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1.
Yeast ; 37(12): 625-637, 2020 12.
Article in English | MEDLINE | ID: mdl-33161614

ABSTRACT

Yeast communities associated with cacti were studied in three ecosystems of Southeast, Central and North Brazil. A total of 473 yeast strains belonging to 72 species were isolated from 190 samples collected. Cactophilic yeast species were prevalent in necrotic tissues, flowers, fruits and insects of cacti collected in Southeast and North Brazil. Pichia cactophila, Candida sonorensis and species of the Sporopachydermia complex were the most prevalent cactophilic species in Southeast and Central regions. Kodamaea nitidulidarum, Candida restingae and Wickerhamiella cacticola were frequently associated with cactus flowers and fruits. The diversity of yeasts associated with the substrates studied was high. Twenty-one novel species were found. One is described here as Kluyveromyces starmeri sp. nov. based on 21 isolates obtained from necrotic tissues, flowers, fruits and associated insects of the columnar cacti Cereus saddianus, Micranthocereus dolichospermaticus and Pilosocereus arrabidae in two different ecosystems in Brazil. Phylogenetic analyses of sequences encoding the gene of the small subunit (SSU) rRNA gene, the internal transcribed spacer, the 5.8S rRNA gene and the D1/D2 domains of the large subunit (LSU) rRNA showed that the species is related to Kluyveromyces dobzhanskii, Kluyveromyces lactis and Kluyveromyces marxianus. Phylogenomic analyses based on 1264 conserved genes shared among the new species and 19 other members of the Saccharomycetaceae confirmed this phylogenetic relationship. The holotype is K. starmeri sp. nov. CBS 16103T (=UFMG-CM-Y3682T ). The Mycobank number is MB 836817.


Subject(s)
Cactaceae/microbiology , Ecosystem , Kluyveromyces/classification , Kluyveromyces/genetics , Mycobiome/genetics , Phylogeny , Yeasts/genetics , Brazil , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Genetic Variation , Genome, Fungal , Geography , Mycological Typing Techniques , RNA, Ribosomal/genetics , Yeasts/classification
2.
Int J Syst Evol Microbiol ; 70(7): 4378-4383, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32584748

ABSTRACT

Four isolates of two novel ascosporogenous species belonging to the clade Starmera were obtained from cactus tissues and rotting wood in Brazil. Results of analyses of the sequences of the ITS and D1/D2 domains of the large subunit rRNA gene indicated that the two isolates of the cactophilic species are related to Starmera caribaea and Starmera pilosocereana, yeasts that are associated with cacti and require an organic source of sulfur for growth. We propose the novel species Starmera foglemanii sp. nov. (CBS 16113T; MycoBank number: MB 834400) to accommodate these isolates. The other two isolates are phylogenetically related to Candida dendrica, Candida laemsonensis and Candida berthetii, also in the Starmera clade. The novel species name Starmera ilhagrandensis sp. nov. (CBS 16316T; MycoBank number: MB 834402) is proposed for this species.


Subject(s)
Cactaceae/microbiology , Phylogeny , Saccharomycetales/classification , Wood/microbiology , Brazil , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Mycological Typing Techniques , Saccharomycetales/isolation & purification , Sequence Analysis, DNA
3.
Hig. aliment ; 33(288/289): 3375-3378, abr.-maio 2019. graf, tab
Article in Portuguese | VETINDEX | ID: biblio-1366308

ABSTRACT

O mandacaru é uma cactácea muito disseminada pela região nordeste, seu fruto apresenta alto teor de umidade e açúcar, podendo ser empregado em processos industriais para produção de doces e bebidas. O presente trabalho, teve por objetivo o desenvolvimento e caracterização físico-química, microbiológica e sensorial da bebida alcoólica fermentada do fruto do mandacaru.. Na bebida foram realizadas análises de pH, sólidos solúveis totais (°Brix) e teor alcoólico (°GL), apresentando os respectivos resultados (pH 4,8), (8° Brix) e (7°GL). A análise microbiológica demonstrou que não houve contaminação na bebida. Com a realização da análise sensorial foi possível averiguar a aceitabilidade do fermentado. Contudo, pode-se concluir que a produção da bebida alcoólica fermentada do fruto do mandacaru é uma alternativa tecnologicamente viável, apresentando-se como uma forma de agregação de valor na cadeia produtiva desse fruto que ainda é pouco explorado.


