Probiotic Potential of Bacillus sp. 62A Isolated from a Marine Extreme Environment.

Antimicrobial resistance is an important health concern globally, and probiotics are considered an alternative to minimize it. The present study examined the in vitro probiotic characteristics and in vivo immunomodulatory potential of Bacillus sp. 62A - an extremophile bacterium. Bacillus sp. 62A was evaluated in vitro for its cytotoxicity, hemolytic activity, antibiotic susceptibility, and resistance to gastrointestinal conditions (bile salts, low pH, and intestinal adherence). Additionally, the immunomodulatory effect of Bacillus sp. 62A was studied in mice. The animals were supplemented daily with phosphate-buffered saline (control) and Bacillus sp. 62A at 1 × 108 colony forming units (CFU). Samples were taken on days 5 and 10. Isolated splenocytes were challenged with Escherichia coli for immunological analyses and immune-related gene expression. Serum and feces were collected for IgA and IgG determination. Bacillus sp. 62A did not show cytotoxicity, hemolytic activity, or resistance to antibiotics. Furthermore, the bacterium has autoaggregation and intestinal adhesion capacities and grows in the presence of bile salts and low pH. Bacillus supplementation in mice improved respiratory burst activity, nitric oxide production, and IL-1ß and IL-6 gene expressions, mainly at 10 days. After E. coli challenge, Bacillus supplementation in mice induced an anti-inflammatory response through a decrease in immunological parameters and an increase in IL-10 gene expression. Moreover, serum IgA and IgG and fecal IgG augmented in supplemented mice. In conclusion, Bacillus sp. 62A has biosafe and immunomodulatory probiotic potential.

Probiotic Debaryomyces hansenii CBS 8339 yeast enhanced immune responses in mice.

This study aimed to examine the effect of Debaryomyces hansenii CBS 8339 on innate immune responses in mice. Thirty BALB/c mice were randomly treated with phosphate buffered saline (PBS) (control) and two D. hansenii (Dh) doses: Dh 10ˆ6 CFU (colony forming units) and Dh 10ˆ8 CFU daily for 15 days. Spleen, blood, and gut samples were taken on days 7 and 15. Mouse splenocytes were isolated and challenged with Escherichia coli. Immunological assays and immune-related gene expressions were performed. Serum was obtained from blood for total IgA and IgG antibody titer determination. Gut samples were taken for yeast colonization assessment. Phagocytosis, respiratory burst activity, and nitric oxide production in mice were mainly enhanced (p < 0.05) upon 7 days of D. hansenii intake at a concentration of 10ˆ8 CFU before and after bacterial challenge. Moreover, oral D. hansenii in mice upregulated (p < 0.05) gene expression of pro-inflammatory cytokines (INF-γ, IL-6 and IL-1ß) before or after E. coli challenge on day 7 but downregulated (p < 0.05) on day 15. Furthermore, total serum IgG and IgA titers were higher (p < 0.05) in Dh 10ˆ8 CFU at days 7 and 15, and only at day 7, respectively, than that in the other dose and control groups. Finally, D. hansenii was detected in the gut of mice that received the treatments, suggesting that yeast survived gastrointestinal transit. Altogether, a short period (7 days) of D. hansenii CBS 8339 oral delivery improved immune innate response on mice.

Potential assessment of probiotic Cystobasidium benthicum LR192 strain in mice.

Antibiotic bacterial resistant is a huge concern worldwide and probiotics offer an alternative to mitigate it. This study explores Cystobasidium benthicum LR192 as possible probiotic through microbiological and immunological analyses in mouse model. C. benthicum LR192 was isolated from lichens in a hyperarid environment in Baja California Sur, Mexico. First, microbiological analysis was assessed using 1 × 105 CFU/mL in YM broth: resistance to 1% of bile salts and pH of 2, 3 and 5 (control). Then, yeast capacity to adhere onto the intestinal mucosa and safety to mouse splenocytes were tested. Finally, immunological parameters (phagocytic ability, respiratory burst and myeloperoxidase activities, nitric oxide and IgG production) and immune-associated gene expression (IL-1ß, IL-6 and INF-γ) were determined in daily supplemented mice with the yeast (1 × 108 CFU) at days 10 and 15. The results indicate that C. benthicum LR192 has medium resistance to bile salts and low pH, can adhere to the intestine and did not cause cytotoxicity in splenocytes. Immune parameters and immune-related gene expression indicated immunomodulation at day 10 and 15, specially in leucocytes challenged with Escherichia coli. In conclusion, C. benthicum LR192 showed safe potential probiotic properties, but further studies should be performed to confirm it as a probiotic prospect for humans.

