Primera evidencia de actividad enzimática nitrilasa en Xylaria sp., y su relación con la biosíntesis de ácido indol-3-acético / First evidence of nitrilase enzymatic activity of Xylaria sp. and its relationship with the biosynthesis of indole-3-acetic acid

Resumen Muchos de los hongos degradadores de madera están implicados en la síntesis de metabolitos bioactivos de naturaleza antimicrobiana y terapéutica, así como de compuestos de importancia biotecnológica, incluyendo derivados indólicos, entre otros. Estos hongos brindan ciertos beneficios ecológicos a las plantas, entre los que se destacan la protección contra fitopatógenos y la promoción del crecimiento radicular. Xylaria sp. es un hongo degradador de celulosa (lignocelulolítico) con potencial biotecnológico. El ácido indol-3-acético (AIA) desempeña un papel sumamente importante en las interacciones planta-microorganismo, ya que es esencial para la fisiología y el correcto desarrollo morfológico vegetal. Se sabe que las enzimas nitrilo-hidrolíticas (nitrilasas) están involucradas en la síntesis de compuestos indólicos en las plantas, no obstante, se dispone de poca información acerca de la naturaleza de estas enzimas en el reino de los hongos. A través de una aproximación bioquímica y de genética molecular, se demuestra por primera vez que Xylaria sp. posee actividad enzimática nitrilasa utilizando compuestos ricos en nitrógeno y carbono como sustrato. La cepa estudiada aumentó sus niveles de expresión génica relativa y mostró crecimiento micelial, ambos en presencia de compuestos químicos como cianobenceno y KCN. Los resultados de este trabajo sugieren que el microorganismo es capaz de degradar moléculas nitrogenadas complejas. Por otra parte, mediante biofertilización con extractos fúngicos, se observó que Xylaria sp. promueve el desarrollo del sistema radicular de plántulas de Arabidopsis thaliana, además de sintetizar AIA.

Abstract Endophytic fungi inhabit plant tissues internally and asymptomatically, and many of them are involved in the synthesis of bioactive metabolites of antifungal and therapeutic nature, as well as other compounds of biotechnological importance including indole derivatives, among many others. Ecologically, they provide some benefits to plants including protection against phy-topathogens and promotion of root growth. In this sense, Xylaria sp. is a cellulose-decomposing fungus with biotechnological potential. It is worth mentioning that indole-3-acetic acid (IAA) also plays an extremely important role in plant-micro-organism interactions, as it is essential for physiology and proper plant morphological development. It is known that nitrile-hydrolytic enzymes (nitrilases) are involved in the synthesis of plant indole compounds; however, relatively little information is available concerning the nature of these enzymes in the fungal kingdom. In view of the above, through a biochemical and molecular-genetic approach, it has been demon-strated for the first time that Xylaria sp. carries out nitrile-hydrolytic enzyme activity using nitrogen and carbonrich compounds as substrate. The studied strain increased its relative gene expression levels and showed mycelial growth, both in the presence of chemical compounds such as cyanobenzene and KCN. Thus, the results of this work suggest that the micro-organism is capable of degrading complex nitrogenous molecules. On the other hand, through fungal biofertilization, it was observed that Xylaria sp. promotes the development of the root system of Arabidopsis thaliana seedlings, in addition to synthesizing IAA.

Prevalence of premalignant cervical lesions among women in community-based screening program using visual inspection with acetic acid in Metro Manila / Philippine Journal of Obstetrics and Gynecology

Background@#Cervical cancer remains a health-care burden in our country. Majority of women afflicted with this cancer are diagnosed in advanced stage. Several groups like the Philippine Society for Cervical Pathology and Colposcopy (PSCPC) have put forth efforts to decrease and eventually eliminate cervical cancer through improvement in level of awareness on the disease and community-based cervical cancer screening programs using visual inspection using acetic acid (VIA). Data on the prevalence of premalignant lesions using this screening method are limited in our country. Thus, the initiative of the society (PSCPC) to embark on this study. @*Objective@#The objective of this study was to determine the prevalence of premalignant cervical lesions among women screened in community-based screening program using VIA in Metro Manila.@*Methodology@#A retrospective cross-sectional study with collection of data from medical records of cervical screening programs done by the PSCPC from March 2017 to December 2019 was done. VIA was done for screening. All VIA-positive women underwent colposcopy and those with abnormal findings had colposcopically guided cervical punch biopsy.@*Results@#A total of 1072 women were screened with a positivity rate of 14.6%. One hundred and fifty-six women were VIA positive and 79 of these women underwent colposcopically guided biopsy. Premalignant cervical lesions were seen in 21 women. The prevalence rate of premalignant cervical lesions in VIA-positive women was 13.5%. The prevalence of premalignant cervical lesions among all women screened was 2%. Risk factors associated with premalignant lesions were early coitarche and smoking.@*Conclusion@#The prevalence of premalignant cervical lesions among women who underwent community-based cervical cancer screening using VIA is lower compared to other studies at 2%.

