organic acids are preferred during pretreatment because they are less hazardous than conventional ones and produce less inhibitory fermentation by-products. In the present study, three organic acids (oxalic acid, citric acid, and acetic acid) and inorganic acid (hydrochloric acid) were studied to produce bioethanol and biogas from sugarcane bagasse. An optimization design (Box–Behnken Design (BBD)) among different optimization designs of response surface methodology (RSM) was considered to determine the pretreatment optimum conditions. On this basis, citric acid (CA)pretreatment resulted in maximum glucose yield (7.93 mg/mL) during saccharification. FTIR analysis of the pretreated samples showed that the structure of lignocellulose was changed in higher proportions for the sample pretreated with an organic acid. An increase in cellulose portion and maximum removal of hemicellulose with lower furan generations was observed in organic acid samples. In this study, the maximum solubilization of hemicellulose in hydrochloric acid was also observed due to the abundance of free H+ ions to catalyze the reaction. The ethanol and biogas yield increased by 1.96 and 1.85-fold for citric acid and oxalic acid pretreated sugarcane bagasse, respectively than untreated samples. The present study concluded that oxalic acid and citric acid pretreatment showed the potential to enhance the yield of bioethanol and biogas, respectively. An organic acid in the pretreatment of lignocellulosic biomass can replace traditional methods of using inorganic acids in biorefineries.

Impact of food preservatives based on immobilized phenolic compounds on an in vitro model of human gut microbiota

To address concerns about the biocompatibility of novel phenolic immobilization-based food preservatives, their impact on the composition and metabonomic profile of a defined community of human gut microbiota was evaluated. Three phenolics (eugenol, vanillin and ferulic acid) presented in two forms (free or immobilized on different supports) were tested at two concentration levels (0.5 and 2 mg/mL). Free eugenol was the phenolic with the greatest impact on gut microbiota, with a remarkable increase in the abundance of Lachnospiraceae and Akkermansiaceae families. In contrast, immobilized phenolics produced an increase in the abundance of Bacteroides with a reduction in the ratio of Firmicutes to Bacteroidetes. The metabonomic profile was also affected by free and immobilized phenolics differently in terms of fermentation by-products and phenolic biotransformation metabolites. Thus the results suggest the importance of evaluating the impact of new compounds or materials added to food on human gut microbiota and their potential use to modulate microbiota composition.

Changes in Bioactive Compounds, Antioxidant Activities and Chemical Properties of Pickled Tea By-Product Fermentation: Promising Waste Management and Value-Added Product

Pickled tea is an ethnic fermented product produced using Assam tea (Camellia sinensis var. assamica) leaves. It is produced in large quantities every year and the liquid waste from its production is estimated to be up to 2500 mL per every kilogram of pickled tea production. To reduce the waste, pickled tea juice remaining from the process was developed into (1) pineapple kombucha and (2) formulated functional drinks as “value added” products. The juice used for making kombucha was collected at 15 days of pickled tea fermentation due to its high value in antioxidant activity (previous study, 2250 µmol TE per g DW). After fermenting the juice with starter culture, the properties of pineapple kombucha were assessed at 0, 1, 3, 5, 7, 9, 11 days. Results showed that the total phenolic of pineapple kombucha was reduced, while antioxidant assay (FRAP and ORAC) slightly increased. The most suitable fermentation period of pineapple kombucha was at day 3. The formulated drink was made from mixing pineapple kombucha with ginger and lemon juice at various ratios including 100:0:0, 80:10:10 and 80:15:5. The ratio 80:10:10 gave the highest TP and antioxidant activity for the functional drink. In addition, for sensory analysis, liking attribute of 80:15:5 fermented juice kombucha pineapple favor was significantly higher compared to other formulations. The study demonstrates the promising second fermentation process of by-product juice from pickled tea production for the conversion to value-added functional drink with reasonable antioxidant properties.

