Multifunctional nutraceutical composition based on fermented spirulina, apple cider vinegar, Jerusalem artichoke, and bovine colostrum

The main purpose of this experiment was to develop a multifunctional nutraceutical composition based on ingredients of different origins (Spirulina powder (SP), bovine colostrum (BC), Jerusalem artichoke powder (JAP), and apple cider vinegar (ACV)) which possess different health benefits through their different mechanisms of action. In order to improve the functional properties of Spirulina and bovine colostrum, fermentation with the Pediococcus acidilactici No. 29 and Lacticaseibacillus paracasei LUHS244 strains, respectively, was carried out. These LAB strains were chosen due to their good antimicrobial properties. The following parameters were analysed: for Spirulina (non-treated and fermented)—pH, colour coordinates, fatty acid profile, and contents of L-glutamic and GABA acids; for bovine colostrum (non-treated and fermented)—pH, colour coordinates, dry matter, and microbiological parameters (total LAB, total bacteria, total enterobacteria, Escherichia coli, and mould/yeast counts); for the produced nutraceuticals—hardness, colour coordinates, and overall acceptability. It was established that fermentation reduced the pH of the SP and BC and affected their colour coordinates. Fermented SP contained a greater concentration of gamma-aminobutyric and L-glutamic acids (by 5.2 times and 31.4% more, respectively), compared to the non-treated SP and BC. In addition, the presence of gamma-linolenic and omega-3 fatty acids was observed in fermented SP. Fermentation of BC reduces Escherichia coli, total bacteria, total enterobacteria, and total mould/yeast counts in samples. The obtained three-layer nutraceutical (I layer—fermented SP; II—fermented BC and JAP; III—ACV) demonstrated a high overall acceptability. Finally, our finding suggest that the selected nutraceutical combination has immense potential in the production of a multifunctional product with improved functionality and a high acceptability.info:eu-repo/semantics/publishedVersio

ANTIMICROBIAL ACTIVITY OF EXTRACTS FROM IN VIVO AND IN VITRO PROPAGATED LAMIUM ALBUM L. PLANTS

The antimicrobial activity of 18 different extracts from in vivo and in vitro grown L. album L. plants was evaluated against clinical bacteria and yeasts using the well diffusion method. All the used extracts demonstrated antibacterial activity, whereas only the water extracts from leaves (in vivo) possessed antifungal activity against Candida albicans NBIMCC 72 and Candida glabrata NBIMCC 8673 (14 and 20 mm diameter of inhibition zones and MIC 10 mg/ml, respectively). The methanol and ethanol extracts obtained from the in vitro propagated plants had a broader spectrum of antibacterial activity than those from in vivo plants, while the opposite tendency was observed for the chloroform extracts. All tested flower extracts possessed antimicrobial activity. The chloroform extract from in vivo flowers demonstrated the highest activity against E. faecalis NBIMCC 3915, S. aureus NBIMCC 3703, P. hauseri NBIMCC 1339 and P. aeruginosa NBIMCC 3700 (22 mm, 13 mm, 11 mm, 23 mm zone diameter of inhibition and MIC 0.313 mg/ml, respectively). The water extracts from leaves (both in vivo and in vitro) possessed higher antibacterial activity than extract from flowers. The obtained results showed that both in vivo and in vitro propagated L. album L. could be used as a source of antibacterial substances

New Exopolysaccharides Produced by Bacillus licheniformis 24 Display Substrate-Dependent Content and Antioxidant Activity

Bacillus licheniformis is a soil bacterium with many industrial applications. In addition to enzymes, platform chemicals, antibiotics and phytohormones, the species produces exopolysaccharides (EPSs) of various biological activities. This study revealed that Bulgarian isolate B. licheniformis 24 produced EPSs consisting of galactose, glucose and mannose with substrate-dependent ratio. From glucose, B. licheniformis 24 secreted EPS1, consisting of 54% galactose, 39% glucose and 7% mannose. From fructose, the strain formed EPS2, containing 51% glucose, 30% mannose and 19% galactose. Batch cultivation in flasks yielded 2.2–2.6 g/L EPS1 and 1.90–2.11 g/L EPS2. Four to five times higher yields of EPS were obtained from both substrates during batch and fed-batch processes in a fermenter at 37.8 °C, pH 6.2 and aeration 3.68 vvm. The batch process with 200 g/L of starting substrates received 9.64 g/L EPS1 and 6.29 g/L EPS2, reaching maximum values at the 33rd and 24th h, respectively. Fed-batch fermentation resulted in the highest yields, 12.61 g/L EPS1 and 7.03 g/L EPS2. In all processes, EPSs were produced only in the exponential growth phase. Both EPSs exhibited antioxidant activity, but EPS2 was much more potent in this regard, reaching 811 μM Vitamin C Equivalent Antioxidant Capacity (versus 135 μM for EPS1). EPS1 displayed antibacterial activity against a non-O1 strain of Vibrio cholerae

