In-vitro antibacterial, antifungal, antioxidant and functional properties of Bacillus amyloliquefaciens

Protein Extraction from Chlorella pyrenoidosa Using Bacillus spp. Isolated from Jeotgal: Strain isolation, Characterization, and Fermentation

Chlorella pyrenoidosa, a versatile microalga with a rich nutritional profile and functional components, has various applications. However, rigid cell walls pose challenges for the effective extraction of proteins. Microbial fermentation is a promising solution for large-scale production and industrial applications. This study aimed to isolate Bacillus spp. with high enzymatic activity from Jeotgal, a Korean traditional fermented food, and enhance protein extraction from C. pyrenoidosa using microbial fermentation with the isolated Bacillus spp. Twenty-two strains of Bacillus spp. were isolated, and eight Bacillus species were selected based on their ability to produce cellulases, proteases, and lipases. Microbial safety was further assessed by testing for biogenic amine production and hemolytic activity. All eight strains exhibited γ-hemolysis, with four strains not producing biogenic amines. Notably, fermentation using Bacillus amyloliquefaciens F2 showed the highest protein extraction yield at 35.45 ± 1.21% (v/v). In conclusion, this study demonstrates the potential of microbial fermentation for protein extraction from C. pyrenoidosa, offering a novel approach for its utilization in the food industry.

Assessment of microbial antagonistic activity and Quorum Sensing Signal Molecule (Cyclopeptides-DKPs and N-Acyl Homoserine Lactones) detection in bacterial strains obtained from avocado thrips (Thysanoptera: Thripidae)

The control of avocado pests and diseases heavily relies on the use of several types of pesticides, some of which are strictly monitored or not internationally accepted. New sources of bioactive molecules produced by phytopathogen-inhibiting microorganisms offer an excellent alternative for the control of pests and diseases. This study explores the potential antagonistic action against phytopathogenic microorganisms, using bacterial strains obtained from avocado thrips. In addition, we detected and identified quorum sensing (QS) signaling molecules that are related to virulence factors and antibiotic production. The results showed that Bacillus, Pantoea, and Serratia strains exhibited antagonism against five fungal phytopathogens. Additionally, some bacteria also produce specific signaling molecules like N-3-(oxododecanoyl)-l-homoserine lactone (OdDHL), N-(3-oxo)-hexanoyl l-HL (OHHL), 4‑hydroxy-2-heptylquinoline (HHQ) or 2-heptyl-3,4-dihydroxyquinoline (PQS, Pseudomonas quinolone signal), cyclo(L-Phe-l-Pro), and cyclo(L-Pro-l-Tyr, which might give them antimicrobial properties. This research explores the biotechnological potential of these bacteria in fighting the diseases affecting avocados in Colombia.

Diversity of culturable bacterial isolates and their potential as antimicrobial against human pathogens from Afar region, Ethiopia

Antimicrobial resistance is a growing global concern exacerbated by the scarcity of new medications and resistance to current antibiotics. Microbes from unexplored habitats are promising sources of natural products to combat this challenge. This study aimed to isolate bacteria producing secondary metabolites and assess their antimicrobial efficacy against human pathogens. Soil and liquid samples were collected from Afar region, Ethiopia. Bacterial isolates were obtained using standard serial dilution techniques. Antimicrobial activity was evaluated using agar plug and well diffusion methods. matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF MS) and whole-genome sequencing (WGS) were conducted for the isolate exhibiting the highest antimicrobial activity. Secondary metabolites were extracted and analyzed using gas chromatography-mass spectra (GC-MS). In this study, 301 bacteria isolates were identified, of which 68 (22.6%) demonstrated antagonistic activity against at least one reference pathogen. Whole-genome sequencing revealed that Sl00103 belongs to the genus Bacillus, designated as Bacillus sp. Sl00103. The extract of Sl00103 showed zones of inhibition ranging between 17.17 ± 0.43 and 26.2 ± 0.4 mm against bacterial pathogens and 19.5 ± 0.44 to 21.0 ± 1.01 mm against Candida albicans. GC-MS analysis of ethyl acetate and n-hexane extracts identified major compounds including (R,R)-butane-2,3-diol; 3-isobutylhexahydropyrrolo[1,2a] pyrazine-1,4-dione; cyclo(L-prolyl-L-valine); and tetradecanoic acid, 12-methyl-, methyl ester; hexadecanoic acid, methyl ester among other. In conclusion, this study isolated several promising bacterial strains from the Afar region in Ethiopia, with strain Sl00103 (Bacillus sp. Sl00103) demonstrating notable antimicrobial and antioxidant activities and warranting further studies.

IMPORTANCE

Antimicrobial resistance (AMR) is an escalating global health threat affecting humans, animals, and the environment, underscoring the urgent need for alternative pathogen control methods. Natural products, particularly secondary metabolites from bacteria, continue to be a vital source of antibiotics. However, microbial habitats and metabolites in Africa remain largely unexplored. In this study, we isolated and screened bacteria from Ethiopia's Afar region, characterized by extreme conditions like high temperatures, volcanic activity, high salinity, and hot springs to identify potential bioactive compounds. We discovered diverse bacterial isolates with antimicrobial activity against various pathogens, including strain Sl00103 (Bacillus sp. Sl00103), which demonstrated significant antimicrobial and antioxidant activities. GC-MS analysis identified several antimicrobial compounds, highlighting strain Sl00103 as a promising source of secondary metabolites with potential pharmaceutical applications and warranting further investigation.

Molecular characterization and multifunctional evaluation of lactic acid bacteria isolated from traditional sourdough

The primary objective of this study was to characterize lactic acid bacteria (LAB) strains derived from sourdough for possible utilization as functional starters to produce sourdough and various cereal-based fermented foods. A total of 350 autochthonous LAB strains were isolated from 65 Type I sourdough samples and characterized using six random amplified polymorphic DNA (RAPD) primers at intra- and interspecific levels. Species identification of selected strains representing distinct clusters from RAPD analysis was performed based on the 16S rRNA region. The LAB strains were identified as Companilactobacillus crustorum (n = 135), Levilactobacillus brevis (n = 125), Latilactobacillus curvatus (n = 40), Companilactobacillus paralimentarius (n = 32), and Lactiplantibacillus plantarum (n = 18). A total of 66 LAB strains were selected for technological characterization along with two commercial strains. The characterization involved acidity development, EPS production potential, leavening activity, and growth abilities under harsh conditions. Principle component analysis (PCA) identified 2 Lp. plantarum and 14 Lev. brevis strains as the most relevant technologically. Among them, Lp. plantarum L35.1 and Lev. brevis L37.1 were resistant to tetracycline. Evaluation of probiotic characteristics (survival in pH 2.5 and bile presence, auto aggregation capacity, hydrophobic activity, antioxidant activity, antimicrobial activity) by PCA identified four strains with relevance to Lactobacillus rhamnosus GG (LGG), which were further selected for in vitro digestion assays. Lactiplantibacillus plantarum L7.8, Lev. brevis L55.1, and L62.2 demonstrated similar viability indices to LGG, along with increased auto aggregation capacity and antioxidant activity. These strains are promising as candidate starters for producing sourdough and sourdough-related fermented food products.

Harnessing bacterial endophytes for environmental resilience and agricultural sustainability

In the current era of environmental disasters and the necessity of sustainable development, bacterial endophytes have gotten attention for their role in improving agricultural productivity and ecological sustainability. This review explores the multifaceted contributions of bacterial endophytes to plant health and ecosystem sustainability. Bacterial endophytes are invaluable sources of bioactive compounds, promising breakthroughs in medicine and biotechnology. They also serve as natural biocontrol agents, reducing the need for synthetic fertilizers and fostering environmentally friendly agricultural practices. It provides eco-friendly solutions that align with the necessity of sustainability since they can improve pest management, increase crop resilience, and facilitate agricultural production. This review also underscores bacterial endophytes' contribution to promoting sustainable and green industrial productions. It also presented how incorporating these microorganisms into diverse industrial sectors can harmonize humankind with ecological stability. The potential of bacterial endophytes has been largely untapped, presenting an opportunity for pioneering advancements in sustainable industrial applications. Their importance caught attention as they provided innovative solutions to the challenging problems of the new era. This review sheds light on the remarkable potential of bacterial endophytes in various industrial sectors. Further research is imperative to discover their multifaceted potential. It will be essential to delve deeper into their mechanisms, broaden their uses, and examine their long-term impacts.

[Identification and antifungal activity of halophilic bacteria isolated from saline soils in Campeche, México]

Phytopathogenic fungi Alternaria alternata and Colletotrichum gloeosporioides cause diseases in plant tissues as well as significant postharvest losses. The use of chemical fungicides for their control has negative effects on health and the environment. Secondary metabolites from halophilic bacteria are a promising alternative for new antifungal compounds. In the present study, halophilic bacteria were isolated and characterized from two sites with saline soils called branquizales in Campeche, Mexico. A total of 64 bacteria were isolated. Agrobacterium, Bacillus, Inquilinus, Gracilibacillus, Metabacillus, Neobacillus, Paenibacillus, Priestia, Staphylococcus, Streptomyces and Virgibacillus were among the identified genera. The antifungal potential of the culture supernatant (CS) of 39 halophilic bacteria was investigated against C. gloeosporioides and A. alternata. The bacteria showing the greatest inhibition of mycelial growth corresponded to Bacillus subtilis CPO 4292, Metabacillus sp. CPO 4266, Bacillus sp. CPO 4295 and Bacillus sp. CPO 4279. The CS of Bacillus sp. CPO 4279 exhibited the highest activity and its ethyl acetate extract (AcOEt) inhibited the germination of C. gloeosporioides, with IC50 values of 8,630μg/ml and IC90 of 10,720μg/ml. The organic partition of the AcOEt extract led to three fractions, with acetonitrile (FAcB9) showing the highest antifungal activity, with values exceeding 66%. Halophilic bacteria from 'blanquizales' soils of the genus Bacillus sp. produce metabolites with antifungal properties that inhibit the phytopathogenic fungus C. gloeosporioides.