Subject(s)
Cactaceae/microbiology , Chemical Phenomena , Fermented Foods
4.
Molecules ; 24(2)2019 Jan 09.
Article in English | MEDLINE | ID: mdl-30634411

ABSTRACT

The market trend for pitaya is increasing, although the preservation of the quality of this fruit after the harvest is challenging due to microbial decay, dehydration, and oxidation. In this work, the application of antimicrobial chitosan-based coatings achieved successful postharvest preservation of pitaya (Stenocereus pruinosus) during storage at 10 ± 2 °C with a relative humidity of 80 ± 5%. The solution of cross-linked chitosan with hydroxypropylmethylcellulose with entrapped Neem oil (16 g·L-1) displayed the best postharvest fruit characteristics. The reduction of physiological weight loss and fungal contamination, with an increased redness index and release of azadirachtin from the microencapsulated oil, resulted in up to a 15 day shelf life for this fruit. This postharvest procedure has the potential to increase commercial exploitation of fresh pitaya, owing to its good taste and high content of antioxidants.


Subject(s)
Antifungal Agents/pharmacology , Chitosan/pharmacology , Food Storage/methods , Hypromellose Derivatives/chemistry , Antifungal Agents/chemistry , Cactaceae/chemistry , Cactaceae/drug effects , Cactaceae/microbiology , Chitosan/chemistry , Cross-Linking Reagents/chemistry , Food Preservation/methods , Fruit/chemistry , Fruit/drug effects , Fruit/microbiology , Glycerides/chemistry , Limonins/analysis , Terpenes/chemistry
5.
Plant Dis ; 103(3): 398-403, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30629463

ABSTRACT

Neobuxbaumia tetetzo (Coulter) Backeberg (tetecho) is a columnar cactus endemic to Mexico. Tetecho plants, flowers, fruits, and seeds play an important role in the semiarid ecosystem, as they serve as a refuge and food for insects, bats, and birds, and are widely used by ethnic groups since pre-Hispanic times. Tetecho is affected by a soft rot that damages the whole plant and causes its fall and disintegration. Eight bacterial colonies of similar morphology were isolated from plants showing soft rot and inoculated in healthy tetecho plants, reproducing typical symptoms of soft rot 9 days after inoculation. Ten representative isolates were selected for phenotypic and genetic identification using 16s rDNA, IGS 16S-23S rDNA, and rpoS genes and for pathogenicity tests on several members of the cactus family and other plants. Based on the results, these bacterial isolates were identified as Pectobacterium carotovorum subsp. brasiliense. Inoculation of this bacteria caused soft rot in different cacti, fruits, leaves, and roots of other plants. This is the first report of the subspecies brasiliense of P. carotovorum causing soft rot and death in cacti in the world and the first report of this subspecies in Mexico.


Subject(s)
Cactaceae , Pectobacterium carotovorum , Cactaceae/microbiology , DNA, Bacterial/genetics , Mexico , Pectobacterium carotovorum/classification , Pectobacterium carotovorum/genetics , Pectobacterium carotovorum/physiology , Plant Diseases/microbiology
6.
J Sci Food Agric ; 99(5): 2267-2274, 2019 Mar 30.
Article in English | MEDLINE | ID: mdl-30328118

ABSTRACT

BACKGROUND: To reduce postharvest losses, substandard fruit and agricultural surpluses can productively be used as raw material for vinegar production. The present study aimed to prepare vinegars from surpluses of physalis (Physalis pubescens L.) and red pitahaya (Hylocereus monacanthus) and then evaluate their sensorial characteristics, antimicrobial activities, total phenolic content (TPC) and total antioxidant capacity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzo thiazoline-6-sulfonic acid) methods. RESULTS: Two vinegars were produced by submerged fermentation using physalis and red pitahaya fruits surpluses. Physalis and red pitahaya vinegars had 47 and 45 g L-1 acetic acid, respectively, and both vinegars contained approximately 1 g L-1 ethanol. Both vinegars displayed antimicrobial activity against Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella enteritidis. The TPC of physalis and red pitahaya vinegar was 0.5638 and 0.3656 g L-1 g gallic acid L-1 for physalis and red pitahaya, respectively. A similar antioxidant activity was detected in both the wines and vinegars. The sensorial analysis revealed that the consumers 'like moderately' each vinegar, and citric aroma was noted in the physalis vinegar. CONCLUSION: In the present study, vinegars with sensorial characteristics approved by consumers were developed using fruit surpluses, adding value through a new product making use of a simple methodology that is both inexpensive and demonstrates a good yield. © 2018 Society of Chemical Industry.