Comparing the predictive value of parameters extracted from circular ROIs with whole liver histogram on Gd-EOB-DTPA enhanced MRI for postoperative liver failure in focal liver lesions / 中华肝胆外科杂志

Objective:To compare the predictive value of parameters extracted from circular region-of-interest (ROI) with whole-liver histogram on gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced T 1 map for postoperative liver failure in patients with liver focal lesions. Methods:The data of patients who underwent Gd-EOB-DTPA-enhanced MRI for focal liver lesions in Zhongshan Hospital, Fudan University from March 2016 to March 2018 were analyzed retrospectively. Forty patients were enrolled, including 30 males and 10 females, aged (56.6±12.1) years. According to the occurrence of postoperative liver failure, forty patients were divided into liver failure group ( n=14) and control group ( n=26). The parameters extracted from circular ROIs and whole liver histogram on T 1 map before Gd-EOB-DTPA enhancement and in hepatobiliary phase (HBP) were compared between the two groups. The receiver operating characteristic (ROC) curve was used to evaluate the value of these parameters in predicting postoperative liver failure. Results:The mean, standard deviation, median and 95% quantile of T 1 HBP in histogram parameters of liver failure group were significantly higher than those of control group (all P<0.05). The three parameters extracted from circular ROIs were not effective in predicting liver failure after hepatectomy (all P>0.05). Among all the liver histogram parameters, the area under the ROC curve of the 95% quantile before T 1 enhancement for predicting postoperative liver failure was 0.702 (95% CI: 0.523-0.881), the standard deviation of T 1 HBP was 0.739 (95% CI: 0.568-0.910), and the 95% quantile of T 1 HBP was 0.721 (95% CI: 0.540-0.903). The predictive efficacy were good (all P<0.05). Among them, the predictive performance of T 1 HBP standard deviation was the best, the area under the ROC curve was 0.739, the sensitivity was 85.7%, the specificity was 57.7%, and the best threshold was 54.8 ms. Conclusions:When Gd-EOB-DTPA enhanced T 1 mapping is used to predict postoperative liver failure in patients with focal liver lesions, the whole-liver histogram analysis is superior to the conventional circular ROI-based statistical method.

Antibacterial Properties of Young and Mature Mango Leaves (Mangifera indica) Extract on Some Clinical Isolates

Aim: This study was carried out to investigate the antibacterial properties and efficacy of mango (Mangifera indica) leaf extracts on some clinical isolates as test rganisms. Study Design: The study employed statistical analysis of the data and interpretationPlace and Duration of Study: Young and mature mango leaves were collected from the Botanical Garden, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Nigeria, and taken to the laboratory for analyses. Methodology: The samples were dried in an oven at 80oC for 3 days. Thereafter, 50 g of each ground mango leaf (young and mature leaves) were soaked separately in 500 ml of water, ethanol (95% v/v), and acetic acid (99.9% v/v) respectively for another 3 days. The soaked materials were filtered through Whatman No. 1 filter paper into sterile beakers and evaporated to dryness in a water bath at 80oC. The dried extracts obtained were reconstituted with water at concentrations of 100, 75, 50, and 25 mg/ml. Test organisms, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Proteus mirabilis, Bacillus cereus, and Pseudomonas aeruginosa were obtained after proper laboratory screening of isolates from the diagnostic laboratory of the Rivers State University Teaching Hospital, Port Harcourt, Nigeria, for confirmation of identity and storage in universal bottles in a refrigerator. Sensitivity tests were carried out with the agar well diffusion method against the test organisms, using tetracycline as the standard control drug, with cultures incubated accordingly. The measured zones of inhibition were compared with the controls and interpreted as resistant, intermediate, or susceptible to mango extracts in accordance with the interpretive guidelines published by the National Committee for Clinical Laboratory Standards (NCCLS). Assay for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was also carried out. Results: Results obtained showed that acetic acid young leaf extract at 100mg/ml produced 50 % susceptibility and 50 % intermediate response of test bacterial species. Generally, at 100 mg/ml, acetic acid young leaf extracts yielded 50% susceptibility and 50% intermediate response among both Gram-positive and Gram-negative bacteria. Ethanolic extracts gave 100% intermediate sensitivity of Gram-negative species and 50% each of resistant and intermediate response in Gram-positive forms. Aqueous extracts also produced no susceptibility among the test organisms as there was 100% resistance. Extracts of mature mango leaves of all solvents and at all concentrations used yielded no susceptibility response among the test bacterial species on the NCCLS scale. Minimum inhibitory and bactericidal concentrations were found to range from 25 mg/ml to 50 mg/ml. Additionally, it was observed that the sensitivity of organisms to mango extracts increased with concentration.Conclusion: In conclusion, acetic acid has a better extracting potential than ethanol and water as a solvent for the extraction of mango parts. More so, young mango leaves extracted with acetic acid possess higher broad-spectrum antibacterial properties than the mature mango leaves extracted from the same plant. It is therefore recommended that young mango leaves, extracted with acetic acid, be used for the treatment of microbial infections at concentrations not below 50 mg/ml.

