scholarly journals Characterization of Biosurfactant From Pseudomonas Stutzeri SJ3 for Remediation of Crude Oil-Contaminated Soil

Author(s):  
Sekar Harikrishnan ◽  
Singaram Jayalakshmi ◽  
Mohamad S. Alsalhi ◽  
Alager Kartick ◽  
Sandhanasamy Devanesan ◽  
...  

Abstract In the present work, production of biosurfactant was studied from the bacterial strains isolated from the soil samples collected from oil contaminated sites in Karaikal ONGC, Puducherry, India. Six morphologically different hydrocarbonoclastic bacterial strains (SJ1-SJ6) isolated on oil agar plates were further screened for biosurfactant production. Based on the screening methods results of 26 mm oil displacement zone, positive results of drop collapse test, 68.14% emulsification index (E24) and 79.2% of bacterial adherence percentage, the isolate SJ3 was selected as the most potent strain and it was identified as P. stutzeri using standard biochemical and 16S rRNA gene sequencing-based methods. Optimization of the P. stutzeri strain showed 36 h incubation, 150 rpm agitation, pH 7.5, 37oC, 1% salinity, 2% glucose as carbon source and 1% yeast extract as nitrogen source were the ideal conditions for growth and the biosurfactant production was found to be growth dependent. The crude biosurfactant showed broad range of antibacterial activity against the bacterial pathogens tested. The P. stutzeri isolated from oil spill site showed biosurfactant with antibacterial activities.

2019 ◽  
Vol 20 (9) ◽  
Author(s):  
Meezan Ardhanu Asagabaldan ◽  
Gilles Bedoux ◽  
Nathalie Bourgougnon ◽  
Rhesi Kristiana ◽  
Diah Ayuningrum ◽  
...  

Abstract. Asagabaldan MA, Bedoux G, Bourgougnon N, Kristiana R, Ayuningrum D, Sabdono A, Trianto A, Radjasa OK. 2019. Bacterial isolates from bryozoan Pleurocodonellina sp.: Diversity and antimicrobial potential against pathogenic bacteria. Biodiversitas 20: 2528-2535.  There is an urgent need to discover new compounds with antibacterial activity, which can be developed into lead structures for the treatment of human disease caused by multidrug-resistant (MDR) bacteria. In this study, we focussed on bryozoan-associated bacteria to screen them toward antibacterial activities, since the microbiome of these organisms can still be regarded as under-investigated. Most of the few publications about bryozoan-associated bacteria focused on taxonomy and the potential as producers of antibacterial natural products were neglected. Four specimens of bryozoan Pleurocodonellina sp. were collected from Teluk Awur, Jepara in Java Sea, Indonesia. Therefrom, 56 bacterial strains were isolated, and 17 displayed antibacterial activities against MDR bacteria Pseudomonas aruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Enterobacter cloacae, and methicillin-resistant Staphylococcus aureus (MRSA). Taxonomic identification of the bacteria by 16S rRNA gene sequencing revealed them belonging to the genera Virgibacillus, Pseudoalteromonas, Halomonas, and Bacillus. Most interestingly, the genus Virgibacillus was dominantly obtained from the Pleurocodonellina sp. specimens, i.e., 12 active isolates. Nevertheless, the best activities against MDR bacteria (both Gram-positive and Gram-negative) were contributed to isolates showing >99% identity to Pseudoalteromonas. The results further suggest adding the genus Virgibacillus as bacteria associated with bryozoan, since to the best of our knowledge there were no reports of this genus isolated from bryozoan.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1344
Author(s):  
Naima Lemjiber ◽  
Khalid Naamani ◽  
Annabelle Merieau ◽  
Abdelhi Dihazi ◽  
Nawal Zhar ◽  
...  

Bacterial burn is one of the major diseases affecting pear trees worldwide, with serious impacts on producers and economy. In Morocco, several pear trees (Pyrus communis) have shown leaf burns since 2015. To characterize the causal agent of this disease, we isolated fourteen bacterial strains from different parts of symptomatic pear trees (leaves, shoots, fruits and flowers) that were tested in planta for their pathogenicity on Louise bonne and Williams cultivars. The results showed necrotic lesions with a significant severity range from 47.63 to 57.77% on leaves of the Louise bonne cultivar inoculated with isolate B10, while the other bacterial isolates did not induce any disease symptom. 16S rRNA gene sequencing did not allow robust taxonomic discrimination of the incriminated isolate. Thus, we conducted whole-genome sequencing (WGS) and phylogenetic analyzes based on gyrA, gyrB and cdaA gene sequences, indicating that this isolate belongs to the Bacillus altitudinis species. This taxonomic classification was further confirmed by the Average Nucleotide Identity (ANI) and the in silico DNA-DNA hybridization (isDDH) analyzes compared to sixty-five Bacillus spp. type strains. The genome was mined for genes encoding carbohydrate-active enzymes (CAZymes) known to play a role in the vegetal tissue degradation. 177 candidates with functions that may support the in planta phytopathogenicity results were identified. To the best of our knowledge, this is the first data reporting B. altitudinis as agent of leaf burn in P. communis in Morocco. Our dataset will improve our knowledge on spread and pathogenicity of B. altitudinis genotypes that appears as emergent phytopathogenic agent, unveiling virulence factors and their genomic location (i.e., within genomic islands or the accessory genome) to induce trees disease.