Subject(s)
Acetic Acid/metabolism , Alcoholic Beverages/analysis , Anti-Bacterial Agents/chemistry , Antioxidants/chemistry , Cactaceae/chemistry , Physalis/chemistry , Acetic Acid/analysis , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Antioxidants/metabolism , Antioxidants/pharmacology , Cactaceae/metabolism , Cactaceae/microbiology , Fermentation , Humans , Phenols/chemistry , Phenols/metabolism , Phenols/pharmacology , Physalis/metabolism , Physalis/microbiology , Taste
7.
Rev. argent. microbiol ; Rev. argent. microbiol;48(4): 333-341, dic. 2016. ilus, tab
Article in Spanish | LILACS | ID: biblio-843176

ABSTRACT

Las cactáceas son la vegetación característica de las zonas áridas en México, donde las lluvias son escasas, la evapotranspiración es elevada y la fertilidad de los suelos es baja. Las plantas han desarrollado estrategias fisiológicas como la asociación con microorganismos en la zona de la rizósfera para incrementar la captación de nutrientes. En el presente trabajo se obtuvieron 4 aislados bacterianos de la rizósfera de Mammillaria magnimamma y Coryphantha radians, los que fueron nombrados como QAP3, QAP19, QAP22 y QAP24 e identificados genéticamente como pertenecientes al género Bacillus. Estos aislados exhibieron in vitro propiedades bioquímicas como solubilización de fosfatos, producción de ácido indolacético y actividad ACC deaminasa, que se relacionan con la promoción del crecimiento de las plantas. Dicha promoción fue ensayada inoculando semillas de M. magnimamma y evaluando luego algunos parámetros. Se encontró que todos los aislados incrementaron la germinación desde un 17% hasta un 34,3% (con respecto a las semillas testigo sin inocular); el aislado QAP24 fue el que presentó el mayor efecto en este sentido y permitió la germinación de todas las semillas viables (84,7%) 3 días antes que en el testigo. La inoculación de este aislado en plantas de Mammillaria zeilmanniana mostró un efecto positivo sobre la floración: en 2 meses dentro del período de un año se detectó un incremento en el número de plantas en floración con respecto a las plantas testigo, de hasta el 31,0% en uno de ellos. Se concluye que los aislados de Bacillus spp. caracterizados poseen potencial para ser empleados en programas de conservación de especies vegetales de zonas áridas.


Cacti are the most representative vegetation of arid zones in Mexico where rainfall is scarce, evapotranspiration is high and soil fertility is low. Plants have developed physiological strategies such as the association with microorganisms in the rhizosphere zone to increase nutrient uptake. In the present work, four bacterial isolates from the rhizosphere of Mammillaria magnimamma and Coryphantha radians were obtained and named as QAP3, QAP19, QAP22 and QAP24, and were genetically identified as belonging to the genus Bacillus, exhibiting in vitro biochemical properties such as phosphate solubilization, indoleacetic acid production and ACC deaminase activity related to plant growth promotion, which was tested by inoculating M. magnimamma seeds. It was found that all isolates increased germination from 17 to 34.3% with respect to the uninoculated control seeds, being QAP24 the one having the greatest effect, accomplishing the germination of viable seeds (84.7%) three days before the control seeds. Subsequently, the inoculation of Mammillari zeilmanniana plants with this isolate showed a positive effect on bloom, registering during two months from a one year period, an increase of up to 31.0% in the number of flowering plants compared to control plants. The characterized Bacillus spp. isolates have potential to be used in conservation programs of plant species from arid zones.


Subject(s)
Bacillus/isolation & purification , Bacillus/classification , Adaptation, Biological/physiology , Conservation of Natural Resources/methods , Cactaceae/microbiology , Rhizosphere , Agricultural Inoculants/growth & development , Germination/drug effects , Flowers/drug effects , Reference Standards/methods
8.
Rev Argent Microbiol ; 48(4): 333-341, 2016.
Article in Spanish | MEDLINE | ID: mdl-27876169