Abstract P067: Sex-Specific Protection Of Fermentable Dietary Fiber On Salt-Sensitive Hypertension And Renal Function

Our recent data show that female Dahl Salt-Sensitive (SS) rats are significantly protected from salt-induced hypertension and renal injury and have stark differences in gut microbiota composition compared to males. Gut-derived metabolites are gaining recognition as mechanistic links between the microbiota and disease. One such metabolite is propionate, a protective short-chain fatty acid byproduct of bacterial fiber fermentation. Metabolomics revealed a specific elevation in serum propionate in female versus male SS rats after high salt (HS) (40.3±3.8 vs 24.4±4.2 μM, female vs male, p&lt;0.02, n=6), and propionate administration to male SS rats blunts salt-induced elevations in mean arterial pressure and albuminuria (MAP, HS21: 160.5±6.6 vs 141.8±3.5 mmHg, p&lt;0.05; albuminuria: 437.8±108.6 vs 263.6±50.33 mg/day, p&lt;0.19, control vs propionate, 200mM p.o.; n=3-4). Therefore, the current study hypothesized that substitution of non-fermentable fiber cellulose with the fermentable fiber inulin (AIN-76A, Dyets Inc), a known precursor of short-chain fatty acids, would attenuate salt-sensitivity in males. Males and females were placed on the 0.4% NaCl (LS) inulin diet for one week prior to the switch to a 4.0% NaCl (HS) inulin diet for 4 weeks (inulin-M: n=7, inulin-F: n=6). Controls were maintained on either LS or HS diets containing cellulose (control-M: n=9, control-F: n=11). While there were no significant MAP differences observed in males, the inulin diet significantly reduced albuminuria (370.8±32.4 vs 174.4±30.0 mg/day on HS28, control-M vs inulin-M, p&lt;0.001), reduced CD45+ renal leukocytes (35% reduction, p&lt;0.03), reduced BUN (21.6±2.0 vs 15.4±0.5 mg/dL, p&lt;0.05), and increased creatinine clearance (0.44±0.02 vs 0.55±0.02 ml/min/g KW, p&lt;0.001). In females, inulin significantly lowered MAP (170.2±6.2 vs 154.6±4.5 mmHg on HS28, control-F vs inulin-F, p&lt;0.01), albuminuria (180.3±27.4 vs 68.0±8.3, p&lt;0.001), BUN (21.7±1.2 vs 17.9±0.6 mg/dL, p&lt;0.05), and improved creatinine clearance (0.53±0.04 vs 0.71±0.05 ml/min/g KW, p&lt;0.05). In summary, substitution of the fermentable fiber inulin reduced blood pressure only in females, but all other measures indicate improved renal injury, function, and inflammation in both sexes.

Influence of free and immobilized chitosan on a defined human gut microbial ecosystem

In this work, the influence of different forms of presentation of chitosan in the human gut microbiota with a defined bacterial community was evaluated. First, the susceptibility of individual gut bacterial isolates against chitosan was studied within a concentration range between 0.125 and 1 mg/mL. Then, the impact of chitosan (0.25 and 1 mg/mL) on a defined human gut microbial ecosystem was studied by metagenomic and metabonomic analyses. The results showed that chitosan in its free form had a high impact on individual isolates with a minimum inhibitory concentration below 1 mg/mL for most of the strains studied. In comparison, chitosan immobilized in the different carriers displayed a diverse effect on gut microbiota. The most susceptible strains were Agathobacter rectalis strain 16-6-I 1 FAA, Clostridium spiroforme strain 16-6-I 21 FAA and Mediterraneibacter faecis strain 16-6-I 30 FAA. The impact of the different modes of presentation of chitosan was strain-specific and species-specific when compared to results obtained from analysis of other strains within the genera Agathobacter, Clostridium and Mediterraneibacter, and therefore a study using a defined ecosystem was needed to extrapolate the results. Significant decreases in defined community richness and diversity and changes in metabolic profile were observed after exposure to free chitosan. Free chitosan produced significant reductions in the abundance of the genera Lachnoclostridium, Anaerotignum, Blautia, Enterococcus, Eubacterium and Ruthenibacterium together with a slight decrease of the production of SCFAs, among other fermentation by-products. The immobilized chitosan significantly alleviated the impact caused by the antimicrobial polymer and significantly increased the relative abundance of the Bacteroidetes phylum compared to free chitosan. These results suggest the significance of assessing the impact of new ingredients and materials included in food on the human gut microbiota with models that simulate the gastrointestinal environment, such as in vitro bioreactor systems.