Current Advances in Microbial Production of Acetoin and 2,3-Butanediol by Bacillus spp.

The growing need for industrial production of bio-based acetoin and 2,3-butanediol (2,3-BD) is due to both environmental concerns, and their widespread use in the food, pharmaceutical, and chemical industries. Acetoin is a common spice added to many foods, but also a valuable reagent in many chemical syntheses. Similarly, 2,3-BD is an indispensable chemical on the platform in the production of synthetic rubber, printing inks, perfumes, antifreeze, and fuel additives. This state-of-the-art review focuses on representatives of the genus Bacillus as prospective producers of acetoin and 2,3-BD. They have the following important advantages: non-pathogenic nature, unpretentiousness to growing conditions, and the ability to utilize a huge number of substrates (glucose, sucrose, starch, cellulose, and inulin hydrolysates), sugars from the composition of lignocellulose (cellobiose, mannose, galactose, xylose, and arabinose), as well as waste glycerol. In addition, these strains can be improved by genetic engineering, and are amenable to process optimization. Bacillus spp. are among the best acetoin producers. They also synthesize 2,3-BD in titer and yield comparable to those of the pathogenic producers. However, Bacillus spp. show relatively lower productivity, which can be increased in the course of challenging future research

Lactic Acid Fermentation of Cereals and Pseudocereals: Ancient Nutritional Biotechnologies with Modern Applications

Grains are a substantial source of macronutrients and energy for humans. Lactic acid (LA) fermentation is the oldest and most popular way to improve the functionality, nutritional value, taste, appearance and safety of cereal foods and reduce the energy required for cooking. This literature review discusses lactic acid fermentation of the most commonly used cereals and pseudocereals by examination of the microbiological and biochemical fundamentals of the process. The study provides a critical overview of the indispensable participation of lactic acid bacteria (LAB) in the production of many traditional, ethnic, ancient and modern fermented cereals and beverages, as the analysed literature covers 40 years. The results reveal that the functional aspects of LAB fermented foods are due to significant molecular changes in macronutrients during LA fermentation. Through the action of a vast microbial enzymatic pool, LAB form a broad spectrum of volatile compounds, bioactive peptides and oligosaccharides with prebiotic potential. Modern applications of this ancient bioprocess include the industrial production of probiotic sourdough, fortified pasta, cereal beverages and “boutique” pseudocereal bread. These goods are very promising in broadening the daily menu of consumers with special nutritional needs

Butanol Tolerance of Lactiplantibacillus plantarum: A Transcriptome Study

Biobutanol is a promising alternative fuel with impaired microbial production thanks to its toxicity. Lactiplantibacillus plantarum (L. plantarum) is among the few bacterial species that can naturally tolerate 3% (v/v) butanol. This study aims to identify the genetic factors involved in the butanol stress response of L. plantarum by comparing the differential gene expression in two strains with very different butanol tolerance: the highly resistant Ym1, and the relatively sensitive 8-1. During butanol stress, a total of 319 differentially expressed genes (DEGs) were found in Ym1, and 516 in 8-1. Fifty genes were upregulated and 54 were downregulated in both strains, revealing the common species-specific effects of butanol stress: upregulation of multidrug efflux transporters (SMR, MSF), toxin-antitoxin system, transcriptional regulators (TetR/AcrR, Crp/Fnr, and DeoR/GlpR), Hsp20, and genes involved in polysaccharide biosynthesis. Strong inhibition of the pyrimidine biosynthesis occurred in both strains. However, the strains differed greatly in DEGs responsible for the membrane transport, tryptophan synthesis, glycerol metabolism, tRNAs, and some important transcriptional regulators (Spx, LacI). Uniquely upregulated in the butanol-resistant strain Ym1 were the genes encoding GntR, GroEL, GroES, and foldase PrsA. The phosphoenolpyruvate flux and the phosphotransferase system (PTS) also appear to be major factors in butanol tolerance