Evaluating bacterial resistance to antimicrobials in isolated bacteria from food contact surfaces / Evaluación de la resistencia bacteriana a los antimicrobianos en bactérias aisladas de superficies en contacto con alimentos / Avaliação da resistência bacteriana a antimicrobianos em bactérias isoladas de superfícies em contacto com alimentos

ABSTRACT Bacteria isolated from food contact surfaces, can transfer resistance factors when exposed to pressure exerted by inappropriate use of antimicrobial agents. This study aimed to evaluate bacterial resistance against antibiotics and disinfectants commonly used (NaOCl and CH3COOH) in bacteria isolated from food contact surfaces. Additionally, using PCR, the presence of tetracycline resistance genes was evaluated. Results showed that 47% of the isolates exhibit resistance against more than one antibiotic, being Tetracycline the antibiotic that most isolates were resistant to (35.3%). A PCR analysis found that the tet M gene is the most frequent of the genes tested. Likewise, it was evidenced that although NaOCl is effective as a surface disinfectant, Aerococcus urinae and Kocuria kristinae isolates could resist up to 10 min of exposure. Likewise, all isolates were resistant to CH3COOH, demonstrating the low inhibitory capacity of this disinfectant. Finally, the observed correlation between resistance to antibiotics and resistance to disinfectants is confirmed. An important factor that should be studied since the generalized use of disinfectants can increase the spectrum of antibiotic resistance.

RESUMEN Bacterias aisladas de superficies en contacto con alimentos pueden transferir factores de resistencia cuando se exponen a presiones ejercidas por el uso inadecuado de agentes antimicrobianos. En este estudio se evaluó la resistencia bacteriana frente a antibióticos y desinfectantes de uso común (NaOCl y CH3COOH) en bacterias aisladas de superficies en contacto con alimentos. Adicionalmente, mediante la PCR se evaluó la presencia de genes de resistencia a la Tetraciclina. Los resultados mostraron que el 47% de los aislados presentaron resistencia a más de un antibiótico, siendo la Tetraciclina al que la mayoría de los aislamientos fueron resistentes (35,3%). El análisis de PCR encontró que el gen tet M fue el más frecuente. Además, se evidenció que, si bien el NaOCl es efectivo como desinfectante de superficies, Aerococcus urinae y Kocuria kristinae pudieron resistir hasta 10 minutos de exposición. Igualmente, todos los aislados fueron resistentes a CH3COOH, demostrando la baja capacidad inhibitoria de este desinfectante. Finalmente, se confirma una correlación entre la resistencia a antibióticos y desinfectantes. Un factor importante que conviene estudiar ya que el uso generalizado de desinfectantes podría incrementar el espectro de resistencia a los antibióticos.

RESUMO Bactérias isoladas de superfícies em contacto com alimentos podem transferir factores de resistência quando expostas a tensões exercidas pela utilização inadequada de agentes antimicrobianos. Neste estudo, foi avaliada a resistência bacteriana aos antibióticos e desinfectantes comummente utilizados (NaOCl e CH3COOOH) em bactérias isoladas de superfícies em contacto com alimentos. Além disso, a presença de genes de resistência à tetraciclina foi avaliada por PCR. Os resultados mostraram que 47% dos isolados mostraram resistência a mais do que um antibiótico, sendo a Tetraciclina a que a maioria dos isolados era resistente (35,3%). A análise PCR constatou que o gene tet M era o mais frequente. Além disso, era evidente que, embora NaOCl seja eficaz como desinfectante de superficie, Aerococcus urinae e Kocuria kristinae foram capazes de resistir até l0 minutos de exposição. Da mesma forma, todos os isolados eram resistentes ao CH3COOH, demonstrando a baixa capacidade inibitória deste desinfectante. Finalmente, é confirmada uma correlação entre a resistência aos antibióticos e a resistência aos desinfectantes. Este é um factor importante que deve ser estudado uma vez que a utilização generalizada de desinfectantes poderia aumentar o espectro da resistência aos antibióticos.

In vitro bioprospecting of rhizospheric fungi associated to cactus (Opuntia cochenillifera) to plant growth promotion / Bioprospección in vitro de hongos rizosféricos asociados al cactus (Opuntia cochenillifera) para la promoción del crecimiento vegetal

Abstract This study aimed to evaluate in vitro the plant growth promotion capacity of rhizospheric fungi from Opuntia cochenillifera. The isolates were submitted to phosphate solubilization, acetic acid-3-indole (AIA) production, antagonism against phytopathogens, and growth under water activity. All test results were subjected to statistical analysis. The studied isolates were able to solubilize phosphate, being F04 (Aspergillus sp.) and F05 (Coprinellus radians) the ones that presented the highest solubilization indices. As to produce AIA, F02 (Penicillium sp.) and F07 (Aspergillus sp.) were the most promising. All isolates could inhibit the growth of Colletotrichum sp. and Fusarium sp. Water restriction provided mycelial growth for all isolates. Therefore, these characteristics confer characteristics as growth promoters in plants.