ABSTRACT

Cacti are the most representative vegetation of arid zones in Mexico where rainfall is scarce, evapotranspiration is high and soil fertility is low. Plants have developed physiological strategies such as the association with microorganisms in the rhizosphere zone to increase nutrient uptake. In the present work, four bacterial isolates from the rhizosphere of Mammillaria magnimamma and Coryphantha radians were obtained and named as QAP3, QAP19, QAP22 and QAP24, and were genetically identified as belonging to the genus Bacillus, exhibiting in vitro biochemical properties such as phosphate solubilization, indoleacetic acid production and ACC deaminase activity related to plant growth promotion, which was tested by inoculating M. magnimamma seeds. It was found that all isolates increased germination from 17 to 34.3% with respect to the uninoculated control seeds, being QAP24 the one having the greatest effect, accomplishing the germination of viable seeds (84.7%) three days before the control seeds. Subsequently, the inoculation of Mammillari zeilmanniana plants with this isolate showed a positive effect on bloom, registering during two months from a one year period, an increase of up to 31.0% in the number of flowering plants compared to control plants. The characterized Bacillus spp. isolates have potential to be used in conservation programs of plant species from arid zones.


Subject(s)
Agricultural Inoculants , Bacillus/isolation & purification , Cactaceae/microbiology , Rhizosphere , Soil Microbiology , Bacillus/classification , Bacillus/physiology , Cactaceae/growth & development , Flowers/growth & development , Germination , Plant Roots/microbiology , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Ribotyping , Seeds/microbiology , Seeds/physiology , Symbiosis
9.
Braz. j. microbiol ; Braz. j. microbiol;47(2): 431-437, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780821

ABSTRACT

Abstract The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5 min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5 min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5 min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.


Subject(s)
Ultrasonics/methods , Cactaceae/microbiology , Escherichia coli/growth & development , Fruit and Vegetable Juices/microbiology , Food Preservation/methods , Ultrasonics , Cactaceae/chemistry , Microbial Viability , Food Storage , Food Preservation/instrumentation , Fruit/microbiology , Fruit/chemistry
10.
Braz. J. Microbiol. ; 47(2): 431-437, Abr-Jun. 2016. tab, graf
Article in English | VETINDEX | ID: vti-23469

ABSTRACT

The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5 min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5 min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5 min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.(AU)


Subject(s)
Escherichia coli/growth & development , Cactaceae/microbiology , Ultrasonics
11.
Braz J Microbiol ; 47(2): 431-7, 2016.
Article in English | MEDLINE | ID: mdl-26991288

ABSTRACT

The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.


Subject(s)
Cactaceae/microbiology , Escherichia coli/growth & development , Food Preservation/methods , Fruit and Vegetable Juices/microbiology , Ultrasonics/methods , Cactaceae/chemistry , Food Preservation/instrumentation , Food Storage , Fruit/chemistry , Fruit/microbiology , Fruit and Vegetable Juices/analysis , Microbial Viability , Ultrasonics/instrumentation
12.
Int J Syst Evol Microbiol ; 65(12): 4474-4478, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26364192

ABSTRACT

Two strains of a novel cactophilic yeast species were isolated from the columnar cactus Pilosocereus arrabidae in a sand dune ecosystem in Rio de Janeiro, Brazil. Phylogenetic analysis of sequences of the large subunit rRNA gene D1/D2 domains showed that the strains represent a sister species to Starmera caribaea, from which it differs by 21 nt substitutions and two indels. The novel species is heterothallic and the asci are deliquescent with the formation of two to four hat-shaped ascospores. The name Starmera pilosocereana sp. nov. is proposed for the species. The type strain is UFMG-CM-Y316T ( = CBS 13266T) and the allotype is UFMG-CM-Y346a ( = CBS 13265). The Mycobank number is MB 810683. In addition, Candida stellimalicola belonging to the Starmera clade, is reassigned to Starmera as a new combination.


Subject(s)
Cactaceae/microbiology , Phylogeny , Saccharomycetales/classification , Brazil , DNA, Fungal/genetics , Ecosystem , Molecular Sequence Data , Mycological Typing Techniques , RNA, Ribosomal/genetics , Saccharomycetales/genetics , Saccharomycetales/isolation & purification , Sequence Analysis, DNA
13.
PLoS One ; 8(9): e73606, 2013.
Article in English | MEDLINE | ID: mdl-24069212

