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1.
Electron J Biotechnol ; 49: 34-41, Jan. 2021. tab, graf
Article in English | LILACS | ID: biblio-1291638

ABSTRACT

BACKGROUND: This work studied how the exposure to an unusual substrate forced a change in microbial populations during anaerobic fermentation of crude glycerol, a by-product of biodiesel production, with freshwater sediment used as an inoculum. RESULTS: The microbial associations almost completely (99.9%) utilized the glycerol contained in crude glycerol 6 g L 1 within four days, releasing gases, organic acids (acetic, butyric) and alcohols (ethanol, n-butanol) under anaerobic conditions. In comparison with control medium without glycerol, adding crude glycerol to the medium increased the amount of ethanol and n-butanol production and it was not significantly affected by incubation temperature (28 C or 37 C), nor incubation time (4 or 8 d), but it resulted in reduced amount of butyric acid. Higher volume of gas was produced at 37 C despite the fact that the overall bacterial count was smaller than the one measured at 20 C. Main microbial phyla of the inoculum were Actinobacteria, Proteobacteria and Firmicutes. During fermentation, significant changes were observed and Firmicutes, especially Clostridium spp., began to dominate, and the number of Actinobacteria and Gammaproteobacteria decreased accordingly. Concentration of Archaea decreased, especially in medium with crude glycerol. These changes were confirmed both by culturing and culture-independent (concentration of 16S rDNA) methods. CONCLUSIONS: Crude glycerol led to the adaptation of freshwater sediment microbial populations to this substrate. Changes of microbial community were a result of a community adaptation to a new source of carbon.


Subject(s)
Bacteria/isolation & purification , Geologic Sediments/microbiology , Fresh Water/microbiology , Glycerol/metabolism , Bacteria/metabolism , Adaptation, Biological , Biofuels , Fermentation , Real-Time Polymerase Chain Reaction/methods , Anaerobiosis
2.
Chinese Journal of Biotechnology ; (12): 3439-3458, 2021.
Article in Chinese | WPRIM | ID: wpr-921440

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants, which have received widespread attentions due to their carcinogenic and mutagenic toxicity. The microbial degradation of PAHs are usually started from the hydroxylation, followed by dehydrogenation, ring cleavage and step-by-step removal of branched chains, and finally mineralized by the tricarboxylic acid cycle. Rieske type non-heme iron aromatic ring-hydroxylating dioxygenases (RHOs) or cytochrome P450 oxidases are responsible for the conversion of hydrophobic PAHs into hydrophilic derivatives by the ring hydroxylation. The ring hydroxylation is the first step of PAHs degradation and also one of the rate-limiting steps. Here, we review the distribution, substrate specificity, and substrate recognition mechanisms of RHOs, along with some techniques and methods used for the research of RHOs and PAHs.


Subject(s)
Bacteria/metabolism , Biodegradation, Environmental , Dioxygenases/metabolism , Iron , Polycyclic Aromatic Hydrocarbons , Substrate Specificity
3.
Article in English | WPRIM | ID: wpr-888787

ABSTRACT

Mushrooms are abundant in bioactive natural compounds. Due to strict growth conditions and long fermentation-time, microbe as a production host is an alternative and sustainable approach for the production of natural compounds. This review focuses on the biosynthetic pathways of mushroom originated natural compounds and microbes as the production host for the production of the above natural compounds.


Subject(s)
Agaricales/chemistry , Bacteria/metabolism , Biological Products/metabolism , Biosynthetic Pathways , Fermentation , Metabolic Engineering
4.
Chinese Journal of Biotechnology ; (12): 2379-2392, 2021.
Article in Chinese | WPRIM | ID: wpr-887804

ABSTRACT

TetR family transcriptional regulators (TFRs) are widely distributed in bacteria and archaea, and the first discovered TFR was confirmed to control the expression of tetracycline efflux pump in Escherichia coli. TFRs can bind DNAs and ligands. Small molecule ligands can induce conformational changes of TFRs, inhibiting or promoting TFRs to control target gene expression. Currently, TFRs have a wide variety of ligands, including carbohydrates, proteins, fatty acids and their derivatives, metal ions, and so on. Due to the diversity of ligands, TFRs regulate a wide range of physiological processes, from basic carbon metabolism and nitrogen metabolism to quorum sensing and antibiotic biosynthesis. On the basis of the recent studies in our laboratory and the literature, we review here the regulatory mechanism mediated by ligands of TFRs in primary and secondary metabolism, as well as the application of ligands for TFRs in the development of gene route and the activation of antibiotic biosynthesis.


