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1.
Braz. j. microbiol ; 49(4): 840-847, Oct.-Dec. 2018. graf
Article in English | LILACS | ID: biblio-974284

ABSTRACT

ABSTRACT Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 µmol mL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 µmol mL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.


Subject(s)
Plant Diseases/prevention & control , Xylariales/chemistry , Paullinia/microbiology , Endophytes/chemistry , Fungicides, Industrial/pharmacology , Phylogeny , Plant Diseases/microbiology , Mass Spectrometry , Xylariales/isolation & purification , Xylariales/genetics , Xylariales/metabolism , Molecular Structure , Colletotrichum/drug effects , Colletotrichum/physiology , Endophytes/isolation & purification , Endophytes/genetics , Endophytes/metabolism , Fungicides, Industrial/isolation & purification , Fungicides, Industrial/chemistry
2.
Braz. j. microbiol ; 49(2): 362-369, Apr.-June 2018. graf
Article in English | LILACS | ID: biblio-889228

ABSTRACT

Abstract Aspergillus sp., Fusarium sp., and Ramularia sp. were endophytic fungi isolated from Rumex gmelini Turcz (RGT), all of these three strains could produce some similar bioactive secondary metabolites of their host. However the ability to produce active components degraded significantly after cultured these fungi alone for a long time, and were difficult to recover. In order to obtain more bioactive secondary metabolites, the co-culture of tissue culture seedlings of RGT and its endophytic fungi were established respectively, and RGT seedling was selected as producer. Among these fungi, Aspergillus sp. showed the most significant enhancement on bioactive components accumulation in RGT seedlings. When inoculated Aspergillus sp. spores into media of RGT seedlings that had taken root for 20 d, and made spore concentration in co-culture medium was 1 × 104 mL-1, after co-cultured for 12 d, the yield of chrysophaein, resveratrol, chrysophanol, emodin and physcion were 3.52-, 3.70-, 3.60-, 4.25-, 3.85-fold of the control group. The extreme value of musizin yield was 0.289 mg, which was not detected in the control groups. The results indicated that co-culture with endophytic fungi could significantly enhance bioactive secondary metabolites production of RGT seedlings.


Subject(s)
Humans , Adolescent , Ascomycota/metabolism , Rumex/metabolism , Rumex/microbiology , Endophytes/metabolism , Phytochemicals/metabolism , Ascomycota/isolation & purification , Ascomycota/growth & development , Time Factors , Coculture Techniques , Rumex/growth & development , Seedlings/growth & development , Seedlings/metabolism , Seedlings/microbiology , Endophytes/isolation & purification , Endophytes/growth & development
3.
Braz. j. microbiol ; 49(2): 210-211, Apr.-June 2018.
Article in English | LILACS | ID: biblio-889231

ABSTRACT

Abstract Paraburkholderia tropica (syn Burkholderia tropica) are nitrogen-fixing bacteria commonly found in sugarcane. The Paraburkholderia tropica strain Ppe8 is part of the sugarcane inoculant consortium that has a beneficial effect on yield. Here, we report a draft genome sequence of this strain elucidating the mechanisms involved in its interaction mainly with Poaceae. A genome size of approximately 8.75 Mb containing 7844 protein coding genes distributed in 526 subsystems was de novo assembled with ABySS and annotated by RAST. Genes related to the nitrogen fixation process, the secretion systems (I, II, III, IV, and VI), and related to a variety of metabolic traits, such as metabolism of carbohydrates, amino acids, vitamins, and proteins, were detected, suggesting a broad metabolic capacity and possible adaptation to plant association.


Subject(s)
Genome, Bacterial , Burkholderiaceae/genetics , Endophytes/genetics , Bacterial Proteins/genetics , Sequence Analysis, DNA , Computational Biology , Saccharum/microbiology , Burkholderiaceae/isolation & purification , Metabolic Networks and Pathways/genetics , Molecular Sequence Annotation , Endophytes/isolation & purification
4.
Braz. j. microbiol ; 49(2): 269-278, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-889232