Fine Focus ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. 171-186
Author(s):  
Olivia J. Rickman ◽  
M. Auður Sigurbjörnsdóttir ◽  
Oddur Vilhemsson

Nine xylanolytic bacterial strains were isolated from fen and heath soils in northern Iceland. They were found by 16S rRNA gene sequencing to belong to the genera Paenibacillus, Bacillus, Pseudomonas, and Stenotrophomonas. Using a simple, plate-based semiquantitative assay with azo-crosslinked xylan as the substrate, it was determined that although isolated from cold environments, most of the strains displayed greater xylanolytic activity under mesophilic conditions, with only the paenibacilli displaying markedly cold-active xylanolytic activity. Indeed, for one isolate, Paenibacillus castaneae OV2122, xylanolytic activity was only detected at 15°C and below under the conditions tested. Of the nine strains, Paenibacillus amylolyticus OV2121 displayed the greatest activity at 5°C. Glycohydrolase family-specific PCR indicated that the paenibacilli produced multiple xylanases of families 10 and 11, whereas a family 8 xylanase was detected in Pseudomonas kilonensis AL1515, and a family 11 xylanase in Stenotrophomonas rhizophila AL1610.


2010 ◽  
Vol 56 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Iftikhar Ahmed ◽  
Toru Fujiwara

Boron (B) is toxic to living cells at levels above a certain threshold. We isolated several B-tolerant bacterial strains from soil samples and studied them for possible mechanisms of B tolerance. 16S rRNA gene sequencing and comparative phylogenetic analysis demonstrated that the isolates belong to the following 6 genera: Arthrobacter , Rhodococcus , Lysinibacillus , Algoriphagus , Gracilibacillus , and Bacillus . These isolates exhibited B-tolerance levels of 80, 100, 150, 300, 450, and 450 mmol/L, respectively, whilst maintaining a significantly lower intracellular B concentration than in the medium. Statistical analysis showed a negative correlation between the protoplasmic B concentration and the degree of tolerance to a high external B concentration. The kinetic assays suggest that the high B efflux and (or) exclusion are the tolerance mechanisms against a high external B concentration in the isolated bacteria.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Nada K. Alharbi ◽  
Albandary Nasser Alsaloom

The objectives of this study were the selection of lactic acid bacteria (LAB) isolated from raw milk and studying their technological properties and antibacterial activities against bacteria as the cause of cattle mastitis. Biochemical and molecular identification using 16S–23S rRNA gene spacer analysis and 16S rRNA gene sequencing highlighted the presence of three species: Lactiplantibacillus plantarum, Lactococcus lactis, and Levilactobacillus brevis. The enzymatic characterization followed by the determination of technofunctional properties showed that LAB strains did not exhibit any hemolytic effect and were able to produce protease and lipase enzymes. Isolates showed very high antagonistic activity against Gram-positive and Gram-negative bacteria by producing H2O2, bacteriocin(s), and organic acid(s). APIZYM micromethod demonstrated that all selected strains are capable of producing valine arylamidase, cystine arylamidase, N-acetyl-β-glucosaminidase, and ᾳ-mannosidase. The antibiotic susceptibility assay showed that all selected strains were sensible to the majority of tested antibiotics. Based on these results, it can be concluded that the technological properties of the selected LAB allow considering their industrial use in order to formulate bioactive functional foods or drug(s).