Resumen El objetivo de este estudio fue evaluar in vitro la capacidad de los hongos rizosféricos aislados del cactus Opuntia cochenillifera para promover el crecimiento de las plantas. Los aislados fueron sometidos a pruebas de solubilización de fosfato, producción de ácido 3-indol acético (AIA), antagonismo contra fitopatógenos y crecimiento bajo actividad de agua. Todos los resultados de las pruebas se sometieron a análisis estadístico. Los aislados estudiados fueron capaces de solubilizar fosfato, siendo F04 (Aspergillus sp.) y F05 (Coprinellus radians) los que presentaron los mayores índices de solubilización. Sobre la producción de AIA, los que más produjeron fueron F02 (Penicillium sp.) y F07 (Aspergillus sp.). Todos los aislados pudieron inhibir el crecimiento de Colletotrichum sp. e Fusarium sp.. La restricción de agua proporcionó el crecimiento del micelio para todos los aislados. Por lo tanto, estes aspectos les confieren características como promotores del crecimiento en las plantas.

Isolation of bacteria with plant growth-promoting activities from a foliar biofertilizer

Aims@#Plant growth-promoting bacteria are the key components of a biofertilizer. This study was aimed to isolate and identify the predominant bacteria found in a foliar biofertilizer and characterizes the potential of the bacterial isolates as plant growth promoters.@*Methodology and results@#Potential bacteria with plant growth-promoting activities were isolated from a foliar biofertilizer on HiCrome™ Bacillus agar and Nutrient agar. Bacteria with unique colonial morphology were selected and categorized by Gram’s differential staining. Subsequently, the bacterial isolates were being further characterized for plant growth-promoting potentials, such as the production of indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and siderophore; as well as the ability of nitrogen fixation and phosphate/potassium solubilization. Based on the characterized traits, three bacterial isolates, namely M17, M22 and M52 showed great potential for being a plant growth promoter. Based on their 16S rRNA gene sequence analysis, M17, M22 and M52 were identified as Leclercia adecarboxylata, Margalitia shackletonii and Lysinibacillus pakistanensis, respectively.@*Conclusion, significance and impact of study@#Bacterial isolates exhibiting plant growth-promoting activities were successfully isolated from a biofertilizer and identified in this study. This finding provides an insight into the potential bacteria of a foliar fertilizer that may promote plant growth. Identification of these plant-growth promoters may help the scientists and agrochemical manufacturers to determine and disclose the key microorganisms of their biofertilizers, thereby contributing to the improvement of biofertilizers and promoting them as reliable alternatives to chemical fertilizers.

Identification of human LDHC4 as a potential target for anticancer drug discovery

One of the distinct hallmarks of cancer cells is aerobic glycolysis (Warburg effect). Lactate dehydrogenase A (LDHA) is thought to play a key role in aerobic glycolysis and has been extensively studied, while lactate dehydrogenase C (LDHC), an isoform of LDHA, has received much less attention. Here we showed that human LDHC was significantly expressed in lung cancer tissues, overexpression of Ldhc in mice could promote tumor growth, and knock-down of LDHC could inhibit the proliferation of lung cancer A549 cells. We solved the first crystal structure of human LDHC4 and found that the active-site loop of LDHC4 adopted a distinct conformation compared to LDHA4 and lactate dehydrogenase B4 (LDHB4). Moreover, we found that (ethylamino) (oxo)acetic acid shows about 10 times selective inhibition against LDHC4 over LDHA4 and LDHB4. Our studies suggest that LDHC4 is a potential target for anticancer drug discovery and (ethylamino) (oxo)acetic acid provides a good start to develop lead compounds for selective drugs targeting LDHC4.

Genome analysis and plant growth promoting activity of Pseudonocardia strain DR1-2 from the root of Dendrobium christyanum Rchb.f

