scholarly journals Production and Characterization of Keratinolytic Protease from New Wool-DegradingBacillusSpecies Isolated from Egyptian Ecosystem

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Mohamed A. Hassan ◽  
Bakry M. Haroun ◽  
Amro A. Amara ◽  
Ehab A. Serour

Novel keratin-degrading bacteria were isolated from sand soil samples collected from Minia Governorate, Egypt. In this study, the isolates were identified asBacillus amyloliquefaciensMA20 andBacillus subtilisMA21 based on morphological and biochemical characteristics as well as 16S rRNA gene sequencing.B. amyloliquefaciensMA20 andB. subtilisMA21 produced alkaline keratinolytic serine protease when cultivated in mineral medium containing 1% of wool straight off sheep as sole carbon and nitrogen source. The two strains were observed to degrade wool completely to powder at pH 7 and 37°C within 5 days. Under these conditions the maximum activity of proteases produced byB. amyloliquefaciensMA20 andB. subtilisMA21 was 922 and 814 U/ml, respectively. The proteases exhibited optimum temperature and pH at 60°C and 9, respectively. However, the keratinolytic proteases were stable in broad range of temperature and pH values towards casein Hammerstein. Furthermore the protease inhibitor studies indicated that the produced proteases belong to serine protease because of their sensitivity to PMSF while they were inhibited partially in presence of EDTA. The two proteases are stable in most of the used organic solvents and enhanced by metals suggesting their potential use in biotechnological applications such as wool industry.

2016 ◽  
Vol 65 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Mosbah Mahdhi ◽  
Nadia Houidheg ◽  
Neji Mahmoudi ◽  
Abdelhakim Msaadek ◽  
Mokhtar Rejili ◽  
...  

Fifty seven bacterial isolates from root nodules of two spontaneous legumes (Astragalus corrugatus and Hippocrepis areolata) growing in the arid areas of Tunisia were characterized by phenotypic features, 16S rDNA PCR-RFLP and 16S rRNA gene sequencing. Phenotypically, our results indicate that A. corrugatus and H. areolata isolates showed heterogenic responses to the different phenotypic features. All isolates were acid producers, fast growers and all of them used different compounds as sole carbon and nitrogen source. The majority of isolate grew at pHs between 6 and 9, at temperatures up to 40°C and tolerated 3% NaCl concentrations. Phylogenetically, the new isolates were affiliated to four genera Sinorhizobium, Rhizobium, Mesorhizobium and Agrobacterium. About 73% of the isolates were species within the genera Sinorhizobium and Rhizobium. The isolates which failed to nodulate their host plants of origin were associated to Agrobacterium genus (three isolates).


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Expedito K. A. Camboim ◽  
Arthur P. Almeida ◽  
Michelle Z. Tadra-Sfeir ◽  
Felício G. Junior ◽  
Paulo P. Andrade ◽  
...  

The objective of this paper was to report the isolation of two fluoroacetate degrading bacteria from the rumen of goats. The animals were adult goats, males, crossbred, with rumen fistula, fed with hay, and native pasture. The rumen fluid was obtained through the rumen fistula and immediately was inoculated 100 μL in mineral medium added with 20 mmol L−1sodium fluoroacetate (SF), incubated at 39°C in an orbital shaker.Pseudomonas fluorescens(strain DSM 8341) was used as positive control for fluoroacetate dehalogenase activity. Two isolates were identified by 16S rRNA gene sequencing asPigmentiphaga kullae(ECPB08) andAncylobacter dichloromethanicus(ECPB09). These bacteria degraded sodium fluoroacetate, releasing 20 mmol L−1of fluoride ion after 32 hours of incubation in Brunner medium containing 20 mmol L−1of SF. There are no previous reports of fluoroacetate dehalogenase activity forP. kullaeandA. dichloromethanicus. Control measures to prevent plant intoxication, including use of fences, herbicides, or other methods of eliminating poisonous plants, have been unsuccessful to avoid poisoning by fluoroacetate containing plants in Brazil. In this way,P. kullaeandA. dichloromethanicusmay be used to colonize the rumen of susceptible animals to avoid intoxication by fluoroacetate containing plants.


Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 489 ◽  
Author(s):  
Adriana Antunes-Rohling ◽  
Silvia Calero ◽  
Nabil Halaihel ◽  
Pedro Marquina ◽  
Javier Raso ◽  
...  