Lysine acetylation of Escherichia coli lactate dehydrogenase regulates enzyme activity and lactate synthesis.

As an evolutionarily conserved posttranslational modification, protein lysine acetylation plays important roles in many physiological and metabolic processes. However, there are few reports about the applications of lysine acetylation in metabolic regulations. Lactate is a main byproduct in microbial fermentation, and itself also an important bulk chemical with considerable commercial values in many fields. Lactate dehydrogenase (LdhA) is the key enzyme catalyzing lactate synthesis from pyruvate. Here, we reported that Escherichia coli LdhA can be acetylated and the acetylated lysine sites were identified by mass spectrometry. The effects and regulatory mechanisms of acetylated sites on LdhA activity were characterized. Finally, lysine acetylation was successfully used to regulate the lactate synthesis. LdhA (K9R) mutant overexpressed strain improved the lactate titer and glucose conversion efficiency by 1.74 folds than that of wild-type LdhA overexpressed strain. LdhA (K154Q-K248Q) mutant can inhibit lactate accumulation and improve 3HP production. Our study established a paradigm for lysine acetylation in lactate synthesis regulation and suggested that lysine acetylation may be a promising strategy to improve the target production and conversion efficiency in microbial synthesis. The application of lysine acetylation in regulating lactate synthesis also provides a reference for the treatment of lactate-related diseases.

Influence of indigenous Hanseniaspora uvarum and Saccharomyces cerevisiae from sugar-rich substrates on the aromatic composition of loquat beer

The demand for unique and exclusive food products and beverages is constantly on the increase. One of the products that mostly evolved to encounter market dynamics in the last decade is craft beer. For a long time, craft breweries have included fruit in beer production to enrich flavour and aroma profile of different beer styles. In this study, for the first time, the use of Saccharomyces and non-Saccharomyces yeast strains isolated from high-sugar matrices (manna and fermented honey by-products) were investigated to diversify fruit craft beer production, in order to improve the fermentation process and highlight the complexity of aroma profiles generated during alcoholic fermentation. Two yeast strains, Hanseniaspora uvarum YGA34 and Saccharomyces cerevisiae MN113, were tested as co-starters and starters for their beer production capacity. Commercial yeast strain US-05 was used as control. Loquat juice was added at the end of primary alcoholic fermentation in all trials. Interestingly, S. cerevisiae MN113 consumed sugars faster than control strain S. cerevisiae US-05, including maltose, even in the case of sequential inoculation. This strain showed an excellent ability to consume rapidly sugars present. All strains showed their concentrations ranged between 5 and 8 Log cycles during fermentation. The absence of off-odours and the improvement of aromatic perception were observed in experimental trials involving the use of S. cerevisiae MN113 as a monoculture and in sequential combination with H. uvarum YGA34. Esters and alcohols were the most abundant compounds emitted from the beers. The beers produced with sequential inoculation of H. uvarum YGA34 and S. cerevisiae MN113 or US-05 are characterised by a higher ester and lower alcohol concentration. These two unconventional yeast strains from high sugar matrices showed great technological properties, representing promising co-starters and starter during craft fruit beer production.

Microbiome-Based Hypothesis on Ivermectin's Mechanism in COVID-19: Ivermectin Feeds Bifidobacteria to Boost Immunity.