2021 ◽  
Vol 8 ◽  
Author(s):  
Elin Oscarsson ◽  
Åsa Håkansson ◽  
Carin Andrén Aronsson ◽  
Göran Molin ◽  
Daniel Agardh

Disturbances of the gut microbiota may influence the development of various autoimmune diseases. This study investigated the effects of supplementations with the probiotic bacteria, Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus paracasei 8700:2, on the microbial community in children with celiac disease autoimmunity (CDA). The study included 78 genetically predisposed children for celiac disease with elevated levels of tissue transglutaminase autoantibodies (tTGA) signaling for ongoing CDA. Among those children, 38 received a placebo and 40 received the probiotic supplement daily for 6 months. Fecal and plasma samples were collected at baseline and after 3 and 6 months, respectively. The bacterial community was investigated with 16S rRNA gene sequencing and terminal restriction fragment length polymorphism (T-RFLP), and tTGA levels were measured in radiobinding assays. In children that received probiotic supplementation, the relative abundance of Lactobacillaceae increased over time, while it remained unchanged in the placebo group. There was no overall correlation between tTGA levels and bacterial genus except for a positive correlation between Dialister and IgG-tTG in the probiotic group. The abundance of specific bacterial amplicon sequence variant (ASV:s) changed during the study in both groups, indicating that specific bacterial strains might be affected by probiotic supplementation.


2019 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
Anshul Sharma ◽  
Jasmine Kaur ◽  
Sulhee Lee ◽  
Young-Seo Park

The present work aimed at tracking intentionally inoculated lactic acid bacteria (LAB) strains in yogurt and probiotic powder. Leuconostoc (Leu.) mesenteroides (11251), Lactobacillus (L.) brevis (B151), and Lactobacillus plantarum (LB41K) strains were tracked in yogurt, and L. plantarum (LB41P) was tracked in a commercial probiotic powder. The yogurt was intentionally inoculated with the selected bacterial strains. Two types of yogurt with known and unknown bacterial pools were utilized. The standard 16S rRNA gene sequencing was used to evaluate the initial screening. The molecular typing tools, random amplified polymorphic DNA (RAPD), repetitive element palindromic PCR (rep-PCR), and comparative gene sequence analysis of selected housekeeping loci were used to track the inoculated dubious strains. Out of 30 random selections for each inoculation, the developed method identified seven (11251), nine (B151), and five (LB41K) colonies in the yogurt. The validation was performed by identifying 7 colonies (LB41P) out of 30 in the probiotic powder. The DNA banding profiles and the gene sequence alignments led to the identification of the correct inoculated strains. Overall, the study summarizes the use of molecular tools to identify the deliberately inoculated LAB strains. In conclusion, the proposed polyphasic approach effectively tracked the intentionally inoculated strains: Leu. mesenteroides, L. brevis, and L. plantarum (LB41K) in yogurt and L. plantarum (LB41P) in probiotic powder. The study demonstrates how to track industrially relevant misused LAB strains in marketable food products.


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 92-102
Author(s):  
Rafeya Sohail ◽  
Nazia Jamil ◽  
Iftikhar Ali ◽  
Sajida Munir

AbstractOil reservoirs contain large amounts of hydrocarbon rich produced water, trapped in underground channels. Focus of this study was isolation of PHA producers from produced water concomitant with optimization of production using animal fat and glycerol as carbon source. Bacterial strains were identified as Bacillus subtilis (PWA), Pseudomonas aeruginosa (PWC), Bacillus tequilensis (PWF), and Bacillus safensis (PWG) based on 16S rRNA gene sequencing. Similar amounts of PHA were obtained using animal fat and glycerol in comparison to glucose. After 24 h, high PHA production on glycerol and animal fat was shown by strain PWC (5.2 g/ L, 6.9 g/ L) and strain PWF (12.4 g/ L, 14.2 g/ L) among all test strains. FTIR analysis of PHA showed 3-hydroxybutyrate units. The capability to produce PHA in the strains was corroborated by PhaC synthase gene sequencing. Focus of future studies can be the use of lipids and glycerol on industrial scale.


2020 ◽  
Vol 36 (3) ◽  
pp. 57-62
Author(s):  
Minh Vo Van ◽  
Tuan Vo Chau ◽  
My Pham Тhi ◽  
Ha Do Thu ◽  
Trang Le Vu Khanh

Nine strains belonging to the Bacillus genus have been isolated from soil samples in Tien Phuoc district, Quang Nam province. They were capable of surviving at 42°C, and the Bl, B4, B7 and B9 strains could produce toxic crystals at this temperature. B7 had the most promising characteristics in terms of spore-forming ability. The result of the 16S rRNA gene sequencing showed that B7 belongs to the Bacillus thuringiensis species, which is known to effectively control root-knot Meloidogyne sp. nematodes attacking pepper tree. This study was aimed at evaluating the inhibitory effect of the bacterial isolate under study on root-knot eggs and juveniles. It was shown that the highest inhibitory activity of the cultures of the bacterial strains under study was observed at their concentration of 109cells/mL; in this case, up to 89.67% of nematode eggs and 100% of juveniles J2 were killed after 10 h of treatment. Bacillus thuringiensis, Meloidogyne sp., pepper tree, root-knot, nematodes We are grateful to the Danang University of Science and Education and Duy Tan University for supporting this study.


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