Aims@#The objective of this study was to analyze the genome of endophytic actinomycete associated with orchids and evaluate its plant hormone activities, including phytohormone, siderophore, ammonia production, zinc and phosphate solubilization.@*Methodology and results@#Strain DR1-2 isolated from the roots of the Thai orchid, Dendrobium christyanum Rchb.f., was closely related to Pseudonocardia alni DSM 44104T, P. antarctica DSM 44749T and P. carboxydivorans Y8T (99.93-100% similarity) based 16S rRNA gene sequence. This strain exhibited IAA production (294.10 ± 12.17 μg/mL), phosphate solubilization (2.20 ± 0.08 solubilization Index, SI), positive for siderophore production and ammonia production (36.99 ± 2.24 μg/mL). It showed a maximum IAA of 489.73 ± 8.90 μg/mL, when optimized using 0.5% Ltryptophan, pH 6 and incubated at 30 °C for 7 days. The IAA of strain enhanced the root length, shoot length, number of roots and fresh weight of rice seedlings (Oryza sativa L. cv. RD49). The draft genome of strain DR1-2 was 6,077,423 bp in 23 contigs with G+C content of 74.6%. The average nucleotide identity-Blast (ANIb) and average nucleotide identity-MUMmer (ANIm) values of strain DR1-2 and related type strains were 95.81 to 97.25% and the digital DNA-DNA hybridization (dDDH) values were 72.60 to 74.00%, respectively. Genomic analysis of strain DR1-2 revealed that the gene encodes the enzyme involved in the phytohormones biosynthesis and gene clusters involved in the biosynthesis of bioactive metabolites.@*Conclusion, significance and impact of study@#Endophytic actinomycete, Pseudonocardia strain DR1-2 from Thai orchid, D. christyanum Rchb.f., exhibited significant IAA production and affected the growth of the plant, which was the potential source of plant hormones for agricultural applications.

Endophytic bacteria Bacillus safensis and Pseudomonas hibiscicola and their ability to increase rice seedling growth

Endophytic bacteria Bacillus safensis RS95 and Pseudomonas hibiscicola RS121 were evaluated for their ability to promote the growth of rice seedlings and produce indole-acetic acid (IAA) and siderophores and to solubilize phosphates. 'Guri' rice seeds were immersed in bacterial endophyte cell suspensions (separated and two-strain mixed), as well as in Escherichia coli DH5α, phosphate-buffered saline (PBS) and water treatments (negative controls). Seeds were sown on agar-water in Petri plates placed vertically at an angle of 65°. The ability of plant growth-promoting endophytic bacteria (PGPEB) to produce IAA and siderophores was determined by Salkowski colorimetric and chrome azurol S (CAS) assays, respectively. Mineral phosphate solubilization activity was calculated by inoculating the endophytes onto medium containing insoluble phosphate. PGPEB showed a positive effect on the growth of rice seedlings, causing a mean growth of shoots and primary-roots of 60 and 67%, respectively. Bacterial strains also showed positive traits for IAA and siderophore production, as well as phosphate-solubilization activity

Mesenchymal stem cells have ameliorative effect on the colitis model via Nrf2/HO-1 pathway

Purpose: To evaluate the ameliorative effect of mesenchymal stem cells (MSCs) on acetic acid colitis model via Nrf2/HO-1 pathway in rats. Methods: In this study, 30 rats were divided into three groups. Acute colitis was induced by rectal administration of 4% solution of acetic acid. MSCs were injected intraperitoneally in the treatment group. Results: Increased levels of tumor necrosis factor-α (TNF-α), pentraxin-3, and malondialdehyde (MDA) in colitis group were revealed biochemically. Increased level of TNF-α and decreased levels of Nrf2 and interleukin-10 (IL-10) were observed in rectum tissues. Increased fibrous tissue proliferation, vascularization and inflammatory cell infiltration were described in the colitis group. Significant improvement was observed in MSCs treated group histopathologically. Increased immunopositivity of TNF-α, vascular endothelial growth factor (VEGF) and CD68 markers was observed in the colitis group cells, and decreased level of this positivity was observed in MSCs treated group. Conclusions: Biochemical, histopathological and immunohistochemical results strongly support the ameliorative effect of MSCs against acetic induced colitis model via Nrf2/HO-1 pathway in rats.

Isolation and Characterization of Plant Growth-Promotion Diazotrophic Endophytic Bacteria Associated to Sugarcane (Saccharum officinarum L.) Grown in Paraíba, Brazil

Abstract: Sugarcane is an important Brazilian commodity, being usually cultivated in soils with low natural fertility. This study aimed to isolate diazotrophic endophytes from sugarcane tissues and evaluate the morphological and physiological characteristics of their colonies as well as their plant growth-promoting (PGP) traits in select diazotrophic endophytic bacteria. Fifty-six bacterial isolates were identified in the sugarcane tissues, and these isolates presented distinct morphological and physiological traits. A total of thirty-five bacterial isolates were biochemically evaluated. Overall, Bacillus was the dominant genus. Isolates of Methylobacterium spp. and Brevibacillus agri were present only in leaves, while Herbaspirillum seropedicae occurred only in stems. Except to IPA-CF45A, all isolates were nitrogenase positive. All endophytes exhibit production of indol 3-acetic acid. Over 50% of endophytes solubilize phosphate, release N-acyl homoserine lactones, and present the activity of 1-aminocyclopropane-1-carboxylic acid deaminase, catalase, lipase and protease. The network analysis showed that isolates belonged to Burkholderia, Herbaspirillum, and Methylobacterium interact with Bacillus. Bacterial endophytes exhibited distinct morphological, physiological, and PGP traits that are useful for sustainable agriculture, highlighting the isolates IPA-CC33, IPA-CF65, IPA-CC9 and IPA-CF27. Further studies on the effects of these diazotrophic endophytes and their potential for providing microbial inoculants for improving sugarcane fields will provide valuable information to maintain the sustainability and environment quality.