Ivermectin is an anti-parasitic agent that has gained attention as a potential COVID-19 therapeutic. It is a compound of the type Avermectin, which is a fermented by-product of Streptomyces avermitilis. Bifidobacterium is a member of the same phylum as Streptomyces spp., suggesting it may have a symbiotic relation with Streptomyces. Decreased Bifidobacterium levels are observed in COVID-19 susceptibility states, including old age, autoimmune disorder, and obesity. We hypothesize that Ivermectin, as a by-product of Streptomyces fermentation, is capable of feeding Bifidobacterium, thereby possibly preventing against COVID-19 susceptibilities. Moreover, Bifidobacterium may be capable of boosting natural immunity, offering more direct COVID-19 protection. These data concord with our study, as well as others, that show Ivermectin protects against COVID-19.

Histological structure and evaluation of cellular layers of Large intestine in Guinea pig (Cavia porcellus)

The Aim of this study is to determine the histological structure in the wall layers of large intestine of guinea pig. The cecum and colon was characterized by a delicate lining that is moisturized by mucus and also by a gel that is a by-product of bacterial fermentation. This study was performed on the cecum and ascending and descending colon in five health animals. The cecum and colon wall was composed of four tunicae (mucosa, submucosa, muscularis and serosa, the tunica mucosa consist of epithelium, lamina propria and muscularis mucosa. The colon lumen lined by simple columnar epithelium with prominent goblet cells. The epithelial surface of the colon is covered by the openings of tubular intestinal glands which penetrate deep into the thick mucosa. The glands consist of absorptive cells that absorb water and salt, goblet cells were secrete the mucus, and scattered Paneth cells. Crypts of Lie beckon (intestinal glands) are a simple tubular glands is observe in most mammals, which extending from the muscularis mucosa through the thickness of the lamina propria and they open into the intestinal lumen. Muscularis mucosa, consisted of very thin two layers of inner circular and outer longitudinal smooth muscles, the greater thickness of the muscularis mucosa was in the adult type and the submucosa was consists of dense a irregular connective tissue. The muscular layer is consists of internal circular and external longitudinal layers of smooth muscles, which mean their thickness is decreased toward the last parts. Thus, the serous coat is a thin layer of loose connective tissue, the thickness was decreases toward the last parts.

Enhanced Acetate Tolerance and Recombinant Protein Accumulation in Escherichia coli by Transgenic Expression of a Heat Shock Protein from Carrot (Daucus carota L.).

In Escherichia coli (E. coli) culture, acetate accumulates as an undesirable by-product of aerobic fermentation on glucose and inhibits cell growth and recombinant protein production. We examined whether the heterologous expression of a eukaryotic heat shock protein (Hsp) can confer tolerance to acetate in E. coli. Transgenic cell lines (TCLs) heterologously expressing a small heat shock protein (sHsp) from carrot (Daucus carota L.), DcHsp17.7, were exposed to heat, sodium acetate, and alkaline conditions. The cell growth and cell viability were examined by measuring O.D.600 and colony-forming units (CFU), respectively. The His-tagged recombinant alcohol dehydrogenase (ADH) gene cloned in a pET11a expression vector was introduced into TCL1 and expressed by isopropyl β-D-1-thiogalactopyranoside treatment. After purifying using Ni-NTA affinity chromatography, its accumulation levels were examined using SDS-PAGE in the presence of acetate. TCLs constitutively expressing DcHsp17.7 showed improved growth, cell density, and cell viability under the stress conditions of heat, acetate, and alkaline compared to an empty vector control line. In acetate stress conditions, TCL1 accumulated more cellular proteins (approximately 130%) than the control. The recombinant ADH accumulated to a higher level in TCL1 (2.2-fold at 16 °C) than the control. The addition of acetate reduced the recombinant ADH level by 70% in the control when compared with the absence of acetate. In contrast, recombinant ADH accumulation was not affected by acetate in TCL1. In the presence of acetate, TCL1 accumulated 6.4-fold more recombinant ADH than did the control. Furthermore, recombinant ADH produced in TCL1 showed 1.5-fold higher enzyme activity than that produced in the control in the presence or absence of acetate. Our study showed that heterologously expressed DcHsp17.7 from carrot can alleviate the negative effects of acetate on E. coli.