scholarly journals Isolation and characterization of algicidal bacteria and its effect on a musty odor-producing cyanobacterium Dolichospermum crassum in a reservoir

2016 ◽  
Vol 17 (3) ◽  
pp. 792-798 ◽  
Author(s):  
Taketoshi Shimizu ◽  
Takuya Oda ◽  
Hiroyuki Ito ◽  
Ichiro Imai
Keyword(s):  
Heterotrophic Bacteria ◽  
Peak Frequency ◽  
Algicidal Bacteria ◽  
Bacterial Strains ◽  
Sequence Analyses ◽  
16S Rdna Sequence ◽  
Isolation And Characterization ◽  
Musty Odor ◽  
Phytoplankton Monitoring

Algicidal bacteria that attack Dolichospermum crassum were isolated from the Karasuhara Reservoir in October 2010. Phytoplankton monitoring was performed from April 2010 to March 2011, and D. crassum was detected from August to November. At its peak frequency (in early October), it accounted for 23% of all phytoplankton cells. Heterotrophic bacteria were isolated from the surface water, and an algicidal assay was conducted. As a result, 3 out of 47 bacterial strains showed strong algicidal activity, and they completely destroyed the trichomes of D. crassum. An initial inoculation dose of only 1.0 × 102 cells ml−1 of these strains was enough to digest D. crassum. These strains were identified as Rheinheimera spp. according to 16S rDNA sequence analyses. This is the first report about algicidal bacteria that attack D. crassum. Algicidal bacteria could be key agents for controlling D. crassum in reservoirs.

Isolation and Characterization of Laccase Activity in a Novel Bacillus amyloliquefaciens LC02

2011 ◽  
Vol 183-185 ◽  
pp. 773-777 ◽  
Author(s):  
Jun Bo Pan ◽  
Min Zhao ◽  
Lei Lu ◽  
Mei Hui Du ◽  
Guo Fu Li ◽  
...  
Keyword(s):  
Bacillus Amyloliquefaciens ◽  
Laccase Activity ◽  
Copper Ions ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
16S Rdna Sequence ◽  
16S Rdna Sequence Analysis ◽  
Isolation And Characterization ◽  
Physiological And Biochemical

Bacterial strains exhibiting laccase activity were isolated from the forest soil. A strain LC02 with syringaldazine oxidation ability was obtained using enrichment medium supplemented with copper ions. The isolated strain was identified as Bacillus amyloliquefaciens using physiological and biochemical tests as well as 16S rDNA sequence analysis. The characterization of spore laccase activity was investigated. The result showed that the optimum pH and temperature of the enzyme was 6.6 and 70°C, respectively. A great thermostability was observed for the spore laccase at 70°C. Laccase activity was strongly inhibited by 0.1 mmol/L NaN3, dithiothreitol and cysteine.

scholarly journals Characterization of a Novel Fructosyltransferase from Lactobacillus reuteri That Synthesizes High-Molecular-Weight Inulin and Inulin Oligosaccharides

2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Lactobacillus Reuteri ◽  
Bacterial Strains ◽  
Potential Health ◽  
Isolation And Characterization ◽  
A Cell ◽  
Encoding Gene ◽  
First Time

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.

scholarly journals Isolation and characterization of bacterial strains with a hydrolytic profile with potential use in bioconversion of agroindustial by-products and waste

2013 ◽  
Vol 33 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Cintia Anabela Mazzucotelli ◽  
Alejandra Graciela Ponce ◽  
Catalina Elena Kotlar ◽  
María del Rosario Moreira
Keyword(s):  
Bacterial Strains ◽  
Isolation And Characterization ◽  
By Products ◽  
Potential Use

scholarly journals Isolation and Characterization of Potentially Probiotic Bacterial Strains from Mice: Proof of Concept for Personalized Probiotics

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1684 ◽  
Author(s):  
Larissa Celiberto ◽  
Roseli Pinto ◽  
Elizeu Rossi ◽  
Bruce Vallance ◽  
Daniela Cavallini
Keyword(s):  
Intestinal Inflammation ◽  
Activity Index ◽  
Disease Activity Index ◽  
Bacterial Strains ◽  
Dss Colitis ◽  
Isolation And Characterization ◽  
Inflammatory Bowel ◽  
Commercial Probiotics ◽  
Lower Disease Activity

