scholarly journals Isolation and characterization of nitrogen-fixing bacteria from soil sample in Dhaka, Bangladesh

2021 ◽  
Vol 11 (1) ◽  
pp. 11-13
Author(s):  
Farzana Yasmin Shomi ◽  
Md Borhan Uddin ◽  
Tamanna Zerin
Keyword(s):  
Soil Sample ◽  
N2 Fixation ◽  
Bromothymol Blue ◽  
Garden Soil ◽  
Good Growth ◽  
Biochemical Tests ◽  
Isolation And Characterization ◽  
Test Culture ◽  
Yeast Extract Mannitol ◽  
Nessler Reagent

Biological nitrogen (N2) fixation is very essential for limiting the growth of plants and agricultural crops. The present study was conducted to potentially isolate N2-fixing bacteria from garden soil sample at Stamford University Bangladesh, Siddeswari, Dhaka. Here, we used culture-dependent method to perform this experiment. Firstly, we collected garden soil sample, diluted and inoculated in N2-free Jensen’s media by maintaining the aseptic procedure. We obtained 5 different colonies from soil samples. We cultured the isolates in N2-free Jensen’s media containing bromothymol blue (BMB) and also, in Yeast Extract Mannitol Agar (YEMA) media containing congo red to confirm nitrogen fixation capacity. We collected the colony characteristics of all the isolates. Only 1A isolate showed good growth after 24 h of incubation among all the isolates. We performed ammonification test with Nessler reagent to confirm N2-fixing ability for our selected isolates. The 1A isolate was positive in ammonification test. Culture, microscopy and biochemical tests were performed to identify isolate 1A. This isolate was presumptively identified as Azotobacter sp. In the present study, Azotobacter sp. that was isolated from the soil sample was found to be a potential N2-fixing bacterium. Isolate 1A can be used for N2-fixation to boost production of crops. Stamford Journal of Microbiology, Vol.11 (1) 2021: 11-13

scholarly journals Morphological and Biochemical Characterization of Soybean Nodulating Rhizobia Indigenous to Zambia

2016 ◽  
Vol 5 (3) ◽  
pp. 84
Author(s):  
Rachael Kapembwa ◽  
Alice M. Mweetwa ◽  
Munsanda Ngulube ◽  
Jones Yengwe ◽  
Jones Yengwe
Keyword(s):  
Biochemical Characterization ◽  
Bromothymol Blue ◽  
Rhizobium Tropici ◽  
Fast Growing ◽  
Isolation And Characterization ◽  
Alkaline Reaction ◽  
Region I ◽  
Yeast Extract Mannitol ◽  
Cultivated Soils

<p>Soybean [<em>Glycine max</em> (L.) Merrill] is known for nitrogen fixation by rhizobia present in the soil with which it establishes an efficient symbiosis. In Zambia, current rhizobial inoculants used in soybeans production are based on non-indigenous strains; this creates a need to isolate local strains that can be used for the development of local inoculants for soybeans in Zambian soils. This paper reports the isolation and characterization of rhizobial isolates from virgin and cultivated soils of the three agro-ecological regions of Zambia. Rhizobia were isolated using the Trap Method and characterized using selected morphological and biochemical markers. A total of 61 isolates were isolated on Yeast Extract Mannitol (YEM) agar medium. Isolates varied in colony form, color, margin and texture. From the 61 isolates from the three regions, 87 % were circular, 8 % irregular and 5 % punctuate in form with 100 % convex elevation. The isolates had 88% entire, 10% undulate and 2 % lobate colony margins with different colors – 56 % cream, 24 % white, 11 % yellow, 5 % transparent and 3 % pink. Transparent colonies were peculiar to Region I and III while pink colonies were peculiar to Region III. All isolates produced mucous, were gram negative and rod shaped, a characteristic of rhizobial cells. None of the isolates could tolerate extremes of pH (4 and 9) in growth medium but grew well at pH 6.8. All isolates utilized glucose as a source of carbon. Based on the Bromothymol Blue (BTB) assay, 59 isolates were fast growing while two isolates from cultivated soils of region II were slow growing. The fast growing 59 isolates showed an acidic reaction changing the medium from green to yellow, while the others showed an alkaline reaction. Based on the results, the 59 fast-growers could be <em>Ensifer fredii </em>or/and<em> Rhizobium tropici </em>rather than <em>Bradyrhizobium</em>. However, further tests to confirm these findings using ketolactose, genetic characterization and inclusion of reference strains, are still needed and are being recommended here.</p>

scholarly journals Isolation and Characterization of a Bacterial Strain Enterobacter cloacae (Accession No. KX438060.1) Capable of Degrading DDTs Under Aerobic Conditions and Its Use in Bioremediation of Contaminated Soil