ABSTRACT

We used the T-RFLP technique combined with Ion Torrent (PGM) sequencing of 16S rRNA and multivariate analysis to study the structure of bulk soil and rhizosphere bacterial communities of a cactus, Cereus jamacaru, from the Brazilian Caatinga biome, which is unique to Brazil. The availability of water shapes the rhizosphere communities, resulting in different patterns during the rainy and dry seasons. Taxonomic approaches and statistical analysis revealed that the phylum Actinobacteria strongly correlated with the dry season, while samples from the rainy season exhibited a strong correlation with the phylum Proteobacteria for rhizosphere samples and with the phyla Bacteroidetes, Firmicutes, Lentisphaerae, and Tenericutes for bulk soil samples. The STAMP software also indicated that the phylum Bacteroidetes, as well as two classes in the Proteobacteria phylum (γ and δ), were the most significant ones during the rainy season. The average abundance of the phylum Actinobacteria and the genus Bacillus was significantly greater during the dry season. Some significant genera found during the dry season might reflect their tolerance to the extreme conditions found in the Caatinga biome. They may also indicate the ecological function that microorganisms play in providing plants with some degree of tolerance to water stress or in assisting in their development through mechanisms of growth promotion. Alterations in microbial communities can be due to the different abilities of native microorganisms to resist and adapt to environmental changes.


Subject(s)
Cactaceae/microbiology , Rhizosphere , Water/chemistry , Brazil , Proteobacteria/classification , Proteobacteria/genetics , RNA, Ribosomal, 16S/genetics
14.
Microbiol Res ; 168(4): 183-91, 2013 May 06.
Article in English | MEDLINE | ID: mdl-23279812

ABSTRACT

Drought is one of the major problems worldwide. The search for new and efficient microorganisms, from unexplored environments, to be used in association with plants to alleviate the negative effects imposed by water stress, is an interesting alternative. Thus, cacti-associated bacteria from the Brazilian semi-arid region were isolated based on their ability to grow in medium with reduced water availability. Strains were tested for the production of exopolysaccharides (EPS), as well as in vitro plant growth promotion traits. A great proportion of the isolates belong to the genus Bacillus. From a total of forty-eight bacteria, 65% were able to grow in medium with reduced water availability (0.919Aw), exopolysaccharide production was observed for 65% of the strains. The production of indole acetic acid (IAA) exceeding 51µgmL(-1) was observed for 4% and the high solubilization of Ca-P was verified for 6% of the isolates. No strain was able to produce hydrogen cyanide (HCN), 71% produced ammonia and 79% showed a halo of carboxymethyl cellulose (CMC) degradation. Zea mays L. growth promotion under water stress (30% of field capacity) was achieved by two strains of Bacillus spp. This is the first report to describe cacti-associated bacteria from Brazilian semi-arid with plant growth-promoting abilities.


Subject(s)
Bacteria/isolation & purification , Cactaceae/microbiology , Plant Growth Regulators/metabolism , Zea mays/growth & development , Ammonia/metabolism , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Brazil , Droughts , Hydrogen Cyanide/metabolism , Indoleacetic Acids/metabolism , Molecular Sequence Data , Water/metabolism , Zea mays/microbiology
15.
Int J Syst Evol Microbiol ; 62(Pt 12): 3067-3071, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22729024

ABSTRACT

A novel species of ascomycetous yeast, Candida coquimbonensis sp. nov., from the necrotic tissue of cacti in Chile and Australia is described. C. coquimbonensis sp. nov. is closely related and phenotypically similar to Phaffomyces opuntiae. There is no overlap in the geographical distribution between C. coquimbonensis and any species in the Phaffomyces clade. However, this is the first member of the clade to be collected in both native (Chile) and non-native (Australia) cactus habitats. The type strain of C. coquimbonensis sp. nov. is TSU 00-206.4B(T) ( = CBS 12348(T) = USCFST 12-103(T)).


Subject(s)
Cactaceae/microbiology , Candida/classification , Phylogeny , Australia , Candida/genetics , Candida/isolation & purification , Chile , DNA, Fungal/genetics , DNA, Ribosomal/genetics , Molecular Sequence Data , Mycological Typing Techniques , Sequence Analysis, DNA
16.
Antonie Van Leeuwenhoek ; 101(4): 891-904, 2012 May.
Article in English | MEDLINE | ID: mdl-22307841