ABSTRACT

Abstract A total of 276 endophytic bacteria were isolated from the root nodules of soybean (Glycine max L.) grown in 14 sites in Henan Province, China. The inhibitory activity of these bacteria against pathogenic fungus Phytophthora sojae 01 was screened in vitro. Six strains with more than 63% inhibitory activities were further characterized through optical epifluorescence microscopic observation, sequencing, and phylogenetic analysis of 16S rRNA gene, potential plant growth-promoting properties analysis, and plant inoculation assay. On the basis of the phylogeny of 16S rRNA genes, the six endophytic antagonists were identified as belonging to five genera: Enterobacter, Acinetobacter, Pseudomonas, Ochrobactrum, and Bacillus. The strain Acinetobacter calcoaceticus DD161 had the strongest inhibitory activity (71.14%) against the P. sojae 01, which caused morphological abnormal changes of fungal mycelia; such changes include fracture, lysis, formation of a protoplast ball at the end of hyphae, and split ends. Except for Ochrobactrum haematophilum DD234, other antagonistic strains showed the capacity to produce siderophore, indole acetic acid, and nitrogen fixation activity. Regression analysis suggested a significant positive correlation between siderophore production and inhibition ratio against P. sojae 01. This study demonstrated that nodule endophytic bacteria are important resources for searching for inhibitors specific to the fungi and for promoting effects for soybean seedlings.


Subject(s)
Plant Growth Regulators/metabolism , Soybeans/growth & development , Soybeans/microbiology , Bacteria/isolation & purification , Root Nodules, Plant/microbiology , Endophytes/isolation & purification , Antibiosis , Phylogeny , Phytophthora/cytology , Phytophthora/growth & development , Phytophthora/drug effects , Bacteria/classification , Bacteria/metabolism , DNA, Ribosomal/genetics , DNA, Ribosomal/chemistry , RNA, Ribosomal, 16S/genetics , Cluster Analysis , China , Sequence Analysis, DNA , Endophytes/classification , Endophytes/metabolism
5.
Braz. j. microbiol ; 49(1): 59-66, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889203

ABSTRACT

ABSTRACT Mangroves are ecosystems located in the transition zone between land and sea that serve as a potential source of biotechnological resources. Brazil's extensive coast contains one of the largest mangrove forests in the world (encompassing an area of 25,000 km2 along all the coast). Endophytic bacteria were isolated from the following three plant species: Rhizophora mangle, Laguncularia racemosa and Avicennia nitida. A large number of these isolates, 115 in total, were evaluated for their ability to fix nitrogen and solubilize phosphorous. Bacteria that tested positive for both of these tests were examined further to determine their level of indole acetic acid production. Two strains with high indole acetic acid production were selected for use as inoculants for reforestation trees, and then the growth of the plants was evaluated under field conditions. The bacterium Pseudomonas fluorescens (strain MCR1.10) had a low phosphorus solubilization index, while this index was higher in the other strain used, Enterobacter sp. (strain MCR1.48). We used the reforestation tree Acacia polyphylla. The results indicate that inoculation with the MCR1.48 endophyte increases Acacia polyphylla shoot dry mass, demonstrating that this strain effectively promotes the plant's growth and fitness, which can be used in the seedling production of this tree. Therefore, we successfully screened the biotechnological potential of endophyte isolates from mangrove, with a focus on plant growth promotion, and selected a strain able to provide limited nutrients and hormones for in plant growth.


Subject(s)
Bacteria/isolation & purification , Trees/microbiology , Acacia/microbiology , Endophytes/isolation & purification , Phylogeny , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Trees/growth & development , Brazil , Acacia/growth & development , Wetlands , Endophytes/classification , Endophytes/genetics , Endophytes/metabolism , Indoleacetic Acids/metabolism
6.
Braz. j. microbiol ; 49(supl.1): 47-58, 2018. tab, graf
Article in English | LILACS | ID: biblio-974328

ABSTRACT

Abstract To know more about the potential roles of endophytic fungi in the formation mechanism of Daodi medicinal material, diversity and communities of culturable endophytic fungi in three types of tree peonies were investigated. Endophytic fungi of three types of tree peonies were isolated and identified. The diversity was analyzed. Bayesian trees constructed by MrBayes 3.2.6 after phylogenetic analysis of the ITS sequences. The endophytic fungi potential for synthesis of natural products was assessed by means of detecting NRPS and PKS gene sequences. In total, 364 endophytic fungi isolates representing 26 genera were recovered from Paeonia ostii 'Feng Dan', Paeonia ostii 'Luoyang Feng Dan', and Paeonia suffruticosa 'Luoyang Hong'. More culturable endophytic fungi appeared in P. suffruticosa 'Luoyang Hong' (206) compared with P. ostii 'Feng Dan' (60) and P. ostii 'Luoyang Feng Dan' (98). The fungal community of P. ostii 'Feng Dan' had the highest richness and diversity. PKSs and NRPS detection rates of endophytic fungi from P. ostii 'Feng Dan' are both the highest among the three types of tree peonies. Results indicate that endophytic fungus is an important factor of Daodi Cortex Moutan forming, and endophytic fungi in peony are related to genuineness of Cortex Moutan.