2021 ◽  
Vol 14 ◽  
pp. 117863612110242
Author(s):  
Sonal Suman ◽  
Tanuja
Keyword(s):  
Contaminated Soil ◽  
Growth Parameters ◽  
Chemical Properties ◽  
Enterobacter Cloacae ◽  
Maximum Growth ◽  
Bacterial Degradation ◽  
Biochemical Tests ◽  
Isolation And Characterization ◽  
16S Rna ◽  
Degrading Bacteria

DDT is one of the most persistent pesticides among all the different types of organo-chlorine pesticides used. Among all the degradation methods, bacterial degradation of DDT is most effective. The present study was conducted to isolate different bacteria present in waste samples which have the ability to degrade DDT present in the soil in the minimum possible period of time and to observe the effect of different physical and chemical properties of the soil samples. Many pesticide degrading bacteria were isolated and identified through cultural, biochemical tests and further identified by 16S RNA sequencing method. The most potent strain DDT 1 growth in mineral salt medium supplemented with DDT as the only source of carbon (5-100 PPM) and was monitored at an optical density of 600 nm. The growth parameters at different physio-chemical conditions were further optimized. The result showed that Enterobacter cloacae had maximum growth in 15 days. FTIR analysis of the residual DDT after 15 days incubation showed that Enterobacter cloacae was able to degrade pesticide into its further metabolites of DDD, DDE, DDNU and other components can be used for biodegradation of DDT present in contaminated soil and water ecosystems.

scholarly journals Isolation and characterization of Pseudomonas syringae isolates affecting stone fruits and almond in Montenegro

2021 ◽  
Author(s):  
Tamara Popović ◽  
Jelena Menković ◽  
Anđelka Prokić ◽  
Nevena Zlatković ◽  
Aleksa Obradović
Keyword(s):  
Pseudomonas Syringae ◽  
Housekeeping Genes ◽  
Molecular Characteristics ◽  
Biochemical Tests ◽  
High Genetic Diversity ◽  
Leaf Petiole ◽  
Molecular Features ◽  
Isolation And Characterization ◽  
Genomic Species

AbstractIn Montenegro, stone fruit species are grown on intensive and semi-intensive commercial plantations. However, almond production is mainly organized on family gardens and for household consumption. During two seasons (2017–2018), we surveyed apricot, peach, nectarine, sweet cherry, Japanese plum, and almond orchards for the presence of bacterial diseases at different geographical locations in Montenegro. From leaf, petiole and fruit lesions, branch or twig cankers, and necrotizing buds, a total of 29 isolates were obtained and subjected to identification based on their morphological, pathogenic, biochemical, and molecular characteristics. Pathogenicity of the isolates was confirmed by reproducing the symptoms on leaves, fruits, and twigs of the corresponding host plants. The biochemical tests indicated that the isolates belong to Pseudomonas syringae. However, isolates’ characterization showed variation in their phenotypic and molecular features. The presence of the syrB gene and ice nucleation activity grouped most of the isolates within pathovar syringae. The results of rep-PCR using the BOX primer revealed high genetic diversity of isolates. Multilocus sequence analysis (MLSA), using four housekeeping genes, showed that 27 isolates belong to the genomic species 1, P. syringae sensu stricto, corresponding to P. syringae phylogroup 2. However, isolates from the same phylogroup 2 did not form a monophyletic group. One strain isolated from apricot was most distinct and similar to members of genomic species 2, phylogroup 3. All tested isolates showed significant levels of resistance to copper sulfate and high level of sensitivity to streptomycin sulfate in vitro.

scholarly journals Prevalence of Vibrio alginolyticus in Sediment Samples of River and Coastal Areas of Bangladesh

2016 ◽  
Vol 29 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R Siddiqui ◽  
MM Alam ◽  
MN Naser ◽  
Y Otomo ◽  
M Yasmin ◽  
...  
Keyword(s):  
Fish Population ◽  
Vibrio Alginolyticus ◽  
Live Cells ◽  
Economic Damage ◽  
Biochemical Tests ◽  
Marine Animals ◽  
Isolation And Characterization ◽  
Vibrio Pathogens ◽  
Positive Results