ABSTRACT

The nature reserve of Tehuacan-Cuicatlan in central Mexico is known for its diversity and endemism mainly in cactus plants. Although the xerophytic flora is reasonably documented, the bacterial communities associated with these species have been largely neglected. We assessed the diversity and composition of bacterial communities in bulk (non-rhizospheric) soil and the rhizosphere of three cactus plant species: Mammillaria carnea, Opuntia pilifera and Stenocereus stellatus, approached using cultivation and molecular techniques, considering the possible effect of dry and rainy seasons. Cultivation-dependent methods were focused on putative N(2)-fixers and heterotrophic aerobic bacteria, in the two media tested the values obtained for dry season samples grouped together regardless of the sample type (rhizospheric or non-rhizospheric), these groups also included the non-rhizospheric sample for rainy season, on each medium. These CFU values were smaller and significantly different from those obtained on rhizospheric samples from rainy season. Genera composition among isolates of the rhizospheric samples was very similar for each season, the most abundant taxa being α-Proteobacteria, Actinobacteria and Firmicutes. Interestingly, the genus Ochrobactrum was highly represented among rhizospheric samples, when cultured in N-free medium. The structure of the bacterial communities was approached with molecular techniques targeting partial 16S rRNA sequences such as denaturing gradient gel electrophoresis and serial analysis of ribosomal sequence tags. Under these approaches, the most represented bacterial phyla were Actinobacteria, Proteobacteria and Acidobacteria. The first two were also highly represented when using isolation techniques.


Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Biota , Cactaceae/microbiology , Plant Roots/microbiology , Rhizosphere , Bacteria/genetics , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Mexico , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Seasons , Sequence Analysis, DNA
17.
Arch Microbiol ; 193(7): 527-41, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21445557

ABSTRACT

The small cactus Mammillaria fraileana is a pioneer rock-colonizing plant harboring endophytic bacteria with the potential for nitrogen fixation and rock weathering (phosphate solubilization and rock degradation). In seeds, only a combination of culture-independent methods, such as fluorescence in situ hybridization, scanning electron microscopy, and fluorescence vital staining, detected significant amounts of non-culturable, but living, endophytic bacteria distributed underneath the membrane covering the embryo, in the undifferentiated tissue of the embryo, and in the vascular tissue. Large populations of culturable endophytic bacteria were detected in stems and roots of wild plants colonizing rocks in the southern Sonoran Desert, but not in seeds. Among 14 endophytic bacterial isolates found in roots, four isolates were identified by full sequencing of their 16S rRNA gene. In vitro tests indicated that Azotobacter vinelandii M2Per is a potent nitrogen fixer. Solubilization of inorganic phosphate was exhibited by Pseudomonas putida M5TSA, Enterobacter sakazakii M2PFe, and Bacillus megaterium M1PCa, while A. vinelandii M2Per, P. putida M5TSA, and B. megaterium M1PCa weathered rock by reducing the size of rock particles, probably by changing the pH of the liquid media. Cultivated seedlings of M. fraileana, derived from disinfected seeds and inoculated with endophytic bacteria, showed re-colonization 105 days after inoculation. Their densities decreased from the root toward the stem and apical zones. Functional traits in planta of culturable and non-culturable endophytic bacteria in seeds remain unknown.


Subject(s)
Bacteria/isolation & purification , Cactaceae/microbiology , Nitrogen Fixation , Phosphates/metabolism , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , DNA, Bacterial/genetics , Desert Climate , In Situ Hybridization, Fluorescence , Mexico , Microscopy, Electron, Scanning , Plant Roots/microbiology , Plant Stems/microbiology , RNA, Ribosomal, 16S/genetics , Seeds/microbiology
18.
Rev. colomb. biotecnol ; 12(2): 223-229, dic. 2010.
Article in Spanish | LILACS | ID: lil-590788

ABSTRACT

Pilosocereus sp es una especie en peligro crítico de extinción, la única población conocida se encuentra en una mina de mármol verde, hoy abandonada, en la que su explotación produjo la disminución del 80% de la población en 3 años; en la actualidad quedan 28 ejemplares, de ellos unos pocos son adultos, de los cuales solo dos producen frutos. Una de las etapas necesaria para su recuperación es la producción de plántulas para realizar el reforzamiento de la población natural. Como las plantas obtenidas serán plantadas en condiciones naturales, donde se enfrentarán a diversas situaciones ambientales, es conveniente realizar un estudio de diversidad genética. El objetivo de este trabajo fue estimar la variabilidad genética de plántulas de Pilosocereus sp empleando la técnica Inverse Sequence Tagged Repeat (ISTR). Se realizó la germinación in vitro de semillas y se determinó la variabilidad genética de las plántulas obtenidas. Con el análisis molecular se detectaron un total de 97 bandas, de ellas el 62,8% fueron polimórficas. El mayor porcentaje de bandas polimórficas (85,7%) se obtuvo con la combinación de oligonucleótidos F6/B6. Con las combinaciones de oligonucleótidos empleados se detectaron de 4 a 6 patrones de banda diferentes. La heterocigosidad media esperada fue de 0,39.