Curcumin Loaded onto Folic acid Carbon dots as a Potent drug Delivery System for Antibacterial and Anticancer Applications

Numerous malignancies have been shown to be successfully treated with Curcumin. Despite its promising effects, Curcumin has limitations in clinical studies because of its stability, low water solubility, and adsorption. Carbon quantum dots with high biocompatibility can be employed as nanostructured material carriers to enhance Curcumin availability. In this study, folic acid was used as the raw material for the hydrothermal preparation of carbon dots, followed by the loading of Curcumin onto the carbon dots to form a folic acid carbon dot/Curcumin nanocomposite. The morphology and the chemical structure of the synthesized carbon dots were investigated. Folic acid carbon dots displayed robust emission peaks with a quantum yield of 41.8%. Moreover, the adsorption effectiveness of Curcumin on carbon dots was determined to be 83.11%. The liberating pattern of Curcumin was pH-dependent and reached 36 and 27% after a few hours at pH 5 and 7.4, respectively. The release occurs via the Fickiann diffusion mechanism with ah n value less than 0.45.The nanocomposite was tested for antibacterial activity against gram-negative Pseudomonas aeruginosa ATCC 27,853 and gram-positive Staphylococcus aureus ATCC 25,923. The nanocomposite displayed antibacterial behavior with MIC 12.5 µg/mL. The anticancer activities of the nanocomposite were further tested against high-folate receptor-expressing Hela cells (cervical malignancy) and low-folate receptor-expressing HepG2 cells (hepatocellular carcinoma). Folic acid carbon dot/Curcumin nanocomposite reduced Hela cell viability at an IC50 of 88.723 ± 0.534 g/mL. On the other hand, HepG2 cells showed no toxicity response.

Probiotic Potentials of Lactic Acid Bacteria and Yeasts from Raw Goat Milk in Nigeria

Probiotic microorganisms are incorporated in foods due to their numerous health benefits. We investigated lactic acid bacteria (LAB) and yeasts isolated from goat milk in Nigeria for novel probiotic strains. In this study, a total of 27 LAB and 23 yeast strains were assessed for their probiotic potentials. Only six LAB strains (Weissella cibaria GM 93m3, Weissella confusa GM 92m1, Pediococcus acidilactici GM 18a, Pediococcus pentosaceus GM 23d, Lactiplantibacillus pentosus GM 102s4, Limosilactobacillus fermentum GM 30m1) and four yeast strains (Candida tropicalis 12a, C. tropicalis 33d, Diutina rugosa 53b, and D. rugosa 77a) identified using partial 16S and 26S rDNA sequencing, respectively, showed survival at pH 2.5, 0.3% bile salt, and simulated gastrointestinal conditions and possessed auto-aggregative and hydrophobic properties, thus satisfying key in vitro criteria as probiotics. All LAB strains showed coaggregation properties and antimicrobial activities against pathogens. Pediococcus pentosaceus GM 23d recorded the strongest coaggregation percentage (34-94%) against 14 pathogens, while W. cibaria GM 93m3 showed the least (6-57%) against eight of the 14 pathogens. The whole cell and extracellular extracts of LAB and yeast strains, with the exception of D. rugosa 77a, had either 2,2-diphenyl-1-picryl-hydrazyl and/or hydroxyl radical scavenging activity. In conclusion, all six LAB and four yeast strains are important probiotic candidates that can be further investigated for use as functional starter cultures.

Effects of the probiotic Bacillus cereus GM on experimental schistosomiasis mansoni

Probiotics contribute to the integrity of the intestinal mucosa and preventing dysbiosis caused by opportunistic pathogens, such as intestinal helminths. Bacillus cereus GM obtained from Biovicerin® was cultured to obtain spores for in vivo evaluation on experimental schistosomiasis. The assay was performed for 90 days, where all animals were infected with 50 cercariae of Schistosoma mansoni on the 15th day. Three experimental groups were formed, as follows: G1-saline solution from the 1st until the 90th day; G2-B. cereus GM (105 spores in 300 μL of sterile saline) from the 1st until the 90th day; and G3-B. cereus GM 35th day (onset of oviposition) until the 90th day. G2 showed a significant reduction of 43.4% of total worms, 48.8% of female worms and 42.5% of eggs in the liver tissue. In G3, the reduction was 25.2%, 29.1%, and 44% of the total number of worms, female worms, and eggs in the liver tissue, respectively. G2 and G3 showed a 25% (p < 0.001) and 22% (p < 0.001) reduction in AST levels, respectively, but ALT levels did not change. ALP levels were reduced by 23% (p < 0.001) in the G2 group, but not in the G3. The average volume of granulomas reduced (p < 0.0001) 65.2% and 46.3% in the liver tissue and 83.0% and 53.2% in the intestine, respectively, in groups G2 and G3. Th1 profile cytokine (IFN-γ, TNF-α, and IL-6) and IL-17 were significantly increased (p < 0.001) stimulated with B. cereus GM in groups G2 and G3. IL-4 showed significant values when the stimulus was mediated by ConA. By modulating the immune response, B. cereus GM reduced the burden of worms, improved some markers of liver function, and reduced the granulomatous inflammatory reaction in mice infected with S. mansoni, especially when administered before infection.

Fusarium solani PQF9 Isolated from Podocarpus pilgeri Growing in Vietnam as a New Producer of Paclitaxel

Endophytic fungi are known as an alternative promising source of anticancer drug, paclitaxel, however fungi inhabiting in medicinal plant Podocarpus pilgeri and their paclitaxel production have not been reported to date. In the present study, a total of 15 culturable fungi classified into 5 genera, were successfully recovered from P. pilgeri collected in Vietnam. Screening fungal dichloromethane extracts for anticancer activity revealed that only PQF9 extract displayed potent inhibitory effects on A549 and MCF7 cancer cell lines with IC50 values of 33.9 ± 2.3 µg/mL and 43.5 ± 1.7 µg/mL, respectively. Through PCR-based molecular screening, the isolate PQF9 was found to possess 3 key genes involved in paclitaxel biosynthesis. Importantly, high-performance liquid chromatography quantification showed that fungal isolate PQF9 was able to produce 18.2 µg/L paclitaxel. The paclitaxel-producing fungus was identified as Fusarium solani PQF9 based on morphological and molecular phylogenetic analysis. Intensive investigations by chromatographic methods and spectroscopic analyses confirmed the presence of paclitaxel along with tyrosol and uracil. The pure paclitaxel had an IC50 value of 80.8 ± 9.4 and 67.9 ± 7.0 nM by using cell viability assay on A549 lung and MCF7 breast cancer cells. In addition, tyrosol exhibited strong antioxidant activity by scavenging 2, 2-diphenyl-picrylhydrazyl (DPPH) (IC50 5.1 ± 0.2 mM) and hydroxyl radical (IC50 3.6 ± 0.1 mM). In contrast, no biological activity was observed for uracil. Thus, the paclitaxel-producing fungus F. solani PQF9 could serve as a new material for large-scale production and deciphering paclitaxel biosynthesis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-023-01119-z.

Utilization of Algae Extracts as Natural Antibacterial and Antioxidants for Controlling Foodborne Bacteria in Meat Products

Padina pavonica, Hormophysa cuneiformis, and Corallina officinalis are three types of algae that are assumed to be used as antibacterial agents. Our study's goal was to look into algal extracts' potential to be used as food preservative agents and to evaluate their ability to inhibit pathogenic bacteria in several meat products (pastirma, beef burger, luncheon, minced meat, and kofta) from the local markets in Alexandria, Egypt. By testing their antibacterial activity, results demonstrated that Padina pavonica showed the highest antibacterial activity towards Bacillus cereus, Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Salmonella spp., and Klebsiella pneumoniae. Padina pavonica extract also possesses most phenolic and flavonoid content overall. It has 24 mg gallic acid equivalent/g and 7.04 mg catechol equivalent/g, respectively. Moreover, the algae extracts were tested for their antioxidant activity, and the findings were measured using ascorbic acid as a benchmark. The IC50 of ascorbic acid was found to be 25.09 μg/mL, while Padina pavonica exhibited an IC50 value of 267.49 μg/mL, Corallina officinalis 305.01 μg/mL, and Hormophysa cuneiformis 325.23 μg/mL. In this study, Padina pavonica extract was utilized in three different concentrations (Treatment 1 g/100 g, Treatment 2 g/100 g, and Treatment 3 g/100 g) on beef burger as a model. The results showed that as the concentration of the extract increased, the bacterial inhibition increased over time. Bacillus cereus was found to be the most susceptible to the extract, while Streptococcus pyogenes was the least. In addition, Padina pavonica was confirmed to be a safe compound through cytotoxicity testing. After conducting a sensory evaluation test, it was confirmed that Padina pavonica in meat products proved to be a satisfactory product.