Modulation of the gut microbiota through the use of probiotics has been widely used to treat or prevent several intestinal diseases. However, inconsistent results have compromised the efficacy of this approach, especially in severe conditions such as inflammatory bowel disease (IBD). The purpose of our study was to develop a personalized probiotic strategy and assess its efficacy in a murine model of intestinal inflammation. Commensal bacterial strains were isolated from the feces of healthy mice and then administered back to the host as a personalized treatment in dextran sodium sulfate (DSS)-induced colitis. Colonic tissues were collected for histological analysis and to investigate inflammatory markers such as Il-1β, Il-6, TGF-β, and Il-10, and the enzyme myeloperoxidase as a neutrophil marker. The group that received the personalized probiotic showed reduced susceptibility to DSS-colitis as compared to a commercial probiotic. This protection was characterized by a lower disease activity index and reduced histopathological damage in the colon. Moreover, the personalized probiotic was more effective in modulating the host immune response, leading to decreased Il-1β and Il-6 and increased TGF-β and Il-10 expression. In conclusion, our study suggests that personalized probiotics may possess an advantage over commercial probiotics in treating dysbiotic-related conditions, possibly because they are derived directly from the host’s own microbiota.

scholarly journals Isolation and Characterization of Lactic Acid Bacteria in Philippine Fermented Milkfish Chanos chanos-Rice Mixture (Burong Bangus)

2018 ◽  
Vol 6 (2) ◽  
pp. 500-508
Author(s):  
Julie Ann A. Arcales ◽  
Garner Algo L.Alolod
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Enzymatic Activity ◽  
Antimicrobial Property ◽  
Food Products ◽  
The Philippines ◽  
Lactobacillus Delbrueckii ◽  
Bacterial Strains ◽  
Isolation And Characterization

Isolation and characterization of bacteria in food products are important to determine and distinguish the beneficial or harmful effects of microbiota in certain samples. Lactic acid bacteria in food products had long been associated to good factors as food preservatives and with added fermentation metabolites. This study isolated and characterized lactic acid bacteria from burong bangus. The culture and purification process of bacteria isolation resulted to 4 strains of lactic acid bacteria namely Enterococcus faecalis, Tetragenococcus muriaticus, Lactobacillus delbrueckii subp. delbrueckii and Carnobacterium divergens. High enzymatic activity were observed with E. faecalis particularly on lipase and protease assay. While C. divergens have no enzymatic activity against lipase, protease, amylase and cellulase. The antimicrobial property of L. delbrueckii is only susceptible to amoxicillin unlike the other three bacteria isolates. No antagonistic activity were observed with the four bacterial strains against Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The result of this study showed promising benefits to the industry especially in developing countries like the Philippines because population are not yet so aware of this organisms and the benefits that can be derived through their consumption.

scholarly journals Isolation and Characterization of Pb Resistant Bacteria from Cilalay Lake, Indonesia

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Kesi Kurnia ◽  
Nina Hermayani Sadi ◽  
Syafitri Jumianto
Keyword(s):  
Heterotrophic Bacteria ◽  
Water Environment ◽  
Resistant Bacteria ◽  
Bacterial Isolates ◽  
Gram Negative ◽  
Isolation And Characterization ◽  
Agar Media ◽  
Physical And Chemical ◽  
Standard Disk

<span>Pollution of water environment with heavy metals is becoming one of the most severe environmental and human health hazards. Lead (Pb) is a major pollutant and highly toxic to human, animals, plants, and microbes. </span><span lang="IN">Toxic metals are difficult to remove from the environment, since they cannot be chemically or biologically degraded and are ultimately indestructible. Biological approaches based on metal-resistant microorganisms have received a great deal of attention as alternative remediation processes. </span><span>This study aim to isolat</span><span lang="IN">e</span><span> and characterize Pb resistant of heterotrophic bacteria in Cilalay Lake, </span><span lang="IN">West Java, </span><span>Indonesia. The water samples were collected </span><span lang="IN">along</span><span> three points around Cilalay Lake. </span><span lang="IN">Water physical and chemical </span><span>determination was performed using the Water Quality Checker</span><span lang="IN">. </span><span>The bacterial isolates were screened on T</span><span lang="IN">r</span><span>ipton</span><span lang="IN">e</span><span> Glucose Yeast (TGY) agar plates. </span><span lang="IN">Afterwards s</span><span>elected isolates were grown on Nutrient Agar media 50% </span><span lang="IN">with </span><span>supplemented Pb 100 ppm by the standard disk. Population of resistant bacteria was counted. The result from metal resistant bacteria indicated that all isolates w</span><span lang="IN">ere</span><span> resistant. The most abundant type of resistant </span><span lang="IN">bacteria </span><span>to lead was Gram negative more than Gram positive. Identified have metal resistant bacteria could be useful for the bioremediation of heavy metal contaminated sewage and waste water</span>