The aim of this study was to characterize the spoilage microbiota of hake fillets stored under modified atmospheres (MAP) (50% CO2/50% N2) at different temperatures using high-throughput 16S rRNA gene sequencing and to compare the results with those obtained using traditional microbiology techniques. The results obtained indicate that, as expected, higher storage temperatures lead to shorter shelf-lives (the time of sensory rejection by panelists). Thus, the shelf-life decreased from six days to two days for Batch A when the storage temperature increased from 1 to 7 °C, and from five to two days—when the same increase in storage temperature was compared—for Batch B. In all cases, the trimethylamine (TMA) levels measured at the time of sensory rejection of hake fillets exceeded the recommended threshold of 5 mg/100 g. Photobacterium and Psychrobacter were the most abundant genera at the time of spoilage in all but one of the samples analyzed: Thus, Photobacterium represented between 19% and 46%, and Psychrobacter between 27% and 38% of the total microbiota. They were followed by Moritella, Carnobacterium, Shewanella, and Vibrio, whose relative order varied depending on the sample/batch analyzed. These results highlight the relevance of Photobacterium as a spoiler of hake stored in atmospheres rich in CO2. Further research will be required to elucidate if other microorganisms, such as Psychrobacter, Moritella, or Carnobacterium, also contribute to spoilage of hake when stored under MAP.


Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 638
Author(s):  
Caitlin E. Older ◽  
Aline Rodrigues Hoffmann ◽  
Kathleen Hoover ◽  
Frane Banovic

Although Staphylococcus pseudintermedius is considered the major pathogen associated with superficial canine pyoderma, no study has investigated the entire bacterial community in these lesions with molecular techniques. The objectives of this study were to characterize the bacterial microbiota in two forms of superficial canine pyoderma lesions, superficial bacterial folliculitis (SBF) and epidermal collarette (EC), especially in terms of the staphylococcal community. Swabs from 12 SBF and 9 EC lesions were obtained from eight and six atopic dogs, respectively. Eight samples from the axilla and groin of four healthy dogs served as controls. DNA was extracted for 16S rRNA gene sequencing and quantitative polymerase chain reaction of Staphylococcus spp. and S. pseudintermedius. Healthy skin samples harbored significantly more diverse bacterial communities than pyoderma samples. Healthy samples had communities that were more similar to each other, and were distinct from pyoderma samples. Staphylococcus spp. abundance was increased in pyoderma samples, especially those from EC samples. Although determining species-level identities of staphylococcal sequences revealed many species, S. pseudintermedius was the primary staphylococcal species found in all sample types. As expected, there are many differences in the microbiota when comparing healthy and canine pyoderma lesions samples. These lesions do not seem to be associated with a change in the relative abundance of specific Staphylococcus species, but simply an overall increase in Staphylococcus spp. abundance. The results of this study provide a starting point for future studies investigating how antimicrobial treatments may further change the microbiota associated with these lesions.


Phytotaxa ◽  
2019 ◽  
Vol 387 (4) ◽  
pp. 269 ◽  
Author(s):  
ELANE D. CUNHA DE OLIVEIRA ◽  
ALAN C. DA CUNHA ◽  
NATALINA B. DA SILVA ◽  
RAQUEL CASTELO-BRANCO ◽  
JOÃO MORAIS ◽  
...  

The Amazon region contains a great diversity of species, and the Amazon River basin accounts for almost 20% of all the freshwater in the world. Despite the favorable environmental conditions in this region, little is known about the cyanobacterial diversity of this waterbody, especially at the mouth of the river. In this paper, we used the polyphasic approach to identify 14 cyanobacterial strains isolated in the Amazon River on the inlet site from a drinking water supply located close to the river mouth. The isolated strains were characterized based on morphology, behavior in culture, 16S rRNA gene sequencing, phylogenetic analysis and potential for toxin production. The isolated strains belong to seven different genera, namely, Alkalinema, Cephalothrix, Limnothrix, Leptolyngbya, Phormidium, Pseudanabaena and an unidentified Nostocales taxa that may represent a new genus. Strikingly, there were no new species, nor detection of gene clusters associated with cyanotoxin production. However, the phylogenetic placements of the Amazonian strains of Limnothrix and Pseudanabaena provide new insight into the taxonomy of these genera, reinforcing the need for taxonomic revision.


2017 ◽  
Vol 2017 (1) ◽  
pp. 2256-2267
Author(s):  
Ruta Suresh Deshpande ◽  
Devi Sundaravadivelu ◽  
Pablo Campo ◽  
Jorge W. SantoDomingo ◽  
Robyn N. Conmy