Enhanced Activity by Genetic Complementarity: Heterologous Secretion of Clostridial Cellulases by Bacillus licheniformis and Bacillus velezensis

To adapt to various ecological niches, the members of genus Bacillus display a wide spectrum of glycoside hydrolases (GH) responsible for the hydrolysis of cellulose and lignocellulose. Being abundant and renewable, cellulose-containing plant biomass may be applied as a substrate in second-generation biotechnologies for the production of platform chemicals. The present study aims to enhance the natural cellulase activity of two promising 2,3-butanediol (2,3-BD) producers, Bacillus licheniformis 24 and B. velezensis 5RB, by cloning and heterologous expression of cel8A and cel48S genes of Acetivibrio thermocellus. In B. licheniformis, the endocellulase Cel8A (GH8) was cloned to supplement the action of CelA (GH9), while in B. velezensis, the cellobiohydrolase Cel48S (GH48) successfully complemented the activity of endo-cellulase EglS (GH5). The expression of the natural and heterologous cellulase genes in both hosts was demonstrated by reverse-transcription PCR. The secretion of clostridial cellulases was additionally enhanced by enzyme fusion to the subtilisin-like signal peptide, reaching a significant increase in the cellulase activity of the cell-free supernatants. The results presented are the first to reveal the possibility of genetic complementation for enhancement of cellulase activity in bacilli, thus opening the prospect for genetic improvement of strains with an important biotechnological application

Enhanced heterologous gene expression in diploid cells of methylotrophic yeast Hansenula (Ogataea) polymorpha

The expression of bacterial gusA gene encoding for E. coli enzyme β-glucuronidase in haploid and diploid cells of methylotrophic yeast Hansenula (Ogataea) polymorpha was studied. Haploid strains were transformed with plasmid carrying gusA gene under the control of strong alcohol oxidase (AOX) promoter and several Gus+ transformants were isolated. They were crossed with wild type strains lacking Gus activity. The resulting diploids were sporulated and several meiotic segregants with increased Gus activity were isolated. Some of these segregants were crossed and the corresponding diploid strains were obtained. It was found that Gus activity of diploid strains was twice higher compared to haploids, whereas Gus activity of diploids was increased about six fold compared to those of haploids. Our results can be used as an approach for development of yeast strains with elevated expression of heterologous proteins

Biogas Production Potential of Thermophilic Anaerobic Biodegradation of Organic Waste by a Microbial Consortium Identified with Metagenomics

Anaerobic digestion (AD) is a widespread biological process treating organic waste for green energy production. In this study, wheat straw and corn stalks without any harsh preliminary treatment were collected as a renewable source to be employed in a laboratory-scale digester to produce biogas/biomethane. Processes parameters of temperature, pH, total solids, volatile solid, concentration of volatile fatty acids (VFA), and cellulose concentration, were followed. The volume of biogas produced was measured. The impact of organic loading was stated, showing that the process at 55 °C tolerated a higher substrate load, up to 45 g/L. Further substrate increase did not lead to biogas accumulation increase, probably due to inhibition or mass transfer limitations. After a 12-day anaerobic digestion process, cumulative volumes of biogas yields were 4.78 L for 1 L of the bioreactor working volume with substrate loading 30 g/L of wheat straw, 7.39 L for 40 g/L and 8.22 L for 45 g/L. The degree of biodegradation was calculated to be 68.9%, 74% and 72%, respectively. A fast, effective process for biogas production was developed from native wheat straw, with the highest quantity of daily biogas production occurring between day 2 and day 5. Biomethane concentration in the biogas was 60%. An analysis of bacterial diversity by metagenomics revealed that more than one third of bacteria belonged to class Clostridia (32.9%), followed by Bacteroidia (21.5%), Betaproteobacteria (11.2%), Gammaproteobacteria (6.1%), and Alphaproteobacteria (5%). The most prominent genera among them were Proteiniphilum, Proteiniborus, and Pseudomonas. Archaeal share was 1.37% of the microflora in the thermophilic bioreactor, as the genera Methanocorpusculum, Methanobacterium, Methanomassiliicoccus, Methanoculleus, and Methanosarcina were the most abundant. A knowledge of the microbiome residing in the anaerobic digester can be further used for the development of more effective processes in conjunction with theidentified consortium