scholarly journals Characterization and phylogenetic analysis of alkaline α-amylase producing Brevibacillus laterosporus from mountain climatic zone of India

2019 ◽  
Vol 9 (3) ◽  
pp. 125-129
Author(s):  
Girish R Nair ◽  
Suresh S.S. Raja

α-amylases (EC3.2.1.1) are glycoside hydrolases that breakdown complex starch and maltodextrins into glucose and maltose by acting upon 1,4-glycosidiclinkages. Several amylases have been isolated and purified from members of Bacillus community, which find extensive application in starch processing, textile and pharmaceutical industry. Keeping this in mind we isolated α-amylase producing gram positive bacterium from soils collected from mountain climatic zone of India and identified it as Brevibacillus laterosporus. We further studied the effect of temperature and pH on the amylase activity of this strain and found a very stable activity at alkaline pH of 10 and temperature of 45 ºC. To our knowledge this a first report on characterization and evolutionary analysis of alkaline α-amylase producing Brevibacillus laterosporus isolated from unexplored sites of mountain climatic zone of India. Keywords: Climatic zone, Brevibacillus, Amylase, 16S rRNA gene sequencing, Phylogenetic analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Camille Grandclément ◽  
Anne Piram ◽  
Marie-Eléonore Petit ◽  
Isabelle Seyssiecq ◽  
Isabelle Laffont-Schwob ◽  
...  

Since bacterial consortia involved in conventional wastewater treatment processes are not efficient in removing diclofenac (DCF), an emerging pollutant frequently detected in water bodies, the identification of microorganisms able to metabolise this pharmaceutical compound is relevant. Thus, DCF removal was investigated using bacteria isolated from aqueous stock solutions of this micropollutant and identified as Bacillus and Brevibacillus species using 16S rRNA gene sequencing. A 100% DCF removal was achieved after 17 hours of experiment at 20°C in a nutrient medium; the biodegradation kinetic followed a pseudo-first order (kbiol = 11 L·gSS−1·d−1). Quantitative assessment of DCF removal showed that its main route was biotic degradation. The main degradation product of DCF, 4′-hydroxy-diclofenac (4′-OH-DCF), was identified using liquid chromatography-electrospray ionisation high-resolution mass spectrometry. Since the ecotoxicological impact of 4′-hydroxy-diclofenac was not reported in the literature, the ecotoxicity of DCF and its metabolite were tentatively evaluated using Vibrio fischeri bioassays. Results from these tests showed that this metabolite is not more toxic than its parent compound and may hopefully be an intermediate product in the DCF transformation. Indeed, no significant difference in ecotoxicity was observed after 30 min between DCF (50 should be writtten in subscript all along the manuscript in EC50 = 23 ± 4 mg·L−1) and 4′-hydroxy-diclofenac (EC50 = 19 ± 2 mg·L−1). Besides, the study highlighted a limit of the Microtox® bioassay, which is largely used to assess ecotoxicity. The bioluminescence of Vibrio fischeri was impacted due to the production of microbial activity and the occurrence of some carbon source in the studied medium.


2007 ◽  
Vol 57 (7) ◽  
pp. 1673-1674 ◽  
Author(s):  
Masami Morotomi ◽  
Fumiko Nagai ◽  
Hiroshi Sakon

Megamonas hypermegale is the sole species of the genus Megamonas included in the List of Prokaryotic Names with Standing in Nomenclature and in the databases of DDBJ, EBI/EMBL and NCBI/GenBank it is placed in the lineage of Bacteroidetes; Bacteroidetes (class); ‘Bacteroidales’; Bacteroidaceae; Megamonas. Phylogenetic analysis based on comparative 16S rRNA gene sequencing showed that this species clustered with species of the family ‘Acidaminococcaceae’ but not with those of the Bacteroidaceae. The genus Megamonas should be placed in the lineage of Firmicutes; Clostridia; Clostridiales; ‘Acidaminococcaceae’; Megamonas.