IDENTIFICATION OF ENDOPHYTIC BACTERIA OF SEEDS FROM Cedrela odorata L. (Meliaceae) WITH BIOTECHNOLOGICAL CHARACTERISTICS / Identificación de bacterias endófitas de semillas de Cedrela odorata L. (Meliaceae) con características biotecnológicas

ABSTRACT In the present study, 62 endophytic bacterial strains of cedar seeds (Cedrela odorata L.), collected in the municipalities of Huehuetán, Motozintla, and Pijijiapan in the state of Chiapas, Mexico were isolated. The goal was to identify characteristics of biotechnological interest such as biocontrol, promotion ofplant growth, and growth in aromatic compounds. The strains were identified by the partial sequence of the 16S ribosomal gene as belonging to the Bacillus genus. The biocontrol capacity of phytopathogenic fungi, production of indoleacetic acid (IAA), solubilization of phosphate, and growth in xenobiotic compounds (phenanthrene, benzene, anthracene, or phenol) were detected in 26 strains of the 62 isolates. 21 % of the strains inhibited the mycelial growth of Alternaria solani and Fusarium sp., and 13 % of the Phytophthora capsici oomycete. IAA production was detected in 24 isolates, phosphate solubilizing activity was identified in 18 isolates, while the ability to grow in the presence of phenanthrene and benzene was found in 26 isolates; 24 isolates grew in the presence of anthracene and only two isolates grew in phenol as the only carbon sources. This is the first report of the isolation and identification of endophytic bacteria from cedar seeds, where biotechnological characteristics were detected for biological control, promotion of plant growth, and growth in the presence of xenobiotic compounds.

RESUMEN En el presente estudio se aislaron 62 cepas bacterianas endófitas de semillas de cedro (Cedrela odorata L.) colectadas en los municipios de Huehuetán, Motozintla y Pijijiapan en el estado de Chiapas, México, con el objetivo de identificar características de interés biotecnológicas como biocontrol, promoción del crecimiento vegetal y crecimiento en compuestos aromáticos. Las cepas se identificaron por la secuencia parcial del gen 16S ribosomal como pertenecientes al género Bacillus. En 26 cepas de las 62 aisladas se detectaron la capacidad de biocontrol de hongos fitopatógenos, la producción de ácido indolacético (AIA), la solubilización de fosfato y el crecimiento en compuestos xenobióticos (fenantreno, benceno, antraceno o fenol). El 21 % de las cepas inhibió el crecimiento miceliar de Alternaria solani y Fusarium sp., y el 13 % del oomiceto Phytophthora capsici. La producción de ácido indolacético se detectó en 24 aislados y la actividad solubilizadora de fosfato se encontró en 18 aislados, mientras que la capacidad de crecer en presencia de fenantreno y benceno se manifestó en 26 aislados (24 aislados crecieron en presencia de antraceno y solo dos aislados crecieron en fenol como únicas fuentes de carbono). Es importante mencionar que este es el primer reporte del aislamiento e identificación de bacterias endófitas de semillas de cedro, en el que se detectaron características biotecnológicas para el control biológico, la promoción del crecimiento vegetal y el crecimiento en presencia de compuestos xenobióticos.

Caracterización de bacterias ácido lácticas con actividad antimicrobiana aisladas del queso crema de Chiapas, México / Characterization of lactic acid bacteria with antimicrobial activity isolated from cream cheese from Chiapas, Mexico

Resumen El queso crema de Chiapas es un producto artesanal fabricado en diferentes regiones de México. La capacidad de las bacterias lácticas, de producir grandes cantidades de ácido láctico y acético, tiene como efecto la disminución del pH, considerado uno de los factores primarios en la inhibición de microorganismos indeseables, como patógenos y bacterias coliformes, en alimentos lácteos. El objetivo de este trabajo fue aislar bacterias ácido lácticas y evaluar su efecto antagónico contra bacterias patógenas in vitro y contra patógenos presentes en la leche cuando se adicionan durante la elaboración del queso crema. Se aislaron cepas de bacterias lácticas del queso crema de Chiapas, México. Los aislados fueron identificados mediante pruebas bioquímicas API 50CH y secuencias del gen ribosomal 16S. Las bacterias de interés se usaron en pruebas de inhibición del crecimiento con cepas patógenas. Se cuantificó la producción de ácido acético y láctico por cromatografía de gases acoplado a masas en los quesos, al inicio y a los 10 d posteriores a su elabo ración. Se aislaron 203 cepas bacterianas, de las cuales 82 tuvieron la capacidad de inhibir el crecimiento de 7 cepas bacterianas patógenas. Las cepas fueron identificadas por la secuencia parcial del gen ribosomal 16S como pertenecientes al género Lactobacillus; la adición de estas cepas en la elaboración del queso crema redujo o eliminó coliformes, Staphylococcus aureus, mohos y levaduras, mientras que en el queso elaborado con leche pasteurizada se detectaron 290 UFC/mL de mohos y levaduras. Estos resultados sugieren que las cepas de Lactobacillus aisladas del queso crema artesanal de Chiapas tienen potencial para su uso como cultivo iniciador con actividad de bioconservación en este y productos similares.