Subject(s)
Anti-Bacterial Agents , Bacteria/metabolism , Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial , Ligands , Quorum Sensing
5.
Rev. Soc. Bras. Med. Trop ; 52: e20180152, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041546

ABSTRACT

Abstract INTRODUCTION: Introducing new antibiotics to the clinic is critical. METHODS: We adapted a plate method described by Kawaguchi and coworkers in 20131 for detecting inhibitory airborne microorganisms. RESULTS: We obtained 51 microbial colonies antagonist to Chromobacterium violaceum, purified and retested them, and of these, 39 (76.5%) were confirmed. They comprised 24 bacteria, 13 fungi, and 2 yeasts. Among the fungi, eight (61.5%) produced active extracts. Among the bacterial, yeast, and fungal strains, 17 (44.7%) and 12 (31.6%) were active against Candida albicans and Candida parapsilosis, respectively. CONCLUSIONS: The proposed screening method is a rapid strategy for discovering potential antibiotic producers.


Subject(s)
Bacteria/isolation & purification , Candida/drug effects , Chromobacterium/drug effects , Air Microbiology , Quorum Sensing , Fungi/isolation & purification , Anti-Bacterial Agents/isolation & purification , Bacteria/metabolism , Colony Count, Microbial , Fungi/metabolism , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology
6.
Braz. j. microbiol ; 49(4): 757-769, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974306

ABSTRACT

ABSTRACT Anthropogenic activity, such as accidental oil spills, are typical sources of urban mangrove pollution that may affect mangrove bacterial communities as well as their mobile genetic elements. To evaluate remediation strategies, we followed over the time the effects of a petroleum hydrocarbon degrading consortium inoculated on mangrove tree Avicennia schaueriana against artificial petroleum contamination in a phytoremediation greenhouse experiment. Interestingly, despite plant protection due to the inoculation, denaturing gradient gel electrophoresis of the bacterial 16S rRNA gene fragments amplified from the total community DNA indicated that the different treatments did not significantly affect the bacterial community composition. However, while the bacterial community was rather stable, pronounced shifts were observed in the abundance of bacteria carrying plasmids. A PCR-Southern blot hybridization analysis indicated an increase in the abundance of IncP-9 catabolic plasmids. Denaturing gradient gel electrophoresis of naphthalene dioxygenase (ndo) genes amplified from cDNA (RNA) indicated the dominance of a specific ndo gene in the inoculated petroleum amendment treatment. The petroleum hydrocarbon degrading consortium characterization indicated the prevalence of bacteria assigned to Pseudomonas spp., Comamonas spp. and Ochrobactrum spp. IncP-9 plasmids were detected for the first time in Comamonas sp. and Ochrobactrum spp., which is a novelty of this study.


Subject(s)
Bacteria/isolation & purification , Bacteria/metabolism , Avicennia/microbiology , Hydrocarbons/metabolism , Plasmids/genetics , Plasmids/metabolism , Soil Pollutants/analysis , Soil Pollutants/metabolism , Bacteria/classification , Bacteria/genetics , Biodegradation, Environmental , DNA, Bacterial/genetics , Petroleum/analysis , RNA, Ribosomal, 16S/genetics , Petroleum Pollution/analysis , Avicennia/metabolism , Rhizosphere
7.
Braz. j. microbiol ; 49(4): 770-776, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974307

ABSTRACT

ABSTRACT Anaerobic digestion is important for the management of livestock manure with high ammonia level. Although ammonia effects on anaerobic digestion have been comprehensively studied, the molecular mechanism underlying ammonia inhibition still remains elusive. In this study, based on metatranscriptomic analysis, the transcriptional profile of microbial community in anaerobic digestion under low (1500 mg L-1) and high NH4 + (5000 mg L-1) concentrations, respectively, were revealed. The results showed that high NH4 + concentrations significantly inhibited methane production but facilitated the accumulations of volatile fatty acids. The expression of methanogenic pathway was significantly inhibited by high NH4 + concentration but most of the other pathways were not significantly affected. Furthermore, the expressions of methanogenic genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase were significantly inhibited by high NH4 + concentration. The inhibition of the co-expressions of the genes which encode acetyl-CoA decarbonylase was observed. Some genes involved in the pathways of aminoacyl-tRNA biosynthesis and ribosome were highly expressed under high NH4 + concentration. Consequently, the ammonia inhibition on anaerobic digestion mainly focused on methanogenic process by suppressing the expressions of genes which encode acetyl-CoA decarbonylase and methyl-coenzyme M reductase. This study improved the accuracy and depth of understanding ammonia inhibition on anaerobic digestion.