2019 ◽  
Vol 42 (2) ◽  
pp. 181-188
Author(s):  
Hayder N. Ayyez ◽  
Yahia I. Khudhair ◽  
Qassim Haleem Kshash

AbstractAnaplasma spp. are widely spread rickettsial bacteria transmitted by ticks and placing high impacts on veterinary and public health. A limited number of studies have been carried out on Anaplasmosis in the central part of Iraq. This study was conducted to determine the presence of Anaplasma spp. in cattle in Al-Qadisiyah province, Iraq. A total of 400 blood specimens were collected from cattle suffering from heavy tick infestation. Cattle were blood-sampled from four hyper-endemic areas with ticks. Blood samples were screened using microscopic and polymerase chain reaction (PCR) methods. Diff-quick stained blood smears revealed Anaplasma-like inclusion bodies in 254 (63.5%) samples. According to the 16S rRNA-gene-based PCR analysis, Anaplasma spp. was detected in 124 of the 400 (31%) samples, divided as 96/254 (37.8%) among the microscopical positive samples and 28/146 (19.17%) among the microscopical negative samples. Phylogenetic analysis based on the partial 16S rRNA gene sequencing of ten-PCR positive samples were 99–97% identical to sequences deposited in the GenBank, revealing presence of A. phagocytophilum, A. marginale and unnamed Anaplasma spp. in 40%, 20%, and 40% samples, respectively. Relationships among Anaplasma spp. infections and cattle breed, age, and sex were analyzed. Calves less than one year old showed significantly higher rates (p<0.005) than those from other age groups, whereas sex and breed demonstrated no significant differences (p˃0.001). This study shows that a variety of Anaplasma spp., were endemic in central part of Iraq and is still a hidden problem in cattle in the hyperendemic areas of tick, which requires serious control strategies.


2010 ◽  
Vol 60 (2) ◽  
pp. 444-450 ◽  
Author(s):  
Dimitry Yu. Sorokin ◽  
Olga L. Kovaleva ◽  
Tatjana P. Tourova ◽  
Gerard Muyzer

A moderately halophilic, obligately chemolithoautotrophic, sulfur-oxidizing bacterium, designated strain HRh1T, was obtained from mixed sediment samples from hypersaline chloride–sulfate lakes in the Kulunda Steppe, in south-western Siberia (Russia), using aerobic enrichment culture at 1 M NaCl with thiocyanate as substrate. Cells of the isolate were short, non-motile rods with a Gram-negative type of cell wall. The bacterium was an obligate aerobe capable of chemolithoautotrophic growth with thiocyanate and thiosulfate. With thiosulfate, it grew at NaCl concentrations of 0.2–3.0 M (optimum 0.5 M) and at pH 6.3–8.0 (optimum pH 7.3–7.5). During growth on thiocyanate, cyanate was identified as an intermediate. The dominant cellular fatty acids were C16 : 0 and C18 : 1 ω7. Phylogenetic analysis based on 16S rRNA gene sequencing placed the isolate in the class Gammaproteobacteria as an independent lineage, with an unclassified marine sulfur-oxidizing bacterium as the closest culturable relative (93 % sequence similarity). A single cbbL gene (coding for the key enzyme of the Calvin–Benson cycle of autotrophic CO2 assimilation) with relatively low similarity to any homologous genes found in chemolithoautotrophs was detected in strain HRh1T. On the basis of our phenotypic and phylogenetic analysis, the halophilic isolate is proposed to represent a new genus and novel species, Thiohalobacter thiocyanaticus gen. nov., sp. nov. The type strain of Thiohalobacter thiocyanaticus is HRh1T (=DSM 21152T =UNIQEM U249T).


2019 ◽  
Vol 31 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Kelsey E. Lawrence ◽  
Khiem C. Lam ◽  
Andrey Morgun ◽  
Natalia Shulzhenko ◽  
Christiane V. Löhr

Knowledge of changes in the composition of microbial communities (microbiota) in tissues after death, over time, is critical to correctly interpret results of microbiologic testing from postmortem examinations. Limited information is available about postmortem changes of the microbiota and the associated microbial genes (microbiome) of internal organs in any species. We examined the effect of time and ambient temperature on the postmortem microbiome (thanatomicrobiome) of tissues typically sampled for microbiologic testing during autopsies. Twenty rabbits were euthanized and their bodies stored at 4°C or 20°C for 6 or 48 h. Ileum, cecum, kidney, and lung tissue were sampled. Bacterial DNA abundance was determined by RT-qPCR. Microbiome diversity was determined by 16S rRNA gene sequencing. By relative abundance of the microbiome composition, intestinal tissues were clearly separated from lungs and kidneys, which were similar to each other, over all times and temperatures. Only cecal thanatomicrobiomes had consistently high concentrations and consistent composition in all conditions. In lungs and kidneys, but not intestine, proteobacteria were highly abundant at specific times and temperatures. Thanatomicrobiome variation was not explained by minor subclinical lesions identified upon microscopic examination of tissues. Bacterial communities typically found in the intestine were not identified at extra-intestinal sites in the first 48 h at 4°C and only in small amounts at 20°C. However, changes in tissue-specific microbiomes during the postmortem interval should be considered when interpreting results of microbiologic testing.


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