Vibrio alginolyticus has been thought to be a halophilic marine bacterium that causes diarrhea, otitis media and wound infection through the consumption of raw or inappropriately cooked sea food. It is one of the main Vibrio pathogens affecting marine animals, such as marine fish, shrimp and shellfish which lead to large economic damage. Although there are reports on the presence of this organism in the coastal area of other countries, not so much work has been done on the isolation and characterization of this species in Bangladesh. The present study was, therefore, undertaken to isolate and characterize V. alginolyticus organisms isolated from the rivers (fresh water) and estuaries (brackish water) of Bangladesh. A total of 9 isolates of Vibrio species were obtained from different water bodies (three from Meghna river, two from Shangu river and four from estuary) and provisionally identified as Vibrio alginolyticus following standard biochemical tests. All these 9 strains showed same pattern of antibiotic resistance to ampicillin, streotomycin, penicillin, but sensitive to nalidixic acid. In the virulence properties test, two isolates showed positive results for toxR gene and none of the isolates showed positive results for tdh gene. Challenge experiments in Singhi fish (Heteropneustes fossi) with the live cells and the culture filtrate prepared from the V. alginolyticus showed high mortality of the fish population. All these studies suggest the presence of pathogenic V. alginolyticus strains in the river water and estuarine bodies of Bangladesh and the extracellular toxin(s) of the V. alginolyticus might be one of the causes for fish mortality.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 1-6

scholarly journals Isolation and Characterization of Wilt-Causing Pathogens of Local Growing Pepper (Capsicum annuum L.) in Gurage Zone, Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Temesgen Oljira ◽  
Sefawdin Berta
Keyword(s):  
Fusarium Oxysporum ◽  
Capsicum Annuum ◽  
Ralstonia Solanacearum ◽  
Disease Assessment ◽  
Management Approach ◽  
Pathogenicity Test ◽  
Biochemical Tests ◽  
Capsicum Annuum L ◽  
Local Cultivar ◽  
Isolation And Characterization

The yield of pepper (Capsicum annuum L.) is extremely threatened by different diseases in Ethiopia. The objective of the study was isolation of wilt-causing pathogens and susceptibility test of local growing pepper. Eighteen pepper farming fields were selected for disease assessment study. The samples of Mareko Fana, Dubi, and Mitmita local cultivar pepper’s pods, seeds, leaves, stems, and roots were collected, surface sterilized, and cultured on potato dextrose agar (PDA). Selective peptone pentachloronitrobenzene (PCNB) agar medium was used for fungus. Similarly, for bacteria isolation, nutrient agar (NA) was used. Morphological and biochemical tests revealed eleven fungal isolates of Fusarium oxysporum f. sp. that were isolated. The pathogenicity test confirmed nine of them were virulent to Mareko Fana, Dubi, and Mitmita local pepper. It is confirmed that Fusarium oxysporum f. sp. is the pathogen Fusarium oxysporum f. sp. capsici. Besides, Ralstonia solanacearum was identified as a bacterium pathogen causing complex pepper wilt disease. The highest mean PDI was registered in Remuga Keble (93.0%) and the lowest in Buyi Keble (58.3%). Similarly, the highest mean PSI was recorded in Buyi Keble (87.0%) and the lowest PSI (54.5%) was registered in Tawlla Keble. Among 60 seeds, Mareko local pepper inoculated by F. oxysporum f. sp. and R. solanacearum shows the highest susceptibility of 55 (91.0%) and 30 (50.0%), respectively. However, Mitmita local pepper was registered as the lowest susceptibility to both F. oxysporum f. sp. and R. solanacearum of 28.3% and 30.0%, respectively. Based on the finding, it can be concluded that pepper wilt was caused by a complex of fungus Fusarium oxysporum f. sp. capsici and bacteria Ralstonia solanacearum sp. in the study area. So, it is recommended that an integrated disease management approach should be implemented to manage the complex diseases of the site.

Isolation and Characterization of a Novel Bacillus subtilis WD23 Exhibiting Laccase Activity from Forest Soil

2010 ◽  
Vol 113-116 ◽  
pp. 725-729 ◽  
Author(s):  
Chun Lei Wang ◽  
Min Zhao ◽  
De Bin Li ◽  
Dai Zong Cui ◽  
Hong Yi Yang ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Forest Soil ◽  
Half Life ◽  
Laccase Activity ◽  
Methyl Violet ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
Alizarin Red ◽  
Optimum Growth Temperature ◽  
Isolation And Characterization

The strain Bacillus sp. WD23 exhibiting laccase activity was screened from forest soil. The M9 medium containing Cu2+ was used for enriching and isolating bacterial strains capable of oxidizing syringaldazine (SGZ). One isolated strain was identified as Bacillus subtilis WD23 based on the results of physiological and biochemical tests and 16S rDNA sequence analysis. The strain WD23 could grow at temperatures ranging from 20 to 55°C and showed optimum growth temperature and pH at 25°C and 7.0, respectively. The sporulation rate of the strain clearly correlated well with the laccase activity. The temperature half-life of the spore laccase was 2.5 h at 80°C and the pH half-life was 15 d at pH 9.0. Its spore laccase could decolorized 50~90% of Remazol brilliant blue R (RBBR), alizarin red, congo red, methyl orange and methyl violet, which suggests the potential application of spore laccase in dyestuff treatment.