Subject(s)
Biological Products/metabolism , Paeonia/microbiology , Biodiversity , Endophytes/isolation & purification , Fungi/isolation & purification , Phylogeny , Drugs, Chinese Herbal/metabolism , Paeonia/classification , Paeonia/growth & development , Paeonia/metabolism , Endophytes/classification , Endophytes/growth & development , Endophytes/genetics , Fungi/classification , Fungi/growth & development , Fungi/genetics
7.
Braz. j. microbiol ; 48(4): 695-705, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-889181

ABSTRACT

ABSTRACT Diverse communities of bacteria inhabit plant tissues and those bacteria play a crucial role for plant health and growth. Tree peony (Paeonia Sect. Moutan) is known for its excellent ornamental and medicinal values as Chinese traditional plant, but little is known about its associated bacterial community under natural conditions. To examine how endophytic bacteria in tree peony vary across tissues and cultivars, PCR-based Illumina was applied to reveal the diversity of endophytic bacteria in tree peony. A total of 149,842 sequences and 21,463 operational taxonomic units (OTUs) were obtained. The OTU abundance of roots was higher than leaves across other three cultivars except for 'Kinkaku' and 'Luoyanghong'. The community was composed of five dominant groups (Proteobacteria, Firmicutes, Bacteroidetes, Acidobacteria and Actinobacteria) in all samples. Endophytic bacteria community structures had changed in leaves and roots. Sequences of Pseudomonas and Enterobacteriaceae were prevalent in root samples, whereas Succinivibrio and Acinetobacter were the dominant genus in leaf samples. Otherwise, the distribution of each dominant genus among the 5 cultivars was either varied. These findings suggested that both plant genotype and tissues contribute to the shaping of the bacterial communities associated with tree peony.


Subject(s)
Bacteria/isolation & purification , Paeonia/microbiology , Biodiversity , Endophytes/isolation & purification , Bacteria/classification , Bacteria/genetics , Trees/microbiology , Polymerase Chain Reaction , Plant Roots/microbiology , Plant Leaves/microbiology , Endophytes/classification , Endophytes/genetics
8.
Braz. j. microbiol ; 48(3): 530-536, July-Sept. 2017. graf
Article in English | LILACS | ID: biblio-889139

ABSTRACT

Abstract Mangrove is an important ecosystem in the world. Mangrove ecosystems have a large capacity in retaining heavy metals, and now they are usually considered as sinks for heavy metals. However, the mechanism of why the soil of mangrove ecosystems can retain heavy metal is not certain. In this research, endophytic fungus Purpureocillium sp. A5 was isolated and identified from the roots of Kandelia candel. When this fungus was added, it protected the growth of K. candel under Cu stress. This can be illustrated by analyzing chlorophyll A and B, RWC and WSD to leaves of K. candel. Purpureocillium sp. A5 reduces uptake of Cu in K. candel and changes the pH characterization of soil. Furthermore, A5 increase the concentration of Cu complexes in soil, and it enhanced the concentration of carbonate-bound Cu, Mn-Fe complexes Cu and organic-bound Cu in soil. Nevertheless, a significant reduction of the Cu ion was noted among A5-treated plants. This study is significant and illustrates a promising potential use for environmental remediation of endophytes, and also may partially explain the large capacity of mangrove ecosystems in retaining heavy metals.


Subject(s)
Copper/metabolism , Rhizophoraceae/metabolism , Rhizophoraceae/microbiology , Endophytes/metabolism , Hypocreales/metabolism , Soil/chemistry , Soil Microbiology , Plant Roots/metabolism , Plant Roots/microbiology , Copper/analysis , Endophytes/isolation & purification , Endophytes/genetics , Hypocreales/isolation & purification , Hypocreales/genetics
9.
Braz. j. microbiol ; 48(2): 333-341, April.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-839367

ABSTRACT

Abstract Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.