Subject(s)
Bacteria/genetics , Bacteria/metabolism , Ammonia/metabolism , Bacteria/isolation & purification , Bacteria/classification , Transcription, Genetic , Bioreactors/microbiology , Fatty Acids, Volatile/metabolism , Microbiota , Anaerobiosis , Methane/metabolism
8.
Braz. j. microbiol ; 49(3): 489-502, July-Sept. 2018. tab, graf
Article in English | LILACS | ID: biblio-951803

ABSTRACT

Abstract Human activities on the Earth's surface change the landscape of natural ecosystems. Mining practices are one of the most severe human activities, drastically altering the chemical, physical and biological properties of the soil environment. Bacterial communities in soil play an important role in the maintenance of ecological relationships. This work shows bacterial diversity, metabolic repertoire and physiological behavior in five ecosystems samples with different levels of impact. These ecosystems belong to a historical area in Iron Quadrangle, Minas Gerais, Brazil, which suffered mining activities until its total depletion without recovery since today. The results revealed Proteobacteria as the most predominant phylum followed by Acidobacteria, Verrucomicrobia, Planctomycetes, and Bacteroidetes. Soils that have not undergone anthropological actions exhibit an increase ability to degrade carbon sources. The richest soil with the high diversity was found in ecosystems that have suffered anthropogenic action. Our study shows profile of diversity inferring metabolic profile, which may elucidate the mechanisms underlying changes in community structure in situ mining sites in Brazil. Our data comes from contributing to know the bacterial diversity, relationship between these bacteria and can explore strategies for natural bioremediation in mining areas or adjacent areas under regeneration process in iron mining areas.


Subject(s)
Soil Microbiology , Bacteria/isolation & purification , Biodiversity , Phylogeny , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Brazil , Ecosystem , Mining
9.
Braz. j. microbiol ; 49(3): 481-488, July-Sept. 2018. graf
Article in English | LILACS | ID: biblio-951816

ABSTRACT

Abstract An increasing production of natural rubber (NR) products has led to major challenges in waste management. In this study, the degradation of rubber latex gloves in a mineral salt medium (MSM) using a bacterial consortium, a mixed culture of the selected bacteria and a pure culture were studied. The highest 18% weight loss of the rubber gloves were detected after incubated with the mixed culture. The increased viable cell counts over incubation time indicated that cells used rubber gloves as sole carbon source leading to the degradation of the polymer. The growth behavior of NR-degrading bacteria on the latex gloves surface was investigated using the scanning electron microscope (SEM). The occurrence of the aldehyde groups in the degradation products was observed by Fourier Transform Infrared Spectroscopy analysis. Rhodococcus pyridinivorans strain F5 gave the highest weight loss of rubber gloves among the isolated strain and posses latex clearing protein encoded by lcp gene. The mixed culture of the selected strains showed the potential in degrading rubber within 30 days and is considered to be used efficiently for rubber product degradation. This is the first report to demonstrate a strong ability to degrade rubber by Rhodococcus pyridinivorans.


Subject(s)
Rubber/metabolism , Soil Microbiology , Rhodococcus/isolation & purification , Rhodococcus/metabolism , Latex/metabolism , Bacteria/isolation & purification , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Biodegradation, Environmental , Rhodococcus/classification , Rhodococcus/genetics , Gloves, Protective/microbiology
10.
Electron. j. biotechnol ; 35: 33-38, sept. 2018. graf
Article in English | LILACS | ID: biblio-1047766