Abstract 2017-271 In recent years, diluted bitumen (or dilbit) has become an important source of hydrocarbon-based fuel. While information on the degradation of crude oils has been well researched, dilbit degradation has been studied at a much lesser extent. The objective of this study was to compare biodegradation of dilbit with a conventional crude oil (CCO) under various conditions. Two different microcosm experiments were set up, one containing a mixed culture acclimated to dilbit (Kalamazoo River Enrichment, KRC) and the other having a mixed culture enriched on soil contaminated with hydrocarbons (Anderson Ferry Enrichment, AFC). The microcosms were run for 60 d at 25 °C and for 72 days at 5 °C in flasks containing sterile Bushnell Hass broth and naturally dispersed oil. Each flask was inoculated with the KRC and AFC mixed cultures, and rotated on an orbital shaker (200 rpm) at the above stated temperatures. On each sampling day, triplicates were sacrificed to determine the residual hydrocarbon concentration. Additionally, some samples were used to determine the bacterial composition using 16S rRNA gene sequencing analysis. Hydrocarbon analysis (alkanes and PAHs) was performed by gas chromatography/mass spectrometry (GC/MS/MS). Higher degradation rates were achieved at 25 °C as compared to 5 °C. All the enrichments metabolized CCO as well dilbit, but the nature and extent of the degradation was distinct. KRC meso culture was the most effective among all, as it completely removed alkanes and most of the PAHs. AFC enrichment performed differently at the two temperatures; an acclimation period (8 d) was observed at 5 °C while there was no lag at 25 °C. KRC cryo culture as well as AFC culture at both temperatures degraded alkanes completely while they were not able to metabolize heavier fractions of the oil (C2–4 homologues of 3- and 4-ring compounds). All cultures showed the presence of diverse oil degrading bacteria and the differences in their compositions affected the biodegradation. Although dilbit was biodegraded, for all the treatments except AFC at 5 °C, the rate of degradation and the extent of degradation was greater for CCO owing to the higher concentrations of lighter hydrocarbons.


2020 ◽  
Author(s):  
Houda Bahig ◽  
Clifton D Fuller ◽  
Aparna Mitra ◽  
Travis Solley ◽  
Sweet Ping Ng ◽  
...  

ABSTRACTPurposeTo describe the baseline and serial tumor microbiome in HPV-associated oropharynx cancer (OPC) over the course of radiotherapy (RT).MethodsPatients with newly diagnosed HPV-associated OPC treated with definitive radiotherapy +/- concurrent chemotherapy were enrolled in this prospective study. Using 16S rRNA gene sequencing, dynamic changes in tumor microbiome during RT were investigated. Surface tumor samples were obtained before RT and at week 1, 3 and 5 of RT. Radiological primary tumor response at mid-treatment was categorized as complete (CR) or partial (PR).ResultsTen patients were enrolled. Mean age was 63 years (range: 51-71). As per AJCC 8th Ed, 50%, 20% and 30% of patients had stage I, II and III, respectively. At 4-weeks, 7 patients had CR and 3 patients had PR; at follow-up imaging post treatment, all patients had CR. Baseline diversity of tumoral and buccal microbiomes was not statistically different. For the entire cohort, alpha diversity was significantly decreased over the course of treatment (p=0.02). There was a significant alteration in the bacterial community within the first week of radiation. Baseline tumor alpha diversity of patients with CR was significantly higher than those with PR (p=0.03). While patients with CR had significant reduction in diversity over the course of radiation (p=0.02), the diversity remained unchanged in patients with PR. Patients with history of smoking had significantly increased abundance of Granulicatella (p=0.04), and Kingella (0.05) and lower abundance of Alloprevotella (p=0.04) compared to never smokers.ConclusionsThe tumor microbiome of HPV-associated OPC exhibits reduced alpha diversity and altered taxa abundance over the course of radiotherapy. The baseline bacterial profiles of smokers vs. non-smokers were inherently different. Baseline tumor alpha diversity of patients with CR was higher than patients with PR, suggesting that the microbiome as a biomarker of radiation response deserves further investigation.


2020 ◽  
Author(s):  
Luisa W. Hugerth ◽  
Marcela Pereira ◽  
Yinghua Zha ◽  
Maike Seifert ◽  
Vilde Kaldhusdal ◽  
...  

AbstractThe vaginal microbiome has been connected to a wide range of health outcomes. This has led to a thriving research environment, but also to the use of conflicting methodologies to study its microbial composition. Here we systematically assess best practices for the sequencing-based characterization of the human vaginal microbiome. As far as 16S rRNA gene sequencing is concerned, the V1-V3 region has the best theoretical properties, but limitations of current sequencing technologies mean that the V3-V4 region performs equally well. Both of these approaches present very good agreement with qPCR quantification of key taxa, provided an appropriate bioinformatic pipeline is used. Shotgun metagenomic sequencing presents an interesting alternative to 16S amplification and sequencing, but it is not without its challenges. We have assessed different tools for the removal of host reads and the taxonomic annotation of metagenomic reads, including a new, easy-to-build and – use, reference database of vaginal taxa. This strategy performed as well as the best performing previously published strategies. Despite the many advantages of shotgun sequencing none of the shotgun approaches assessed here had as good agreement with the qPCR data as 16S rRNA gene sequencing.ImportanceThe vaginal microbiome has been connected to a wide range of health outcomes, from susceptibility to sexually transmitted infections to gynecological cancers and pregnancy outcomes. This has led to a thriving research environment, but also to conflicting available methodologies, including many studies that do not report their molecular biological and bioinformatic methods in sufficient detail for them to be considered reproducible. This can lead to conflicting messages and delay progress from descriptive to intervention studies. By systematically assessing best practices for the characterization of the human vaginal microbiome, this study will enable past studies to be assessed more critically and assist future studies in the selection of appropriate methods for their specific research questions.


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