Abstract Chiapas cream cheese is an artisanal product manufactured in different regions of Mexico. The ability of lactic bacteria to produce large amounts of lactic and acetic acid has the effect of decreasing the pH, considered one of the primary factors in the inhibition of undesirable microorganisms such as pathogens and coliform bacteria, in dairy foods. The objective of this work was to isolate lactic acid bacteria and evaluate their antagonistic effect against pathogenic bacteria in vitro, as well as their effect against pathogens that are present in milk when they are added in the preparation of cream cheese. Strains of lactic bacteria were isolated from cream cheese from Chiapas, Mexico. Isolates were identified by API 50CH biochemical tests and 16S ribosomal gene sequences. The bacteria under study were used in pathogen growth inhibition tests. The production of acetic and lactic acid was quantified by gas chromatography coupled to masses in the cheeses at the beginning and 10 d after its elaboration. 203 bacterial strains were isolated, 82 of which had the ability to inhibit the growth of 7 pathogenic bacterial strains. The strains were identified by the partial sequence of the 16S ribosomal gene as belonging to the genus Lactobacillus; The addition of these strains in the elaboration of cream cheese reduces or eliminates coliforms, Staphylococcus aureus, molds and yeasts, while in the cheese made with pasteurized milk 290 CFU/mL of molds and yeasts were detected. These results suggest that Lactobacillus strains isolated from Chiapas artisanal cream cheese has the potential to be used as a starter culture with bioconservation activity in this and similar products.

Overexpression of a leucine transfer RNA gene tL(CAA)K improves the acetic acid tolerance of Saccharomyces cerevisiae / 生物工程学报

Acetic acid is a common inhibitor present in lignocellulosic hydrolysate. Development of acetic acid tolerant strains may improve the production of biofuels and bio-based chemicals using lignocellulosic biomass as raw materials. Current studies on stress tolerance of yeast Saccharomyces cerevisiae have mainly focused on transcription control, but the role of transfer RNA (tRNA) was rarely investigated. We found that some tRNA genes showed elevated transcription levels in a stress tolerant yeast strain. In this study, we further investigated the effects of overexpressing an arginine transfer RNA gene tR(ACG)D and a leucine transfer RNA gene tL(CAA)K on cell growth and ethanol production of S. cerevisiae BY4741 under acetic acid stress. The tL(CAA)K overexpression strain showed a better growth and a 29.41% higher ethanol productivity than that of the control strain. However, overexpression of tR(ACG)D showed negative influence on cell growth and ethanol production. Further studies revealed that the transcriptional levels of HAA1, MSN2, and MSN4, which encode transcription regulators related to stress tolerance, were up-regulated in tL(CAA)K overexpressed strain. This study provides an alternative strategy to develop robust yeast strains for cellulosic biorefinery, and also provides a basis for investigating how yeast stress tolerance is regulated by tRNA genes.

Identification and characterization of plant growth-promoting properties of bacterial endophytes from selected Zingiberaceae plants

Aims@#This study aims to isolate, characterize and screen the plant growth-promoting bacteria from Zingiberaceae plants. Plant promoting activities such as indole-3-acetic acid (IAA), phosphate solubilization, zinc solubilization and nitrogen-fixing capabilities are determined, and the IAA production of selected isolates are optimized. @*Methodology and results@#Endophytic bacteria were isolated from the plant samples by surface sterilization on nutrient agar (NA) plates and incubated at 30 °C for 2-3 days. The bacteria were identified based on their phenotypic characteristics and 16S rRNA gene sequence analyses. All isolates were identified as genera Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella. The isolates exhibited phosphate solubilization (1.5 ± 0.75-37.5 ± 8.75 Solubilization Index, SI), zinc solubilization (2.5 ± 0-60 ± 1.5 SI) and IAA production (0.1 ± 0.2-115.7 ± 1.6 µg/mL), while 3 isolates possessed nitrogen-fixing capabilities. Five isolates (PHAS-2, PWS-2, PWR-2, PHBS-2 and SCG-2) were selected for IAA optimization. Isolate PWR-2 produced the maximum IAA at 447.7 ± 0 µg/mL when tryptophan concentration was maintained at 1.0%.@*Conclusion, significance and impact of study@#Genera of bacteria included Bacillus, Lysinibacillus, Kerstersia, Klebsiella and Brucella were successfully isolated from Zingiberaceae plants. All the isolates showed the capability to produce IAA, while some isolates exhibited phosphate solubilization and zinc solubilization, and a few possessed nitrogen-fixing capabilities. The potential IAA production isolates could be applied for the enhancement of agricultural production that will be becoming a more widely accepted practice.