ABSTRACT

Background: Anaerobic digestion is an alternative bioprocess used to treat effluents containing toxic compounds such as phenol and p-cresol. Selection of an adequate sludge as inoculum containing an adapted microbial consortium is a relevant factor to improve the removal of these pollutants. The objective of this study is to identify the key microorganisms involved in the anaerobic digestion of phenol and p-cresol and elucidate the relevance of the bamA gene abundance (a marker gene for aromatic degraders) in the process, in order to establish new strategies for inocula selection and improve the system's performance. Results: Successive batch anaerobic digestion of phenol and p-cresol was performed using granular or suspended sludge. Granular sludge in comparison to suspended sludge showed higher degradation rates both for phenol (11.3 ± 0.7 vs 8.1 ± 1.1 mg l-1 d-1) and p-cresol (7.8 ± 0.4 vs 3.7 ± 1.0 mg l-1 d-1). After three and four re-feedings of phenol and p-cresol, respectively, the microbial structure from both sludges was clearly different from the original sludges. Anaerobic digestion of phenol and p-cresol generated an abundance increase in Syntrophorhabdus genus and bamA gene, together with hydrogenotrophic and aceticlastic archaea. Analysis of results indicates that differences in methanogenic pathways and levels of Syntrophorhabdus and bamA gene in the inocula, could be the causes of dissimilar degradation rates between each sludge. Conclusions: Syntrophorhabdus and bamA gene play relevant roles in anaerobic degradation of phenolics. Estimation of these components could serve as a fast screening tool to find the most acclimatized sludge to efficiently degrade mono-aromatic compounds.


Subject(s)
Bacteria/metabolism , Anaerobic Digestion , Phenol/metabolism , Cresols/metabolism , Phenols/metabolism , Sewage , Biodegradation, Environmental , Deltaproteobacteria , Microbial Consortia , Real-Time Polymerase Chain Reaction
11.
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
12.
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
13.
Braz. j. microbiol ; 49(1): 87-96, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889214

ABSTRACT

ABSTRACT Variations in microbial communities promoted by alterations in environmental conditions are reflected in similarities/differences both at taxonomic and functional levels. Here we used a natural gradient within mangroves from seashore to upland, to contrast the natural variability in bacteria, cyanobacteria and diazotroph assemblages in a pristine area compared to an oil polluted area along a timespan of three years, based on ARISA (bacteria and cyanobacteria) and nifH T-RFLP (diazotrophs) fingerprinting. The data presented herein indicated that changes in all the communities evaluated were mainly driven by the temporal effect in the contaminated area, while local effects were dominant on the pristine mangrove. A positive correlation of community structure between diazotrophs and cyanobacteria was observed, suggesting the functional importance of this phylum as nitrogen fixers in mangroves soils. Different ecological patterns explained the microbial behavior in the pristine and polluted mangroves. Stochastic models in the pristine mangrove indicate that there is not a specific environmental factor that determines the bacterial distribution, while cyanobacteria and diazotrophs better fitted in deterministic model in the same area. For the contaminated mangrove site, deterministic models better represented the variations in the communities, suggesting that the presence of oil might change the microbial ecological structures over time. Mangroves represent a unique environment threatened by global change, and this study contributed to the knowledge of the microbial distribution in such areas and its response on persistent contamination historic events.


Subject(s)
Soil/chemistry , Soil Microbiology , Bacteria/isolation & purification , Phylogeny , Soil Pollutants/analysis , Soil Pollutants/metabolism , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Petroleum/analysis , Petroleum/metabolism , Biodiversity , Wetlands , Nitrogen/metabolism
14.
Electron. j. biotechnol ; 31: 34-43, Jan. 2018. ilus, tab, graf
Article in English | LILACS | ID: biblio-1022040

ABSTRACT

Background: Microbial Fuel Cell (MFC) technology is used in various applications such as wastewater treatment with the production of electrical energy. The objective of this study was to estimate the biodepuration of oils and fats, the elimination of blue dye brl and bioelectro-characterization in MFCs with Chlorella vulgaris and bacterial community. Results: The operation of MFCs at 32 d showed an increase in bioelectrogenic activity (from 23.17 to 327.67 mW/m2 ) and in the potential (from 200 to 954 mV), with biodepuration of fats and oils (95%) in the microalgal cathode, and a removal of the chemical oxygen demand COD (anode, 71%, cathode, 78.6%) and the blue dye brl (73%) at the anode, here biofilms were formed by the bacterial community consisting of Actinobacteria and Deltaproteobacteria. Conclusions: These findings suggest that MFCs with C. vulgaris and bacterial community have a simultaneous efficiency in the production of bioelectricity and bioremediation processes, becoming an important source of bioenergy in the future.