scholarly journals Study on the metabolites of DH-e, a Halomonas marine bacterium, against three toxic dinoflagellate species

2018 ◽  
Vol 78 (7) ◽  
pp. 1535-1544 ◽  
Author(s):  
Di Wang ◽  
Liling Xie ◽  
Xingbiao Zhu ◽  
Xiao Bi ◽  
Yuzhong Zheng ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Morphological Characteristics ◽  
Alexandrium Tamarense ◽  
Algicidal Bacteria ◽  
Bacterial Strains ◽  
16S Rdna Sequence ◽  
Algicidal Bacterium ◽  
16S Rdna Sequence Analysis ◽  
Acetone Peroxide

Abstract Algicidal bacteria play an important role in mitigating harmful algal blooms (HABs). In the study, five bacterial strains were isolated from the East China Sea. One strain of algicidal bacterium, named DH-e, was found to selectively inhibit the motor ability of Prorocentrum donghaiense, Alexandrium tamarense (ATDH-47) and Karenia mikimotoi Hansen. Both 16S rDNA sequence analysis and morphological characteristics revealed that the algicidal DH-e bacterium belonged to Halomonas. Furthermore, results showed that the metabolites in the DH-e cell-free filtrate could kill algae directly, and the minimum inhibitory concentrations (MICs) of the bacterial metabolites on the cells of the three dinoflagellate species ranged from 35.0–70.0 μg/mL. Following short-term inhibitory tests, the dinoflagellates in mixed crude extract solution (0.7 mg/mL) ceased movement after 5 min. The algicidal mechanism of the metabolites was investigated through enzyme activities, including that of catalase (CAT), alkaline phosphatase (AKP), acetone peroxide (T-ATP) synthetase and nitrite reductase (NR). Results indicated that metabolites did not disrupt the energy or nutrient routes of the algae (P &gt; 0.05), but did initiate an increase in free radicals in the algal cells, which might explain the subsequent death of sensitive algae. Thus, the metabolites of the DH-e bacterium showed promising potential for controlling HABs.

ISOLATION AND CHARACTERIZATION OF BIOTECHNOLOGY RELEVANT BACTERIA FROM MARINE ENVIRONMENT

2015 ◽  
Vol 77 (31) ◽  
Author(s):  
Suganthi Thevarajoo ◽  
Chitra Selvaratnam ◽  
Kian Mau Goh ◽  
Fazilah Abd. Manan ◽  
Zaharah Ibrahim ◽  
...  
Keyword(s):  
16S Rrna ◽  
Marine Environment ◽  
Antibiotic Sensitivity ◽  
Marine Microorganisms ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
16S Rrna Sequence ◽  
Gram Staining ◽  
Isolation And Characterization

Marine environment remained as largely unexplored source for researchers to discover marine microorganisms with novel properties. This study aims to isolate marine bacteria from the seashore of Desaru, Malaysia. Totally, six bacterial strains were successfully obtained and were identified by complete 16S rRNA sequencing. The characterizations of bacterial strains were performed based on morphological tests, Gram-staining, biochemical tests, and antibiotic sensitivity. The 16S rRNA sequence of D-2, D-4, D-7, D-15, D-31, and D-33 revealed a high identity of 97 to 99% with taxa belong to genera of Pseudomonas, Marinomonas, Exiquobacterium, Micrococcus, Pseudoalteromonas, and Shewanella respectively. Strain D-31 exhibited higher tolerance towards antibiotics kanamycin, ampicillin, and erythromycin while the growth of other strains were retarded by at least two of these antibiotics. We further characterized strain D-4 and D-31 that belonged to Marinomonas sp. and Pseudoalteromonas sp.. Both genera are interesting as earlier researchers have discovered new antibacterial substances, industrial enzymes and unique secondary metabolites.

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