Subject(s)
Oryza/physiology , Oryza/microbiology , Stress, Physiological , Dehydration , Endophytes/growth & development , Plant Proteins/analysis , Oryza/enzymology , Brazil , Plant Roots/microbiology , Endophytes/isolation & purification , Antioxidants/analysis
10.
Rev. argent. microbiol ; 49(1): 3-6, mar. 2017. ilus, tab
Article in English | LILACS | ID: biblio-1041774

ABSTRACT

Antibiotic resistance results in higher medical costs, prolonged hospital stays and increased mortality and is rising to dangerously high levels in all parts of the world. Therefore, this study aims to search for new antimicrobial agents through bioprospecting of extracts of endophytic fungi from Bauhinia guianensis, a typical Amazonian plant used in combating infections. Seventeen (17) fungi were isolated and as result the methanolic extract of the fungus Exserohilum rostratum showed good activity against the bacteria tested. The polyketide monocerin was isolated by the chromatographic technique, identified by NMR and MS, showing broad antimicrobial spectrum.


La resistencia a los antibióticos conduce a mayores costos médicos, hospitalizaciones prolongadas e incremento de la mortalidad, y está aumentando a niveles peligrosamente altos en todas partes del mundo. Este estudio tuvo como objetivo la búsqueda de nuevos agentes antimicrobianos a través de la bioprospección de extractos de hongos endófitos de Bauhinia guianensis, una planta amazónica típica, utilizada en la lucha contra problemas infecciosos. Fueron aislados 17 hongos; el extracto metanólico del hongo Exserohilum rostratum mostró buena actividad contra las bacterias probadas. Se aisló monocerina policétido por la técnica de cromatografía; este compuesto fue identificado por RM y EM, y mostró un amplio espectro antimicrobiano.


Subject(s)
Bauhinia/microbiology , Endophytes/isolation & purification , Polyketides/isolation & purification , Fungi/drug effects , Anti-Infective Agents/analysis , Anti-Bacterial Agents/analysis , Drug Resistance, Microbial/drug effects , Chromatography/methods , Bioprospecting/methods
11.
Braz. j. microbiol ; 47(2): 480-488, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780842

ABSTRACT

Abstract The aim of this paper is to identify and investigate an endophytic fungus (strain 28) that was isolated from Houttuynia cordata Thunb, a famous and widely-used Traditional Chinese Medicine. Based on morphological methods and a phylogenetic analysis of ITS sequences, this strain was identified as Chaetomium globosum. An antifungal activity bioassay demonstrated that the crude ethyl acetate (EtOAc) extracts of strain 28 had a wide antifungal spectrum and strong antimicrobial activity, particularly against Exserohilum turcicum (Pass.) Leonard et Suggs, Botrytis cinerea persoon and Botrytis cinerea Pers. ex Fr. Furthermore, the fermentation conditions, extraction method and the heat stability of antifungal substances from strain 28 were also studied. The results showed that optimal antifungal activity can be obtained with the following parameters: using potato dextrose broth (PDB) as the base culture medium, fermentation for 4–8 d (initial pH: 7.5), followed by extraction with EtOAc. The extract was stable at temperatures up to 80 °C. This is the first report on the isolation of endophytic C. globosum from H. cordata to identify potential alternative biocontrol agents that could provide new opportunities for practical applications involving H. cordata.


Subject(s)
Chaetomium/isolation & purification , Chaetomium/metabolism , Houttuynia/microbiology , Endophytes/metabolism , Antifungal Agents/metabolism , Phylogeny , Chaetomium/classification , Chaetomium/genetics , Endophytes/isolation & purification , Endophytes/classification , Endophytes/genetics , Fungi/growth & development , Fungi/drug effects , Antifungal Agents/pharmacology
12.
Rev. biol. trop ; 64(2): 733-745, abr.-jun. 2016. tab, ilus
Article in English | LILACS | ID: biblio-843309