Unraveling the Radioprotective Mechanisms of UV-Resistant Bacillus subtilis ASM-1 Extracted Compounds through Molecular Docking

Radioresistant microorganisms possess inimitable capabilities enabling them to thrive under extreme radiation. However, the existence of radiosensitive microorganisms inhabiting such an inhospitable environment is still a mystery. The current study examines the potential of radioresistant microorganisms to protect radiosensitive microorganisms in harsh environments. Bacillus subtilis strain ASM-1 was isolated from the Thal desert in Pakistan and evaluated for antioxidative and radioprotective potential after being exposed to UV radiation. The strain exhibited 54.91% survivability under UVB radiation (5.424 × 103 J/m2 for 8 min) and 50.94% to mitomycin-C (4 µg/mL). Extracellular fractions collected from ASM-1 extracts showed significant antioxidant potential, and chemical profiling revealed a pool of bioactive compounds, including pyrrolopyrazines, amides, alcoholics, and phenolics. The E-2 fraction showed the maximum antioxidant potential via DPPH assay (75%), and H2O2 scavenging assay (68%). A combination of ASM-1 supernatant with E-2 fraction (50 µL in a ratio of 2:1) provided substantial protection to radiosensitive cell types, Bacillus altitudinis ASM-9 (MT722073) and E. coli (ATCC 10536), under UVB radiation. Docking studies reveal that the compound supported by literature against the target proteins have strong binding affinities which further inferred its medical uses in health care treatment. This is followed by molecular dynamic simulations where it was observed among trajectories that there were no significant changes in major secondary structure elements, despite the presence of naturally flexible loops. This behavior can be interpreted as a strategy to enhance intermolecular conformational stability as the simulation progresses. Thus, our study concludes that Bacillus subtilis ASM-1 protects radiosensitive strains from radiation-induced injuries via biofilm formation and secretion of antioxidative and radioprotective compounds in the environment.

Bismuth Oxide Composite-Based Agricultural Waste for Wound Dressing Applications

The purpose of this study was to enhance the antimicrobial activity of bagasse paper by coating the paper with bismuth oxide (Bi2O3) and using it to accelerate the process of wound healing. Paper sheets were prepared from sugarcane waste (bagasse). First, the paper sheets were coated with different Bi2O3 concentrations to improve the antimicrobial activity of the paper. After that, the paper sheets were allowed to dry in an oven at 50 °C for 3 h. Then, in vitro antimicrobial activity was evaluated against different microbial species, including Gram-negative bacteria (i.e., Klebsiella pneumonia, Escherichia coli) and Gram-positive bacteria (i.e., Staphylococcus aureus, Streptococcus pyogenes). The obtained results showed that the paper coated with 25% and 100% Bi2O3 had activity against all models of bacteria; however, the paper coated with 100% Bi2O3 composite had the strongest inhibitory effect. Then, bagasse paper was coated with 100% Bi2O3 and different antibiotics, to investigate their wound-healing potency in a wounded rat model for 14 days. Moreover, the paper coated with 100% Bi2O3 inhibited the cellular migration in vitro. Conclusively, coating paper with Bi2O3 enhances the wound-healing potential when applied to wounds. This impact could be ascribed to Bi2O3's broad antibacterial activity, which reduced infection and accelerated the healing process.

Unveiling the Antibiotic Susceptibility and Antimicrobial Potential of Bacteria from Human Breast Milk of Pakistani Women: An Exploratory Study

BACKGROUND

Human life quality and expectancy have increased dramatically over the past 5 decades because of improvements in nutrition and antibiotic's usage fighting against infectious diseases. Yet, it was soon revealed that the microbes adapted to develop resistance to any of the drugs that were used. Recently, there is great concern that commensal bacteria from food and the gastrointestinal tract of humans and animals could act as a reservoir for antibiotic resistance genes. Methodology. This study was intended for evaluating the phenotypic antibiotic resistance/sensitivity profiles of probiotic bacteria from human breast milk and evaluating the inhibitory effect of the probiotic bacteria against both Gram-negative and Gram-positive bacteria.

RESULTS

The results point out that some of the isolated bacteria were resistant to diverse antibiotics including gentamycin, imipenem, trimethoprim sulfamethoxazole, and nalidixic acid. Susceptibility profile to certain antibiotics like vancomycin, tetracycline, ofloxacin, chloramphenicol, streptomycin, rifampicin, and bacitracin was also observed. The antimicrobial qualities of cell-free supernatants of some probiotic bacteria inhibited the growth of indicator bacteria. Also, antimicrobial properties of the probiotic bacteria from the present study attributed to the production of organic acid, bacterial adhesion to hydrocarbons (BATH), salt aggregation, coaggregation with pathogens, and bacteriocin production. Some isolated bacteria from human milk displayed higher hydrophobicity in addition to intrinsic probiotic properties like Gram-positive classification, catalase-negative activity, resistance to gastric juice (pH 2), and bile salt (0.3%) concentration.

CONCLUSION

This study has added to the data of the antibiotic and antimicrobial activity of some probiotic bacteria from some samples of Pakistani women breast milk. Probiotic bacteria are usually considered to decrease gastrointestinal tract diseases by adhering to the gut epithelial and reducing population of pathogens and in the case of Streptococcus lactarius MB622 and Streptococcus salivarius MB620 in terms of hydrophobicity and exclusion of indicator pathogenic strains.

Characterization of Bacillus spp. isolated from the intestines of Rhynchocypris lagowskii as a potential probiotic and their effects on fish pathogens

Probiotics sourced from fish intestinal microbiota have a merit over other bacterial sources due to colonization ability and effective time. This study aimed to evaluate the bacilli isolated from the Rhynchocypris lagowskii intestines and their validity as a probiotic. Three isolates were selected (LSG 2-5, LSG 3-7, and LSG 3-8) and defined by morphological and 16S rRNA analysis as Bacillus velezensis, Bacillus aryabhattai, and Bacillus mojavensis, respectively. Results showed the strain tolerant abilities to gastrointestinal fluid, bile salt, pH, and temperature expotures. Additionally, all bacterial strains showed anti-pathogenic activity against at least four strains out of six tested pathogen strains (Staphylococcus aureus, Aeromonas hydrophila, Escherichia coli, Aeromonas veronii, Edwardsiella, and Aeromonas sobria). The bacterial strains also showed a high percentage of co-aggregation activity, more than 70%, with Aer. hydrophile, Staph. epidermidis, and Klebsiella aerogenes. At the same time, the results of competition, rejection, and substitution activity with Aer. hydrophila and Aer. veronii indicated the ability of the isolated strains to reduce the adhesion of pathogens to mucin. All strains showed safety properties, non-hemolytic, and sensitivity characteristics for most of tested antibiotics. In vivo test after injecting these strains into fish at various concentrations showed no side effects in the internal or external organs of fish compared to controls, proving that this is safe for these fish. Furthermore, the three strains produced lipase, amylase, and protease enzymes. The strains also showed bile salt hydrolase activity and biofilm formation, allowing them to tolerate stressful conditions. Conclusion: Based on these strains characteristics and features, they could be considered a promising candidate probiotic and can be used as an anti-pathogenic, especially in aquaculture.

Evaluation of the Prevalence of Staphylococcus aureus in Chicken Fillets and Its Bio-Control Using Different Seaweed Extracts

This study aims to assess the occurrence of Staphylococcus aureus in chicken fillets and to control its growth using various lyophilized seaweed extracts (i.e., Halimeda opuntia (HO), Actinotrichia fragilis, and Turbinaria turbinata) by an agar disk diffusion assay in vitro. Results showed that prevalence of S. aureus in breast and thigh samples reached of 92% and 84%, respectively. Lyophilized HO extract was the only seaweed that showed the antibacterial activity against S aureus with a significant difference at p < 0.05. The minimum inhibitory concentration (MIC) of HO extract was 1.5%, with an inhibition zone of 8.16 ± 0.73 mm. Regarding 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, IC50 was recorded at 55.36 μg/mL, whereas cytotoxic IC50 of the lyophilized HO extract on peripheral blood mononuclear cells (PBMCs) was 33.7 µg/mL; a higher IC50 of HO extracts permits their use as a safe food additive in meat products. Moreover, total phenolic compounds and total flavonoids compounds recorded 20.36 ± 0.092 and 16.59 ± 0.029 mg/mL, respectively. HPLC analyses of phenolic compounds profiles exhibited many bioactive substances and the higher ratio was daidzein with 10.84 ± 0.005 µg/mL and followed by gallic acid with a value of 4.06 ± 0.006 µg/mL. In a challenge study, chicken fillet (CHF) experimentally inoculated with S. aureus (ST) and treated with the lyophilized HO algal extract at 4% and 6% (CHF/ST/HO) showed a complete reduction of S. aureus count on the 6th and 4th days in chicken fillet stored at 4 °C, respectively. Moreover, CHF/ST/HO at 4% and 6% of HO extract enhanced the sensory attributes of grilled un-inoculated chicken fillet. Thus, lyophilized HO extracts are promising antibacterial and antioxidant candidates in the chicken meat industry.