Pilosocereus sp is a species in critical extinction danger, the only known population is in a mine of green marble, abandoned today, but it exploitation produced the decrease of the population's 80% in 3 years, at the present time they are 28 individuals, of them some few ones are mature, of those which alone two produce fruits. One of the necessary stages for their recovery is the seedlings production to carry out the natural population's reinforcement. As the obtained plants they will be planted under natural conditions, where they will face diverse environmental situations, it is convenient to carry out a study of genetic diversity. The objective of this work was to estimate the genetic variability using the technical Inverse Sequence Tagged Repeat (ISTR). In vitro germination of seeds of Pilosocereus sp and the genetic variability of the obtained seedlings was determined. With the molecular analysis a total of 97 bands were detected, of them 62.8% were polymorphic. The biggest percentage of polymorphism (85.7%) was obtained with the primer combination F6/B6. With the primer combinations employed were detected from 4 to 6 different band patterns. The heterocigocity hoped was 0.39.


Subject(s)
Biomarkers/analysis , Cactaceae/classification , Cactaceae/adverse effects , Cactaceae/immunology , Cactaceae/microbiology , Cactaceae/chemistry , Cactaceae/ultrastructure
19.
Mycopathologia ; 170(4): 279-85, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20306144

ABSTRACT

Cryptococcus neoformans and Cryptococcus gattii are found in distinct environments with some overlap around different parts of the world. However, no systematic surveys of these two pathogens have been reported from Puerto Rico, a tropical island uniquely situated between mainland USA and countries in South America. We carried out an exhaustive environmental survey in southwestern Puerto Rico for pathogenic Cryptococcus species. Twenty-two presumptive isolates of C. gattii from cacti and tree detritus were characterized in detail by physiological and molecular methods and seventeen strains were confirmed as C. gattii. Cryptococcus gattii isolates were haploid and majority of them were MATa [corrected] strains. Sixteen out of seventeen C. gattii isolates belonged to VGII/AFLP6 genotype while one isolate was a VGIV/AFLP7 genotype. The results are significant as Puerto Rico strains are distinct from VGIII/AFLP5 strains reported from Southern California, but similar to C. gattii VGII/AFLP6 molecular type implicated in recent outbreaks of cryptococcosis in Pacific Northwest and British Columbia, Canada, but different in its M13 fingerprinting, and a common genotype in South America.


Subject(s)
Cactaceae/microbiology , Cryptococcus gattii/classification , Cryptococcus gattii/isolation & purification , Environmental Microbiology , Amplified Fragment Length Polymorphism Analysis , Cluster Analysis , Cryptococcus gattii/genetics , DNA Fingerprinting , Genotype , Molecular Sequence Data , Puerto Rico , Sequence Analysis, DNA , Tropical Climate
20.
Mycologia ; 99(4): 602-11, 2007.
Article in English | MEDLINE | ID: mdl-18065011

ABSTRACT

A new succulenticolous Myxomycete species, Didymium wildpretii, found on decaying remains of various species of cacti, is described from two arid zones of the world. This species was collected from central Mexico, at the southern limit of the Chihuahuan Desert, and from the Canary Islands (Spain). The new species has small, pale yellow sporocarps, 0.1-0.7 mm high, that are sessile or have short, orange-yellow, calcareous stalks and small, uniformly warted spores. The stability of the taxonomic characters of the species was confirmed with both moist chamber cultures and spore-to-spore culture on agar. Life cycle events are described from germination to sporulation. Myxomycete specimens were examined with scanning electron microscopy and light microscopy, and micrographs of relevant morphological details are included.


Subject(s)
Cactaceae/microbiology , Physarida/classification , Agar , Animals , Culture Media , Desert Climate , Mexico , Microscopy, Electron, Scanning , Physarida/growth & development , Physarida/isolation & purification , Physarida/physiology , Spain , Species Specificity , Spores, Fungal/physiology , Spores, Fungal/ultrastructure
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