ABSTRACT

AbstractPasteurella multocida is an important veterinary pathogen causing infections in animals and birds. Nowadays, different reports have described the severity of infections, increasing resistance of micro-organisms to antibiotics, and the contribution of ethnoveterinary practices towards the treatment of various ailments of animals. The aim of the present study was to investigate the antibacterial efficacy of the ethanolic extracts of endophytic fungi against P. multocida Capsular Type A strains. A total of six endophytic fungi were isolated from two tropical ethnoveterinary plants: Garcinia xanthochymus H. and Polygonum chinense L. The ethanolic extracts of the endophytic fungi were subjected to in vitro antimicrobial activity by the well diffusion method. Besides, we evaluated the treatment of mice with the potent fungal extract and observed the effects in different organs under electron microscopy. Our results showed that four fungi had antimicrobial activity against the selected pathogen. The best antibacterial activity was showed by the extract of the endophytic fungi, Glomerella magna isolated from G. xanthochymus, with a minimum inhibitory concentration of 46.9 µg/mL and minimum bactericidal concentration of 750 µg/mL. Treatment of mice with the potent fungal extract caused a considerable inhibitory effect on the pathogen growth in vital organs, results that was also confirmed by histopathological studies made by scanning electron microscopy. The present findings indicated that the endophytic fungi G. magna has the potential to provide an effective treatment against infections caused by Pasteurella multocida. However, the isolation of bioactive components needs further investigation. Rev. Biol. Trop. 64 (2): 733-745. Epub 2016 June 01.


ResumenPasteurella multocida es un importante patógeno veterinario que causa infecciones en animales y aves. Hoy en día, diferentes informes han descrito la gravedad de las infecciones, aumentando la resistencia de los microorganismos a los antibióticos, y la contribución de las prácticas etnoveterinarias hacia el tratamiento de diversas enfermedades de los animales. El objetivo del presente estudio fue investigar la eficacia antibacteriana de los extractos etanólicos de hongos endófitos contra cepas de P. multocida tipo capsular A. Un total de seis hongos endófitos fueron aisladas de dos plantas etnoveterinarias tropicales: Garcinia xanthochymus H. y Polygonum chinense L. Los extractos etanólicos de los hongos endófitos fueron sometidos a la actividad antimicrobiana in vitro por el método de difusión. Además, se evaluó el tratamiento de ratones con el extracto de hongos potente y observamos los efectos en diferentes órganos bajo el microscopio electrónico. Nuestros resultados mostraron que cuatro hongos tenían actividad antimicrobiana contra el patógeno seleccionado. La mejor actividad antibacteriana la mostró el extracto de los hongos endófitos, Glomerella magna aislado de G. xanthochymus, con una concentración inhibitoria mínima de 46.9 mg/ml y la concentración bactericida mínima de 750 mg/ml. El tratamiento de ratones con el extracto de hongos potente causó un considerable efecto inhibidor sobre el crecimiento de patógenos en órganos vitales, resultados que también fueron confirmados por estudios histopatológicos realizados por microscopía electrónica de barrido. Los presentes hallazgos indican que el hongos endófitos G. magna tienen el potencial de proporcionar un tratamiento eficaz contra las infecciones causadas por Pasteurella multocida. Sin embargo, el aislamiento de componentes bioactivos necesita más investigación.


Subject(s)
Animals , Rabbits , Pasteurella multocida/drug effects , Polygonum/microbiology , Garcinia/microbiology , Endophytes/chemistry , Liver/drug effects , Anti-Bacterial Agents/pharmacology , Microscopy, Electron, Scanning , Pasteurella multocida/ultrastructure , Disk Diffusion Antimicrobial Tests , Endophytes/isolation & purification , Liver/ultrastructure , Anti-Bacterial Agents/isolation & purification
13.
Braz. j. microbiol ; 47(1): 96-101, Jan.-Mar. 2016. tab, graf
Article in English | LILACS | ID: lil-775130

ABSTRACT

Abstract One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 µg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27 µg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 µg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 µg/mL and 74.62 µg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.


Subject(s)
Animals , Alternaria/chemistry , Anti-Infective Agents/isolation & purification , Endophytes/chemistry , Lactones/isolation & purification , Alternaria/isolation & purification , Anti-Infective Agents/metabolism , Bacteria/drug effects , Endophytes/isolation & purification , Lactones/metabolism , Microbial Sensitivity Tests , Magnaporthe/drug effects , Nematoda/drug effects , Plant Roots/microbiology , Salvia/microbiology
14.
Braz. j. microbiol ; 46(4): 977-989, Oct.-Dec. 2015. tab, graf
Article in English | LILACS | ID: lil-769669