Fillet Fish Fortified with Algal Extracts of Codium tomentosum and Actinotrichia fragilis, as a Potential Antibacterial and Antioxidant Food Supplement

With respect to the potential natural resources in the marine environment, marine macroalgae or seaweeds are recognized to have health impacts. Two marine algae that are found in the Red Sea, Codium tomentosum (Green algae) and Actinotrichia fragilis (Red algae), were collected. Antibacterial and antioxidant activities of aqueous extracts of these algae were evaluated in vitro. Polyphenols from the extracts were determined using HPLC. Fillet fish was fortified with these algal extracts in an attempt to improve its nutritional value, and sensory evaluation was performed. The antibacterial effect of C. tomentosum extract was found to be superior to that of A. fragilis extract. Total phenolic contents of C. tomentosum and A. fragilis aqueous extract were 32.28 ± 1.63 mg/g and 19.96 ± 1.28 mg/g, respectively, while total flavonoid contents were 4.54 ± 1.48 mg/g and 3.86 ± 1.02 mg/g, respectively. Extract of C. tomentosum demonstrates the highest antioxidant activity, with an IC₅₀ value of 75.32 ± 0.07 μg/mL. The IC₅₀ of L-ascorbic acid as a positive control was 22.71 ± 0.03 μg/mL. The IC₅₀ values for inhibiting proliferation on normal PBMC cells were 33.7 ± 1.02 µg/mL and 51.0 ± 1.14 µg/mL for C. tomentosum and A. fragilis, respectively. The results indicated that both algal aqueous extracts were safe, with low toxicity to normal cells. Interestingly, fillet fish fortified with C. tomentosum extract demonstrated the greatest overall acceptance score. These findings highlight the potential of these seaweed species for cultivation as a sustainable and safe source of therapeutic compounds for treating human and fish diseases, as well as effective food supplements and preservatives instead of chemical ones after performing in vivo assays.

Synergetic antibacterial activity of Vernonia auriculifera Hiern and Buddleja polystachya Fresen on selected human pathogenic bacteria

Background

Medicinal plants have been used as traditional treatments for various human diseases for many years and they are still widely practiced throughout the world. Due to the long history of the practice, medicinal plants have become an integral part of the Ethiopian culture. This study aimed to evaluate the antibacterial activities of Vernonia auriculifera Hiern and Buddleja polystachya Fresen leaf extracts and their synergistic effect against some selected human pathogenic bacteria.

Methods

Ethanol, methanol, and n-hexane crude extracts of Vernonia auriculifera, Buddleja polystachya, and a mixture of the two-plant respective of each solvent were evaluated against tested pathogenic bacteria using the agar well diffusion method; the inhibition zones were recorded in millimeters. Gentamycin was used as a positive control, while dimethyl sulfoxide served as a negative control. The minimum inhibitory concentration of the plant extracts against test bacteria was evaluated using two-fold broth dilution methods and then Minimum bactericidal concentration was determined by sub-culturing the test dilutions from minimum inhibitory concentration tubes onto fresh Muller Hinton Agar plates incubated at 37 °C for 24 h.

Results

Maximum antibacterial inhibition zone was observed on methanol extracts of synergism against S. Typhimurium (ATCC 1333) (31.00 ± 1.73 mm) while, a minimum inhibition zone was observed on methanol extract of Buddleja polystachya, against E. coli (ATCC 35218) (5.67 ± 0.57). Minimum inhibitory concentration and minimum bactericidal concentration values of the crude extracts of Vernonia auriculifera, Buddleja polystachya, and their mixture lies between (3.125%–12.5%) and (6.25%–25%) respectively. The data were analyzed using the SPSS software package version 20 for windows.

Conclusion

The present study revealed that ethanol and methanol extracts of Vernonia auriculifera and Buddleja polystachya possess significant inhibitory effects against tested pathogens and the antibacterial activity of both plants leaf extracts was greater than the activity of currently used antibiotics (Gentamycin) against some selected organisms.

Distribution, cytotoxicity, and antioxidant activity of fungal endophytes isolated from Tsuga chinensis (Franch.) Pritz. in Ha Giang province, Vietnam

Purpose

An endangered Tsuga chinensis (Franch.) Pritz. is widely used as a natural medicinal herb in many countries, but little has been reported on its culturable endophytic fungi capable of producing secondary metabolites applied in modern medicine and pharmacy. The present study aimed to evaluate the distribution of fungal endophytes and their cytotoxic and antioxidant properties.

Methods

This study used the surface sterilization method to isolate endophytic fungi which were then identified using morphological characteristics and ITS sequence analysis. The antimicrobial and cytotoxic potentials of fungal ethyl acetate extracts were evaluated by the minimum inhibitory concentration (MIC) and sulforhodamine B (SRB) assays, respectively. Paclitaxel-producing fungi were primarily screened using PCR-based molecular markers. Additionally, biochemical assays were used to reveal the antioxidant potencies of selected strains.

Results

A total of sixteen endophytic fungi that belonged to 7 known and 1 unknown genera were isolated from T. chinensis. The greatest number of endophytes was found in leaves (50%), followed by stems (31.3%) and roots (18.7%). Out of 16 fungal strains, 33.3% of fungal extracts showed significant antimicrobial activities against at least 4 pathogens with inhibition zones ranging from 11.0 ± 0.4 to 25.8 ± 0.6 mm. The most prominent cytotoxicity against A549 and MCF7 cell lines (IC50 value < 92.4 μg/mL) was observed in Penicillium sp. SDF4, Penicillium sp. SDF5, Aspergillus sp. SDF8, and Aspergillus sp. SDF17. Out of three key genes (dbat, bapt, ts) involved in paclitaxel biosynthesis, strains SDF4, SDF8, and SDF17 gave one or two positive hits, holding the potential for producing the billion-dollar anticancer drug paclitaxel. Furthermore, four bioactive strains also displayed remarkable and wide-range antioxidant activity against DPPH, hydroxyl radical, and superoxide anion, which was in relation to the high content of flavonoids and polyphenols detected.

Conclusion

The present study exploited for the first time fungal endophytes from T. chinensis as a promising source for the discovery of new bioactive compounds or leads for the new drug candidates.

ZnO-chlorogenic acid nanostructured complex inhibits Covid-19 pathogenesis and increases hydroxychloroquine efficacy

Objective

The study purpose was to compare the anti- novel coronavirus disease 2019 (COVID-19) property of chlorogenic acid (CGA) and Zinc oxide nanoparticles (ZnO-NP) with the new valid synthesized complex of ZnO /CGA-NPs.

Methods

The facile mixing method was utilized to prepare ZnO/CGA-NPs. The in vitro effect of different ZnO/CGA-NPs concentrations on papain-like protease (PL^pro) and spike protein- receptor-binding domain (RBD) was measured by ELISA technique. The compounds effects on SARS-CoV2 were determined on viral entry, replication, and assembly by using plaque reduction assay, qPCR, and ELISA techniques. Their individual effects or mixed with hydroxychloroquine (HCQ) on erythrocytes (RBCs) and leukocytes (WBCs) were evaluated by routine cell culture technique. Finally, turbidity and agar well diffusion assays were done to evaluate their antimicrobial properties against Escherichia. coli, klebsila pneumonia, Streptococcus pyogenes, Staphylococcus aureus, and Candida albicans.

Results

The results confirmed that the uniformly dispersed ZnO-NPs were converted to aggregated form of ZnO/CGA-NPs upon the addition of CGA. The inhibitory concentration 50 (IC₅₀) of ZnO /CGA-NPs against RBD, angiotensin-converting enzyme 2 (ACE2) and PL^pro were 1647.7, 323.3 µg/mL and 38.7 µg/mL, respectively. Also, it inhibited E-gene, RdRp gene, E-protein, and spike protein with an IC₅₀ of 0.11, 0.13, 0.48, and 0.37 µg/mL, respectively. It acted as an antimicrobial against all tested organisms with a minimum inhibitory concentration (MIC) of 26 µg/mL. Finally, ZnO/CGA-NPs Complex (0.1 IC₅₀) prevented the cytotoxic effect of HCQ on RBCs and WBC by 92.3 and 90 %, respectively.

Conclusion

ZnO/CGA-NPs Complex can be considered as a new anti- severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) compound.

Genome-Guided Investigation Provides New Insights into Secondary Metabolites of Streptomyces parvulus SX6 from Aegiceras corniculatum

Whole-genome sequencing and genome mining are recently considered an efficient approach to shine more light on the underlying secondary metabolites of Streptomyces. The present study unearths the biosynthetic potential of endophytic SX6 as a promising source of biologically active substances and plant-derived compounds for the first time. Out of 38 isolates associated with Aegiceras corniculatum (L.) Blanco, Streptomyces parvulus SX6 was highly active against Pseudomonas aeruginosa ATCC® 9027™ and methicillin-resistant Staphylococcus epidermidis (MRSE) ATCC® 35984™. Additionally, S. parvulus SX6 culture extract showed strong cytotoxicity against Hep3B, MCF-7, and A549 cell lines at a concentration of 30 μg/ml, but not in non-cancerous HEK-293 cells. The genome contained 7.69 Mb in size with an average G + C content of 72.8% and consisted of 6,779 protein-coding genes. AntiSMASH analysis resulted in the identification of 29 biosynthetic gene clusters (BGCs) for secondary metabolites. Among them, 4 BGCs showed low similarity (28–67% of genes show similarity) to actinomycin, streptovaricin, and polyoxypeptin gene clusters, possibly attributed to antibacterial and anticancer activities observed. In addition, the complete biosynthetic pathways of plant-derived compounds, including daidzein and genistein were identified using genome mining and HPLC-DAD-MS analysis. These findings portray an exciting avenue for future characterization of promising secondary metabolites from mangrove endophytic S. parvulus.