scholarly journals In Vitro Characterization of Indigenous Probiotic Strains Isolated from Colombian Creole Pigs

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1204 ◽  
Author(s):  
César Betancur ◽  
Yordan Martínez ◽  
Guillermo Tellez-Isaias ◽  
Mavir Carolina Avellaneda ◽  
Borja Velázquez-Martí
Keyword(s):  
Lactobacillus Plantarum ◽  
Lactobacillus Brevis ◽  
Coli Strain ◽  
Good Growth ◽  
Biochemical Tests ◽  
Enteropathogenic Bacteria ◽  
In Vitro Characterization ◽  
Serovar Typhimurium ◽  
Probiotic Strains

Three lactic acid strains were isolated from feces of the native Zungo Pelado breed of pigs (n = 5) and presumably identified as belonging to the Lactobacillaceae family by morphological techniques showing that they were Gram-positive/rod-shaped and catalase- and oxidase-negative. They were then identified by biochemical tests using API 50CHL as Lactobacillus plantarum (CAM6), Lactobacillus brevis (CAM7), and Lactobacillus acidophilus (CL4). However, 16S rRNA identification showed that all three strains were Lactobacillus plantarum. Additionally, all three isolates were able to grow in pH 3 and 4. Interestingly, the growth of the CAM7 strain decreased at pH 5.6 compared to that of the CAM6 strain (p < 0.05), and the growth of the CL4 strain was reduced at pH 7(p < 0.05). All three candidates showed good growth on bile salts (≥0.15%), and CAM6 and CAM7 showed better tolerance at higher concentrations (0.30%). Similarly, all strains tolerated sodium chloride (NaCl) concentrations from 2 to 10%. These strains also grew well at all temperatures tested (30, 37, and 42 °C). The CAM6 strain showed in vitro antibacterial activity against selected enteropathogenic bacteria (Escherichia coli strain NBRC 102203 and Salmonella enterica serovar Typhimurium 4.5.12) and commensal bacteria (Klebsiella pneumoniae ATCC BAA-1705D-5 and Pseudomonas aeruginosa ATCC 15442) and resistance to all antibiotics except amoxicillin. Further studies to evaluate the effects of these probiotic candidate strains in commercial pigs are currently underway.

scholarly journals Isolation and Characterization of a Novel Bacterium from the Marine Environment for Trichloroacetic Acid Bioremediation

2020 ◽  
Vol 10 (13) ◽  
pp. 4593 ◽  
Author(s):  
Mahshid Heidarrezaei ◽  
Hoofar Shokravi ◽  
Fahrul Huyop ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů
Keyword(s):  
16S Rrna ◽  
Trichloroacetic Acid ◽  
Specific Activity ◽  
Morphological Observation ◽  
Rrna Gene ◽  
Industrial Chemicals ◽  
Halogenated Compounds ◽  
Biochemical Tests ◽  
Isolation And Characterization ◽  
Halogenated Compound

Halogenated compounds are an important class of environmental pollutants that are widely used in industrial chemicals such as solvents, herbicides, and pesticides. Many studies have been carried out to explore the biodegradation of these chemicals. Trichloroacetic acid (TCA) is one of the main halogenated compounds that are carcinogenic to humans and animals. The bacterium was isolated from the northern coastline of Johor Strait. In this study, the ability of strain MH2 to biodegrade TCA was evaluated by a growth experiment and dehalogenase enzyme assay. The growth profile of the isolated strain was examined. The doubling time for L. boronitolerans MH2 was found to be 32 h. The release of chloride ion in the degradation process was measured at 0.33 × 10−3 ± 0.03 mol∙L−1 after 96 h when the growth curve had reached its maximum within the late bacterial exponential phase. The results showed that the strain had a promising ability to degrade TCA by producing dehalogenase enzyme when cell-free extracts were prepared from growth on TCA as the sole carbon source with enzyme-specific activity, 1.1 ± 0.05 µmolCl−min−1∙mg−1 protein. Furthermore, the morphological, and biochemical aspects of the isolated bacterium were studied to identify and characterize the strain. The morphological observation of the isolated bacterium was seen to be a rod-shaped, Gram-positive, motile, heterotrophic, and spore-forming bacterium. The amplification of the 16S rRNA and gene analysis results indicated that the isolated bacterium had 98% similarity to Lysinibacillus boronitolerans. The morphological and biochemical tests supported the 16S rRNA gene amplification. To the best of the authors’ knowledge, this is the first reported case of this genus of bacteria to degrade this type of halogenated compound.

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