HALOBACTERIAS PROMOTORAS DE CRECIMIENTO VEGETAL ASOCIADAS A Lippia palmer! (VERBENACEAE) EN LA ZONA ÁRIDA DEL NOROESTE DE MÉXICO / Plant growth promoting halobacteria associated to plant growth promoting halobacteria associated to Lippia palmeri (Verbenaceae) in the arid zone of northwestern Mexico

RESUMEN La producción de orégano es de relevancia económica en el noroeste de México. Sin embargo, los productores para obtener altos rendimientos recurren a la fertilización química, pero su mal uso, agudiza la salinidad. Lippia palmeri crece de manera natural en suelos áridos, pobres en materia orgánica, alta salinidad y temperatura en el noroeste de México. En el contexto de una agricultura sustentable, los microorganismos mantienen la fertilidad del suelo e incrementan la productividad de la planta. Actualmente existe interés en proponer biofertilizantes en la agricultura de alta intrusión salina y elevadas temperaturas para el cultivo de orégano. Las Halobacterias Promotoras del Crecimiento de Plantas (HPCP), se han destacado por beneficiar a los cultivos nutrimentalmente y mitigar el efecto de la salinidad. El objetivo del presente trabajo consistió en identificar termo- y halo-tolerantes HPCP asociadas a la rizosfera de L. palmeri; se evaluó la actividad solubilizadora de fosfatos, producción de ácidos orgánicos, sideróforos y fijación de nitrógeno; se identificaron mediante el gen ARNr-16S aquellas con alta actividad evaluándose su efecto en la germinación y longitud radicular. Quince diferentes colonias sobresalieron al crecer en NaCl (0.25, 0.50 y 0.75 M) a 35 y 45 °C, destacando tres bacterias identificadas: Bacillus amyloliquefaciens, Bacillus subtilis y Bacillus licheniformis. El efecto en la longitud radicular es significativo por la aplicación de B. amyloliquefaciens. Estudios relacionados con la promoción vegetal deben ser considerados en posteriores estudios. Este es el primer informe de B. amyloliquefaciens como una bacteria fijadora de nitrógeno asociada a L. palmeri.

ABSTRACT The production of oregano is of economic relevance in northwestern Mexico. However, to obtain high yields, producers resort to chemical fertilization, but its misuse increases salinity. Lippia palmeri Watts is a species of oregano that naturally grows in arid soils with poor organic matter, high salinity and temperature in the northwestern Mexico. In the context of sustainable agriculture, microorganisms activate soil fertility and increase plant productivity. Currently there is interest in proposing biofertilizers in the agriculture with high saline intrusion and temperatures for the cultivation of oregano. The Plant Growth Promoting Halobacteria (HPCP) have stood out by the beneficiary of the nutritious crops and mitigate the effect of the salinity. The goal of this work was to identify HPCP associated to the rhizosphere of L. palmeri, thermo and halotolerant; phosphate solubilizing activity, organic acid production, siderophores and nitrogen fixation were evaluated; the highest activity colonies were identified by the rRNA-16S gene and the effect on germination and root length was evaluated. Fifteen different colonies stood out when growing in NaCl (G.25, G.5G and G.75 M) at 35 and 45 °C, from which three bacteria were identified: Bacillus amyloliquefaciens, Bacillus subtilis and Bacillus licheniformis. The effect on root length was significant for B. amyloliquefaciens. Studies related to plant promotion should be involved in subsequent studies. This is the first report of Bacillus amyloliquefaciens as a nitrogen fixing bacteria associated with Lipia palmeri.

Composition, antioxidant capacity, intestinal, and immunobiological effects of oregano (Lippia palmeri Watts) in goats: preliminary in vitro and in vivo studies.