Biosurfactant Production by Bacillus amyloliquefaciens C11 and Streptomyces lavendulae C27 Isolated from a Biopurification System for Environmental Applications

Biosurfactant-producing bacteria can be found in contaminated environments such as biopurification systems (BPS) for pesticide treatments. A total of 18 isolates were screened to determine their ability to produce extracellular biosurfactants, using olive oil as the main carbon source. Out of the eighteen isolates, two strains (C11 and C27) were selected for biosurfactant production. The emulsification activities of the C11 and C27 strains using sunflower oil was 58.4 and 53.7%, respectively, and 46.6 and 48.0% using olive oil. Using molecular techniques and MALDI-TOF, the strains were identified as Bacillus amyloliquefaciens (C11) and Streptomyces lavendulae (C27). The submerged cultivation of the two selected strains was carried out in a 1 L stirred-tank bioreactor. The maximum biosurfactant production, indicated by the lowest surface tension measurement, was similar (46 and 45 mN/m) for both strains, independent of the fact that the biomass of the B. amyloliquefaciens C11 strain was 50% lower than the biomass of the S. lavendulae C27 strain. The partially purified biosurfactants produced by B. amyloliquefaciens C11 and S. lavendulae C27 were characterized as a lipopeptide and a glycolipid, respectively. These outcomes highlight the potential of the selected biosurfactant-producing microorganisms for improving pesticides’ bioavailability and therefore the degradational efficacy of BPS.

Electrospun non-wovens potential wound dressing material based on polyacrylonitrile/chicken feathers keratin nanofiber

Electrospinning nanofibers have a tremendous interest in biomedical applications such as tissue engineering, drug administration, and wound healing because of their ability to replicate and restore the function of the natural extracellular matrix found in tissues. The study’s highlight is the electrospinning preparation and characterization of polyacrylonitrile with chicken feather keratin as an additive. In this study, keratin was extracted from chicken feather waste using an environmentally friendly method and used to reinforce polymeric nanofiber mats. Scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy were used to examine the morphology and the structure of the prepared nanofiber mats. The effect of keratin on the porosity and the tensile strength of reinforcing nanofibers is investigated. The porosity ratio of the nanofiber mats goes up from 24.52 ± 2.12 for blank polyacrylonitrile (PAN (NF)) to 90.89 ± 1.91% for polyacrylonitrile nanofiber with 0.05 wt% keratin (PAN/0.05% K). Furthermore, keratin reinforcement improves the nanofiber's mechanical properties, which are important for wound dressing application, as well as its antibacterial activity without causing hemolysis (less than 2%). The best antibacterial activities were observed against Pseudomonas aeruginosa (30 ± 0.17 mm inhibition zone) and Staphylococcus aureus (29 ± 0.31 mm inhibition zone) for PAN/0.05% K sample, according to the antibacterial test. This research has a good potential to broaden the use of feather keratin-based nanofibers in wound healing.

Improving the nutritional value and bioactivity of soybean meal in solid-state fermentation using Bacillus strains newly isolated from the gut of the termite Termes propinquus

The present study aimed to isolate and characterize proteolytic Bacillus spp. from termite guts to test the possibility of application for improving the nutritional value and bioactivity of fermented soybean meal (FSBM). Aerobic endospore-forming bacteria were isolated from the gut of the termite Termes propinquus. Ten isolates with high levels of soy milk degradation were selected and tested for extracellular enzyme production. Among them, two isolates, Tp-5 and Tp-7, exhibited all tested hydrolytic enzyme activities (cellulase, xylanase, pectinase, amylase, protease, lipase and phytase), weak alpha hemolytic and also antagonistic activities against fish pathogenic species of Aeromonas and Streptococcus. Both phylogenetic and biochemical analyses indicated that they were closely related to Bacillus amyloliquefaciens. During solid-state fermentation of SBM, Tp-5 and Tp-7 exhibited the highest protease activity (1127.2 and 1552.4 U g-1, respectively) at 36 h, and the resulting FSBMs showed a significant increase in crude protein content and free radical-scavenging ability (P < 0.05), as well as an improvement in the composition of amino acids, metabolites and other nutrients, while indigestible materials such as fiber, lignin and hemicellulose were decreased. The potential strains, especially Tp-7, improved the nutritional value of FSBM by their strong hydrolytic and antioxidant activities, together with reducing antinutritional components.

Bacillus Probiotics as Alternatives to In-feed Antibiotics and Its Influence on Growth, Serum Chemistry, Antioxidant Status, Intestinal Histomorphology, and Lesion Scores in Disease-Challenged Broiler Chickens

In commercial poultry production, chickens are reared under intensive conditions, which may allow infections to spread quickly. Antibiotics are used at sub-therapeutic doses in livestock and poultry feed to prevent diseases and improve productivity. However, restrictions on the use of antibiotics at sub-therapeutic concentrations in livestock feed due to growing concerns of antimicrobial resistance (AMR), together with antibiotic residues in meat and eggs has prompted poultry researchers and feed producers to look for viable alternatives. Thus, there is increasing interest in developing natural alternatives to in-feed antibiotics to improve chicken productivity and health. Probiotics, specifically from the genus Bacillus have proven to be effective due to their spore-forming capabilities. Furthermore, their ability to withstand heat during feed processing and be stored for a long time without losing viability as well as their potential to function in the acidic medium of the chicken gut, provide them with several advantages over conventional probiotics. Several studies regarding the antimicrobial and antioxidant activities of Bacillus probiotics and their positive impact in chicken nutrition have been documented. Therefore, the present review shields light on the positive effect of Bacillus probiotics as alternatives to in-feed antibiotics on growth performance, serum chemistry, antioxidant status, intestinal histomorphology and lesion scores of disease-challenged broiler chickens and the mechanisms by which they exert their actions. It is concluded that Bacillus probiotics supplementation improve growth, health and productive indices of disease-challenged broiler chickens and can be a good alternative to in-feed antibiotics. However, more studies are required on the effect of Bacillus probiotics supplementation in broiler chickens to maximize productivity and achieve the ultimate goal of stopping the usage of antibiotics at sub-therapeutic doses in broiler chicken feed to enhance performance.

Application of Levan-Rich Digestate Extract in the Production of Safe-to-Use and Functional Natural Body Wash Cosmetics

The study focused on the evaluation of the possibility of using a levan-rich digestate extract in the production of safe and functional body wash cosmetics. Model shower gels were designed and formulated on the basis of raw materials of natural origin. Prepared prototypes contained various extract concentrations (16.7; 33; 50%). A gel without extract was used as a reference. The samples were evaluated for their safety in use and functionality. The results showed that the use of high-concentration levan-rich digestate extract in a shower gel resulted in a significant reduction in the negative impact on the skin. For example, the zein value decreased by over 50% in relation to the preparation without the extract. An over 40% reduction in the emulsifying capacity of hydrophobic substances was also demonstrated, which reduces skin dryness after the washing process. However, the presence of the extract did not significantly affect the parameters related to functionality. Overall, it was indicated that levan-rich digestate extract can be successfully used as a valuable ingredient in natural cleansing cosmetics.

Bacterial Diversity, Organic Acid, and Flavor Analysis of Dacha and Ercha Fermented Grains of Fen Flavor Baijiu

Fen flavor Baijiu needs two rounds of fermentation, which will obtain Dacha after initial fermentation and Ercha after secondary fermentation. The quality of Baijiu is closely related to the microbes within fermented grains. However, the bacterial diversity in Dacha and Ercha fermented grains of Fen flavor Baijiu has not been reported. In the present study, the structure and diversity of bacteria communities within fermented grains of Fen flavor Baijiu were analyzed and evaluated using MiSeq platform's HTS with a sequencing target of the V3-V4 region of the 16S rRNA gene. Through the analysis of physical and chemical indexes and electronic senses, the relationship between bacterial flora, organic acid, taste, and aroma in fermented grains was clarified. The results indicated that Lactobacillus was the main bacteria in Dacha, and the mean relative content was 97.53%. The bacteria within Ercha samples were Pseudomonas and Bacillus, mean relative content was 37.16 and 28.02%, respectively. The diversity of bacterial communities in Ercha samples was significantly greater than that in Dacha samples. The correlation between Lactobacillus and organic acids, especially lactic acid, led to the difference between Dacha and Ercha organic acids, which also made the pH value of Dacha lower and the sour taste significantly higher than Ercha. Lactobacillus was significantly positively correlated with a variety of aromas, which made Dacha the response value of aromas higher. In addition, Bacillus had a significant positive correlation with bitterness and aromatic compounds, which led to a higher response value of bitterness in Ercha and made it present an aromatic aroma. This study provides an in-depth analysis of the difference between different stages of Fen flavor Baijiu, and theoretical support for the standard production and improvement in quality of Fen flavor Baijiu in the future.

Functional properties of Rhizopus oryzae strains isolated from agricultural soils as a potential probiotic for broiler feed fermentation

The most crucial and expensive fragment in the broiler chicken production industry is the feed. Because of the rising demand, finding a cheap and effective feed is an urgent necessity. Fermentation of broiler feed by probiotic fungal starters can enhance the nutrient's availability and digestibility while preventing pathogenic growth. In this study different Rhizopus spp. have been isolated from agricultural soils around Izmir, Turkey, and tested for their probiotic potential and fermentative capacity. The isolated Rhizopus strains first underwent microscopical fluorescent investigation to exclude endofungal bacterial presence, then, those without endofungal bacteria (totally 82) were tested for antimicrobial activity counter bacterial and fungal pathogens. The ones with wide-spectrum antimicrobial activity (totally 10) were tested for gastrointestinal tolerance and antioxidant ability. Upon phenotypic and genotypic identification, the 10 isolates were found to belong to Rhizopus oryzae species. While all 10 strains showed variable gastrointestinal tolerance and antioxidant activities, three of them (92/1, 236/2, and 284) had relatively high antioxidant activity. Upon fermentative capacity assay, compared to unfermented commercial feed, there was a general decrease in crude fiber content by 56% after fermentation by 92/1 isolate for 4 days and 236/2 isolate for 2 days. The highest increase in crude protein content (by 14.5%) occurred after a 4-day fermentation period by 236/2 isolate. The highest increase in metabolizable energy was 8.64%, by the 284 isolate after 2 days of fermentation. In conclusion, the three strains showed good probiotic properties and fermentative capacities hence can be beneficial for the poultry industry.