ABSTRACT

Abstract A total of 48 endophytic bacteria were isolated from surface-sterilized tissues of the medicinal plant Lonicera japonica, which is grown in eastern China; six strains were selected for further study based on their potential ability to promote plant growth in vitro (siderophore and indoleacetic acid production). The bacteria were characterized by phylogenetically analyzing their 16S rRNA gene similarity, by examining their effect on the mycelial development of pathogenic fungi, by testing their potential plant growth-promoting characteristics, and by measuring wheat growth parameters after inoculation. Results showed that the number of endophytic bacteria in L. japonica varied among different tissues, but it remained relatively stable in the same tissues from four different plantation locations. Among the three endophytic strains, strains 122 and 124 both had high siderophore production, with the latter showing the highest phosphate solubilization activity (45.6 mg/L) and aminocyclopropane-1-carboxylic acid deaminase activity (47.3 nmol/mg/h). Strain 170 had the highest indoleacetic acid (IAA) production (49.2 mg/L) and cellulase and pectinase activities. After inoculation, most of the six selected isolates showed a strong capacity to promote wheat growth. Compared with the controls, the increase in the shoot length, root length, fresh weight, dry weight, and chlorophyll content was most remarkable in wheat seedlings inoculated with strain 130. The positive correlation between enzyme (cellulose and pectinase) activity and inhibition rate on Fusarium oxysporum, the IAA production, and the root length of wheat seedlings inoculated with each tested endophytic strain was significant in regression analysis. Deformity of pathogenic fungal mycelia was observed under a microscope after the interaction with the endophytic isolates. Such deformity may be directly related to the production of hydrolytic bacterial enzymes (cellulose and pectinase). The six endophytic bacterial strains were identified to be Paenibacillus and Bacillus strains based on the results of 16S rRNA gene sequencing analysis and their physiological and biochemical characteristics. Results indicate the promising application of endophytic bacteria to the biological control of pathogenic fungi and the improvement of wheat crop growth.


Subject(s)
Bacillus/classification , Bacillus/genetics , Bacillus/growth & development , Bacillus/isolation & purification , Bacillus/metabolism , Bacillus/microbiology , China/classification , China/genetics , China/growth & development , China/isolation & purification , China/metabolism , China/microbiology , Endophytes/classification , Endophytes/genetics , Endophytes/growth & development , Endophytes/isolation & purification , Endophytes/metabolism , Endophytes/microbiology , Indoleacetic Acids/classification , Indoleacetic Acids/genetics , Indoleacetic Acids/growth & development , Indoleacetic Acids/isolation & purification , Indoleacetic Acids/metabolism , Indoleacetic Acids/microbiology , Lonicera/classification , Lonicera/genetics , Lonicera/growth & development , Lonicera/isolation & purification , Lonicera/metabolism , Lonicera/microbiology , Molecular Sequence Data/classification , Molecular Sequence Data/genetics , Molecular Sequence Data/growth & development , Molecular Sequence Data/isolation & purification , Molecular Sequence Data/metabolism , Molecular Sequence Data/microbiology , Paenibacillus/classification , Paenibacillus/genetics , Paenibacillus/growth & development , Paenibacillus/isolation & purification , Paenibacillus/metabolism , Paenibacillus/microbiology , Phylogeny/classification , Phylogeny/genetics , Phylogeny/growth & development , Phylogeny/isolation & purification , Phylogeny/metabolism , Phylogeny/microbiology , Plant Roots/classification , Plant Roots/genetics , Plant Roots/growth & development , Plant Roots/isolation & purification , Plant Roots/metabolism , Plant Roots/microbiology , Siderophores/classification , Siderophores/genetics , Siderophores/growth & development , Siderophores/isolation & purification , Siderophores/metabolism , Siderophores/microbiology , Triticum/classification , Triticum/genetics , Triticum/growth & development , Triticum/isolation & purification , Triticum/metabolism , Triticum/microbiology
15.
Braz. j. microbiol ; 46(2): 359-366, Apr-Jun/2015. tab, graf
Article in English | LILACS | ID: lil-749714

ABSTRACT

Endophytes are being considered for use in biological control, and the enzymes they secrete might facilitate their initial colonization of internal plant tissues and direct interactions with microbial pathogens. Microbial proteases are also biotechnologically important products employed in bioremediation processes, cosmetics, and the pharmaceutical, photographic and food industries. In the present study, we evaluated antagonism and competitive interactions between 98 fungal endophytes and Alternaria alternata, Colletotrichum sp., Phyllosticta citricarpa and Moniliophthora perniciosa. We also examined the proteolytic activities of endophytes grown in liquid medium and conducted cup plate assays. The results showed that certain strains in the assemblage of P. hispidum endophytes are important sources of antifungal properties, primarily Lasiodiplodia theobromae JF766989, which reduced phytopathogen growth by approximately 54 to 65%. We detected 28 endophytes producing enzymatic halos of up to 16.40 mm in diameter. The results obtained in the present study highlight the proteolytic activity of the endophytes Phoma herbarum JF766995 and Schizophyllum commune JF766994, which presented the highest enzymatic halo diameters under at least one culture condition tested. The increased activities of certain isolates in the presence of rice or soy flour as a substrate (with halos up to 17.67 mm in diameter) suggests that these endophytes have the potential to produce enzymes using agricultural wastes.