Subject(s)
Bacteria/metabolism , Bioelectric Energy Sources/microbiology , Water Purification/methods , Chlorella vulgaris/metabolism , Bacteria/chemistry , Biofilms , Chlorella vulgaris/chemistry , Electricity , Electrodes , Microalgae , Denaturing Gradient Gel Electrophoresis , Waste Water
15.
Braz. j. microbiol ; 49(supl.1): 25-33, 2018. tab, graf
Article in English | LILACS | ID: biblio-974330

ABSTRACT

Abstract The biodiversity and evolution of the microbial community in açai fruits (AF) between three geographical origins and two spontaneous decay conditions were examined by applying culture-independent methods. Culture-independent methods based on 16S rRNA from fifteen samples revealed that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria were the most abundant phyla. At the genus level, Massilia (taxon with more than 50% of the sequences remaining constant during the 30 h of decay), Pantoea, Naxibacter, Enterobacter, Raoultella and Klebsiella were identified, forming the carposphere bacterial microbiota of AF. AF is fibre-rich and Massilia bacteria could find a large quantity of substrate for its growth through cellulase production. Beta diversity showed that the quality parameters of AF (pH, soluble solids, titratable acidity and lipids) and elemental analysis (C, N, H and C/N ratio) were unable to drive microbial patterns in AF. This research offers new insight into the indigenous bacterial community composition on AF as a function of spontaneous postharvest decay.


Subject(s)
Bacteria/isolation & purification , Euterpe/chemistry , Fruit/microbiology , Phylogeny , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , Biodiversity , High-Throughput Nucleotide Sequencing , Microbiota , Euterpe/microbiology , Fruit/chemistry
16.
An. acad. bras. ciênc ; 90(1,supl.1): 943-992, 2018. tab, graf
Article in English | LILACS | ID: biblio-886937

ABSTRACT

ABSTRACT Several enzymatic reactions of heteroatom-containing compounds have been explored as unnatural substrates. Considerable advances related to the search for efficient enzymatic systems able to support a broader substrate scope with high catalytic performance are described in the literature. These reports include mainly native and mutated enzymes and whole cells biocatalysis. Herein, we describe the historical background along with the progress of biocatalyzed reactions involving the heteroatom(S, Se, B, P and Si) from hetero-organic substrates.


Subject(s)
Bacteria/metabolism , Biotransformation , Enzymes/metabolism , Biocatalysis , Fungi/metabolism , Substrate Specificity , Biosensing Techniques , Enzymes/chemistry
17.
Braz. j. microbiol ; 48(4): 615-616, Oct.-Dec. 2017. tab
Article in English | LILACS | ID: biblio-889157

ABSTRACT

ABSTRACT Chelatococcus daeguensis TAD1 is a themophilic bacterium isolated from a biotrickling filter used to treat NOx in Ruiming Power Plant, located in Guangzhou, China, which shows an excellent aerobic denitrification activity at high temperature. The complete genome sequence of this strain was reported in the present study. Genes related to the aerobic denitrification were identified through whole genome analysis. This work will facilitate the mechanism of aerobic denitrification and provide evidence for its potential application in the nitrogen removal.


Subject(s)
Bacteria/isolation & purification , Genome, Bacterial , Power Plants , Bacteria/classification , Bacteria/genetics , Bacteria/metabolism , China , Aerobiosis , Denitrification , Hot Temperature , Micropore Filters/microbiology , Nitrogen/metabolism
18.
An. acad. bras. ciênc ; 89(4): 2945-2954, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-886833