Acid tolerant bacterium Bacillus amyloliquefaciens MBNC retains biocontrol efficiency against fungal phytopathogens in low pH

Soil pH conditions have important consequences for microbial community structure, their dynamics, ecosystem processes, and interactions with plants. Low soil pH affects the growth and functional activity of bacterial biocontrol agents which may experience a paradigm shift in their ability to act antagonistically against fungal phytopathogens. In this study, the antifungal activity of an acid-tolerant soil bacterium Bacillus amyloliquefaciens MBNC was evaluated under low pH and compared to its activity in neutral pH conditions. Bacterial supernatant from 3-day-old culture (approximately 11.2 × 10⁸ cells/mL) grown in low pH conditions was found more effective against fungal pathogens. B. amyloliquefaciens MBNC harboured genes involved in the synthesis of secondary metabolites of which surfactin homologues, with varying chain length (C11-C15), were identified through High-Resolution Mass Spectroscopy. The pH of the medium influenced the production of these metabolites. Surfactin C15 was exclusive to the extract of pH 4.5; production of iturinA and surfactin C11 was detected only in pH 7.0, while surfactin C12, C13 and C14 were detected in extracts of both the pH conditions. The secretion of phytohormones viz. indole acetic acid and gibberellic acid by B. amyloliquefaciens MBNC was detected in higher amounts in neutral condition compared to acidic condition. Although, secretion of metabolites and phytohormones in B. amyloliquefaciens MBNC was influenced by the pH condition of the medium, the isolate retained its antagonistic efficiency against several fungal phyto-pathogens under acidic condition.

Antioxidant and antimutagenic properties of probiotic Lactobacilli determined using LUX-biosensors

The initial screening of probiotic strains in vitro, carried out by different methods, may omit strains that are promising from the point of view of biotechnology or, conversely, mark as promising strains those that will lose activity when transferred in vivo. It is known that the release of metabolites by probiotic bacteria, in particular, lactobacilli, is highly dependent on the biochemical context. In this work, we modified the method that was previously successfully used for the selection of probiotics for poultry, based on their antioxidant and DNA-protective properties. A comparison was made of this activity on standard media and on an artificial intestinal medium that mimics the intestines of a bird. As a result, three Lactobacillus strains were selected, which not only exhibit antioxidant and DNA-protective properties but also do not lose these activities in an artificial intestinal medium.

Biostimulation of Bacteria in Liquid Culture for Identification of New Antimicrobial Compounds

We hypothesized that environmental microbiomes contain a wide range of bacteria that produce yet uncharacterized antimicrobial compounds (AMCs) that can potentially be used to control pathogens. Over 600 bacterial strains were isolated from soil and food compost samples, and 68 biocontrol bacteria with antimicrobial activity were chosen for further studies based on inhibition assays against a wide range of food and plant pathogens. For further characterization of the bioactive compounds, a new method was established that used living pathogens in a liquid culture to stimulate bacteria to produce high amounts of AMCs in bacterial supernatants. A peptide gel electrophoresis microbial inhibition assay was used to concurrently achieve size separation of the antimicrobial peptides. Fifteen potential bioactive peptides were then further characterized by tandem MS, revealing cold-shock proteins and 50S ribosomal proteins. To identify non-peptidic AMCs, bacterial supernatants were analyzed by HPLC followed by GC/MS. Among the 14 identified bioactive compounds, 3-isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione and 2-acetyl-3-methyl-octahydropyrrolo[1,2-a]piperazine-1,4-dione were identified as new AMCs. Our work suggests that antimicrobial compound production in microbes is enhanced when faced with a threat from other microorganisms, and that this approach can rapidly lead to the development of new antimicrobials with the potential for upscaling.

Antibacterial activity and action mechanism of a novel chitosan oligosaccharide derivative against dominant spoilage bacteria isolated from shrimp Penaeus vannamei

With the aim of exploring the potential application of a novel chitosan oligosaccharide derivative (COS-All-Tio) in shrimp preservation, six dominant spoilage bacteria in the spoiled shrimp (Penaeus vannamei) were isolated and identified as Shewanella putrefaciens (RMS1), S. putrefaciens (S2), Pseudomonas weihenstephanensis (P1), P. gessardii (P2), Aeromonas bestiarum (A1) and Aeromonas molluscorum (A2). The antibacterial effect of COS-All-Tio against the six bacterial isolates were studied. Bacterial inhibition zone determination, and minimum inhibitory concentration and minimum bactericidal concentration assays indicated that the antibacterial activity of COS-All-Tio was greatly improved when compared to that of chitosan oligosaccharide (COS). The antibacterial mechanism investigation against S. putrefaciens (RMS1) revealed that COS-All-Tio could inhibit bacterial growth by influencing of membrane integrity. Such disturbance of membrane structure resulted in the leakage of intracellular substance of the bacteria. A strong synergistic antibacterial effect against S. putrefaciens (RMS1) was observed when COS-All-Tio was used in combination with food preservatives (e.g. ε-polylysine hydrochloride). Therefore, COS-All-Tio might have potential in shrimp preservation.

KDP, a Lactobacilli Product from Kimchi, Enhances Mucosal Immunity by Increasing Secretory IgA in Mice and Exhibits Antimicrobial Activity

The potential of KDP, a lactic acid bacterial strain of Lactobacillus sakei, to enhance the production of mucosal specific immunoglobulin A (IgA) in mice and thereby enhance gut mucosal immunity was examined. KDP is composed of dead cells isolated from the Korean traditional food kimchi. Female BALB/c mice orally received 0.25 mg KDP once daily for 5 weeks and were co-administrated ovalbumin (OVA) for negative control and cholera toxin for positive control. Mice administered KDP exhibited increased secretory IgA (sIgA) contents in the small intestine, Peyer’s patches, serum, colon, and lungs as examined by ELISA. KDP also significantly increased the gene expression of Bcl-6, IL-10, IL-12p40, IL-21, and STAT4. In addition, KDP acted as a potent antioxidant, as indicated by its significant inhibitory effects in the range of 16.5–59.4% for DPPH, nitric oxide, maximum total antioxidant capacity, and maximum reducing power. Finally, KDP exhibited potent antimicrobial activity as evidenced by a significant decrease in the growth of 7 samples of gram-negative and gram-positive bacteria and Candida albicans. KDP’s adjuvant effect is shown to be comparable to that of cholera toxin. We conclude that KDP can significantly enhance the intestine’s secretory immunity to OVA, as well as act as a potent antioxidant and antimicrobial agent. These results suggest that orally administered KDP should be studied in clinical trials for antigen-specific IgA production.

Detoxification of Aflatoxin B1 and Ochratoxin A Using Salvia farinacea and Azadirachta indica Water Extract and Application in Meat Products

Seventy-five samples of selected meat products, including luncheon, beef burger, sausage, basterma, and kofta, were collected from Alexandria and New Borg El-Arab cities (Egypt). The samples were subjected to mycological examination as well as for detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA) residues. Besides, the study evaluated the effect of aqueous leaf extracts from mealycup sage (Salvia farinacea) and neem (Azadirachta indica), individually and in combination, on the growth of human pathogens Aspergillus parasiticus and Aspergillus flavus producing AFB1, as well as Aspergillus ochraceus and Aspergillus niger which produce OTA. The obtained results revealed that sausage samples had the highest mould count with a mean value of 13.20×102/g, followed by basterma samples 12.05×102/g, then beef burger 7.39×102/g. In contrast, luncheon and kofta samples had the lowest count with a mean value of 5.51×102/g and 2.82×102/g. The findings revealed the antifungal potential of tested extracts. The total inhibition of A. parasitcus and A. niger growth was observed at 2 mg/mL of the combined extract. Salvia farinacea extract had the highest total phenolic content and total flavonoid content with a value of 174.1 and 52.6 mg g-1, respectively. Rutin was the major phenolic component in neem and combined extracts, accounting for 19123 and 8882 μg/g, respectively. Besides, the study investigated detoxification of AFB1 and OTA using combined extract in albino rats. The results confirmed the convenient and safe use of Salvia farinacea and Azadirachta indica extract and their combination as natural antifungal and antioxidant agents. The combined extract could be used as a natural preservative in food processing to control or prevent contamination.

A Leap Forward Towards Unraveling Newer Anti-infective Agents from an Unconventional Source: a Draft Genome Sequence Illuminating the Future Promise of Marine Heterotrophic Bacillus sp. Against Drug-Resistant Pathogens

During the previous decade, genome-built researches on marine heterotrophic microorganisms displayed the chemical heterogeneity of natural product resources coupled with the efficacies of harnessing the genetic divergence in various strains. Herein, we describe the whole genome data of heterotrophic Bacillus amyloliquefaciens MB6 (MTCC 12,716), isolated from a marine macroalga Hypnea valentiae, a 4,107,511-bp circular chromosome comprising 186 contigs, with 4154 protein-coding DNA sequences and a coding ratio of 86%. Simultaneously, bioactivity-guided purification of the bacterial extract resulted in six polyketide classes of compounds with promising antibacterial activity. Draft genome sequence of B. amyloliquefaciens MB6 unveiled biosynthetic gene clusters (BGCs) engaged in the biosynthesis of polyketide-originated macrolactones with prospective antagonistic activity (MIC ≤ 5 µg/mL) against nosocomial pathogens. Genome analysis manifested 34 putative BGCs necessitated to synthesize biologically active polyketide-originated frameworks or their derivatives. These results provide insights into the genetic basis of heterotrophic B. amyloliquefaciens MTCC 12,716 as a prospective lead for biotechnological and pharmaceutical applications.