Subject(s)
Antifungal Agents/metabolism , Endophytes/isolation & purification , Endophytes/metabolism , Fungi/isolation & purification , Fungi/metabolism , Peptide Hydrolases/metabolism , Piper/microbiology , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Fungi/classification , Fungi/drug effects , Microbiological Techniques , Molecular Sequence Data , Sequence Analysis, DNA
16.
Braz. j. microbiol ; 46(1): 49-57, 05/2015. tab, graf
Article in English | LILACS | ID: lil-748247

ABSTRACT

Bauhinia forficata is native to South America and used with relative success in the folk medicine in Brazil. The diversity, antibacterial activity, and extracellular hydrolytic enzymes of endophytic fungi associated with this plant were studied. Plant samples, which included leaves, sepals, stems, and seeds, were used. Ninety-five endophytic fungal were isolated (18 from leaves, 22 from sepals, 46 from stems, and nine from seeds), comprising 28 species. The most frequently isolated species were Acremonium curvulum (9.5%), Aspergillus ochraceus (7.37%), Gibberella fujikuroi (10.53%), Myrothecium verrucaria (10.53%) and Trichoderma piluliferum (7.37%). Diversity and species richness were higher in stem tissues, and Sorensen’s index of similarity between the tissues was low. Eleven fungi showed antibacterial activity. Aspergillus ochraceus, Gibberella baccata, Penicillium commune, and P. glabrum were those with the greatest antibacterial activity against Staphylococcus aureus and/or Streptococcus pyogenes. Thirteen species showed proteolytic activity, particularly Phoma putaminum. Fourteen species were cellulase positive, particularly the Penicillium species and Myrmecridium schulzeri. All isolates tested were xylanase positive and 10 showed lipolytic activity, especially Penicillium glabrum. It is clear that the endophytic fungi from B. forficata have potential for the production of bioactive compounds and may be a source of new therapeutic agents for the effective treatment of diseases in humans, other animals, and plants. To our knowledge, this is the first study of endophytic fungi from different tissues of B. forficata and their biotechnological potential.


Subject(s)
Anti-Infective Agents/metabolism , Biodiversity , Bauhinia/microbiology , Endophytes/classification , Fungi/metabolism , Hydrolases/metabolism , Plants, Medicinal/microbiology , Brazil , Bacteria/drug effects , Biological Products/metabolism , Biotechnology/methods , Endophytes/isolation & purification , Endophytes/metabolism , Fungi/classification , Fungi/isolation & purification , Microbial Sensitivity Tests , South America , Technology, Pharmaceutical/methods
17.
Braz. j. microbiol ; 45(4): 1333-1339, Oct.-Dec. 2014. graf, tab
Article in English | LILACS | ID: lil-741284

ABSTRACT

Agave tequilana Weber var. 'Azul' is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost.


Subject(s)
Agave/microbiology , Bacteria/classification , Bacteria/metabolism , Endophytes/classification , Endophytes/metabolism , Plant Growth Regulators/metabolism , Plant Leaves/microbiology , Bacteria/isolation & purification , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Endophytes/isolation & purification , Molecular Sequence Data , Promoter Regions, Genetic , /genetics , Sequence Analysis, DNA
18.
Braz. j. microbiol ; 45(4): 1503-1511, Oct.-Dec. 2014. ilus, graf, tab
Article in English | LILACS | ID: lil-741306