ABSTRACT

ABSTRACT Forty isolates of endophytic bacteria isolated from banana tree roots were assessed as to their capacity to solubilize phosphate in a solid culture medium supplemented with different inorganic and one organic source of phosphorus. The amount of phosphorus (P) in each liquid medium was quantified, and an indirect assessment of acid phosphatase activity was performed. All assays had a fully randomized design, with three repetitions. Approximately 67.5% of the 40 isolates assessed in solid medium solubilized phosphorus from tricalcium phosphate and 7.5% of the isolates solubilized phosphorus from soy lecithin; no isolates exhibited P solubilization capacity in medium supplemented with iron phosphate. Acid phosphatase activity was detected in 65% of the isolates; Aneurinibacillus sp. and Lysinibacillus sp. isolates presented with the best solubilization indexes. All of the assessed isolates exhibited a capacity to reduce the potential of hydrogen in liquid medium supplemented with tricalcium phosphate. Isolate EB. 78 (Bacillus sp.) exhibited P solubilization capacity in solid media when Ca3(PO4)2 and soy lecithin were used as P sources; this isolate significantly reduced the pH of the liquid medium and exhibited acid phosphatase activity. The results of the present study highlight isolates that exhibit variations in their capacity to solubilize P. These isolates should be used in future tests to assess their field performance.


Subject(s)
Phosphates/metabolism , Bacteria/metabolism , Biodegradation, Environmental , Musa/microbiology , Endophytes/physiology , Bacteria/classification
19.
Braz. j. microbiol ; 48(3): 442-450, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889132

ABSTRACT

Abstract Large quantities of kitchen waste are produced in modern society and its disposal poses serious environmental and social problems. The aim of this study was to isolate degradative strains from kitchen waste and to develop a novel and effective microbial agent. One hundred and four strains were isolated from kitchen waste and the 84 dominant strains were used to inoculate protein-, starch-, fat- and cellulose-containing media for detecting their degradability. Twelve dominant strains of various species with high degradability (eight bacteria, one actinomycetes and three fungi) were selected to develop a compound microbial agent "YH" and five strains of these species including H7 (Brevibacterium epidermidis), A3 (Paenibacillus polymyxa), E3 (Aspergillus japonicus), F9 (Aspergillus versicolor) and A5 (Penicillium digitatum), were new for kitchen waste degradation. YH was compared with three commercial microbial agents-"Tiangeng" (TG), "Yilezai" (YLZ) and Effective Microorganisms (EM), by their effects on reduction, maturity and deodorization. The results showed that YH exerted the greatest efficacy on mass loss which decreased about 65.87% after 14 days. The agent inhibited NH3 and H2S emissions significantly during composting process. The concentration of NH3 decreased from 7.1 to 3.2 ppm and that of H2S reduced from 0.7 to 0.2 ppm. Moreover, E4/E6 (Extinction value460nm/Extinction value665nm) of YH decreased from 2.51 to 1.31, which meant YH had an obvious maturity effect. These results highlighted the potential application of YH in composting kitchen waste.


Subject(s)
Bacteria/metabolism , Vegetables/microbiology , Refuse Disposal/methods , Fungi/metabolism , Vegetables/metabolism , Biodegradation, Environmental
20.
Braz. j. microbiol ; 48(3): 515-521, July-Sept. 2017. graf
Article in English | LILACS | ID: biblio-889145

ABSTRACT

Abstract Ammonia-oxidizing bacteria were immobilized by polyvinyl alcohol (PVA) and sodium alginate. The immobilization conditions and ammonia oxidation ability of the immobilized bacteria were investigated. The following immobilization conditions were observed to be optimal: PVA, 12%; sodium alginate, 1.1%; calcium chloride, 1.0%; inoculum concentration, 1.3 immobilized balls/mL of immobilized medium; pH, 10; and temperature, 30 °C. The immobilized ammonia-oxidizing bacteria exhibited strong ammonia oxidation ability even after being recycled four times. The ammonia nitrogen removal rate of the immobilized ammonia-oxidizing bacteria reached 90.30% under the optimal immobilization conditions. When compared with ammonia-oxidizing bacteria immobilized by sodium alginate alone, the bacteria immobilized by PVA and sodium alginate were superior with respect to pH resistance, the number of reuses, material cost, heat resistance, and ammonia oxidation ability.


Subject(s)
Bacteria/chemistry , Microbiological Techniques/methods , Ammonia/metabolism , Oxidation-Reduction , Polyvinyl Alcohol/chemistry , Temperature , Bacteria/metabolism , Microbiological Techniques/economics , Microbiological Techniques/instrumentation , Cells, Immobilized/metabolism , Cells, Immobilized/chemistry , Glucuronic Acid/chemistry , Alginates/chemistry , Hexuronic Acids/chemistry , Hydrogen-Ion Concentration
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