Nanoparticles of ZnO/Berberine complex contract COVID-19 and respiratory co-bacterial infection in addition to elimination of hydroxychloroquine toxicity

PURPOSE

A novel coronavirus (COVID-19) that has not been previously identified in humans and has no specific treatment has recently spread. Treatment trials using antiviral and immune-modulating drugs such as hydroxychloroquine (HCQ) were used to control this viral outbreak however several side effects have emerged. Berberine (BER) is an alkaloid that has been reported to reveal some pharmacological properties including antioxidant and antimicrobial activities. Additionally, Zinc oxide nanoparticles (ZnO-NPs) possess potent antioxidant and anti-inflammatory properties. Therefore, this study was undertaken to estimate the efficiency of both BER and synthetic ZnO/BER complex as an anti-COVID-19 therapy.

METHODS

First, the ZnO/BER complex was prepared by the facile mixing method. Then in vitro studies on the two compounds were conducted including VeroE6 toxicity, anti-COVID-19 activity, determination of inhibitory activity towards papain-like proteinase (PL pro) and spike protein- and receptor- binding domain (RBD) as well as assessment of drug toxicity on RBCs.

RESULTS

The results showed that ZnO/BER complex acts as an anti-COVID-19 by inhibiting spike protein binding with angiotensin-converting enzyme II (ACE II), PL pro activity, spike protein and E protein levels, and expression of both E-gene and RNA dependent RNA polymerase (RdRp) at a concentration lower than that of BER or ZnO-NPs alone. Furthermore, ZnO/BER complex had antioxidant and antimicrobial properties where it prevents the auto oxidation of 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and the culture of lower respiratory system bacteria that affected Covid 19 patients. The ZnO/BER complex prevented as well the HCQ cytotoxic effect on both RBC and WBC (in vitro) and hepatotoxicity, nephrotoxicity and anemia that occurred after HCQ long administration in vivo.

CONCLUSION

The ZnO/BER complex can be accounted as promising anti-COVID 19 candidate because it inhibited the virus entry, replication, and assembly. Furthermore, it could be used to treat a second bacterial infection that took place in hospitalized COVID 19 patients. Moreover, ZnO/BER complex was found to eliminate the toxicity of long-term administration of HCQ in vivo.

Antioxidant and Antiradical Properties of Probiotic Strains Bacillus amyloliquefaciens ssp. plantarum

The aim of the present study was to investigate the in vitro antioxidant potential of the cell-free extracts (CFE) of two probiotic bacteria Bacillus amyloliquefaciens ssp. plantarum IMV B-7142 and Bacillus amyloliquefaciens ssp. plantarum IMV B-7143 and their hepatoprotective effects. These strains are the main components of the veterinary probiotic preparation endosporyn. The CFE of probiotic bacteria were able to stabilize the 2.2-diphenyl-1-picrylhydrazyl radical to its neutral form at their cultivation during 24-48 h. But this index was more pronounced for the IMV B-7142 strain and amounted to 44.4-51.2%. The hydroxyl radical scavenging activity of the CFE of probiotic bacteria increased more than 70-80% regardless of the cultivation period (24-48 h). The antioxidant potential of probiotic strains is associated with the synthesis of the multiple biologically active molecules. The phenolic and benzoic acids-antioxidants (gallic, 4-hydroxyphenylacetic, caffeic, syringic, p-coumaric, trans-ferulic, and trans-cinnamic acids) were identified among metabolites of B. amyloliquefaciens ssp. plantarum strains. The CFE of probiotic strains were able to protect of rat hepatocytes from the toxic effects of the carbon tetrachloride (CCl₄). Post-treatment of stress-induced rat hepatocytes by CFE of the IMV B-7042 was accompanied by an increase of the catalase activity of cells by 485.2 mM/min × mg of protein, compared to stress-damaged sample. In doing so, the content of the main markers of oxidative stress: lipid hydroperoxides and malondialdehyde decreased significantly. The results suggested that CFE of both probiotic strains have potent antioxidant properties and effectively protect of stress-damaged rat hepatocytes.

Rhizobacterial Bacillus mycoides functions in stimulating the antioxidant defence system and multiple phytohormone signalling pathways to regulate plant growth and stress tolerance

AIMS

To analyse effects and mechanisms of plant growth promotion mediated by Bacillus mycoides strain A3 (BmA3), in Arabidopsis thaliana seedlings.

METHODS AND RESULTS

Bacillus mycoides strain A3 (BmA3) isolated from the bamboo rhizosphere produced phytohormones, including indole-3-acetic acid (IAA) and gibberellic acid (GA), and exhibited phosphate solubilization and radical scavenging activities. A. thaliana seedlings inoculated with BmA3 exhibited an altered root architecture including an increased number of lateral roots and root hairs. Likewise, enhanced photosynthetic efficiency through the accumulation of higher levels of chlorophyll and starch, and increased plant size and fresh weight were observed in the BmA3-treated seedlings. This bacterial inoculation stimulated the antioxidant defence system by increasing the activities of catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and phenylalanine ammonia-lyase (PAL). Secondary metabolites, including phenolic compounds, flavonoids and glucosinolates, were induced to higher levels in the BmA3-treated plants. Under drought and heat stresses, lower levels of H₂ O₂ , malondialdehyde (MDA) and electrolyte leakage were noticed in the treated seedlings. Genes involved in the signalling pathway of jasmonic acid (JA) including MYC2 and lipoxygenase 1 (LOX1) and salicylic acid (SA) including SAR DEFICIENT 1 (SARD1) and CAM-BINDING PROTEIN 60-LIKE G (CBP60G), and the antioxidant defence system including Ascorbate peroxidase (AtAPX) and alternative oxidase (AOX) were upregulated in BmA3-treated plants. Moreover, pathogenesis-related protein 1 (PR-1) and PR-2, marker genes for disease resistance, as well as DREB2A and HsFA2, which function in abiotic stress regulation, were also upregulated.

CONCLUSIONS

BmA3 was able to activate JA and SA signalling pathways to induce plant growth and abiotic stress tolerance in A. thaliana seedlings.

SIGNIFICANCE AND IMPACT OF STUDY

The plant growth promotion and increased stress tolerance induced by BmA3 were the result of the combined effects of microbial metabolites and activated host plant responses, including phytohormone signalling pathways and antioxidant defence systems.

Genome Mining Associated with Analysis of Structure, Antioxidant Activity Reveals the Potential Production of Levan-Rich Exopolysaccharides by Food-Derived Bacillus velezensis VTX20

Exopolysaccharides (EPSs) produced by Bacillus species have recently emerged as promising commercial antioxidants in various industries, such as pharmaceutics and biomedicine. However, little is known about EPS production and function from Bacillus velezensis so far. In the present study, the effect of sugar sources on EPS production by B. velezensis VTX20 and the genetic biosynthesis, characteristics, and antioxidant activity of the resulting EPS were evaluated. The strain VTX20 produced the maximum EPS yield of 75.5 ± 4.8 g/L from an initial 200 g/L of sucrose after a 48-h cultivation. Through genomic analysis, ls-levB operon was found, for the first time, to be responsible for the levan-type EPS production in B. velezensis. Biochemical and structural characterization further confirmed the majority of levan, followed by an extremely low level of dextran biopolymer. The water solubility index and water holding capacity of the EPSs were 81.9 ± 3.4% and 100.2 ± 3.4%, respectively. In vitro antioxidant activity analyses showed strong scavenging activity for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical values of 40.1–64.0% and 16.0–40%, respectively. These findings shed light on the EPS biosynthesis of B. velezensis at both structural and genetic levels and the potential application of EPS as a natural antioxidant for pharmaceutical and biomedical industries.

A Review of the Effects and Production of Spore-Forming Probiotics for Poultry

Simple Summary

Spore-forming probiotics are widely used in the poultry industry for their beneficial impact on host health. The main feature that separates spore-forming probiotics from the more common lactic acid probiotics is their high resistance to external and internal factors, resulting in higher viability in the host and correspondingly, greater efficiency. Their most important effect is the ability to confront pathogens, which makes them a perfect substitute for antibiotics. In this review, we cover and discuss the interactions of spore-forming probiotic bacteria with poultry as the host, their health promotion effects and mechanisms of action, impact on poultry productivity parameters, and ways to manufacture the probiotic formulation. The key focus of this review is the lack of reproducibility in poultry research studies on the evaluation of probiotics’ effects, which should be solved by developing and publishing a set of standard protocols in the professional community for conducting probiotic trials in poultry.

Abstract

One of the main problems in the poultry industry is the search for a viable replacement for antibiotic growth promoters. This issue requires a “one health” approach because the uncontrolled use of antibiotics in poultry can lead to the development of antimicrobial resistance, which is a concern not only in animals, but for humans as well. One of the promising ways to overcome this challenge is found in probiotics due to their wide range of features and mechanisms of action for health promotion. Moreover, spore-forming probiotics are suitable for use in the poultry industry because of their unique ability, encapsulation, granting them protection from the harshest conditions and resulting in improved availability for hosts’ organisms. This review summarizes the information on gastrointestinal tract microbiota of poultry and their interaction with commensal and probiotic spore-forming bacteria. One of the most important topics of this review is the absence of uniformity in spore-forming probiotic trials in poultry. In our opinion, this problem can be solved by the creation of standards and checklists for these kinds of trials such as those used for pre-clinical and clinical trials in human medicine. Last but not least, this review covers problems and challenges related to spore-forming probiotic manufacturing.