ABSTRACT

Extracellular lipases from the endophytic yeast Candida guilliermondii isolated from castor leaves (Ricinus communis L.) were produced using low-cost raw materials such as agro-industrial residues and applying them in the esterification of oleic acid for evaluating their potential use in biodiesel production. After partial purification using ammonium sulfate, the enzyme was characterized and presented higher activity (26.8 ± 1.5 U mL-1) in the presence of 5 mmol L-1 NaCl at 30 ºC and pH 6.5. The production through submerged fermentation was formerly performed in 150 mL erlenmeyer flasks and, once the enzyme production was verified, assays in a 14 L bioreactor were conducted, obtaining 18 ± 1.4 U mL-1. The produced enzyme was applied in the oleic acid esterification under different solvents: hexane, cyclohexane or cyclohexanone) and different acid:alcohol molar ratios. Higher ester conversion rate (81%) was obtained using hexane and the molar ratio of 1:9 was the best conditions using methanol. The results suggest the potential for development of endophytic yeast in the production of biocatalyst through submerged fermentation using agroindustrial residues as culture medium.


Subject(s)
Candida/enzymology , Candida/metabolism , Lipase/isolation & purification , Lipase/metabolism , Candida/growth & development , Candida/isolation & purification , Culture Media/chemistry , Esterification , Endophytes/enzymology , Endophytes/growth & development , Endophytes/isolation & purification , Endophytes/metabolism , Hydrogen-Ion Concentration , Oleic Acid/metabolism , Plant Leaves/microbiology , Ricinus/microbiology , Sodium Chloride/metabolism , Temperature
19.
Braz. j. microbiol ; 45(3): 977-983, July-Sept. 2014. ilus, tab
Article in English | LILACS | ID: lil-727029

ABSTRACT

Extraneous DNA interferes with PCR studies of endophytic fungi. A procedure was developed with which to evaluate the removal of extraneous DNA. Wheat (Triticum aestivum) leaves were sprayed with Saccharomyces cerevisiae and then subjected to physical and chemical surface treatments. The fungal ITS1 products were amplified from whole tissue DNA extractions. ANOVA was performed on the DNA bands representing S. cerevisiae on the agarose gel. Band profile comparisons using permutational multivariate ANOVA (PERMANOVA) and non-metric multidimensional scaling (NMDS) were performed on DGGE gel data, and band numbers were compared between treatments. Leaf surfaces were viewed under variable pressure scanning electron microscopy (VPSEM). Yeast band analysis of the agarose gel showed that there was no significant difference in the mean band DNA quantity after physical and chemical treatments, but they both differed significantly (p < 0.05) from the untreated control. PERMANOVA revealed a significant difference between all treatments (p < 0.05). The mean similarity matrix showed that the physical treatment results were more reproducible than those from the chemical treatment results. The NMDS showed that the physical treatment was the most consistent. VPSEM indicated that the physical treatment was the most effective treatment to remove surface microbes and debris. The use of molecular and microscopy methods for the post-treatment detection of yeast inoculated onto wheat leaf surfaces demonstrated the effectiveness of the surface treatment employed, and this can assist researchers in optimizing their surface sterilization techniques in DNA-based fungal endophyte studies.


Subject(s)
Endophytes/isolation & purification , Microbiological Techniques/methods , Sterilization/methods , Triticum/microbiology , Denaturing Gradient Gel Electrophoresis , DNA, Fungal/genetics , DNA, Fungal/isolation & purification , DNA, Plant/chemistry , DNA, Plant/genetics , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/isolation & purification , Microscopy, Electron, Scanning , Polymerase Chain Reaction , Plant Leaves/microbiology , Plant Leaves/ultrastructure , Surface Properties , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/isolation & purification , Saccharomyces cerevisiae/ultrastructure , Triticum/ultrastructure
20.
Braz. j. microbiol ; 45(2): 621-625, Apr.-June 2014. ilus, tab
Article in English | LILACS | ID: lil-723126

ABSTRACT

Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.


Subject(s)
Azospirillum brasilense/isolation & purification , Bacillus/isolation & purification , Endophytes/isolation & purification , Hordeum/microbiology , Nitrogen Fixation , Pseudomonas/isolation & purification , Seeds/microbiology , Antibiosis , Azospirillum brasilense/classification , Azospirillum brasilense/genetics , Azospirillum brasilense/metabolism , Bacillus/classification , Bacillus/genetics , Bacillus/metabolism , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Endophytes/classification , Endophytes/genetics , Endophytes/metabolism , Indoleacetic Acids/metabolism , Molecular Typing , Pseudomonas/classification , Pseudomonas/genetics , Pseudomonas/metabolism , Random Amplified Polymorphic DNA Technique , /genetics , Sequence Analysis, DNA
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