Discovery of thiosemicarbazone derivatives as effective New Delhi metallo-β-lactamase-1 (NDM-1) inhibitors against NDM-1 producing clinical isolates

@#New Delhi metallo-β-lactamase-1 (NDM-1) is capable of hydrolyzing nearly all β-lactam antibiotics, posing an emerging threat to public health. There are currently less effective treatment options for treating NDM-1 positive “superbug”, and no promising NDM-1 inhibitors were used in clinical practice. In this study, structure–activity relationship based on thiosemicarbazone derivatives was systematically characterized and their potential activities combined with meropenem (MEM) were evaluated. Compounds 19bg and 19bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance. Further studies demonstrated compounds 19bg and 19bh were uncompetitive NDM-1 inhibitors with Ki = 0.63 and 0.44 μmol/L, respectively. Molecular docking speculated that compounds 19bg and 19bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem. Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/mL against red blood cells. In vivo experimental results showed combination of MEM and compound 19bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice. Our finding showed that compound 19bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.

Salsola imbricata Forssk. ameliorates acetic acid-induced inflammatory bowel disease by modulating dysregulated antioxidant enzyme system and cytokine signaling pathways in mice

Objective: To explore the protective effect of the crude extract of Salsola imbricata against acetic acid-induced inflammatory bowel disease in mice and its mechanism of action. Methods: Ethanolic crude extract of Salsola imbricata was characterized by HPLC. Salsola imbricata extract at different doses was administered and ulcerative colitis was induced by 200 μL, 7.5% acetic acid and macroscopic parameters were evaluated to assess the homeostatic condition of intestinal mucosa along with hematological and biochemical assays. The levels of malondialdehyde, glutathione peroxidase 1, superoxide dismutase, and catalase were determined in colon tissues. Proinflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) were quantified by ELISA. The extent of tissue damage was assessed by histological analysis. Results: Phytochemical analysis confirmed the presence of phytochemicals including quercetin, gallic acid, syringic acid, benzoic acid and chlorogenic acid in the crude extract. The crude extract of Salsola imbricata (300 and 500 mg/kg) markedly decreased malondialdehyde and nitric oxide (P<0.01) and increased antioxidant activities of glutathione peroxidase 1 (P<0.001) and superoxide dismutase (P<0.001). Moreover, it decreased the levels of IL-1β, IL-6 and TNF-α significantly (P<0.001) and reduced the damage to the colon mucosa, promoting tissue healing and regeneration. Conclusions: Salsola imbricata extract restores the colonic epithelial layers by maintaining mucosal homeostasis and cell integrity by modulating antioxidant defense system and inflammatory cytokine signaling in ulcerative colitis mice.

Short-chain fatty acids production by Bifidobacterium species in the presence of salep

BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.

Comparative study of effectiveness of Papanicolaou smear and visual inspection using acetic acid and visual inspection using Lugol’s iodine for screening of premalignant and malignant lesions of cervix

Background: In developing and resource-limited countries alternative screening methods like VIA, VILI, and Pap smear are used in detection of premalignant and malignant lesions of cervix. The aim of our study was to compare the efficacies of VIA, VILI, and Pap smear in detection of premalignant and malignant lesions of cervix.Methods: The study was conducted for a period of one year in the department of obstetrics and gynaecology, Dr. Rajendra Prasad Government Medical College, Kangra at Tanda, Himachal Pradesh. Women who attended the outdoor patient department of obstetrics and gynecology were subjected to collection of Pap Smear, VIA followed by VILI and a thorough pelvic examination.Results: Among the 350 women studied, 59 women (16.9%) had abnormal VIA, 64 women (18.2%) had abnormal VILI. On pap smear, 10 women were reported as ASCUS, 11 as L-SIL and 1 as H-SIL. Cervical biopsy was done in 98 women, out of which 70 had one or more abnormality on VIA, VILI, or Pap, and 28 women who had normal results. Sixteen women (16.3%) reported as CIN-1 and 2 women (2.07%) as CIN-3. VIA and VILI had a higher sensitivity as compared to pap. However, pap was more specific. The PPV of pap was also much higher as compared to VIA and VILI, whereas there was no difference in NPV of the three.Conclusions: Authors observed that VIA presented the best sensitivity (88.8%), followed by VILI (83.3%), and Pap (72.2%). Pap smear had the highest specificity of 97.2%. The positive predictive value of Pap was higher as compared to VIA and VILI, whereas there was no difference in NPV of the three. VIA and VILI have good sensitivity, with reasonable specificity and because of their cost effectiveness and ease of availability, these can be an alternative screening modality for cervical cancer screening.