This study investigated Lippia palmeri Watt (oregano) phytochemical compounds, their antioxidant capacity, and immunological effects on goat peripheral blood leukocytes (PBL), and on the presence of intermediate polar compounds in goat feces fed dietary oregano. The polar and nonpolar fractions of L. palmeri W. were characterized and phytochemical contents and antioxidant capacity were determined. Twelve healthy Anglo-Nubian goats were used for the in vivo trials, which were randomly assigned to control fed with basal diet, or oregano group fed with basal diet + 2.6% (DM basis) dried oregano leaves. Goat peripheral blood leukocytes (PBL) were isolated for the in vitro study, and PBL were stimulated with oregano extracts at 100 and 150 µg/mL after 24 h. For the in vivo trial, dietary oregano (2.6% on DM basis) was evaluated in the goats for 90 days. Relatively high abundance of carvacrol and thymol phytochemical compounds was found in oregano. The highest antioxidant capacity of oregano extracts was detected at 100 and 150 µg/mL. Nitric oxide production, phagocytosis, and superoxide dismutase activities increased (p < 0.05) in stimulated PBL with oregano extracts, whereas the pro-inflammatory (TNF-α and IL-1ß) transcription and antioxidant (CAT and GPX-4) genes downregulated. In the in vivo experiment, dietary oregano enabled the detection of nine compounds found in goat feces, from which caproic (C6) was in a high relative quantity compared with the control group. Oregano has phytochemical compounds with strong antioxidant capacity that protect cells against oxidative stress damage and could modulate immune response and feces composition in goats.

Phytochemical composition and immunobiological activity of Hawthorn Crataegus mexicana nanoencapsulated in Longfin yellowtail Seriola rivoliana leukocytes.

The aims of this study were to determine the presence of phenolic compounds in Hawthorn Crataegus mexicana, species native to Mexico, nanoencapsulated (CmNano) with maltodextrin at 100 and 170 °C (CmNano100 and CmNano170) and its antioxidant and immunological effects in Longfin yellowtail Seriola rivoliana leukocytes. The phytochemical study revealed an important level of total phenolic (TPC), flavonoid (TFC) and tannin (CTC) contents in CmNano100, which correlated with a strong antioxidant capacity. CmNano100 or 170 were safe or not cytotoxic for head-kidney (HKL) and peripheral blood (PBL) leukocytes. The in vitro study demonstrated that CmNano increased the percentage of phagocytic cells, stimulated the production of reactive oxygen species, and modulated antioxidant ability by increasing superoxide dismutase activity in leukocytes with respect to the control group. In addition, CmNano100 also increased the transcription of proinflammatory cytokine IL-1ß and down-regulated MyD88 and TNF-α mRNA transcription. These results suggest that maltodextrin nanoencapsulates protected and maintained the antioxidant properties of C. mexicana. In addition, they enhanced antioxidant and immunological parameters in Longfin yellowtail S. rivoliana leukocytes. Therefore, this study provides novel insights of CmNano for its potential application as functional food in aquaculture.

Caspase -1, -3, -8 and antioxidant enzyme genes are key molecular effectors following Vibrio parahaemolyticus and Aeromonas veronii infection in fish leukocytes.

Caspases are a family of proteases involved in many important biological processes including apoptosis and inflammation. In order to get insights into the caspase gene family and antioxidant enzymes in Totoaba macdonaldi during bacterial infection, an in vitro assay was performed involving three different types of caspases (Casp-1, Casp-3 and Casp-8) and antioxidant enzymes (catalase, gluthathione peroxidase 1 and 4) after Vibrio parahaemolyticus and Aeromonas veronii infection, using head-kidney and spleen leukocytes from the teleost fish totoaba at 12 and 24 h post-exposure. Characterization of caspases by bioinformatics analyses showed that TmCas-1, TmCas-3 and TmCas-8 shared overall sequence identities of 82-61%, 85-97% and 77-63%, respectively, with other teleost fish. Caspase-1, -3 and -8 proteins revealed a conserved penta-peptide sequence at the catalytic site and three amino acid residues involved in the catalysis (H, G and C), as well as two conserved domains. The expression levels of the three caspases were detected in a wide range of fish tissues; however, they varied among tissues and caspases, which were highly up-regulated in immune organs, such as head-kidney, liver and/or spleen. The pathogen-induced gene expression pattern revealed two interesting facts; first, that the expression of all the caspase genes and antioxidant enzyme genes evaluated in this study were strongly induced following V. parahaemolyticus infection; second, these up-regulations reached a maximum level at 24 h post-infection in head-kidney whereas in spleen leukocytes, it was observed at 6-h post-infection. In conclusion, based on these observations, the acute toxic effects of V. parahaemolyticus are associated to cell death and release of free radicals. This information provides a better understanding of the effects and nature of early immune response against common bacterial infections in totoaba leukocytes.