Probiotic Potential of Bacillus Strains Isolated from an Acidic Fermented Food Idli

Present study is intended to assess the probiotic properties of Bacillus spp. isolated from idli batter, a traditional fermented food of Southern India and Sri Lanka. A total of 32 isolates were screened for potential pathogenic behaviour through haemolysis assay, DNase activity and antibiotics sensitivity. Two of the isolates were found to be potentially safe and identified as Bacillus spp. These strains were characterized for in vitro probiotic attributes and antioxidant activity. Both the strains showed strong acid and bile tolerance, transit tolerance, lysozyme tolerance, cell surface hydrophobicity, auto-aggregation, co-aggregation, biofilm formation potential and adhesion to human colon adenocarcinoma (HT 29) cell line demonstrating potential probiotic ability. These strains also exhibited considerable cholesterol binding, thermostability, β-galactosidase production, proteolytic, amylolytic and lipolytic activity. Cell-free supernatant inhibited the biofilm formation by Pseudomonas aeruginosa (KT266804) to 90%. Intact cells showed significant DPPH (41%), hydroxyl (31%), radical scavenging activity and lipid peroxidation inhibition (20.38%), while cell-free extracts exhibited significant superoxide anion radical scavenging activity (16.25%). Results revealed that isolates could be potential probiotic candidate after further assessment of in vivo probiotic properties and safety evaluation and could be utilised as starter cultures in functional foods.

Growth of Bacillus amyloliquefaciens as influence by Si nutrition

The aim of study was to determine the influence of soluble and solid forms of Si on the growth of B. amyloliquefaciens. The experiment was conducted at two regimes: under sterile conditions (without B. amyloliquefaciens) and infected conditions (with B. amyloliquefaciens). New formed silica gel, diatomite and monosilicic acid at 1 mM Si and 2 mM Si were used as source of Si. The concentration of monosilicic acid in the solution was measured on second and tenth days of experiment. The total carbon in the solution before and after centrifugation was determined on day 10 of the experiment. The experiment has demonstrated a significant positive effect (by 4.7-41.2%) on B. amyloliquefaciens growth in water system. The presence of B. amyloliquefaciens in Si-rich solution reduced the concentration of monosilicic acid in the solution up to 16.2%. About 13.5-30.7% of B. amyloliquefaciens can be attached to the Si-rich surface without formation of cell clusters. Si can be classified as a beneficial nutrient for B. amyloliquefaciens. The tested strain of Bacillus can form channels in silica gel. The presence of monosilicic acid resulted in the formation of an aligned positioning of cells in water-based solution. This study is the first to demonstrate the direct influence of active Si forms on bacteria growth. The research showed that monosilicic acid or Si-rich solid substances with high solubility on Si can be recommended to increase B. amyloliquefaciens growth in soil, water or reactors.

Bacillus amyloliquefaciens B10 can alleviate aflatoxin B1-induced kidney oxidative stress and apoptosis in mice

Aflatoxin B1(AFB1) widely exists in food and feed, which seriously endangers human and animal health. How to detoxify AFB1 is a research hotspot at present. This study attempts to use the Bacillus amyloliquefaciens B10, one of probiotics strain as the research object to ascertain whether it can alleviate the kidney injury induced by AFB1 in mice and its mechanism. Fifty-six mice were divided into four groups (control, AFB1, AFB1 + B10, and B10). The mice that received intragastric administration for 28 days were euthanised, and serum was collected for biochemical index detection with fresh kidney tissue taken for HE staining, TUNEL detection, and protein expression detection. Our results showed that the biochemical indices changed, significant pathological changes appeared, the number of apoptotic cells increased in the kidney tissue of the AFB1 group mice; the protein expressions of Nrf2, HO-1,AKT, P-AKT, and Bcl-2 in the AFB1 group were significantly decreased; the protein expressions of Keap-1, PTEN, Bax, Caspase-9, and Caspase-3 were significantly increased. After B. amyloliquefaciens B10 co-treatment, compared with the AFB1 group, the biochemical indices, pathological changes, and protein expressions were significantly reversed. The results indicated that B. amyloliquefaciens B10 can alleviate AFB1-induced kidney injury in mice.

Effect of Bacillus subtilis on antioxidant enzyme activities in tomato grafting

Grafting generally means stress to a plant and this triggers antioxidant defense systems. An imbalance in reactive oxygen species may negatively affect the grafting success. Several research projects have studied the association with plant growth-promoting rhizobacteria (PGPR) and it has been documented that they enhance nutrient acquisition, regulate hormone levels, and influence the antioxidant response in crops. However, little is known about the strategy of inoculating grafted herbaceous plants with PGPR and its effect on the antioxidant response. The effects of inoculating a strain of Bacillus subtilis on the antioxidant metabolism of grafted tomato were evaluated. In this study, two different rootstocks were used for tomato (Solanum lycopersicum L. var. Rio Grande (RG)): [S. lycopersicum L. var. cerasiforme (Ch)] and eggplant [(Solanum melanogena L. (Ber)] to establish a compatible graft (RGCh) and a semicompatible graft (RGBer). Enzyme activities involved in the antioxidant defense system: superoxide dismutase (SOD), catalase (CAT), phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), and total phenols were measured during 4 weeks after grafting. The results show that for RGCh, during the first two weeks after grafting, the tendency was a decrease of the enzyme activity for SOD, CAT, PAL when inoculated with B. subtilis; while in the semicompatible graft RGBer, PPO and PAL decreased their activity after inoculation. For both combinations, the quantity of total phenols varied depending on the day. In both graft combinations, applications of B. subtilis resulted in 86 and 80% callusing compared with the uninoculated control where the percentages were 74 and 70% for RGCh and RGBer, respectively. The highest significant graft success (95%) was recorded 28 days after grafting for inoculated RGBer. These findings imply that B. subtilis induced antioxidant mechanisms in grafted plants and suggest that inoculation with this growth-promoting bacterium can represent a biotechnological approach to improve success in tomato grafting.

Bacillus amyloliquefaciens CECT 5940 improves performance and gut function in broilers fed different levels of protein and/or under necrotic enteritis challenge

Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940 (BA) as a probiotic on growth performance, amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis (NE) challenge and/or fed diets with different levels of crude protein (CP). Both studies consisted of a 2 × 2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens. In study 1, treatments included 1) NE challenge (+/-), and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/-). In study 2, all birds were under NE challenge, and treatments were 1) CP level (Standard/Reduced [2% less than standard]) and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/-). After inducing NE infection, blood samples were taken on d 16 for uric acid evaluation, and cecal samples were collected for bacterial enumeration. In both studies, ileal digesta was collected on d 35 for nutrient digestibility evaluation. In study 1, the NE challenge reduced body weight gain (BWG), supressed feed conversion ratio (FCR) and serum uric acid levels (P < 0.001). Supplementation of BA increased BWG (P < 0.001) and reduced FCR (P = 0.043) across dietary treatments, regardless of challenge. Bacillus (P = 0.030) and Ruminococcus (P = 0.029) genomic DNA copy numbers and concentration of butyrate (P = 0.017) were higher in birds fed the diets supplemented with BA. In study 2, reduced protein (RCP) diets decreased BWG (P = 0.010) and uric acid levels in serum (P < 0.001). Supplementation of BA improved BWG (P = 0.001) and FCR (P = 0.005) and increased Ruminococcus numbers (P = 0.018) and butyrate concentration (P = 0.033) in the ceca, regardless of dietary CP level. Further, addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets (P = 0.039). At d 35, BA supplemented diets showed higher apparent ileal digestibility of cystine (P = 0.013), valine (P = 0.020), and lysine (P = 0.014). In conclusion, this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.

Spectroscopic and chromatographic identification of bioprospecting bioactive compounds from cow feces: Antimicrobial and antioxidant activities evaluation of gut bacterium Pseudomonas aeruginosa KD155

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Isolation and screening of P. aeruginosa from cow dung having antagonistic potential.

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Molecular characterization of the isolate and thermodynamic stability study.

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Antimicrobial activity of extracellular crude extract of P. aeruginosa against microorganisms of medical importance.

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Antioxidant activity of extracellular crude extracts using DPPH scavenging activity.

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Isolation and characterisation of bioactive compound using HP-TLC, FTIR and GC-MS.

The prime objective of our study was to evaluate antimicrobial and antioxidant activities of Pseudomonas aeruginosa KD155 isolated from cow dung. For identification of the isolate KD155, molecular techniques were employed and obtained 16S rRNA gene sequence was deposited in the NCBI GenBank under the accession number MK801234. Extracellular crude extract of P. aeruginosa KD155 displayed significant antimicrobial activity against Bacillus subtilis (MTCC 441) and Staphylococcus aureus (MTCC 7443) in comparison to tetracycline and ketoconazole. The resistance of extracellular crude chloroform extract to DPPH scavenging activity was also observed with 77.49% inhibition rate reflecting strong antioxidant activity. In addition, HP-TLC, FT-IR and GC-MS analysis of extracellular chloroform crude extract was done which revealed phenolic compound (quercetin) as major bioactive metabolite being produced by our isolate KD155. Further, the stability of 16S rRNA sequence of the strain was studied using bioinformatics tools viz. mfold and NEB cutter indicating the thermodynamic stability of its gene sequence.